1 //! Built-in attributes and `cfg` flag gating.
6 use crate::{Features, Stability}
;
8 use rustc_data_structures
::fx
::FxHashMap
;
9 use rustc_span
::symbol
::{sym, Symbol}
;
11 use std
::lazy
::SyncLazy
;
13 type GateFn
= fn(&Features
) -> bool
;
17 (|features
| features
.$field
) as GateFn
21 pub type GatedCfg
= (Symbol
, Symbol
, GateFn
);
23 /// `cfg(...)`'s that are feature gated.
24 const GATED_CFGS
: &[GatedCfg
] = &[
25 // (name in cfg, feature, function to check if the feature is enabled)
26 (sym
::target_thread_local
, sym
::cfg_target_thread_local
, cfg_fn
!(cfg_target_thread_local
)),
27 (sym
::target_has_atomic
, sym
::cfg_target_has_atomic
, cfg_fn
!(cfg_target_has_atomic
)),
28 (sym
::target_has_atomic_load_store
, sym
::cfg_target_has_atomic
, cfg_fn
!(cfg_target_has_atomic
)),
30 sym
::target_has_atomic_equal_alignment
,
31 sym
::cfg_target_has_atomic
,
32 cfg_fn
!(cfg_target_has_atomic
),
34 (sym
::sanitize
, sym
::cfg_sanitize
, cfg_fn
!(cfg_sanitize
)),
35 (sym
::version
, sym
::cfg_version
, cfg_fn
!(cfg_version
)),
36 (sym
::panic
, sym
::cfg_panic
, cfg_fn
!(cfg_panic
)),
39 /// Find a gated cfg determined by the `pred`icate which is given the cfg's name.
40 pub fn find_gated_cfg(pred
: impl Fn(Symbol
) -> bool
) -> Option
<&'
static GatedCfg
> {
41 GATED_CFGS
.iter().find(|(cfg_sym
, ..)| pred(*cfg_sym
))
44 // If you change this, please modify `src/doc/unstable-book` as well. You must
45 // move that documentation into the relevant place in the other docs, and
46 // remove the chapter on the flag.
48 #[derive(Copy, Clone, PartialEq, Debug)]
49 pub enum AttributeType
{
50 /// Normal, builtin attribute that is consumed
51 /// by the compiler before the unused_attribute check
54 /// Builtin attribute that may not be consumed by the compiler
55 /// before the unused_attribute check. These attributes
56 /// will be ignored by the unused_attribute lint
59 /// Builtin attribute that is only allowed at the crate level
63 #[derive(Clone, Copy)]
64 pub enum AttributeGate
{
65 /// Is gated by a given feature gate, reason
66 /// and function to check if enabled
67 Gated(Stability
, Symbol
, &'
static str, fn(&Features
) -> bool
),
69 /// Ungated attribute, can be used on all release channels
74 impl std
::fmt
::Debug
for AttributeGate
{
75 fn fmt(&self, fmt
: &mut std
::fmt
::Formatter
<'_
>) -> std
::fmt
::Result
{
77 Self::Gated(ref stab
, name
, expl
, _
) => {
78 write
!(fmt
, "Gated({:?}, {}, {})", stab
, name
, expl
)
80 Self::Ungated
=> write
!(fmt
, "Ungated"),
86 fn is_deprecated(&self) -> bool
{
87 matches
!(*self, Self::Gated(Stability
::Deprecated(_
, _
), ..))
91 /// A template that the attribute input must match.
92 /// Only top-level shape (`#[attr]` vs `#[attr(...)]` vs `#[attr = ...]`) is considered now.
93 #[derive(Clone, Copy, Default)]
94 pub struct AttributeTemplate
{
96 pub list
: Option
<&'
static str>,
97 pub name_value_str
: Option
<&'
static str>,
100 /// A convenience macro for constructing attribute templates.
101 /// E.g., `template!(Word, List: "description")` means that the attribute
102 /// supports forms `#[attr]` and `#[attr(description)]`.
103 macro_rules
! template
{
104 (Word
) => { template!(@ true, None, None) }
;
105 (List
: $descr
: expr
) => { template!(@ false, Some($descr), None) }
;
106 (NameValueStr
: $descr
: expr
) => { template!(@ false, None, Some($descr)) }
;
107 (Word
, List
: $descr
: expr
) => { template!(@ true, Some($descr), None) }
;
108 (Word
, NameValueStr
: $descr
: expr
) => { template!(@ true, None, Some($descr)) }
;
109 (List
: $descr1
: expr
, NameValueStr
: $descr2
: expr
) => {
110 template
!(@
false, Some($descr1
), Some($descr2
))
112 (Word
, List
: $descr1
: expr
, NameValueStr
: $descr2
: expr
) => {
113 template
!(@
true, Some($descr1
), Some($descr2
))
115 (@ $word
: expr
, $list
: expr
, $name_value_str
: expr
) => { AttributeTemplate
{
116 word
: $word
, list
: $list
, name_value_str
: $name_value_str
120 macro_rules
! ungated
{
121 ($attr
:ident
, $typ
:expr
, $tpl
:expr $
(,)?
) => {
122 (sym
::$attr
, $typ
, $tpl
, Ungated
)
127 ($attr
:ident
, $typ
:expr
, $tpl
:expr
, $gate
:ident
, $msg
:expr $
(,)?
) => {
128 (sym
::$attr
, $typ
, $tpl
, Gated(Stability
::Unstable
, sym
::$gate
, $msg
, cfg_fn
!($gate
)))
130 ($attr
:ident
, $typ
:expr
, $tpl
:expr
, $msg
:expr $
(,)?
) => {
131 (sym
::$attr
, $typ
, $tpl
, Gated(Stability
::Unstable
, sym
::$attr
, $msg
, cfg_fn
!($attr
)))
135 macro_rules
! rustc_attr
{
136 (TEST
, $attr
:ident
, $typ
:expr
, $tpl
:expr $
(,)?
) => {
144 "]` attribute is just used for rustc unit tests \
145 and will never be stable",
149 ($attr
:ident
, $typ
:expr
, $tpl
:expr
, $msg
:expr $
(,)?
) => {
154 Gated(Stability
::Unstable
, sym
::rustc_attrs
, $msg
, cfg_fn
!(rustc_attrs
)),
159 macro_rules
! experimental
{
161 concat
!("the `#[", stringify
!($attr
), "]` attribute is an experimental feature")
165 const IMPL_DETAIL
: &str = "internal implementation detail";
166 const INTERNAL_UNSTABLE
: &str = "this is an internal attribute that will never be stable";
168 pub type BuiltinAttribute
= (Symbol
, AttributeType
, AttributeTemplate
, AttributeGate
);
170 /// Attributes that have a special meaning to rustc or rustdoc.
172 pub const BUILTIN_ATTRIBUTES
: &[BuiltinAttribute
] = &[
173 // ==========================================================================
174 // Stable attributes:
175 // ==========================================================================
177 // Conditional compilation:
178 ungated
!(cfg
, Normal
, template
!(List
: "predicate")),
179 ungated
!(cfg_attr
, Normal
, template
!(List
: "predicate, attr1, attr2, ...")),
182 ungated
!(ignore
, Normal
, template
!(Word
, NameValueStr
: "reason")),
184 should_panic
, Normal
,
185 template
!(Word
, List
: r
#"expected = "reason"#, NameValueStr: "reason"),
187 // FIXME(Centril): This can be used on stable but shouldn't.
188 ungated!(reexport_test_harness_main, Normal, template!(NameValueStr: "name")),
191 ungated!(derive, Normal, template!(List: "Trait1, Trait2, ...")),
192 ungated!(automatically_derived, Normal, template!(Word)),
194 ungated!(macro_use, Normal, template!(Word, List: "name1, name2, ...")),
195 ungated!(macro_escape, Normal, template!(Word)), // Deprecated synonym for `macro_use`.
196 ungated!(macro_export, Normal, template!(Word, List: "local_inner_macros")),
197 ungated!(proc_macro, Normal, template!(Word)),
199 proc_macro_derive, Normal,
200 template!(List: "TraitName, /*opt*/ attributes(name1, name2, ...)"),
202 ungated!(proc_macro_attribute, Normal, template!(Word)),
205 ungated!(warn, Normal, template!(List: r#"lint1, lint2, ..., /*opt*/ reason = "...""#)),
206 ungated!(allow, Normal, template!(List: r#"lint1, lint2, ..., /*opt*/ reason = "...""#)),
207 ungated!(forbid, Normal, template!(List: r#"lint1, lint2, ..., /*opt*/ reason = "...""#)),
208 ungated!(deny, Normal, template!(List: r#"lint1, lint2, ..., /*opt*/ reason = "...""#)),
209 ungated!(must_use, AssumedUsed, template!(Word, NameValueStr: "reason")),
215 List: r#"/*opt*/ since = "version", /*opt*/ note = "reason""#,
216 NameValueStr: "reason"
221 ungated!(crate_name, CrateLevel, template!(NameValueStr: "name")),
222 ungated!(crate_type, CrateLevel, template!(NameValueStr: "bin|lib|...")),
223 ungated!(crate_id, CrateLevel, template!(NameValueStr: "ignored")),
225 // ABI, linking, symbols, and FFI
228 template!(List: r#"name = "...", /*opt*/ kind = "dylib|static|...", /*opt*/ wasm_import_module = "...""#),
230 ungated!(link_name, AssumedUsed, template!(NameValueStr: "name")),
231 ungated!(no_link, Normal, template!(Word)),
232 ungated!(repr, Normal, template!(List: "C")),
233 ungated!(export_name, AssumedUsed, template!(NameValueStr: "name")),
234 ungated!(link_section, AssumedUsed, template!(NameValueStr: "name")),
235 ungated!(no_mangle, AssumedUsed, template!(Word)),
236 ungated!(used, AssumedUsed, template!(Word)),
239 ungated!(recursion_limit, CrateLevel, template!(NameValueStr: "N")),
240 ungated!(type_length_limit, CrateLevel, template!(NameValueStr: "N")),
242 const_eval_limit, CrateLevel, template!(NameValueStr: "N"), const_eval_limit,
243 experimental!(const_eval_limit)
247 ungated!(main, Normal, template!(Word)),
248 ungated!(start, Normal, template!(Word)),
249 ungated!(no_start, CrateLevel, template!(Word)),
250 ungated!(no_main, CrateLevel, template!(Word)),
252 // Modules, prelude, and resolution:
253 ungated!(path, Normal, template!(NameValueStr: "file")),
254 ungated!(no_std, CrateLevel, template!(Word)),
255 ungated!(no_implicit_prelude, Normal, template!(Word)),
256 ungated!(non_exhaustive, AssumedUsed, template!(Word)),
259 ungated!(windows_subsystem, AssumedUsed, template!(NameValueStr: "windows|console")),
260 ungated!(panic_handler, Normal, template!(Word)), // RFC 2070
263 ungated!(inline, AssumedUsed, template!(Word, List: "always|never")),
264 ungated!(cold, AssumedUsed, template!(Word)),
265 ungated!(no_builtins, AssumedUsed, template!(Word)),
266 ungated!(target_feature, AssumedUsed, template!(List: r#"enable = "name""#)),
267 ungated!(track_caller, AssumedUsed, template!(Word)),
269 no_sanitize, AssumedUsed,
270 template!(List: "address, memory, thread"),
271 experimental!(no_sanitize)
274 // FIXME: #14408 assume docs are used since rustdoc looks at them.
275 ungated!(doc, AssumedUsed, template!(List: "hidden|inline|...", NameValueStr: "string")),
277 // ==========================================================================
278 // Unstable attributes:
279 // ==========================================================================
282 gated!(naked, AssumedUsed, template!(Word), naked_functions, experimental!(naked)),
284 link_args, Normal, template!(NameValueStr: "args"),
285 "the `link_args` attribute is experimental and not portable across platforms, \
286 it is recommended to use `#[link(name = \"foo\")] instead",
289 link_ordinal, AssumedUsed, template!(List: "ordinal"), raw_dylib,
290 experimental!(link_ordinal)
295 sym::plugin_registrar, Normal, template!(Word),
297 Stability::Deprecated(
298 "https://github.com/rust-lang/rust/pull/64675",
299 Some("may be removed in a future compiler version"),
301 sym
::plugin_registrar
,
302 "compiler plugins are deprecated",
303 cfg_fn
!(plugin_registrar
)
307 sym
::plugin
, CrateLevel
, template
!(List
: "name"),
309 Stability
::Deprecated(
310 "https://github.com/rust-lang/rust/pull/64675",
311 Some("may be removed in a future compiler version"),
314 "compiler plugins are deprecated",
320 gated
!(allow_fail
, Normal
, template
!(Word
), experimental
!(allow_fail
)),
322 test_runner
, CrateLevel
, template
!(List
: "path"), custom_test_frameworks
,
323 "custom test frameworks are an unstable feature",
326 gated
!(marker
, Normal
, template
!(Word
), marker_trait_attr
, experimental
!(marker
)),
328 thread_local
, AssumedUsed
, template
!(Word
),
329 "`#[thread_local]` is an experimental feature, and does not currently handle destructors",
331 gated
!(no_core
, CrateLevel
, template
!(Word
), experimental
!(no_core
)),
334 optimize
, AssumedUsed
, template
!(List
: "size|speed"), optimize_attribute
,
335 experimental
!(optimize
),
338 gated
!(instruction_set
, AssumedUsed
, template
!(List
: "set"), isa_attribute
, experimental
!(instruction_set
)),
340 gated
!(ffi_returns_twice
, AssumedUsed
, template
!(Word
), experimental
!(ffi_returns_twice
)),
341 gated
!(ffi_pure
, AssumedUsed
, template
!(Word
), experimental
!(ffi_pure
)),
342 gated
!(ffi_const
, AssumedUsed
, template
!(Word
), experimental
!(ffi_const
)),
344 register_attr
, CrateLevel
, template
!(List
: "attr1, attr2, ..."),
345 experimental
!(register_attr
),
348 register_tool
, CrateLevel
, template
!(List
: "tool1, tool2, ..."),
349 experimental
!(register_tool
),
352 gated
!(cmse_nonsecure_entry
, AssumedUsed
, template
!(Word
), experimental
!(cmse_nonsecure_entry
)),
354 // ==========================================================================
355 // Internal attributes: Stability, deprecation, and unsafe:
356 // ==========================================================================
358 ungated
!(feature
, CrateLevel
, template
!(List
: "name1, name1, ...")),
359 // FIXME(#14407) -- only looked at on-demand so we can't
360 // guarantee they'll have already been checked.
362 rustc_deprecated
, AssumedUsed
,
363 template
!(List
: r
#"since = "version", reason = "...""#)
366 ungated
!(stable
, AssumedUsed
, template
!(List
: r
#"feature = "name", since = "version""#)),
369 unstable
, AssumedUsed
,
370 template
!(List
: r
#"feature = "name", reason = "...", issue = "N""#),
373 ungated
!(rustc_const_unstable
, AssumedUsed
, template
!(List
: r
#"feature = "name""#)),
375 ungated
!(rustc_const_stable
, AssumedUsed
, template
!(List
: r
#"feature = "name""#)),
377 allow_internal_unstable
, AssumedUsed
, template
!(Word
, List
: "feat1, feat2, ..."),
378 "allow_internal_unstable side-steps feature gating and stability checks",
381 rustc_allow_const_fn_unstable
, AssumedUsed
, template
!(Word
, List
: "feat1, feat2, ..."),
382 "rustc_allow_const_fn_unstable side-steps feature gating and stability checks"
385 allow_internal_unsafe
, Normal
, template
!(Word
),
386 "allow_internal_unsafe side-steps the unsafe_code lint",
389 // ==========================================================================
390 // Internal attributes: Type system related:
391 // ==========================================================================
393 gated
!(fundamental
, AssumedUsed
, template
!(Word
), experimental
!(fundamental
)),
395 may_dangle
, Normal
, template
!(Word
), dropck_eyepatch
,
396 "`may_dangle` has unstable semantics and may be removed in the future",
399 // ==========================================================================
400 // Internal attributes: Runtime related:
401 // ==========================================================================
403 rustc_attr
!(rustc_allocator
, AssumedUsed
, template
!(Word
), IMPL_DETAIL
),
404 rustc_attr
!(rustc_allocator_nounwind
, AssumedUsed
, template
!(Word
), IMPL_DETAIL
),
405 gated
!(alloc_error_handler
, Normal
, template
!(Word
), experimental
!(alloc_error_handler
)),
407 default_lib_allocator
, AssumedUsed
, template
!(Word
), allocator_internals
,
408 experimental
!(default_lib_allocator
),
411 needs_allocator
, Normal
, template
!(Word
), allocator_internals
,
412 experimental
!(needs_allocator
),
414 gated
!(panic_runtime
, AssumedUsed
, template
!(Word
), experimental
!(panic_runtime
)),
415 gated
!(needs_panic_runtime
, AssumedUsed
, template
!(Word
), experimental
!(needs_panic_runtime
)),
417 unwind
, AssumedUsed
, template
!(List
: "allowed|aborts"), unwind_attributes
,
418 experimental
!(unwind
),
421 compiler_builtins
, AssumedUsed
, template
!(Word
),
422 "the `#[compiler_builtins]` attribute is used to identify the `compiler_builtins` crate \
423 which contains compiler-rt intrinsics and will never be stable",
426 profiler_runtime
, AssumedUsed
, template
!(Word
),
427 "the `#[profiler_runtime]` attribute is used to identify the `profiler_builtins` crate \
428 which contains the profiler runtime and will never be stable",
431 // ==========================================================================
432 // Internal attributes, Linkage:
433 // ==========================================================================
436 linkage
, AssumedUsed
, template
!(NameValueStr
: "external|internal|..."),
437 "the `linkage` attribute is experimental and not portable across platforms",
439 rustc_attr
!(rustc_std_internal_symbol
, AssumedUsed
, template
!(Word
), INTERNAL_UNSTABLE
),
441 // ==========================================================================
442 // Internal attributes, Macro related:
443 // ==========================================================================
445 rustc_attr
!(rustc_builtin_macro
, AssumedUsed
, template
!(Word
, NameValueStr
: "name"), IMPL_DETAIL
),
446 rustc_attr
!(rustc_proc_macro_decls
, Normal
, template
!(Word
), INTERNAL_UNSTABLE
),
448 rustc_macro_transparency
, AssumedUsed
,
449 template
!(NameValueStr
: "transparent|semitransparent|opaque"),
450 "used internally for testing macro hygiene",
453 // ==========================================================================
454 // Internal attributes, Diagnostics related:
455 // ==========================================================================
458 rustc_on_unimplemented
, AssumedUsed
,
460 List
: r
#"/*opt*/ message = "...", /*opt*/ label = "...", /*opt*/ note = "...""#,
461 NameValueStr
: "message"
465 // Enumerates "identity-like" conversion methods to suggest on type mismatch.
466 rustc_attr
!(rustc_conversion_suggestion
, AssumedUsed
, template
!(Word
), INTERNAL_UNSTABLE
),
468 // ==========================================================================
469 // Internal attributes, Const related:
470 // ==========================================================================
472 rustc_attr
!(rustc_promotable
, AssumedUsed
, template
!(Word
), IMPL_DETAIL
),
473 rustc_attr
!(rustc_args_required_const
, AssumedUsed
, template
!(List
: "N"), INTERNAL_UNSTABLE
),
475 // ==========================================================================
476 // Internal attributes, Layout related:
477 // ==========================================================================
480 rustc_layout_scalar_valid_range_start
, AssumedUsed
, template
!(List
: "value"),
481 "the `#[rustc_layout_scalar_valid_range_start]` attribute is just used to enable \
482 niche optimizations in libcore and will never be stable",
485 rustc_layout_scalar_valid_range_end
, AssumedUsed
, template
!(List
: "value"),
486 "the `#[rustc_layout_scalar_valid_range_end]` attribute is just used to enable \
487 niche optimizations in libcore and will never be stable",
490 rustc_nonnull_optimization_guaranteed
, AssumedUsed
, template
!(Word
),
491 "the `#[rustc_nonnull_optimization_guaranteed]` attribute is just used to enable \
492 niche optimizations in libcore and will never be stable",
495 // ==========================================================================
496 // Internal attributes, Misc:
497 // ==========================================================================
499 lang
, Normal
, template
!(NameValueStr
: "name"), lang_items
,
500 "language items are subject to change",
503 sym
::rustc_diagnostic_item
,
505 template
!(NameValueStr
: "name"),
509 "diagnostic items compiler internal support for linting",
510 cfg_fn
!(rustc_attrs
),
515 prelude_import
, AssumedUsed
, template
!(Word
),
516 "`#[prelude_import]` is for use by rustc only",
519 rustc_paren_sugar
, Normal
, template
!(Word
), unboxed_closures
,
520 "unboxed_closures are still evolving",
523 rustc_inherit_overflow_checks
, AssumedUsed
, template
!(Word
),
524 "the `#[rustc_inherit_overflow_checks]` attribute is just used to control \
525 overflow checking behavior of several libcore functions that are inlined \
526 across crates and will never be stable",
528 rustc_attr
!(rustc_reservation_impl
, Normal
, template
!(NameValueStr
: "reservation message"),
529 "the `#[rustc_reservation_impl]` attribute is internally used \
530 for reserving for `for<T> From<!> for T` impl"
533 rustc_test_marker
, Normal
, template
!(Word
),
534 "the `#[rustc_test_marker]` attribute is used internally to track tests",
537 rustc_unsafe_specialization_marker
, Normal
, template
!(Word
),
538 "the `#[rustc_unsafe_specialization_marker]` attribute is used to check specializations"
541 rustc_specialization_trait
, Normal
, template
!(Word
),
542 "the `#[rustc_specialization_trait]` attribute is used to check specializations"
545 // ==========================================================================
546 // Internal attributes, Testing:
547 // ==========================================================================
549 rustc_attr
!(TEST
, rustc_outlives
, Normal
, template
!(Word
)),
550 rustc_attr
!(TEST
, rustc_capture_analysis
, Normal
, template
!(Word
)),
551 rustc_attr
!(TEST
, rustc_variance
, Normal
, template
!(Word
)),
552 rustc_attr
!(TEST
, rustc_layout
, Normal
, template
!(List
: "field1, field2, ...")),
553 rustc_attr
!(TEST
, rustc_regions
, Normal
, template
!(Word
)),
555 TEST
, rustc_error
, AssumedUsed
,
556 template
!(Word
, List
: "delay_span_bug_from_inside_query")
558 rustc_attr
!(TEST
, rustc_dump_user_substs
, AssumedUsed
, template
!(Word
)),
559 rustc_attr
!(TEST
, rustc_if_this_changed
, AssumedUsed
, template
!(Word
, List
: "DepNode")),
560 rustc_attr
!(TEST
, rustc_then_this_would_need
, AssumedUsed
, template
!(List
: "DepNode")),
562 TEST
, rustc_dirty
, AssumedUsed
,
563 template
!(List
: r
#"cfg = "...", /*opt*/ label = "...", /*opt*/ except = "...""#),
566 TEST
, rustc_clean
, AssumedUsed
,
567 template
!(List
: r
#"cfg = "...", /*opt*/ label = "...", /*opt*/ except = "...""#),
570 TEST
, rustc_partition_reused
, AssumedUsed
,
571 template
!(List
: r
#"cfg = "...", module = "...""#),
574 TEST
, rustc_partition_codegened
, AssumedUsed
,
575 template
!(List
: r
#"cfg = "...", module = "...""#),
578 TEST
, rustc_expected_cgu_reuse
, AssumedUsed
,
579 template
!(List
: r
#"cfg = "...", module = "...", kind = "...""#),
581 rustc_attr
!(TEST
, rustc_synthetic
, AssumedUsed
, template
!(Word
)),
582 rustc_attr
!(TEST
, rustc_symbol_name
, AssumedUsed
, template
!(Word
)),
583 rustc_attr
!(TEST
, rustc_polymorphize_error
, AssumedUsed
, template
!(Word
)),
584 rustc_attr
!(TEST
, rustc_def_path
, AssumedUsed
, template
!(Word
)),
585 rustc_attr
!(TEST
, rustc_mir
, AssumedUsed
, template
!(List
: "arg1, arg2, ...")),
586 rustc_attr
!(TEST
, rustc_dump_program_clauses
, AssumedUsed
, template
!(Word
)),
587 rustc_attr
!(TEST
, rustc_dump_env_program_clauses
, AssumedUsed
, template
!(Word
)),
588 rustc_attr
!(TEST
, rustc_object_lifetime_default
, AssumedUsed
, template
!(Word
)),
589 rustc_attr
!(TEST
, rustc_dummy
, Normal
, template
!(Word
/* doesn't matter*/)),
591 omit_gdb_pretty_printer_section
, AssumedUsed
, template
!(Word
),
592 "the `#[omit_gdb_pretty_printer_section]` attribute is just used for the Rust test suite",
596 pub fn deprecated_attributes() -> Vec
<&'
static BuiltinAttribute
> {
597 BUILTIN_ATTRIBUTES
.iter().filter(|(.., gate
)| gate
.is_deprecated()).collect()
600 pub fn is_builtin_attr_name(name
: Symbol
) -> bool
{
601 BUILTIN_ATTRIBUTE_MAP
.get(&name
).is_some()
604 pub static BUILTIN_ATTRIBUTE_MAP
: SyncLazy
<FxHashMap
<Symbol
, &BuiltinAttribute
>> =
606 let mut map
= FxHashMap
::default();
607 for attr
in BUILTIN_ATTRIBUTES
.iter() {
608 if map
.insert(attr
.0, attr
).is_some() {
609 panic
!("duplicate builtin attribute `{}`", attr
.0);