src/librustc_feature/builtin_attrs.rs

   1 //! Built-in attributes and `cfg` flag gating.
   2
   3 use AttributeGate::*;
   4 use AttributeType::*;
   5
   6 use crate::{Features, Stability};
   7
   8 use lazy_static::lazy_static;
   9 use rustc_data_structures::fx::FxHashMap;
  10 use rustc_span::symbol::{sym, Symbol};
  11
  12 type GateFn = fn(&Features) -> bool;
  13
  14 macro_rules! cfg_fn {
  15     ($field: ident) => {
  16         (|features| features.$field) as GateFn
  17     };
  18 }
  19
  20 pub type GatedCfg = (Symbol, Symbol, GateFn);
  21
  22 /// `cfg(...)`'s that are feature gated.
  23 const GATED_CFGS: &[GatedCfg] = &[
  24     // (name in cfg, feature, function to check if the feature is enabled)
  25     (sym::target_thread_local, sym::cfg_target_thread_local, cfg_fn!(cfg_target_thread_local)),
  26     (sym::target_has_atomic, sym::cfg_target_has_atomic, cfg_fn!(cfg_target_has_atomic)),
  27     (sym::target_has_atomic_load_store, sym::cfg_target_has_atomic, cfg_fn!(cfg_target_has_atomic)),
  28     (sym::sanitize, sym::cfg_sanitize, cfg_fn!(cfg_sanitize)),
  29 ];
  30
  31 /// Find a gated cfg determined by the `pred`icate which is given the cfg's name.
  32 pub fn find_gated_cfg(pred: impl Fn(Symbol) -> bool) -> Option<&'static GatedCfg> {
  33     GATED_CFGS.iter().find(|(cfg_sym, ..)| pred(*cfg_sym))
  34 }
  35
  36 // If you change this, please modify `src/doc/unstable-book` as well. You must
  37 // move that documentation into the relevant place in the other docs, and
  38 // remove the chapter on the flag.
  39
  40 #[derive(Copy, Clone, PartialEq, Debug)]
  41 pub enum AttributeType {
  42     /// Normal, builtin attribute that is consumed
  43     /// by the compiler before the unused_attribute check
  44     Normal,
  45
  46     /// Builtin attribute that may not be consumed by the compiler
  47     /// before the unused_attribute check. These attributes
  48     /// will be ignored by the unused_attribute lint
  49     Whitelisted,
  50
  51     /// Builtin attribute that is only allowed at the crate level
  52     CrateLevel,
  53 }
  54
  55 #[derive(Clone, Copy)]
  56 pub enum AttributeGate {
  57     /// Is gated by a given feature gate, reason
  58     /// and function to check if enabled
  59     Gated(Stability, Symbol, &'static str, fn(&Features) -> bool),
  60
  61     /// Ungated attribute, can be used on all release channels
  62     Ungated,
  63 }
  64
  65 // fn() is not Debug
  66 impl std::fmt::Debug for AttributeGate {
  67     fn fmt(&self, fmt: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
  68         match *self {
  69             Self::Gated(ref stab, name, expl, _) => {
  70                 write!(fmt, "Gated({:?}, {}, {})", stab, name, expl)
  71             }
  72             Self::Ungated => write!(fmt, "Ungated"),
  73         }
  74     }
  75 }
  76
  77 impl AttributeGate {
  78     fn is_deprecated(&self) -> bool {
  79         match *self {
  80             Self::Gated(Stability::Deprecated(_, _), ..) => true,
  81             _ => false,
  82         }
  83     }
  84 }
  85
  86 /// A template that the attribute input must match.
  87 /// Only top-level shape (`#[attr]` vs `#[attr(...)]` vs `#[attr = ...]`) is considered now.
  88 #[derive(Clone, Copy, Default)]
  89 pub struct AttributeTemplate {
  90     pub word: bool,
  91     pub list: Option<&'static str>,
  92     pub name_value_str: Option<&'static str>,
  93 }
  94
  95 /// A convenience macro for constructing attribute templates.
  96 /// E.g., `template!(Word, List: "description")` means that the attribute
  97 /// supports forms `#[attr]` and `#[attr(description)]`.
  98 macro_rules! template {
  99     (Word) => { template!(@ true, None, None) };
 100     (List: $descr: expr) => { template!(@ false, Some($descr), None) };
 101     (NameValueStr: $descr: expr) => { template!(@ false, None, Some($descr)) };
 102     (Word, List: $descr: expr) => { template!(@ true, Some($descr), None) };
 103     (Word, NameValueStr: $descr: expr) => { template!(@ true, None, Some($descr)) };
 104     (List: $descr1: expr, NameValueStr: $descr2: expr) => {
 105         template!(@ false, Some($descr1), Some($descr2))
 106     };
 107     (Word, List: $descr1: expr, NameValueStr: $descr2: expr) => {
 108         template!(@ true, Some($descr1), Some($descr2))
 109     };
 110     (@ $word: expr, $list: expr, $name_value_str: expr) => { AttributeTemplate {
 111         word: $word, list: $list, name_value_str: $name_value_str
 112     } };
 113 }
 114
 115 macro_rules! ungated {
 116     ($attr:ident, $typ:expr, $tpl:expr $(,)?) => {
 117         (sym::$attr, $typ, $tpl, Ungated)
 118     };
 119 }
 120
 121 macro_rules! gated {
 122     ($attr:ident, $typ:expr, $tpl:expr, $gate:ident, $msg:expr $(,)?) => {
 123         (sym::$attr, $typ, $tpl, Gated(Stability::Unstable, sym::$gate, $msg, cfg_fn!($gate)))
 124     };
 125     ($attr:ident, $typ:expr, $tpl:expr, $msg:expr $(,)?) => {
 126         (sym::$attr, $typ, $tpl, Gated(Stability::Unstable, sym::$attr, $msg, cfg_fn!($attr)))
 127     };
 128 }
 129
 130 macro_rules! rustc_attr {
 131     (TEST, $attr:ident, $typ:expr, $tpl:expr $(,)?) => {
 132         rustc_attr!(
 133             $attr,
 134             $typ,
 135             $tpl,
 136             concat!(
 137                 "the `#[",
 138                 stringify!($attr),
 139                 "]` attribute is just used for rustc unit tests \
 140                 and will never be stable",
 141             ),
 142         )
 143     };
 144     ($attr:ident, $typ:expr, $tpl:expr, $msg:expr $(,)?) => {
 145         (
 146             sym::$attr,
 147             $typ,
 148             $tpl,
 149             Gated(Stability::Unstable, sym::rustc_attrs, $msg, cfg_fn!(rustc_attrs)),
 150         )
 151     };
 152 }
 153
 154 macro_rules! experimental {
 155     ($attr:ident) => {
 156         concat!("the `#[", stringify!($attr), "]` attribute is an experimental feature")
 157     };
 158 }
 159
 160 const IMPL_DETAIL: &str = "internal implementation detail";
 161 const INTERNAL_UNSTABLE: &str = "this is an internal attribute that will never be stable";
 162
 163 pub type BuiltinAttribute = (Symbol, AttributeType, AttributeTemplate, AttributeGate);
 164
 165 /// Attributes that have a special meaning to rustc or rustdoc.
 166 #[rustfmt::skip]
 167 pub const BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[
 168     // ==========================================================================
 169     // Stable attributes:
 170     // ==========================================================================
 171
 172     // Conditional compilation:
 173     ungated!(cfg, Normal, template!(List: "predicate")),
 174     ungated!(cfg_attr, Normal, template!(List: "predicate, attr1, attr2, ...")),
 175
 176     // Testing:
 177     ungated!(ignore, Normal, template!(Word, NameValueStr: "reason")),
 178     ungated!(
 179         should_panic, Normal,
 180         template!(Word, List: r#"expected = "reason"#, NameValueStr: "reason"),
 181     ),
 182     // FIXME(Centril): This can be used on stable but shouldn't.
 183     ungated!(reexport_test_harness_main, Normal, template!(NameValueStr: "name")),
 184
 185     // Macros:
 186     ungated!(derive, Normal, template!(List: "Trait1, Trait2, ...")),
 187     ungated!(automatically_derived, Normal, template!(Word)),
 188     // FIXME(#14407)
 189     ungated!(macro_use, Normal, template!(Word, List: "name1, name2, ...")),
 190     ungated!(macro_escape, Normal, template!(Word)), // Deprecated synonym for `macro_use`.
 191     ungated!(macro_export, Normal, template!(Word, List: "local_inner_macros")),
 192     ungated!(proc_macro, Normal, template!(Word)),
 193     ungated!(
 194         proc_macro_derive, Normal,
 195         template!(List: "TraitName, /*opt*/ attributes(name1, name2, ...)"),
 196     ),
 197     ungated!(proc_macro_attribute, Normal, template!(Word)),
 198
 199     // Lints:
 200     ungated!(warn, Normal, template!(List: r#"lint1, lint2, ..., /*opt*/ reason = "...""#)),
 201     ungated!(allow, Normal, template!(List: r#"lint1, lint2, ..., /*opt*/ reason = "...""#)),
 202     ungated!(forbid, Normal, template!(List: r#"lint1, lint2, ..., /*opt*/ reason = "...""#)),
 203     ungated!(deny, Normal, template!(List: r#"lint1, lint2, ..., /*opt*/ reason = "...""#)),
 204     ungated!(must_use, Whitelisted, template!(Word, NameValueStr: "reason")),
 205     // FIXME(#14407)
 206     ungated!(
 207         deprecated, Normal,
 208         template!(
 209             Word,
 210             List: r#"/*opt*/ since = "version", /*opt*/ note = "reason""#,
 211             NameValueStr: "reason"
 212         ),
 213     ),
 214
 215     // Crate properties:
 216     ungated!(crate_name, CrateLevel, template!(NameValueStr: "name")),
 217     ungated!(crate_type, CrateLevel, template!(NameValueStr: "bin|lib|...")),
 218     ungated!(crate_id, CrateLevel, template!(NameValueStr: "ignored")),
 219
 220     // ABI, linking, symbols, and FFI
 221     ungated!(
 222         link, Whitelisted,
 223         template!(List: r#"name = "...", /*opt*/ kind = "dylib|static|...", /*opt*/ wasm_import_module = "...""#),
 224     ),
 225     ungated!(link_name, Whitelisted, template!(NameValueStr: "name")),
 226     ungated!(no_link, Normal, template!(Word)),
 227     ungated!(repr, Normal, template!(List: "C")),
 228     ungated!(export_name, Whitelisted, template!(NameValueStr: "name")),
 229     ungated!(link_section, Whitelisted, template!(NameValueStr: "name")),
 230     ungated!(no_mangle, Whitelisted, template!(Word)),
 231     ungated!(used, Whitelisted, template!(Word)),
 232
 233     // Limits:
 234     ungated!(recursion_limit, CrateLevel, template!(NameValueStr: "N")),
 235     ungated!(type_length_limit, CrateLevel, template!(NameValueStr: "N")),
 236     gated!(
 237         const_eval_limit, CrateLevel, template!(NameValueStr: "N"), const_eval_limit,
 238         experimental!(const_eval_limit)
 239     ),
 240
 241     // Entry point:
 242     ungated!(main, Normal, template!(Word)),
 243     ungated!(start, Normal, template!(Word)),
 244     ungated!(no_start, CrateLevel, template!(Word)),
 245     ungated!(no_main, CrateLevel, template!(Word)),
 246
 247     // Modules, prelude, and resolution:
 248     ungated!(path, Normal, template!(NameValueStr: "file")),
 249     ungated!(no_std, CrateLevel, template!(Word)),
 250     ungated!(no_implicit_prelude, Normal, template!(Word)),
 251     ungated!(non_exhaustive, Whitelisted, template!(Word)),
 252
 253     // Runtime
 254     ungated!(windows_subsystem, Whitelisted, template!(NameValueStr: "windows|console")),
 255     ungated!(panic_handler, Normal, template!(Word)), // RFC 2070
 256
 257     // Code generation:
 258     ungated!(inline, Whitelisted, template!(Word, List: "always|never")),
 259     ungated!(cold, Whitelisted, template!(Word)),
 260     ungated!(no_builtins, Whitelisted, template!(Word)),
 261     ungated!(target_feature, Whitelisted, template!(List: r#"enable = "name""#)),
 262     gated!(
 263         no_sanitize, Whitelisted,
 264         template!(List: "address, memory, thread"),
 265         experimental!(no_sanitize)
 266     ),
 267
 268     // FIXME: #14408 whitelist docs since rustdoc looks at them
 269     ungated!(doc, Whitelisted, template!(List: "hidden|inline|...", NameValueStr: "string")),
 270
 271     // ==========================================================================
 272     // Unstable attributes:
 273     // ==========================================================================
 274
 275     // Linking:
 276     gated!(naked, Whitelisted, template!(Word), naked_functions, experimental!(naked)),
 277     gated!(
 278         link_args, Normal, template!(NameValueStr: "args"),
 279         "the `link_args` attribute is experimental and not portable across platforms, \
 280         it is recommended to use `#[link(name = \"foo\")] instead",
 281     ),
 282     gated!(
 283         link_ordinal, Whitelisted, template!(List: "ordinal"), raw_dylib,
 284         experimental!(link_ordinal)
 285     ),
 286
 287     // Plugins:
 288     (
 289         sym::plugin_registrar, Normal, template!(Word),
 290         Gated(
 291             Stability::Deprecated(
 292                 "https://github.com/rust-lang/rust/pull/64675",
 293                 Some("may be removed in a future compiler version"),
 294             ),
 295             sym::plugin_registrar,
 296             "compiler plugins are deprecated",
 297             cfg_fn!(plugin_registrar)
 298         )
 299     ),
 300     (
 301         sym::plugin, CrateLevel, template!(List: "name"),
 302         Gated(
 303             Stability::Deprecated(
 304                 "https://github.com/rust-lang/rust/pull/64675",
 305                 Some("may be removed in a future compiler version"),
 306             ),
 307             sym::plugin,
 308             "compiler plugins are deprecated",
 309             cfg_fn!(plugin)
 310         )
 311     ),
 312
 313     // Testing:
 314     gated!(allow_fail, Normal, template!(Word), experimental!(allow_fail)),
 315     gated!(
 316         test_runner, CrateLevel, template!(List: "path"), custom_test_frameworks,
 317         "custom test frameworks are an unstable feature",
 318     ),
 319     // RFC #1268
 320     gated!(marker, Normal, template!(Word), marker_trait_attr, experimental!(marker)),
 321     gated!(
 322         thread_local, Whitelisted, template!(Word),
 323         "`#[thread_local]` is an experimental feature, and does not currently handle destructors",
 324     ),
 325     gated!(no_core, CrateLevel, template!(Word), experimental!(no_core)),
 326     // RFC 2412
 327     gated!(
 328         optimize, Whitelisted, template!(List: "size|speed"), optimize_attribute,
 329         experimental!(optimize),
 330     ),
 331
 332     gated!(ffi_returns_twice, Whitelisted, template!(Word), experimental!(ffi_returns_twice)),
 333     gated!(track_caller, Whitelisted, template!(Word), experimental!(track_caller)),
 334     gated!(
 335         register_attr, CrateLevel, template!(List: "attr1, attr2, ..."),
 336         experimental!(register_attr),
 337     ),
 338     gated!(
 339         register_tool, CrateLevel, template!(List: "tool1, tool2, ..."),
 340         experimental!(register_tool),
 341     ),
 342
 343     // ==========================================================================
 344     // Internal attributes: Stability, deprecation, and unsafe:
 345     // ==========================================================================
 346
 347     ungated!(feature, CrateLevel, template!(List: "name1, name1, ...")),
 348     // FIXME(#14407) -- only looked at on-demand so we can't
 349     // guarantee they'll have already been checked.
 350     ungated!(
 351         rustc_deprecated, Whitelisted,
 352         template!(List: r#"since = "version", reason = "...""#)
 353     ),
 354     // FIXME(#14407)
 355     ungated!(stable, Whitelisted, template!(List: r#"feature = "name", since = "version""#)),
 356     // FIXME(#14407)
 357     ungated!(
 358         unstable, Whitelisted,
 359         template!(List: r#"feature = "name", reason = "...", issue = "N""#),
 360     ),
 361     // FIXME(#14407)
 362     ungated!(rustc_const_unstable, Whitelisted, template!(List: r#"feature = "name""#)),
 363     // FIXME(#14407)
 364     ungated!(rustc_const_stable, Whitelisted, template!(List: r#"feature = "name""#)),
 365     gated!(
 366         allow_internal_unstable, Normal, template!(Word, List: "feat1, feat2, ..."),
 367         "allow_internal_unstable side-steps feature gating and stability checks",
 368     ),
 369     gated!(
 370         allow_internal_unsafe, Normal, template!(Word),
 371         "allow_internal_unsafe side-steps the unsafe_code lint",
 372     ),
 373
 374     // ==========================================================================
 375     // Internal attributes: Type system related:
 376     // ==========================================================================
 377
 378     gated!(fundamental, Whitelisted, template!(Word), experimental!(fundamental)),
 379     gated!(
 380         may_dangle, Normal, template!(Word), dropck_eyepatch,
 381         "`may_dangle` has unstable semantics and may be removed in the future",
 382     ),
 383
 384     // ==========================================================================
 385     // Internal attributes: Runtime related:
 386     // ==========================================================================
 387
 388     rustc_attr!(rustc_allocator, Whitelisted, template!(Word), IMPL_DETAIL),
 389     rustc_attr!(rustc_allocator_nounwind, Whitelisted, template!(Word), IMPL_DETAIL),
 390     gated!(alloc_error_handler, Normal, template!(Word), experimental!(alloc_error_handler)),
 391     gated!(
 392         default_lib_allocator, Whitelisted, template!(Word), allocator_internals,
 393         experimental!(default_lib_allocator),
 394     ),
 395     gated!(
 396         needs_allocator, Normal, template!(Word), allocator_internals,
 397         experimental!(needs_allocator),
 398     ),
 399     gated!(panic_runtime, Whitelisted, template!(Word), experimental!(panic_runtime)),
 400     gated!(needs_panic_runtime, Whitelisted, template!(Word), experimental!(needs_panic_runtime)),
 401     gated!(
 402         unwind, Whitelisted, template!(List: "allowed|aborts"), unwind_attributes,
 403         experimental!(unwind),
 404     ),
 405     gated!(
 406         compiler_builtins, Whitelisted, template!(Word),
 407         "the `#[compiler_builtins]` attribute is used to identify the `compiler_builtins` crate \
 408         which contains compiler-rt intrinsics and will never be stable",
 409     ),
 410     gated!(
 411         profiler_runtime, Whitelisted, template!(Word),
 412         "the `#[profiler_runtime]` attribute is used to identify the `profiler_builtins` crate \
 413         which contains the profiler runtime and will never be stable",
 414     ),
 415
 416     // ==========================================================================
 417     // Internal attributes, Linkage:
 418     // ==========================================================================
 419
 420     gated!(
 421         linkage, Whitelisted, template!(NameValueStr: "external|internal|..."),
 422         "the `linkage` attribute is experimental and not portable across platforms",
 423     ),
 424     rustc_attr!(rustc_std_internal_symbol, Whitelisted, template!(Word), INTERNAL_UNSTABLE),
 425
 426     // ==========================================================================
 427     // Internal attributes, Macro related:
 428     // ==========================================================================
 429
 430     rustc_attr!(rustc_builtin_macro, Whitelisted, template!(Word), IMPL_DETAIL),
 431     rustc_attr!(rustc_proc_macro_decls, Normal, template!(Word), INTERNAL_UNSTABLE),
 432     rustc_attr!(
 433         rustc_macro_transparency, Whitelisted,
 434         template!(NameValueStr: "transparent|semitransparent|opaque"),
 435         "used internally for testing macro hygiene",
 436     ),
 437
 438     // ==========================================================================
 439     // Internal attributes, Diagnostics related:
 440     // ==========================================================================
 441
 442     rustc_attr!(
 443         rustc_on_unimplemented, Whitelisted,
 444         template!(
 445             List: r#"/*opt*/ message = "...", /*opt*/ label = "...", /*opt*/ note = "...""#,
 446             NameValueStr: "message"
 447         ),
 448         INTERNAL_UNSTABLE
 449     ),
 450     // Whitelists "identity-like" conversion methods to suggest on type mismatch.
 451     rustc_attr!(rustc_conversion_suggestion, Whitelisted, template!(Word), INTERNAL_UNSTABLE),
 452
 453     // ==========================================================================
 454     // Internal attributes, Const related:
 455     // ==========================================================================
 456
 457     rustc_attr!(rustc_promotable, Whitelisted, template!(Word), IMPL_DETAIL),
 458     rustc_attr!(rustc_allow_const_fn_ptr, Whitelisted, template!(Word), IMPL_DETAIL),
 459     rustc_attr!(rustc_args_required_const, Whitelisted, template!(List: "N"), INTERNAL_UNSTABLE),
 460
 461     // ==========================================================================
 462     // Internal attributes, Layout related:
 463     // ==========================================================================
 464
 465     rustc_attr!(
 466         rustc_layout_scalar_valid_range_start, Whitelisted, template!(List: "value"),
 467         "the `#[rustc_layout_scalar_valid_range_start]` attribute is just used to enable \
 468         niche optimizations in libcore and will never be stable",
 469     ),
 470     rustc_attr!(
 471         rustc_layout_scalar_valid_range_end, Whitelisted, template!(List: "value"),
 472         "the `#[rustc_layout_scalar_valid_range_end]` attribute is just used to enable \
 473         niche optimizations in libcore and will never be stable",
 474     ),
 475     rustc_attr!(
 476         rustc_nonnull_optimization_guaranteed, Whitelisted, template!(Word),
 477         "the `#[rustc_nonnull_optimization_guaranteed]` attribute is just used to enable \
 478         niche optimizations in libcore and will never be stable",
 479     ),
 480
 481     // ==========================================================================
 482     // Internal attributes, Misc:
 483     // ==========================================================================
 484     gated!(
 485         lang, Normal, template!(NameValueStr: "name"), lang_items,
 486         "language items are subject to change",
 487     ),
 488     (
 489         sym::rustc_diagnostic_item,
 490         Normal,
 491         template!(NameValueStr: "name"),
 492         Gated(
 493             Stability::Unstable,
 494             sym::rustc_attrs,
 495             "diagnostic items compiler internal support for linting",
 496             cfg_fn!(rustc_attrs),
 497         ),
 498     ),
 499     gated!(
 500         // Used in resolve:
 501         prelude_import, Whitelisted, template!(Word),
 502         "`#[prelude_import]` is for use by rustc only",
 503     ),
 504     gated!(
 505         rustc_paren_sugar, Normal, template!(Word), unboxed_closures,
 506         "unboxed_closures are still evolving",
 507     ),
 508     rustc_attr!(
 509         rustc_inherit_overflow_checks, Whitelisted, template!(Word),
 510         "the `#[rustc_inherit_overflow_checks]` attribute is just used to control \
 511         overflow checking behavior of several libcore functions that are inlined \
 512         across crates and will never be stable",
 513     ),
 514     rustc_attr!(rustc_reservation_impl, Normal, template!(NameValueStr: "reservation message"),
 515                 "the `#[rustc_reservation_impl]` attribute is internally used \
 516                  for reserving for `for<T> From<!> for T` impl"
 517     ),
 518     rustc_attr!(
 519         rustc_test_marker, Normal, template!(Word),
 520         "the `#[rustc_test_marker]` attribute is used internally to track tests",
 521     ),
 522     rustc_attr!(
 523         rustc_unsafe_specialization_marker, Normal, template!(Word),
 524         "the `#[rustc_unsafe_specialization_marker]` attribute is used to check specializations"
 525     ),
 526     rustc_attr!(
 527         rustc_specialization_trait, Normal, template!(Word),
 528         "the `#[rustc_specialization_trait]` attribute is used to check specializations"
 529     ),
 530
 531     // ==========================================================================
 532     // Internal attributes, Testing:
 533     // ==========================================================================
 534
 535     rustc_attr!(TEST, rustc_outlives, Normal, template!(Word)),
 536     rustc_attr!(TEST, rustc_variance, Normal, template!(Word)),
 537     rustc_attr!(TEST, rustc_layout, Normal, template!(List: "field1, field2, ...")),
 538     rustc_attr!(TEST, rustc_regions, Normal, template!(Word)),
 539     rustc_attr!(
 540         TEST, rustc_error, Whitelisted,
 541         template!(Word, List: "delay_span_bug_from_inside_query")
 542     ),
 543     rustc_attr!(TEST, rustc_dump_user_substs, Whitelisted, template!(Word)),
 544     rustc_attr!(TEST, rustc_if_this_changed, Whitelisted, template!(Word, List: "DepNode")),
 545     rustc_attr!(TEST, rustc_then_this_would_need, Whitelisted, template!(List: "DepNode")),
 546     rustc_attr!(
 547         TEST, rustc_dirty, Whitelisted,
 548         template!(List: r#"cfg = "...", /*opt*/ label = "...", /*opt*/ except = "...""#),
 549     ),
 550     rustc_attr!(
 551         TEST, rustc_clean, Whitelisted,
 552         template!(List: r#"cfg = "...", /*opt*/ label = "...", /*opt*/ except = "...""#),
 553     ),
 554     rustc_attr!(
 555         TEST, rustc_partition_reused, Whitelisted,
 556         template!(List: r#"cfg = "...", module = "...""#),
 557     ),
 558     rustc_attr!(
 559         TEST, rustc_partition_codegened, Whitelisted,
 560         template!(List: r#"cfg = "...", module = "...""#),
 561     ),
 562     rustc_attr!(
 563         TEST, rustc_expected_cgu_reuse, Whitelisted,
 564         template!(List: r#"cfg = "...", module = "...", kind = "...""#),
 565     ),
 566     rustc_attr!(TEST, rustc_synthetic, Whitelisted, template!(Word)),
 567     rustc_attr!(TEST, rustc_symbol_name, Whitelisted, template!(Word)),
 568     rustc_attr!(TEST, rustc_def_path, Whitelisted, template!(Word)),
 569     rustc_attr!(TEST, rustc_mir, Whitelisted, template!(List: "arg1, arg2, ...")),
 570     rustc_attr!(TEST, rustc_dump_program_clauses, Whitelisted, template!(Word)),
 571     rustc_attr!(TEST, rustc_dump_env_program_clauses, Whitelisted, template!(Word)),
 572     rustc_attr!(TEST, rustc_object_lifetime_default, Whitelisted, template!(Word)),
 573     rustc_attr!(TEST, rustc_dummy, Normal, template!(Word /* doesn't matter*/)),
 574     gated!(
 575         omit_gdb_pretty_printer_section, Whitelisted, template!(Word),
 576         "the `#[omit_gdb_pretty_printer_section]` attribute is just used for the Rust test suite",
 577     ),
 578 ];
 579
 580 pub fn deprecated_attributes() -> Vec<&'static BuiltinAttribute> {
 581     BUILTIN_ATTRIBUTES.iter().filter(|(.., gate)| gate.is_deprecated()).collect()
 582 }
 583
 584 pub fn is_builtin_attr_name(name: Symbol) -> bool {
 585     BUILTIN_ATTRIBUTE_MAP.get(&name).is_some()
 586 }
 587
 588 lazy_static! {
 589     pub static ref BUILTIN_ATTRIBUTE_MAP: FxHashMap<Symbol, &'static BuiltinAttribute> = {
 590         let mut map = FxHashMap::default();
 591         for attr in BUILTIN_ATTRIBUTES.iter() {
 592             if map.insert(attr.0, attr).is_some() {
 593                 panic!("duplicate builtin attribute `{}`", attr.0);
 594             }
 595         }
 596         map
 597     };
 598 }