1 //! # Lints in the Rust compiler
3 //! This currently only contains the definitions and implementations
4 //! of most of the lints that `rustc` supports directly, it does not
5 //! contain the infrastructure for defining/registering lints. That is
6 //! available in `rustc::lint` and `rustc_plugin` respectively.
10 //! This API is completely unstable and subject to change.
12 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/")]
14 #![cfg_attr(test, feature(test))]
15 #![feature(box_patterns)]
16 #![feature(box_syntax)]
18 #![feature(rustc_diagnostic_macros)]
20 #![recursion_limit="256"]
22 #![deny(rust_2018_idioms)]
29 mod nonstandard_style;
35 use rustc::lint::{EarlyContext, LateContext, LateLintPass, EarlyLintPass, LintPass, LintArray};
36 use rustc::lint::builtin::{
38 ABSOLUTE_PATHS_NOT_STARTING_WITH_CRATE,
39 ELIDED_LIFETIMES_IN_PATHS,
40 EXPLICIT_OUTLIVES_REQUIREMENTS,
41 INTRA_DOC_LINK_RESOLUTION_FAILURE,
42 MISSING_DOC_CODE_EXAMPLES,
44 parser::QUESTION_MARK_MACRO_SEP,
45 parser::ILL_FORMED_ATTRIBUTE_INPUT,
49 use rustc::hir::def_id::DefId;
50 use rustc::ty::query::Providers;
51 use rustc::ty::TyCtxt;
54 use syntax::edition::Edition;
59 use lint::FutureIncompatibleInfo;
61 use nonstandard_style::*;
65 use rustc::lint::internal::*;
67 /// Useful for other parts of the compiler.
68 pub use builtin::SoftLints;
70 pub fn provide(providers: &mut Providers<'_>) {
71 *providers = Providers {
77 fn lint_mod<'tcx>(tcx: TyCtxt<'_, 'tcx, 'tcx>, module_def_id: DefId) {
78 lint::late_lint_mod(tcx, module_def_id, BuiltinCombinedModuleLateLintPass::new());
81 macro_rules! pre_expansion_lint_passes {
82 ($macro:path, $args:tt) => (
84 KeywordIdents: KeywordIdents,
85 UnusedDocComment: UnusedDocComment,
90 macro_rules! early_lint_passes {
91 ($macro:path, $args:tt) => (
93 UnusedParens: UnusedParens,
94 UnusedImportBraces: UnusedImportBraces,
95 UnsafeCode: UnsafeCode,
96 AnonymousParameters: AnonymousParameters,
97 EllipsisInclusiveRangePatterns: EllipsisInclusiveRangePatterns::default(),
98 NonCamelCaseTypes: NonCamelCaseTypes,
99 DeprecatedAttr: DeprecatedAttr::new(),
104 macro_rules! declare_combined_early_pass {
105 ([$name:ident], $passes:tt) => (
106 early_lint_methods!(declare_combined_early_lint_pass, [pub $name, $passes]);
110 pre_expansion_lint_passes!(declare_combined_early_pass, [BuiltinCombinedPreExpansionLintPass]);
111 early_lint_passes!(declare_combined_early_pass, [BuiltinCombinedEarlyLintPass]);
113 macro_rules! late_lint_passes {
114 ($macro:path, $args:tt) => (
116 // FIXME: Look into regression when this is used as a module lint
117 // May Depend on constants elsewhere
118 UnusedBrokenConst: UnusedBrokenConst,
120 // Uses attr::is_used which is untracked, can't be an incremental module pass.
121 UnusedAttributes: UnusedAttributes::new(),
123 // Needs to run after UnusedAttributes as it marks all `feature` attributes as used.
124 UnstableFeatures: UnstableFeatures,
126 // Tracks state across modules
127 UnnameableTestItems: UnnameableTestItems::new(),
129 // Tracks attributes of parents
130 MissingDoc: MissingDoc::new(),
132 // Depends on access levels
133 // FIXME: Turn the computation of types which implement Debug into a query
134 // and change this to a module lint pass
135 MissingDebugImplementations: MissingDebugImplementations::default(),
140 macro_rules! late_lint_mod_passes {
141 ($macro:path, $args:tt) => (
143 HardwiredLints: HardwiredLints,
144 WhileTrue: WhileTrue,
145 ImproperCTypes: ImproperCTypes,
146 VariantSizeDifferences: VariantSizeDifferences,
147 BoxPointers: BoxPointers,
148 PathStatements: PathStatements,
150 // Depends on referenced function signatures in expressions
151 UnusedResults: UnusedResults,
153 NonUpperCaseGlobals: NonUpperCaseGlobals,
154 NonShorthandFieldPatterns: NonShorthandFieldPatterns,
155 UnusedAllocation: UnusedAllocation,
157 // Depends on types used in type definitions
158 MissingCopyImplementations: MissingCopyImplementations,
160 PluginAsLibrary: PluginAsLibrary,
162 // Depends on referenced function signatures in expressions
163 MutableTransmutes: MutableTransmutes,
165 // Depends on types of fields, checks if they implement Drop
166 UnionsWithDropFields: UnionsWithDropFields,
168 TypeAliasBounds: TypeAliasBounds,
170 TrivialConstraints: TrivialConstraints,
171 TypeLimits: TypeLimits::new(),
173 NonSnakeCase: NonSnakeCase,
174 InvalidNoMangleItems: InvalidNoMangleItems,
176 // Depends on access levels
177 UnreachablePub: UnreachablePub,
179 ExplicitOutlivesRequirements: ExplicitOutlivesRequirements,
184 macro_rules! declare_combined_late_pass {
185 ([$v:vis $name:ident], $passes:tt) => (
186 late_lint_methods!(declare_combined_late_lint_pass, [$v $name, $passes], ['tcx]);
190 // FIXME: Make a separate lint type which do not require typeck tables
191 late_lint_passes!(declare_combined_late_pass, [pub BuiltinCombinedLateLintPass]);
193 late_lint_mod_passes!(declare_combined_late_pass, [BuiltinCombinedModuleLateLintPass]);
195 /// Tell the `LintStore` about all the built-in lints (the ones
196 /// defined in this crate and the ones defined in
197 /// `rustc::lint::builtin`).
198 pub fn register_builtins(store: &mut lint::LintStore, sess: Option<&Session>) {
199 macro_rules! add_lint_group {
200 ($sess:ident, $name:expr, $($lint:ident),*) => (
201 store.register_group($sess, false, $name, None, vec![$(LintId::of($lint)),*]);
205 macro_rules! register_pass {
206 ($method:ident, $constructor:expr, [$($args:expr),*]) => (
207 store.$method(sess, false, false, $($args,)* box $constructor);
211 macro_rules! register_passes {
212 ([$method:ident, $args:tt], [$($passes:ident: $constructor:expr,)*]) => (
214 register_pass!($method, $constructor, $args);
219 if sess.map(|sess| sess.opts.debugging_opts.no_interleave_lints).unwrap_or(false) {
220 pre_expansion_lint_passes!(register_passes, [register_pre_expansion_pass, []]);
221 early_lint_passes!(register_passes, [register_early_pass, []]);
222 late_lint_passes!(register_passes, [register_late_pass, [false]]);
223 late_lint_mod_passes!(register_passes, [register_late_pass, [true]]);
225 store.register_pre_expansion_pass(
229 box BuiltinCombinedPreExpansionLintPass::new()
231 store.register_early_pass(sess, false, true, box BuiltinCombinedEarlyLintPass::new());
232 store.register_late_pass(
233 sess, false, true, true, box BuiltinCombinedModuleLateLintPass::new()
235 store.register_late_pass(
236 sess, false, true, false, box BuiltinCombinedLateLintPass::new()
240 add_lint_group!(sess,
242 NON_CAMEL_CASE_TYPES,
244 NON_UPPER_CASE_GLOBALS);
246 add_lint_group!(sess,
254 UNREACHABLE_PATTERNS,
262 UNUSED_EXTERN_CRATES,
267 add_lint_group!(sess,
270 UNUSED_EXTERN_CRATES,
271 ELLIPSIS_INCLUSIVE_RANGE_PATTERNS,
272 ELIDED_LIFETIMES_IN_PATHS,
273 EXPLICIT_OUTLIVES_REQUIREMENTS
275 // FIXME(#52665, #47816) not always applicable and not all
276 // macros are ready for this yet.
279 // FIXME macro crates are not up for this yet, too much
280 // breakage is seen if we try to encourage this lint.
281 // MACRO_USE_EXTERN_CRATE,
284 add_lint_group!(sess,
286 INTRA_DOC_LINK_RESOLUTION_FAILURE,
287 MISSING_DOC_CODE_EXAMPLES,
290 // Guidelines for creating a future incompatibility lint:
292 // - Create a lint defaulting to warn as normal, with ideally the same error
293 // message you would normally give
294 // - Add a suitable reference, typically an RFC or tracking issue. Go ahead
295 // and include the full URL, sort items in ascending order of issue numbers.
296 // - Later, change lint to error
297 // - Eventually, remove lint
298 store.register_future_incompatible(sess, vec![
299 FutureIncompatibleInfo {
300 id: LintId::of(PRIVATE_IN_PUBLIC),
301 reference: "issue #34537 <https://github.com/rust-lang/rust/issues/34537>",
304 FutureIncompatibleInfo {
305 id: LintId::of(PUB_USE_OF_PRIVATE_EXTERN_CRATE),
306 reference: "issue #34537 <https://github.com/rust-lang/rust/issues/34537>",
309 FutureIncompatibleInfo {
310 id: LintId::of(PATTERNS_IN_FNS_WITHOUT_BODY),
311 reference: "issue #35203 <https://github.com/rust-lang/rust/issues/35203>",
314 FutureIncompatibleInfo {
315 id: LintId::of(DUPLICATE_MACRO_EXPORTS),
316 reference: "issue #35896 <https://github.com/rust-lang/rust/issues/35896>",
317 edition: Some(Edition::Edition2018),
319 FutureIncompatibleInfo {
320 id: LintId::of(KEYWORD_IDENTS),
321 reference: "issue #49716 <https://github.com/rust-lang/rust/issues/49716>",
322 edition: Some(Edition::Edition2018),
324 FutureIncompatibleInfo {
325 id: LintId::of(SAFE_EXTERN_STATICS),
326 reference: "issue #36247 <https://github.com/rust-lang/rust/issues/36247>",
329 FutureIncompatibleInfo {
330 id: LintId::of(INVALID_TYPE_PARAM_DEFAULT),
331 reference: "issue #36887 <https://github.com/rust-lang/rust/issues/36887>",
334 FutureIncompatibleInfo {
335 id: LintId::of(LEGACY_DIRECTORY_OWNERSHIP),
336 reference: "issue #37872 <https://github.com/rust-lang/rust/issues/37872>",
339 FutureIncompatibleInfo {
340 id: LintId::of(LEGACY_CONSTRUCTOR_VISIBILITY),
341 reference: "issue #39207 <https://github.com/rust-lang/rust/issues/39207>",
344 FutureIncompatibleInfo {
345 id: LintId::of(MISSING_FRAGMENT_SPECIFIER),
346 reference: "issue #40107 <https://github.com/rust-lang/rust/issues/40107>",
349 FutureIncompatibleInfo {
350 id: LintId::of(ILLEGAL_FLOATING_POINT_LITERAL_PATTERN),
351 reference: "issue #41620 <https://github.com/rust-lang/rust/issues/41620>",
354 FutureIncompatibleInfo {
355 id: LintId::of(ANONYMOUS_PARAMETERS),
356 reference: "issue #41686 <https://github.com/rust-lang/rust/issues/41686>",
357 edition: Some(Edition::Edition2018),
359 FutureIncompatibleInfo {
360 id: LintId::of(PARENTHESIZED_PARAMS_IN_TYPES_AND_MODULES),
361 reference: "issue #42238 <https://github.com/rust-lang/rust/issues/42238>",
364 FutureIncompatibleInfo {
365 id: LintId::of(LATE_BOUND_LIFETIME_ARGUMENTS),
366 reference: "issue #42868 <https://github.com/rust-lang/rust/issues/42868>",
369 FutureIncompatibleInfo {
370 id: LintId::of(SAFE_PACKED_BORROWS),
371 reference: "issue #46043 <https://github.com/rust-lang/rust/issues/46043>",
374 FutureIncompatibleInfo {
375 id: LintId::of(ORDER_DEPENDENT_TRAIT_OBJECTS),
376 reference: "issue #56484 <https://github.com/rust-lang/rust/issues/56484>",
379 FutureIncompatibleInfo {
380 id: LintId::of(TYVAR_BEHIND_RAW_POINTER),
381 reference: "issue #46906 <https://github.com/rust-lang/rust/issues/46906>",
382 edition: Some(Edition::Edition2018),
384 FutureIncompatibleInfo {
385 id: LintId::of(UNSTABLE_NAME_COLLISIONS),
386 reference: "issue #48919 <https://github.com/rust-lang/rust/issues/48919>",
388 // Note: this item represents future incompatibility of all unstable functions in the
389 // standard library, and thus should never be removed or changed to an error.
391 FutureIncompatibleInfo {
392 id: LintId::of(ABSOLUTE_PATHS_NOT_STARTING_WITH_CRATE),
393 reference: "issue #53130 <https://github.com/rust-lang/rust/issues/53130>",
394 edition: Some(Edition::Edition2018),
396 FutureIncompatibleInfo {
397 id: LintId::of(WHERE_CLAUSES_OBJECT_SAFETY),
398 reference: "issue #51443 <https://github.com/rust-lang/rust/issues/51443>",
401 FutureIncompatibleInfo {
402 id: LintId::of(PROC_MACRO_DERIVE_RESOLUTION_FALLBACK),
403 reference: "issue #50504 <https://github.com/rust-lang/rust/issues/50504>",
406 FutureIncompatibleInfo {
407 id: LintId::of(QUESTION_MARK_MACRO_SEP),
408 reference: "issue #48075 <https://github.com/rust-lang/rust/issues/48075>",
409 edition: Some(Edition::Edition2018),
411 FutureIncompatibleInfo {
412 id: LintId::of(MACRO_EXPANDED_MACRO_EXPORTS_ACCESSED_BY_ABSOLUTE_PATHS),
413 reference: "issue #52234 <https://github.com/rust-lang/rust/issues/52234>",
416 FutureIncompatibleInfo {
417 id: LintId::of(ILL_FORMED_ATTRIBUTE_INPUT),
418 reference: "issue #57571 <https://github.com/rust-lang/rust/issues/57571>",
421 FutureIncompatibleInfo {
422 id: LintId::of(AMBIGUOUS_ASSOCIATED_ITEMS),
423 reference: "issue #57644 <https://github.com/rust-lang/rust/issues/57644>",
426 FutureIncompatibleInfo {
427 id: LintId::of(NESTED_IMPL_TRAIT),
428 reference: "issue #59014 <https://github.com/rust-lang/rust/issues/59014>",
431 FutureIncompatibleInfo {
432 id: LintId::of(MUTABLE_BORROW_RESERVATION_CONFLICT),
433 reference: "issue #59159 <https://github.com/rust-lang/rust/issues/59159>",
438 // Register renamed and removed lints.
439 store.register_renamed("single_use_lifetime", "single_use_lifetimes");
440 store.register_renamed("elided_lifetime_in_path", "elided_lifetimes_in_paths");
441 store.register_renamed("bare_trait_object", "bare_trait_objects");
442 store.register_renamed("unstable_name_collision", "unstable_name_collisions");
443 store.register_renamed("unused_doc_comment", "unused_doc_comments");
444 store.register_renamed("async_idents", "keyword_idents");
445 store.register_removed("unknown_features", "replaced by an error");
446 store.register_removed("unsigned_negation", "replaced by negate_unsigned feature gate");
447 store.register_removed("negate_unsigned", "cast a signed value instead");
448 store.register_removed("raw_pointer_derive", "using derive with raw pointers is ok");
449 // Register lint group aliases.
450 store.register_group_alias("nonstandard_style", "bad_style");
451 // This was renamed to `raw_pointer_derive`, which was then removed,
452 // so it is also considered removed.
453 store.register_removed("raw_pointer_deriving", "using derive with raw pointers is ok");
454 store.register_removed("drop_with_repr_extern", "drop flags have been removed");
455 store.register_removed("fat_ptr_transmutes", "was accidentally removed back in 2014");
456 store.register_removed("deprecated_attr", "use `deprecated` instead");
457 store.register_removed("transmute_from_fn_item_types",
458 "always cast functions before transmuting them");
459 store.register_removed("hr_lifetime_in_assoc_type",
460 "converted into hard error, see https://github.com/rust-lang/rust/issues/33685");
461 store.register_removed("inaccessible_extern_crate",
462 "converted into hard error, see https://github.com/rust-lang/rust/issues/36886");
463 store.register_removed("super_or_self_in_global_path",
464 "converted into hard error, see https://github.com/rust-lang/rust/issues/36888");
465 store.register_removed("overlapping_inherent_impls",
466 "converted into hard error, see https://github.com/rust-lang/rust/issues/36889");
467 store.register_removed("illegal_floating_point_constant_pattern",
468 "converted into hard error, see https://github.com/rust-lang/rust/issues/36890");
469 store.register_removed("illegal_struct_or_enum_constant_pattern",
470 "converted into hard error, see https://github.com/rust-lang/rust/issues/36891");
471 store.register_removed("lifetime_underscore",
472 "converted into hard error, see https://github.com/rust-lang/rust/issues/36892");
473 store.register_removed("extra_requirement_in_impl",
474 "converted into hard error, see https://github.com/rust-lang/rust/issues/37166");
475 store.register_removed("legacy_imports",
476 "converted into hard error, see https://github.com/rust-lang/rust/issues/38260");
477 store.register_removed("coerce_never",
478 "converted into hard error, see https://github.com/rust-lang/rust/issues/48950");
479 store.register_removed("resolve_trait_on_defaulted_unit",
480 "converted into hard error, see https://github.com/rust-lang/rust/issues/48950");
481 store.register_removed("private_no_mangle_fns",
482 "no longer a warning, #[no_mangle] functions always exported");
483 store.register_removed("private_no_mangle_statics",
484 "no longer a warning, #[no_mangle] statics always exported");
485 store.register_removed("bad_repr",
486 "replaced with a generic attribute input check");
487 store.register_removed("duplicate_matcher_binding_name",
488 "converted into hard error, see https://github.com/rust-lang/rust/issues/57742");
489 store.register_removed("incoherent_fundamental_impls",
490 "converted into hard error, see https://github.com/rust-lang/rust/issues/46205");
493 pub fn register_internals(store: &mut lint::LintStore, sess: Option<&Session>) {
494 store.register_early_pass(sess, false, false, box DefaultHashTypes::new());
495 store.register_late_pass(sess, false, false, false, box TyTyKind);
496 store.register_group(
502 LintId::of(DEFAULT_HASH_TYPES),
503 LintId::of(USAGE_OF_TY_TYKIND),
504 LintId::of(TY_PASS_BY_REFERENCE),
505 LintId::of(USAGE_OF_QUALIFIED_TY),