src/librustc_lint/lib.rs

   1 //! # Lints in the Rust compiler
   2 //!
   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_driver::plugin` respectively.
   7 //!
   8 //! ## Note
   9 //!
  10 //! This API is completely unstable and subject to change.
  11
  12 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/")]
  13 #![cfg_attr(test, feature(test))]
  14 #![feature(bool_to_option)]
  15 #![feature(box_patterns)]
  16 #![feature(box_syntax)]
  17 #![feature(crate_visibility_modifier)]
  18 #![feature(nll)]
  19 #![recursion_limit = "256"]
  20
  21 #[macro_use]
  22 extern crate rustc;
  23 #[macro_use]
  24 extern crate rustc_session;
  25
  26 mod array_into_iter;
  27 pub mod builtin;
  28 mod early;
  29 mod late;
  30 mod levels;
  31 mod non_ascii_idents;
  32 mod nonstandard_style;
  33 mod redundant_semicolon;
  34 mod types;
  35 mod unused;
  36
  37 use rustc::lint;
  38 use rustc::lint::builtin::{
  39     BARE_TRAIT_OBJECTS, ELIDED_LIFETIMES_IN_PATHS, EXPLICIT_OUTLIVES_REQUIREMENTS,
  40     INTRA_DOC_LINK_RESOLUTION_FAILURE, MISSING_DOC_CODE_EXAMPLES, PRIVATE_DOC_TESTS,
  41 };
  42 use rustc::lint::{EarlyContext, EarlyLintPass, LateContext, LateLintPass};
  43 use rustc::ty::query::Providers;
  44 use rustc::ty::TyCtxt;
  45 use rustc_hir as hir;
  46 use rustc_hir::def_id::DefId;
  47 use rustc_session::lint::{LintArray, LintPass};
  48
  49 use rustc_span::Span;
  50 use syntax::ast;
  51
  52 use lint::LintId;
  53
  54 use array_into_iter::ArrayIntoIter;
  55 use builtin::*;
  56 use non_ascii_idents::*;
  57 use nonstandard_style::*;
  58 use redundant_semicolon::*;
  59 use rustc::lint::internal::*;
  60 use types::*;
  61 use unused::*;
  62
  63 /// Useful for other parts of the compiler.
  64 pub use builtin::SoftLints;
  65 pub use early::check_ast_crate;
  66 pub use late::check_crate;
  67
  68 pub fn provide(providers: &mut Providers<'_>) {
  69     levels::provide(providers);
  70     *providers = Providers { lint_mod, ..*providers };
  71 }
  72
  73 fn lint_mod(tcx: TyCtxt<'_>, module_def_id: DefId) {
  74     late::late_lint_mod(tcx, module_def_id, BuiltinCombinedModuleLateLintPass::new());
  75 }
  76
  77 macro_rules! pre_expansion_lint_passes {
  78     ($macro:path, $args:tt) => {
  79         $macro!($args, [KeywordIdents: KeywordIdents, UnusedDocComment: UnusedDocComment,]);
  80     };
  81 }
  82
  83 macro_rules! early_lint_passes {
  84     ($macro:path, $args:tt) => {
  85         $macro!(
  86             $args,
  87             [
  88                 UnusedParens: UnusedParens,
  89                 UnusedImportBraces: UnusedImportBraces,
  90                 UnsafeCode: UnsafeCode,
  91                 AnonymousParameters: AnonymousParameters,
  92                 EllipsisInclusiveRangePatterns: EllipsisInclusiveRangePatterns::default(),
  93                 NonCamelCaseTypes: NonCamelCaseTypes,
  94                 DeprecatedAttr: DeprecatedAttr::new(),
  95                 WhileTrue: WhileTrue,
  96                 NonAsciiIdents: NonAsciiIdents,
  97                 IncompleteFeatures: IncompleteFeatures,
  98                 RedundantSemicolon: RedundantSemicolon,
  99             ]
 100         );
 101     };
 102 }
 103
 104 macro_rules! declare_combined_early_pass {
 105     ([$name:ident], $passes:tt) => (
 106         early_lint_methods!(declare_combined_early_lint_pass, [pub $name, $passes]);
 107     )
 108 }
 109
 110 pre_expansion_lint_passes!(declare_combined_early_pass, [BuiltinCombinedPreExpansionLintPass]);
 111 early_lint_passes!(declare_combined_early_pass, [BuiltinCombinedEarlyLintPass]);
 112
 113 macro_rules! late_lint_passes {
 114     ($macro:path, $args:tt) => {
 115         $macro!(
 116             $args,
 117             [
 118                 // FIXME: Look into regression when this is used as a module lint
 119                 // May Depend on constants elsewhere
 120                 UnusedBrokenConst: UnusedBrokenConst,
 121                 // Uses attr::is_used which is untracked, can't be an incremental module pass.
 122                 UnusedAttributes: UnusedAttributes::new(),
 123                 // Needs to run after UnusedAttributes as it marks all `feature` attributes as used.
 124                 UnstableFeatures: UnstableFeatures,
 125                 // Tracks state across modules
 126                 UnnameableTestItems: UnnameableTestItems::new(),
 127                 // Tracks attributes of parents
 128                 MissingDoc: MissingDoc::new(),
 129                 // Depends on access levels
 130                 // FIXME: Turn the computation of types which implement Debug into a query
 131                 // and change this to a module lint pass
 132                 MissingDebugImplementations: MissingDebugImplementations::default(),
 133                 ArrayIntoIter: ArrayIntoIter,
 134             ]
 135         );
 136     };
 137 }
 138
 139 macro_rules! late_lint_mod_passes {
 140     ($macro:path, $args:tt) => {
 141         $macro!(
 142             $args,
 143             [
 144                 HardwiredLints: HardwiredLints,
 145                 ImproperCTypes: ImproperCTypes,
 146                 VariantSizeDifferences: VariantSizeDifferences,
 147                 BoxPointers: BoxPointers,
 148                 PathStatements: PathStatements,
 149                 // Depends on referenced function signatures in expressions
 150                 UnusedResults: UnusedResults,
 151                 NonUpperCaseGlobals: NonUpperCaseGlobals,
 152                 NonShorthandFieldPatterns: NonShorthandFieldPatterns,
 153                 UnusedAllocation: UnusedAllocation,
 154                 // Depends on types used in type definitions
 155                 MissingCopyImplementations: MissingCopyImplementations,
 156                 // Depends on referenced function signatures in expressions
 157                 MutableTransmutes: MutableTransmutes,
 158                 TypeAliasBounds: TypeAliasBounds,
 159                 TrivialConstraints: TrivialConstraints,
 160                 TypeLimits: TypeLimits::new(),
 161                 NonSnakeCase: NonSnakeCase,
 162                 InvalidNoMangleItems: InvalidNoMangleItems,
 163                 // Depends on access levels
 164                 UnreachablePub: UnreachablePub,
 165                 ExplicitOutlivesRequirements: ExplicitOutlivesRequirements,
 166                 InvalidValue: InvalidValue,
 167             ]
 168         );
 169     };
 170 }
 171
 172 macro_rules! declare_combined_late_pass {
 173     ([$v:vis $name:ident], $passes:tt) => (
 174         late_lint_methods!(declare_combined_late_lint_pass, [$v $name, $passes], ['tcx]);
 175     )
 176 }
 177
 178 // FIXME: Make a separate lint type which do not require typeck tables
 179 late_lint_passes!(declare_combined_late_pass, [pub BuiltinCombinedLateLintPass]);
 180
 181 late_lint_mod_passes!(declare_combined_late_pass, [BuiltinCombinedModuleLateLintPass]);
 182
 183 pub fn new_lint_store(no_interleave_lints: bool, internal_lints: bool) -> lint::LintStore {
 184     let mut lint_store = lint::LintStore::new();
 185
 186     register_builtins(&mut lint_store, no_interleave_lints);
 187     if internal_lints {
 188         register_internals(&mut lint_store);
 189     }
 190
 191     lint_store
 192 }
 193
 194 /// Tell the `LintStore` about all the built-in lints (the ones
 195 /// defined in this crate and the ones defined in
 196 /// `rustc::lint::builtin`).
 197 fn register_builtins(store: &mut lint::LintStore, no_interleave_lints: bool) {
 198     macro_rules! add_lint_group {
 199         ($name:expr, $($lint:ident),*) => (
 200             store.register_group(false, $name, None, vec![$(LintId::of($lint)),*]);
 201         )
 202     }
 203
 204     macro_rules! register_pass {
 205         ($method:ident, $ty:ident, $constructor:expr) => {
 206             store.register_lints(&$ty::get_lints());
 207             store.$method(|| box $constructor);
 208         };
 209     }
 210
 211     macro_rules! register_passes {
 212         ($method:ident, [$($passes:ident: $constructor:expr,)*]) => (
 213             $(
 214                 register_pass!($method, $passes, $constructor);
 215             )*
 216         )
 217     }
 218
 219     if no_interleave_lints {
 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);
 223         late_lint_mod_passes!(register_passes, register_late_mod_pass);
 224     } else {
 225         store.register_lints(&BuiltinCombinedPreExpansionLintPass::get_lints());
 226         store.register_lints(&BuiltinCombinedEarlyLintPass::get_lints());
 227         store.register_lints(&BuiltinCombinedModuleLateLintPass::get_lints());
 228         store.register_lints(&BuiltinCombinedLateLintPass::get_lints());
 229     }
 230
 231     add_lint_group!(
 232         "nonstandard_style",
 233         NON_CAMEL_CASE_TYPES,
 234         NON_SNAKE_CASE,
 235         NON_UPPER_CASE_GLOBALS
 236     );
 237
 238     add_lint_group!(
 239         "unused",
 240         UNUSED_IMPORTS,
 241         UNUSED_VARIABLES,
 242         UNUSED_ASSIGNMENTS,
 243         DEAD_CODE,
 244         UNUSED_MUT,
 245         UNREACHABLE_CODE,
 246         UNREACHABLE_PATTERNS,
 247         OVERLAPPING_PATTERNS,
 248         UNUSED_MUST_USE,
 249         UNUSED_UNSAFE,
 250         PATH_STATEMENTS,
 251         UNUSED_ATTRIBUTES,
 252         UNUSED_MACROS,
 253         UNUSED_ALLOCATION,
 254         UNUSED_DOC_COMMENTS,
 255         UNUSED_EXTERN_CRATES,
 256         UNUSED_FEATURES,
 257         UNUSED_LABELS,
 258         UNUSED_PARENS
 259     );
 260
 261     add_lint_group!(
 262         "rust_2018_idioms",
 263         BARE_TRAIT_OBJECTS,
 264         UNUSED_EXTERN_CRATES,
 265         ELLIPSIS_INCLUSIVE_RANGE_PATTERNS,
 266         ELIDED_LIFETIMES_IN_PATHS,
 267         EXPLICIT_OUTLIVES_REQUIREMENTS // FIXME(#52665, #47816) not always applicable and not all
 268                                        // macros are ready for this yet.
 269                                        // UNREACHABLE_PUB,
 270
 271                                        // FIXME macro crates are not up for this yet, too much
 272                                        // breakage is seen if we try to encourage this lint.
 273                                        // MACRO_USE_EXTERN_CRATE
 274     );
 275
 276     add_lint_group!(
 277         "rustdoc",
 278         INTRA_DOC_LINK_RESOLUTION_FAILURE,
 279         MISSING_DOC_CODE_EXAMPLES,
 280         PRIVATE_DOC_TESTS
 281     );
 282
 283     // Register renamed and removed lints.
 284     store.register_renamed("single_use_lifetime", "single_use_lifetimes");
 285     store.register_renamed("elided_lifetime_in_path", "elided_lifetimes_in_paths");
 286     store.register_renamed("bare_trait_object", "bare_trait_objects");
 287     store.register_renamed("unstable_name_collision", "unstable_name_collisions");
 288     store.register_renamed("unused_doc_comment", "unused_doc_comments");
 289     store.register_renamed("async_idents", "keyword_idents");
 290     store.register_removed("unknown_features", "replaced by an error");
 291     store.register_removed("unsigned_negation", "replaced by negate_unsigned feature gate");
 292     store.register_removed("negate_unsigned", "cast a signed value instead");
 293     store.register_removed("raw_pointer_derive", "using derive with raw pointers is ok");
 294     // Register lint group aliases.
 295     store.register_group_alias("nonstandard_style", "bad_style");
 296     // This was renamed to `raw_pointer_derive`, which was then removed,
 297     // so it is also considered removed.
 298     store.register_removed("raw_pointer_deriving", "using derive with raw pointers is ok");
 299     store.register_removed("drop_with_repr_extern", "drop flags have been removed");
 300     store.register_removed("fat_ptr_transmutes", "was accidentally removed back in 2014");
 301     store.register_removed("deprecated_attr", "use `deprecated` instead");
 302     store.register_removed(
 303         "transmute_from_fn_item_types",
 304         "always cast functions before transmuting them",
 305     );
 306     store.register_removed(
 307         "hr_lifetime_in_assoc_type",
 308         "converted into hard error, see https://github.com/rust-lang/rust/issues/33685",
 309     );
 310     store.register_removed(
 311         "inaccessible_extern_crate",
 312         "converted into hard error, see https://github.com/rust-lang/rust/issues/36886",
 313     );
 314     store.register_removed(
 315         "super_or_self_in_global_path",
 316         "converted into hard error, see https://github.com/rust-lang/rust/issues/36888",
 317     );
 318     store.register_removed(
 319         "overlapping_inherent_impls",
 320         "converted into hard error, see https://github.com/rust-lang/rust/issues/36889",
 321     );
 322     store.register_removed(
 323         "illegal_floating_point_constant_pattern",
 324         "converted into hard error, see https://github.com/rust-lang/rust/issues/36890",
 325     );
 326     store.register_removed(
 327         "illegal_struct_or_enum_constant_pattern",
 328         "converted into hard error, see https://github.com/rust-lang/rust/issues/36891",
 329     );
 330     store.register_removed(
 331         "lifetime_underscore",
 332         "converted into hard error, see https://github.com/rust-lang/rust/issues/36892",
 333     );
 334     store.register_removed(
 335         "extra_requirement_in_impl",
 336         "converted into hard error, see https://github.com/rust-lang/rust/issues/37166",
 337     );
 338     store.register_removed(
 339         "legacy_imports",
 340         "converted into hard error, see https://github.com/rust-lang/rust/issues/38260",
 341     );
 342     store.register_removed(
 343         "coerce_never",
 344         "converted into hard error, see https://github.com/rust-lang/rust/issues/48950",
 345     );
 346     store.register_removed(
 347         "resolve_trait_on_defaulted_unit",
 348         "converted into hard error, see https://github.com/rust-lang/rust/issues/48950",
 349     );
 350     store.register_removed(
 351         "private_no_mangle_fns",
 352         "no longer a warning, `#[no_mangle]` functions always exported",
 353     );
 354     store.register_removed(
 355         "private_no_mangle_statics",
 356         "no longer a warning, `#[no_mangle]` statics always exported",
 357     );
 358     store.register_removed("bad_repr", "replaced with a generic attribute input check");
 359     store.register_removed(
 360         "duplicate_matcher_binding_name",
 361         "converted into hard error, see https://github.com/rust-lang/rust/issues/57742",
 362     );
 363     store.register_removed(
 364         "incoherent_fundamental_impls",
 365         "converted into hard error, see https://github.com/rust-lang/rust/issues/46205",
 366     );
 367     store.register_removed(
 368         "legacy_constructor_visibility",
 369         "converted into hard error, see https://github.com/rust-lang/rust/issues/39207",
 370     );
 371     store.register_removed(
 372         "legacy_directory_ownership",
 373         "converted into hard error, see https://github.com/rust-lang/rust/issues/37872",
 374     );
 375     store.register_removed(
 376         "safe_extern_statics",
 377         "converted into hard error, see https://github.com/rust-lang/rust/issues/36247",
 378     );
 379     store.register_removed(
 380         "parenthesized_params_in_types_and_modules",
 381         "converted into hard error, see https://github.com/rust-lang/rust/issues/42238",
 382     );
 383     store.register_removed(
 384         "duplicate_macro_exports",
 385         "converted into hard error, see https://github.com/rust-lang/rust/issues/35896",
 386     );
 387     store.register_removed(
 388         "nested_impl_trait",
 389         "converted into hard error, see https://github.com/rust-lang/rust/issues/59014",
 390     );
 391     store.register_removed("plugin_as_library", "plugins have been deprecated and retired");
 392 }
 393
 394 fn register_internals(store: &mut lint::LintStore) {
 395     store.register_lints(&DefaultHashTypes::get_lints());
 396     store.register_early_pass(|| box DefaultHashTypes::new());
 397     store.register_lints(&LintPassImpl::get_lints());
 398     store.register_early_pass(|| box LintPassImpl);
 399     store.register_lints(&TyTyKind::get_lints());
 400     store.register_late_pass(|| box TyTyKind);
 401     store.register_group(
 402         false,
 403         "rustc::internal",
 404         None,
 405         vec![
 406             LintId::of(DEFAULT_HASH_TYPES),
 407             LintId::of(USAGE_OF_TY_TYKIND),
 408             LintId::of(LINT_PASS_IMPL_WITHOUT_MACRO),
 409             LintId::of(TY_PASS_BY_REFERENCE),
 410             LintId::of(USAGE_OF_QUALIFIED_TY),
 411         ],
 412     );
 413 }