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