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