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