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