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