src/librustc_lint/lib.rs

   1 // Copyright 2015 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 //! # Lints in the Rust compiler
  12 //!
  13 //! This currently only contains the definitions and implementations
  14 //! of most of the lints that `rustc` supports directly, it does not
  15 //! contain the infrastructure for defining/registering lints. That is
  16 //! available in `rustc::lint` and `rustc_plugin` respectively.
  17 //!
  18 //! ## Note
  19 //!
  20 //! This API is completely unstable and subject to change.
  21
  22 #![doc(html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
  23       html_favicon_url = "https://doc.rust-lang.org/favicon.ico",
  24       html_root_url = "https://doc.rust-lang.org/nightly/")]
  25
  26 #![cfg_attr(test, feature(test))]
  27 #![feature(box_patterns)]
  28 #![feature(box_syntax)]
  29 #![feature(nll)]
  30 #![feature(quote)]
  31 #![feature(rustc_diagnostic_macros)]
  32
  33 #[macro_use]
  34 extern crate syntax;
  35 #[macro_use]
  36 extern crate rustc;
  37 #[macro_use]
  38 extern crate log;
  39 extern crate rustc_target;
  40 extern crate syntax_pos;
  41 extern crate rustc_data_structures;
  42
  43 mod diagnostics;
  44 mod nonstandard_style;
  45 pub mod builtin;
  46 mod types;
  47 mod unused;
  48
  49 use rustc::lint;
  50 use rustc::lint::{LateContext, LateLintPass, LintPass, LintArray};
  51 use rustc::lint::builtin::{
  52     BARE_TRAIT_OBJECTS,
  53     ABSOLUTE_PATHS_NOT_STARTING_WITH_CRATE,
  54     ELIDED_LIFETIMES_IN_PATHS,
  55     EXPLICIT_OUTLIVES_REQUIREMENTS,
  56     parser::QUESTION_MARK_MACRO_SEP
  57 };
  58 use rustc::session;
  59 use rustc::util;
  60 use rustc::hir;
  61
  62 use syntax::ast;
  63 use syntax::edition::Edition;
  64 use syntax_pos::Span;
  65
  66 use session::Session;
  67 use lint::LintId;
  68 use lint::FutureIncompatibleInfo;
  69
  70 use nonstandard_style::*;
  71 use builtin::*;
  72 use types::*;
  73 use unused::*;
  74
  75 /// Useful for other parts of the compiler.
  76 pub use builtin::SoftLints;
  77
  78 /// Tell the `LintStore` about all the built-in lints (the ones
  79 /// defined in this crate and the ones defined in
  80 /// `rustc::lint::builtin`).
  81 pub fn register_builtins(store: &mut lint::LintStore, sess: Option<&Session>) {
  82     macro_rules! add_early_builtin {
  83         ($sess:ident, $($name:ident),*,) => (
  84             {$(
  85                 store.register_early_pass($sess, false, box $name);
  86             )*}
  87         )
  88     }
  89
  90     macro_rules! add_pre_expansion_builtin {
  91         ($sess:ident, $($name:ident),*,) => (
  92             {$(
  93                 store.register_pre_expansion_pass($sess, box $name);
  94             )*}
  95         )
  96     }
  97
  98     macro_rules! add_early_builtin_with_new {
  99         ($sess:ident, $($name:ident),*,) => (
 100             {$(
 101                 store.register_early_pass($sess, false, box $name::new());
 102             )*}
 103         )
 104     }
 105
 106     macro_rules! add_lint_group {
 107         ($sess:ident, $name:expr, $($lint:ident),*) => (
 108             store.register_group($sess, false, $name, None, vec![$(LintId::of($lint)),*]);
 109         )
 110     }
 111
 112     add_pre_expansion_builtin!(sess,
 113         KeywordIdents,
 114     );
 115
 116     add_early_builtin!(sess,
 117                        UnusedParens,
 118                        UnusedImportBraces,
 119                        AnonymousParameters,
 120                        UnusedDocComment,
 121                        BadRepr,
 122                        EllipsisInclusiveRangePatterns,
 123                        );
 124
 125     add_early_builtin_with_new!(sess,
 126                                 DeprecatedAttr,
 127                                 );
 128
 129     late_lint_methods!(declare_combined_late_lint_pass, [BuiltinCombinedLateLintPass, [
 130         HardwiredLints: HardwiredLints,
 131         WhileTrue: WhileTrue,
 132         ImproperCTypes: ImproperCTypes,
 133         VariantSizeDifferences: VariantSizeDifferences,
 134         BoxPointers: BoxPointers,
 135         UnusedAttributes: UnusedAttributes,
 136         PathStatements: PathStatements,
 137         UnusedResults: UnusedResults,
 138         NonCamelCaseTypes: NonCamelCaseTypes,
 139         NonSnakeCase: NonSnakeCase,
 140         NonUpperCaseGlobals: NonUpperCaseGlobals,
 141         NonShorthandFieldPatterns: NonShorthandFieldPatterns,
 142         UnsafeCode: UnsafeCode,
 143         UnusedAllocation: UnusedAllocation,
 144         MissingCopyImplementations: MissingCopyImplementations,
 145         UnstableFeatures: UnstableFeatures,
 146         InvalidNoMangleItems: InvalidNoMangleItems,
 147         PluginAsLibrary: PluginAsLibrary,
 148         MutableTransmutes: MutableTransmutes,
 149         UnionsWithDropFields: UnionsWithDropFields,
 150         UnreachablePub: UnreachablePub,
 151         UnnameableTestItems: UnnameableTestItems::new(),
 152         TypeAliasBounds: TypeAliasBounds,
 153         UnusedBrokenConst: UnusedBrokenConst,
 154         TrivialConstraints: TrivialConstraints,
 155         TypeLimits: TypeLimits::new(),
 156         MissingDoc: MissingDoc::new(),
 157         MissingDebugImplementations: MissingDebugImplementations::new(),
 158         ExplicitOutlivesRequirements: ExplicitOutlivesRequirements,
 159     ]], ['tcx]);
 160
 161     store.register_late_pass(sess, false, box BuiltinCombinedLateLintPass::new());
 162
 163     add_lint_group!(sess,
 164                     "nonstandard_style",
 165                     NON_CAMEL_CASE_TYPES,
 166                     NON_SNAKE_CASE,
 167                     NON_UPPER_CASE_GLOBALS);
 168
 169     add_lint_group!(sess,
 170                     "unused",
 171                     UNUSED_IMPORTS,
 172                     UNUSED_VARIABLES,
 173                     UNUSED_ASSIGNMENTS,
 174                     DEAD_CODE,
 175                     UNUSED_MUT,
 176                     UNREACHABLE_CODE,
 177                     UNREACHABLE_PATTERNS,
 178                     UNUSED_MUST_USE,
 179                     UNUSED_UNSAFE,
 180                     PATH_STATEMENTS,
 181                     UNUSED_ATTRIBUTES,
 182                     UNUSED_MACROS,
 183                     UNUSED_ALLOCATION,
 184                     UNUSED_DOC_COMMENTS,
 185                     UNUSED_EXTERN_CRATES,
 186                     UNUSED_FEATURES,
 187                     UNUSED_LABELS,
 188                     UNUSED_PARENS);
 189
 190     add_lint_group!(sess,
 191                     "rust_2018_idioms",
 192                     BARE_TRAIT_OBJECTS,
 193                     UNUSED_EXTERN_CRATES,
 194                     ELLIPSIS_INCLUSIVE_RANGE_PATTERNS,
 195                     ELIDED_LIFETIMES_IN_PATHS,
 196                     EXPLICIT_OUTLIVES_REQUIREMENTS
 197
 198                     // FIXME(#52665, #47816) not always applicable and not all
 199                     // macros are ready for this yet.
 200                     // UNREACHABLE_PUB,
 201
 202                     // FIXME macro crates are not up for this yet, too much
 203                     // breakage is seen if we try to encourage this lint.
 204                     // MACRO_USE_EXTERN_CRATE,
 205                     );
 206
 207     // Guidelines for creating a future incompatibility lint:
 208     //
 209     // - Create a lint defaulting to warn as normal, with ideally the same error
 210     //   message you would normally give
 211     // - Add a suitable reference, typically an RFC or tracking issue. Go ahead
 212     //   and include the full URL, sort items in ascending order of issue numbers.
 213     // - Later, change lint to error
 214     // - Eventually, remove lint
 215     store.register_future_incompatible(sess, vec![
 216         FutureIncompatibleInfo {
 217             id: LintId::of(PRIVATE_IN_PUBLIC),
 218             reference: "issue #34537 <https://github.com/rust-lang/rust/issues/34537>",
 219             edition: None,
 220         },
 221         FutureIncompatibleInfo {
 222             id: LintId::of(PUB_USE_OF_PRIVATE_EXTERN_CRATE),
 223             reference: "issue #34537 <https://github.com/rust-lang/rust/issues/34537>",
 224             edition: None,
 225         },
 226         FutureIncompatibleInfo {
 227             id: LintId::of(PATTERNS_IN_FNS_WITHOUT_BODY),
 228             reference: "issue #35203 <https://github.com/rust-lang/rust/issues/35203>",
 229             edition: None,
 230         },
 231         FutureIncompatibleInfo {
 232             id: LintId::of(DUPLICATE_MACRO_EXPORTS),
 233             reference: "issue #35896 <https://github.com/rust-lang/rust/issues/35896>",
 234             edition: Some(Edition::Edition2018),
 235         },
 236         FutureIncompatibleInfo {
 237             id: LintId::of(KEYWORD_IDENTS),
 238             reference: "issue #49716 <https://github.com/rust-lang/rust/issues/49716>",
 239             edition: Some(Edition::Edition2018),
 240         },
 241         FutureIncompatibleInfo {
 242             id: LintId::of(SAFE_EXTERN_STATICS),
 243             reference: "issue #36247 <https://github.com/rust-lang/rust/issues/36247>",
 244             edition: None,
 245         },
 246         FutureIncompatibleInfo {
 247             id: LintId::of(INVALID_TYPE_PARAM_DEFAULT),
 248             reference: "issue #36887 <https://github.com/rust-lang/rust/issues/36887>",
 249             edition: None,
 250         },
 251         FutureIncompatibleInfo {
 252             id: LintId::of(LEGACY_DIRECTORY_OWNERSHIP),
 253             reference: "issue #37872 <https://github.com/rust-lang/rust/issues/37872>",
 254             edition: None,
 255         },
 256         FutureIncompatibleInfo {
 257             id: LintId::of(LEGACY_CONSTRUCTOR_VISIBILITY),
 258             reference: "issue #39207 <https://github.com/rust-lang/rust/issues/39207>",
 259             edition: None,
 260         },
 261         FutureIncompatibleInfo {
 262             id: LintId::of(MISSING_FRAGMENT_SPECIFIER),
 263             reference: "issue #40107 <https://github.com/rust-lang/rust/issues/40107>",
 264             edition: None,
 265         },
 266         FutureIncompatibleInfo {
 267             id: LintId::of(ILLEGAL_FLOATING_POINT_LITERAL_PATTERN),
 268             reference: "issue #41620 <https://github.com/rust-lang/rust/issues/41620>",
 269             edition: None,
 270         },
 271         FutureIncompatibleInfo {
 272             id: LintId::of(ANONYMOUS_PARAMETERS),
 273             reference: "issue #41686 <https://github.com/rust-lang/rust/issues/41686>",
 274             edition: Some(Edition::Edition2018),
 275         },
 276         FutureIncompatibleInfo {
 277             id: LintId::of(PARENTHESIZED_PARAMS_IN_TYPES_AND_MODULES),
 278             reference: "issue #42238 <https://github.com/rust-lang/rust/issues/42238>",
 279             edition: None,
 280         },
 281         FutureIncompatibleInfo {
 282             id: LintId::of(LATE_BOUND_LIFETIME_ARGUMENTS),
 283             reference: "issue #42868 <https://github.com/rust-lang/rust/issues/42868>",
 284             edition: None,
 285         },
 286         FutureIncompatibleInfo {
 287             id: LintId::of(SAFE_PACKED_BORROWS),
 288             reference: "issue #46043 <https://github.com/rust-lang/rust/issues/46043>",
 289             edition: None,
 290         },
 291         FutureIncompatibleInfo {
 292             id: LintId::of(INCOHERENT_FUNDAMENTAL_IMPLS),
 293             reference: "issue #46205 <https://github.com/rust-lang/rust/issues/46205>",
 294             edition: None,
 295         },
 296         FutureIncompatibleInfo {
 297             id: LintId::of(TYVAR_BEHIND_RAW_POINTER),
 298             reference: "issue #46906 <https://github.com/rust-lang/rust/issues/46906>",
 299             edition: Some(Edition::Edition2018),
 300         },
 301         FutureIncompatibleInfo {
 302             id: LintId::of(UNSTABLE_NAME_COLLISIONS),
 303             reference: "issue #48919 <https://github.com/rust-lang/rust/issues/48919>",
 304             edition: None,
 305             // Note: this item represents future incompatibility of all unstable functions in the
 306             //       standard library, and thus should never be removed or changed to an error.
 307         },
 308         FutureIncompatibleInfo {
 309             id: LintId::of(ABSOLUTE_PATHS_NOT_STARTING_WITH_CRATE),
 310             reference: "issue #53130 <https://github.com/rust-lang/rust/issues/53130>",
 311             edition: Some(Edition::Edition2018),
 312         },
 313         FutureIncompatibleInfo {
 314             id: LintId::of(WHERE_CLAUSES_OBJECT_SAFETY),
 315             reference: "issue #51443 <https://github.com/rust-lang/rust/issues/51443>",
 316             edition: None,
 317         },
 318         FutureIncompatibleInfo {
 319             id: LintId::of(PROC_MACRO_DERIVE_RESOLUTION_FALLBACK),
 320             reference: "issue #50504 <https://github.com/rust-lang/rust/issues/50504>",
 321             edition: None,
 322         },
 323         FutureIncompatibleInfo {
 324             id: LintId::of(QUESTION_MARK_MACRO_SEP),
 325             reference: "issue #48075 <https://github.com/rust-lang/rust/issues/48075>",
 326             edition: Some(Edition::Edition2018),
 327         },
 328         FutureIncompatibleInfo {
 329             id: LintId::of(MACRO_EXPANDED_MACRO_EXPORTS_ACCESSED_BY_ABSOLUTE_PATHS),
 330             reference: "issue #52234 <https://github.com/rust-lang/rust/issues/52234>",
 331             edition: None,
 332         },
 333         ]);
 334
 335     // Register renamed and removed lints.
 336     store.register_renamed("single_use_lifetime", "single_use_lifetimes");
 337     store.register_renamed("elided_lifetime_in_path", "elided_lifetimes_in_paths");
 338     store.register_renamed("bare_trait_object", "bare_trait_objects");
 339     store.register_renamed("unstable_name_collision", "unstable_name_collisions");
 340     store.register_renamed("unused_doc_comment", "unused_doc_comments");
 341     store.register_renamed("async_idents", "keyword_idents");
 342     store.register_removed("unknown_features", "replaced by an error");
 343     store.register_removed("unsigned_negation", "replaced by negate_unsigned feature gate");
 344     store.register_removed("negate_unsigned", "cast a signed value instead");
 345     store.register_removed("raw_pointer_derive", "using derive with raw pointers is ok");
 346     // Register lint group aliases.
 347     store.register_group_alias("nonstandard_style", "bad_style");
 348     // This was renamed to `raw_pointer_derive`, which was then removed,
 349     // so it is also considered removed.
 350     store.register_removed("raw_pointer_deriving", "using derive with raw pointers is ok");
 351     store.register_removed("drop_with_repr_extern", "drop flags have been removed");
 352     store.register_removed("fat_ptr_transmutes", "was accidentally removed back in 2014");
 353     store.register_removed("deprecated_attr", "use `deprecated` instead");
 354     store.register_removed("transmute_from_fn_item_types",
 355         "always cast functions before transmuting them");
 356     store.register_removed("hr_lifetime_in_assoc_type",
 357         "converted into hard error, see https://github.com/rust-lang/rust/issues/33685");
 358     store.register_removed("inaccessible_extern_crate",
 359         "converted into hard error, see https://github.com/rust-lang/rust/issues/36886");
 360     store.register_removed("super_or_self_in_global_path",
 361         "converted into hard error, see https://github.com/rust-lang/rust/issues/36888");
 362     store.register_removed("overlapping_inherent_impls",
 363         "converted into hard error, see https://github.com/rust-lang/rust/issues/36889");
 364     store.register_removed("illegal_floating_point_constant_pattern",
 365         "converted into hard error, see https://github.com/rust-lang/rust/issues/36890");
 366     store.register_removed("illegal_struct_or_enum_constant_pattern",
 367         "converted into hard error, see https://github.com/rust-lang/rust/issues/36891");
 368     store.register_removed("lifetime_underscore",
 369         "converted into hard error, see https://github.com/rust-lang/rust/issues/36892");
 370     store.register_removed("extra_requirement_in_impl",
 371         "converted into hard error, see https://github.com/rust-lang/rust/issues/37166");
 372     store.register_removed("legacy_imports",
 373         "converted into hard error, see https://github.com/rust-lang/rust/issues/38260");
 374     store.register_removed("coerce_never",
 375         "converted into hard error, see https://github.com/rust-lang/rust/issues/48950");
 376     store.register_removed("resolve_trait_on_defaulted_unit",
 377         "converted into hard error, see https://github.com/rust-lang/rust/issues/48950");
 378     store.register_removed("private_no_mangle_fns",
 379         "no longer an warning, #[no_mangle] functions always exported");
 380     store.register_removed("private_no_mangle_statics",
 381         "no longer an warning, #[no_mangle] statics always exported");
 382 }