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(macro_vis_matcher)]
  30 #![feature(quote)]
  31 #![feature(rustc_diagnostic_macros)]
  32 #![feature(macro_at_most_once_rep)]
  33
  34 extern crate syntax;
  35 #[macro_use]
  36 extern crate rustc;
  37 #[macro_use]
  38 extern crate log;
  39 extern crate rustc_mir;
  40 extern crate rustc_target;
  41 extern crate syntax_pos;
  42
  43 use rustc::lint;
  44 use rustc::lint::{LateContext, LateLintPass, LintPass, LintArray};
  45 use rustc::lint::builtin::{
  46     BARE_TRAIT_OBJECTS,
  47     ABSOLUTE_PATHS_NOT_STARTING_WITH_CRATE,
  48     ELIDED_LIFETIMES_IN_PATHS,
  49     parser::QUESTION_MARK_MACRO_SEP
  50 };
  51 use rustc::session;
  52 use rustc::util;
  53 use rustc::hir;
  54
  55 use syntax::ast;
  56 use syntax_pos::Span;
  57
  58 use session::Session;
  59 use syntax::edition::Edition;
  60 use lint::LintId;
  61 use lint::FutureIncompatibleInfo;
  62
  63 mod bad_style;
  64 pub mod builtin;
  65 mod types;
  66 mod unused;
  67
  68 use bad_style::*;
  69 use builtin::*;
  70 use types::*;
  71 use unused::*;
  72
  73 /// Useful for other parts of the compiler.
  74 pub use builtin::SoftLints;
  75
  76 /// Tell the `LintStore` about all the built-in lints (the ones
  77 /// defined in this crate and the ones defined in
  78 /// `rustc::lint::builtin`).
  79 pub fn register_builtins(store: &mut lint::LintStore, sess: Option<&Session>) {
  80     macro_rules! add_early_builtin {
  81         ($sess:ident, $($name:ident),*,) => (
  82             {$(
  83                 store.register_early_pass($sess, false, box $name);
  84                 )*}
  85             )
  86     }
  87
  88     macro_rules! add_pre_expansion_builtin {
  89         ($sess:ident, $($name:ident),*,) => (
  90             {$(
  91                 store.register_early_pass($sess, false, box $name);
  92                 )*}
  93             )
  94     }
  95
  96     macro_rules! add_early_builtin_with_new {
  97         ($sess:ident, $($name:ident),*,) => (
  98             {$(
  99                 store.register_early_pass($sess, false, box $name::new());
 100                 )*}
 101             )
 102     }
 103
 104     macro_rules! add_lint_group {
 105         ($sess:ident, $name:expr, $($lint:ident),*) => (
 106             store.register_group($sess, false, $name, vec![$(LintId::of($lint)),*]);
 107             )
 108     }
 109
 110     add_pre_expansion_builtin!(sess,
 111         Async2018,
 112     );
 113
 114     add_early_builtin!(sess,
 115                        UnusedParens,
 116                        UnusedImportBraces,
 117                        AnonymousParameters,
 118                        UnusedDocComment,
 119                        BadRepr,
 120                        EllipsisInclusiveRangePatterns,
 121                        );
 122
 123     add_early_builtin_with_new!(sess,
 124                                 DeprecatedAttr,
 125                                 );
 126
 127     late_lint_methods!(declare_combined_late_lint_pass, [BuiltinCombinedLateLintPass, [
 128         HardwiredLints: HardwiredLints,
 129         WhileTrue: WhileTrue,
 130         ImproperCTypes: ImproperCTypes,
 131         VariantSizeDifferences: VariantSizeDifferences,
 132         BoxPointers: BoxPointers,
 133         UnusedAttributes: UnusedAttributes,
 134         PathStatements: PathStatements,
 135         UnusedResults: UnusedResults,
 136         NonCamelCaseTypes: NonCamelCaseTypes,
 137         NonSnakeCase: NonSnakeCase,
 138         NonUpperCaseGlobals: NonUpperCaseGlobals,
 139         NonShorthandFieldPatterns: NonShorthandFieldPatterns,
 140         UnsafeCode: UnsafeCode,
 141         UnusedAllocation: UnusedAllocation,
 142         MissingCopyImplementations: MissingCopyImplementations,
 143         UnstableFeatures: UnstableFeatures,
 144         UnconditionalRecursion: UnconditionalRecursion,
 145         InvalidNoMangleItems: InvalidNoMangleItems,
 146         PluginAsLibrary: PluginAsLibrary,
 147         MutableTransmutes: MutableTransmutes,
 148         UnionsWithDropFields: UnionsWithDropFields,
 149         UnreachablePub: UnreachablePub,
 150         UnnameableTestFunctions: UnnameableTestFunctions,
 151         TypeAliasBounds: TypeAliasBounds,
 152         UnusedBrokenConst: UnusedBrokenConst,
 153         TrivialConstraints: TrivialConstraints,
 154         TypeLimits: TypeLimits::new(),
 155         MissingDoc: MissingDoc::new(),
 156         MissingDebugImplementations: MissingDebugImplementations::new(),
 157     ]], ['tcx]);
 158
 159     store.register_late_pass(sess, false, box BuiltinCombinedLateLintPass::new());
 160
 161     add_lint_group!(sess,
 162                     "bad_style",
 163                     NON_CAMEL_CASE_TYPES,
 164                     NON_SNAKE_CASE,
 165                     NON_UPPER_CASE_GLOBALS);
 166
 167     add_lint_group!(sess,
 168                     "nonstandard_style",
 169                     NON_CAMEL_CASE_TYPES,
 170                     NON_SNAKE_CASE,
 171                     NON_UPPER_CASE_GLOBALS);
 172
 173     add_lint_group!(sess,
 174                     "unused",
 175                     UNUSED_IMPORTS,
 176                     UNUSED_VARIABLES,
 177                     UNUSED_ASSIGNMENTS,
 178                     DEAD_CODE,
 179                     UNUSED_MUT,
 180                     UNREACHABLE_CODE,
 181                     UNREACHABLE_PATTERNS,
 182                     UNUSED_MUST_USE,
 183                     UNUSED_UNSAFE,
 184                     PATH_STATEMENTS,
 185                     UNUSED_ATTRIBUTES,
 186                     UNUSED_MACROS,
 187                     UNUSED_ALLOCATION,
 188                     UNUSED_DOC_COMMENTS,
 189                     UNUSED_EXTERN_CRATES,
 190                     UNUSED_FEATURES,
 191                     UNUSED_LABELS,
 192                     UNUSED_PARENS);
 193
 194     add_lint_group!(sess,
 195                     "rust_2018_idioms",
 196                     BARE_TRAIT_OBJECTS,
 197                     UNUSED_EXTERN_CRATES,
 198                     ELLIPSIS_INCLUSIVE_RANGE_PATTERNS,
 199                     ELIDED_LIFETIMES_IN_PATHS
 200
 201                     // FIXME(#52665, #47816) not always applicable and not all
 202                     // macros are ready for this yet.
 203                     // UNREACHABLE_PUB,
 204
 205                     // FIXME macro crates are not up for this yet, too much
 206                     // breakage is seen if we try to encourage this lint.
 207                     // MACRO_USE_EXTERN_CRATE,
 208                     );
 209
 210     // Guidelines for creating a future incompatibility lint:
 211     //
 212     // - Create a lint defaulting to warn as normal, with ideally the same error
 213     //   message you would normally give
 214     // - Add a suitable reference, typically an RFC or tracking issue. Go ahead
 215     //   and include the full URL, sort items in ascending order of issue numbers.
 216     // - Later, change lint to error
 217     // - Eventually, remove lint
 218     store.register_future_incompatible(sess,
 219                                        vec![
 220         FutureIncompatibleInfo {
 221             id: LintId::of(PRIVATE_IN_PUBLIC),
 222             reference: "issue #34537 <https://github.com/rust-lang/rust/issues/34537>",
 223             edition: None,
 224         },
 225         FutureIncompatibleInfo {
 226             id: LintId::of(PUB_USE_OF_PRIVATE_EXTERN_CRATE),
 227             reference: "issue #34537 <https://github.com/rust-lang/rust/issues/34537>",
 228             edition: None,
 229         },
 230         FutureIncompatibleInfo {
 231             id: LintId::of(PATTERNS_IN_FNS_WITHOUT_BODY),
 232             reference: "issue #35203 <https://github.com/rust-lang/rust/issues/35203>",
 233             edition: None,
 234         },
 235         FutureIncompatibleInfo {
 236             id: LintId::of(DUPLICATE_MACRO_EXPORTS),
 237             reference: "issue #35896 <https://github.com/rust-lang/rust/issues/35896>",
 238             edition: Some(Edition::Edition2018),
 239         },
 240         FutureIncompatibleInfo {
 241             id: LintId::of(ASYNC_IDENTS),
 242             reference: "issue #49716 <https://github.com/rust-lang/rust/issues/49716>",
 243             edition: Some(Edition::Edition2018),
 244         },
 245         FutureIncompatibleInfo {
 246             id: LintId::of(SAFE_EXTERN_STATICS),
 247             reference: "issue #36247 <https://github.com/rust-lang/rust/issues/36247>",
 248             edition: None,
 249         },
 250         FutureIncompatibleInfo {
 251             id: LintId::of(INVALID_TYPE_PARAM_DEFAULT),
 252             reference: "issue #36887 <https://github.com/rust-lang/rust/issues/36887>",
 253             edition: None,
 254         },
 255         FutureIncompatibleInfo {
 256             id: LintId::of(LEGACY_DIRECTORY_OWNERSHIP),
 257             reference: "issue #37872 <https://github.com/rust-lang/rust/issues/37872>",
 258             edition: None,
 259         },
 260         FutureIncompatibleInfo {
 261             id: LintId::of(LEGACY_CONSTRUCTOR_VISIBILITY),
 262             reference: "issue #39207 <https://github.com/rust-lang/rust/issues/39207>",
 263             edition: None,
 264         },
 265         FutureIncompatibleInfo {
 266             id: LintId::of(MISSING_FRAGMENT_SPECIFIER),
 267             reference: "issue #40107 <https://github.com/rust-lang/rust/issues/40107>",
 268             edition: None,
 269         },
 270         FutureIncompatibleInfo {
 271             id: LintId::of(ILLEGAL_FLOATING_POINT_LITERAL_PATTERN),
 272             reference: "issue #41620 <https://github.com/rust-lang/rust/issues/41620>",
 273             edition: None,
 274         },
 275         FutureIncompatibleInfo {
 276             id: LintId::of(ANONYMOUS_PARAMETERS),
 277             reference: "issue #41686 <https://github.com/rust-lang/rust/issues/41686>",
 278             edition: None,
 279         },
 280         FutureIncompatibleInfo {
 281             id: LintId::of(PARENTHESIZED_PARAMS_IN_TYPES_AND_MODULES),
 282             reference: "issue #42238 <https://github.com/rust-lang/rust/issues/42238>",
 283             edition: None,
 284         },
 285         FutureIncompatibleInfo {
 286             id: LintId::of(LATE_BOUND_LIFETIME_ARGUMENTS),
 287             reference: "issue #42868 <https://github.com/rust-lang/rust/issues/42868>",
 288             edition: None,
 289         },
 290         FutureIncompatibleInfo {
 291             id: LintId::of(SAFE_PACKED_BORROWS),
 292             reference: "issue #46043 <https://github.com/rust-lang/rust/issues/46043>",
 293             edition: None,
 294         },
 295         FutureIncompatibleInfo {
 296             id: LintId::of(INCOHERENT_FUNDAMENTAL_IMPLS),
 297             reference: "issue #46205 <https://github.com/rust-lang/rust/issues/46205>",
 298             edition: None,
 299         },
 300         FutureIncompatibleInfo {
 301             id: LintId::of(TYVAR_BEHIND_RAW_POINTER),
 302             reference: "issue #46906 <https://github.com/rust-lang/rust/issues/46906>",
 303             edition: Some(Edition::Edition2018),
 304         },
 305         FutureIncompatibleInfo {
 306             id: LintId::of(UNSTABLE_NAME_COLLISIONS),
 307             reference: "issue #48919 <https://github.com/rust-lang/rust/issues/48919>",
 308             edition: None,
 309             // Note: this item represents future incompatibility of all unstable functions in the
 310             //       standard library, and thus should never be removed or changed to an error.
 311         },
 312         FutureIncompatibleInfo {
 313             id: LintId::of(ABSOLUTE_PATHS_NOT_STARTING_WITH_CRATE),
 314             reference: "issue TBD",
 315             edition: Some(Edition::Edition2018),
 316         },
 317         FutureIncompatibleInfo {
 318             id: LintId::of(WHERE_CLAUSES_OBJECT_SAFETY),
 319             reference: "issue #51443 <https://github.com/rust-lang/rust/issues/51443>",
 320             edition: None,
 321         },
 322         FutureIncompatibleInfo {
 323             id: LintId::of(DUPLICATE_ASSOCIATED_TYPE_BINDINGS),
 324             reference: "issue #50589 <https://github.com/rust-lang/rust/issues/50589>",
 325             edition: None,
 326         },
 327         FutureIncompatibleInfo {
 328             id: LintId::of(PROC_MACRO_DERIVE_RESOLUTION_FALLBACK),
 329             reference: "issue #50504 <https://github.com/rust-lang/rust/issues/50504>",
 330             edition: None,
 331         },
 332         FutureIncompatibleInfo {
 333             id: LintId::of(QUESTION_MARK_MACRO_SEP),
 334             reference: "issue #48075 <https://github.com/rust-lang/rust/issues/48075>",
 335             edition: Some(Edition::Edition2018),
 336         }
 337         ]);
 338
 339     // Register renamed and removed lints
 340     store.register_renamed("single_use_lifetime", "single_use_lifetimes");
 341     store.register_renamed("elided_lifetime_in_path", "elided_lifetimes_in_paths");
 342     store.register_renamed("bare_trait_object", "bare_trait_objects");
 343     store.register_renamed("unstable_name_collision", "unstable_name_collisions");
 344     store.register_renamed("unused_doc_comment", "unused_doc_comments");
 345     store.register_renamed("unknown_features", "unused_features");
 346     store.register_removed("unsigned_negation", "replaced by negate_unsigned feature gate");
 347     store.register_removed("negate_unsigned", "cast a signed value instead");
 348     store.register_removed("raw_pointer_derive", "using derive with raw pointers is ok");
 349     // This was renamed to raw_pointer_derive, which was then removed,
 350     // so it is also considered removed
 351     store.register_removed("raw_pointer_deriving", "using derive with raw pointers is ok");
 352     store.register_removed("drop_with_repr_extern", "drop flags have been removed");
 353     store.register_removed("fat_ptr_transmutes", "was accidentally removed back in 2014");
 354     store.register_removed("deprecated_attr", "use `deprecated` instead");
 355     store.register_removed("transmute_from_fn_item_types",
 356         "always cast functions before transmuting them");
 357     store.register_removed("hr_lifetime_in_assoc_type",
 358         "converted into hard error, see https://github.com/rust-lang/rust/issues/33685");
 359     store.register_removed("inaccessible_extern_crate",
 360         "converted into hard error, see https://github.com/rust-lang/rust/issues/36886");
 361     store.register_removed("super_or_self_in_global_path",
 362         "converted into hard error, see https://github.com/rust-lang/rust/issues/36888");
 363     store.register_removed("overlapping_inherent_impls",
 364         "converted into hard error, see https://github.com/rust-lang/rust/issues/36889");
 365     store.register_removed("illegal_floating_point_constant_pattern",
 366         "converted into hard error, see https://github.com/rust-lang/rust/issues/36890");
 367     store.register_removed("illegal_struct_or_enum_constant_pattern",
 368         "converted into hard error, see https://github.com/rust-lang/rust/issues/36891");
 369     store.register_removed("lifetime_underscore",
 370         "converted into hard error, see https://github.com/rust-lang/rust/issues/36892");
 371     store.register_removed("extra_requirement_in_impl",
 372         "converted into hard error, see https://github.com/rust-lang/rust/issues/37166");
 373     store.register_removed("legacy_imports",
 374         "converted into hard error, see https://github.com/rust-lang/rust/issues/38260");
 375     store.register_removed("coerce_never",
 376         "converted into hard error, see https://github.com/rust-lang/rust/issues/48950");
 377     store.register_removed("resolve_trait_on_defaulted_unit",
 378         "converted into hard error, see https://github.com/rust-lang/rust/issues/48950");
 379 }