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 #![cfg_attr(stage0, feature(macro_vis_matcher))]
  30 #![cfg_attr(not(stage0), feature(nll))]
  31 #![cfg_attr(not(stage0), feature(infer_outlives_requirements))]
  32 #![feature(quote)]
  33 #![feature(rustc_diagnostic_macros)]
  34 #![feature(macro_at_most_once_rep)]
  35
  36 extern crate syntax;
  37 #[macro_use]
  38 extern crate rustc;
  39 #[macro_use]
  40 extern crate log;
  41 extern crate rustc_mir;
  42 extern crate rustc_target;
  43 extern crate syntax_pos;
  44
  45 use rustc::lint;
  46 use rustc::lint::{LateContext, LateLintPass, LintPass, LintArray};
  47 use rustc::lint::builtin::{
  48     BARE_TRAIT_OBJECTS,
  49     ABSOLUTE_PATHS_NOT_STARTING_WITH_CRATE,
  50     ELIDED_LIFETIMES_IN_PATHS,
  51     parser::QUESTION_MARK_MACRO_SEP
  52 };
  53 use rustc::session;
  54 use rustc::util;
  55 use rustc::hir;
  56
  57 use syntax::ast;
  58 use syntax_pos::Span;
  59
  60 use session::Session;
  61 use syntax::edition::Edition;
  62 use lint::LintId;
  63 use lint::FutureIncompatibleInfo;
  64
  65 mod bad_style;
  66 pub mod builtin;
  67 mod types;
  68 mod unused;
  69
  70 use bad_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             {$(
  93                 store.register_early_pass($sess, false, 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, $name, vec![$(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         UnconditionalRecursion: UnconditionalRecursion,
 147         InvalidNoMangleItems: InvalidNoMangleItems,
 148         PluginAsLibrary: PluginAsLibrary,
 149         MutableTransmutes: MutableTransmutes,
 150         UnionsWithDropFields: UnionsWithDropFields,
 151         UnreachablePub: UnreachablePub,
 152         UnnameableTestFunctions: UnnameableTestFunctions,
 153         TypeAliasBounds: TypeAliasBounds,
 154         UnusedBrokenConst: UnusedBrokenConst,
 155         TrivialConstraints: TrivialConstraints,
 156         TypeLimits: TypeLimits::new(),
 157         MissingDoc: MissingDoc::new(),
 158         MissingDebugImplementations: MissingDebugImplementations::new(),
 159     ]], ['tcx]);
 160
 161     store.register_late_pass(sess, false, box BuiltinCombinedLateLintPass::new());
 162
 163     add_lint_group!(sess,
 164                     "bad_style",
 165                     NON_CAMEL_CASE_TYPES,
 166                     NON_SNAKE_CASE,
 167                     NON_UPPER_CASE_GLOBALS);
 168
 169     add_lint_group!(sess,
 170                     "nonstandard_style",
 171                     NON_CAMEL_CASE_TYPES,
 172                     NON_SNAKE_CASE,
 173                     NON_UPPER_CASE_GLOBALS);
 174
 175     add_lint_group!(sess,
 176                     "unused",
 177                     UNUSED_IMPORTS,
 178                     UNUSED_VARIABLES,
 179                     UNUSED_ASSIGNMENTS,
 180                     DEAD_CODE,
 181                     UNUSED_MUT,
 182                     UNREACHABLE_CODE,
 183                     UNREACHABLE_PATTERNS,
 184                     UNUSED_MUST_USE,
 185                     UNUSED_UNSAFE,
 186                     PATH_STATEMENTS,
 187                     UNUSED_ATTRIBUTES,
 188                     UNUSED_MACROS,
 189                     UNUSED_ALLOCATION,
 190                     UNUSED_DOC_COMMENTS,
 191                     UNUSED_EXTERN_CRATES,
 192                     UNUSED_FEATURES,
 193                     UNUSED_LABELS,
 194                     UNUSED_PARENS);
 195
 196     add_lint_group!(sess,
 197                     "rust_2018_idioms",
 198                     BARE_TRAIT_OBJECTS,
 199                     UNUSED_EXTERN_CRATES,
 200                     ELLIPSIS_INCLUSIVE_RANGE_PATTERNS,
 201                     ELIDED_LIFETIMES_IN_PATHS
 202
 203                     // FIXME(#52665, #47816) not always applicable and not all
 204                     // macros are ready for this yet.
 205                     // UNREACHABLE_PUB,
 206
 207                     // FIXME macro crates are not up for this yet, too much
 208                     // breakage is seen if we try to encourage this lint.
 209                     // MACRO_USE_EXTERN_CRATE,
 210                     );
 211
 212     // Guidelines for creating a future incompatibility lint:
 213     //
 214     // - Create a lint defaulting to warn as normal, with ideally the same error
 215     //   message you would normally give
 216     // - Add a suitable reference, typically an RFC or tracking issue. Go ahead
 217     //   and include the full URL, sort items in ascending order of issue numbers.
 218     // - Later, change lint to error
 219     // - Eventually, remove lint
 220     store.register_future_incompatible(sess,
 221                                        vec![
 222         FutureIncompatibleInfo {
 223             id: LintId::of(PRIVATE_IN_PUBLIC),
 224             reference: "issue #34537 <https://github.com/rust-lang/rust/issues/34537>",
 225             edition: None,
 226         },
 227         FutureIncompatibleInfo {
 228             id: LintId::of(PUB_USE_OF_PRIVATE_EXTERN_CRATE),
 229             reference: "issue #34537 <https://github.com/rust-lang/rust/issues/34537>",
 230             edition: None,
 231         },
 232         FutureIncompatibleInfo {
 233             id: LintId::of(PATTERNS_IN_FNS_WITHOUT_BODY),
 234             reference: "issue #35203 <https://github.com/rust-lang/rust/issues/35203>",
 235             edition: None,
 236         },
 237         FutureIncompatibleInfo {
 238             id: LintId::of(DUPLICATE_MACRO_EXPORTS),
 239             reference: "issue #35896 <https://github.com/rust-lang/rust/issues/35896>",
 240             edition: Some(Edition::Edition2018),
 241         },
 242         FutureIncompatibleInfo {
 243             id: LintId::of(KEYWORD_IDENTS),
 244             reference: "issue #49716 <https://github.com/rust-lang/rust/issues/49716>",
 245             edition: Some(Edition::Edition2018),
 246         },
 247         FutureIncompatibleInfo {
 248             id: LintId::of(SAFE_EXTERN_STATICS),
 249             reference: "issue #36247 <https://github.com/rust-lang/rust/issues/36247>",
 250             edition: None,
 251         },
 252         FutureIncompatibleInfo {
 253             id: LintId::of(INVALID_TYPE_PARAM_DEFAULT),
 254             reference: "issue #36887 <https://github.com/rust-lang/rust/issues/36887>",
 255             edition: None,
 256         },
 257         FutureIncompatibleInfo {
 258             id: LintId::of(LEGACY_DIRECTORY_OWNERSHIP),
 259             reference: "issue #37872 <https://github.com/rust-lang/rust/issues/37872>",
 260             edition: None,
 261         },
 262         FutureIncompatibleInfo {
 263             id: LintId::of(LEGACY_CONSTRUCTOR_VISIBILITY),
 264             reference: "issue #39207 <https://github.com/rust-lang/rust/issues/39207>",
 265             edition: None,
 266         },
 267         FutureIncompatibleInfo {
 268             id: LintId::of(MISSING_FRAGMENT_SPECIFIER),
 269             reference: "issue #40107 <https://github.com/rust-lang/rust/issues/40107>",
 270             edition: None,
 271         },
 272         FutureIncompatibleInfo {
 273             id: LintId::of(ILLEGAL_FLOATING_POINT_LITERAL_PATTERN),
 274             reference: "issue #41620 <https://github.com/rust-lang/rust/issues/41620>",
 275             edition: None,
 276         },
 277         FutureIncompatibleInfo {
 278             id: LintId::of(ANONYMOUS_PARAMETERS),
 279             reference: "issue #41686 <https://github.com/rust-lang/rust/issues/41686>",
 280             edition: Some(Edition::Edition2018),
 281         },
 282         FutureIncompatibleInfo {
 283             id: LintId::of(PARENTHESIZED_PARAMS_IN_TYPES_AND_MODULES),
 284             reference: "issue #42238 <https://github.com/rust-lang/rust/issues/42238>",
 285             edition: None,
 286         },
 287         FutureIncompatibleInfo {
 288             id: LintId::of(LATE_BOUND_LIFETIME_ARGUMENTS),
 289             reference: "issue #42868 <https://github.com/rust-lang/rust/issues/42868>",
 290             edition: None,
 291         },
 292         FutureIncompatibleInfo {
 293             id: LintId::of(SAFE_PACKED_BORROWS),
 294             reference: "issue #46043 <https://github.com/rust-lang/rust/issues/46043>",
 295             edition: None,
 296         },
 297         FutureIncompatibleInfo {
 298             id: LintId::of(INCOHERENT_FUNDAMENTAL_IMPLS),
 299             reference: "issue #46205 <https://github.com/rust-lang/rust/issues/46205>",
 300             edition: None,
 301         },
 302         FutureIncompatibleInfo {
 303             id: LintId::of(TYVAR_BEHIND_RAW_POINTER),
 304             reference: "issue #46906 <https://github.com/rust-lang/rust/issues/46906>",
 305             edition: Some(Edition::Edition2018),
 306         },
 307         FutureIncompatibleInfo {
 308             id: LintId::of(UNSTABLE_NAME_COLLISIONS),
 309             reference: "issue #48919 <https://github.com/rust-lang/rust/issues/48919>",
 310             edition: None,
 311             // Note: this item represents future incompatibility of all unstable functions in the
 312             //       standard library, and thus should never be removed or changed to an error.
 313         },
 314         FutureIncompatibleInfo {
 315             id: LintId::of(ABSOLUTE_PATHS_NOT_STARTING_WITH_CRATE),
 316             reference: "issue TBD",
 317             edition: Some(Edition::Edition2018),
 318         },
 319         FutureIncompatibleInfo {
 320             id: LintId::of(WHERE_CLAUSES_OBJECT_SAFETY),
 321             reference: "issue #51443 <https://github.com/rust-lang/rust/issues/51443>",
 322             edition: None,
 323         },
 324         FutureIncompatibleInfo {
 325             id: LintId::of(DUPLICATE_ASSOCIATED_TYPE_BINDINGS),
 326             reference: "issue #50589 <https://github.com/rust-lang/rust/issues/50589>",
 327             edition: None,
 328         },
 329         FutureIncompatibleInfo {
 330             id: LintId::of(PROC_MACRO_DERIVE_RESOLUTION_FALLBACK),
 331             reference: "issue #50504 <https://github.com/rust-lang/rust/issues/50504>",
 332             edition: None,
 333         },
 334         FutureIncompatibleInfo {
 335             id: LintId::of(QUESTION_MARK_MACRO_SEP),
 336             reference: "issue #48075 <https://github.com/rust-lang/rust/issues/48075>",
 337             edition: Some(Edition::Edition2018),
 338         },
 339         FutureIncompatibleInfo {
 340             id: LintId::of(MACRO_EXPANDED_MACRO_EXPORTS_ACCESSED_BY_ABSOLUTE_PATHS),
 341             reference: "issue #52234 <https://github.com/rust-lang/rust/issues/52234>",
 342             edition: None,
 343         },
 344         ]);
 345
 346     // Register renamed and removed lints
 347     store.register_renamed("single_use_lifetime", "single_use_lifetimes");
 348     store.register_renamed("elided_lifetime_in_path", "elided_lifetimes_in_paths");
 349     store.register_renamed("bare_trait_object", "bare_trait_objects");
 350     store.register_renamed("unstable_name_collision", "unstable_name_collisions");
 351     store.register_renamed("unused_doc_comment", "unused_doc_comments");
 352     store.register_renamed("async_idents", "keyword_idents");
 353     store.register_removed("unknown_features", "replaced by an error");
 354     store.register_removed("unsigned_negation", "replaced by negate_unsigned feature gate");
 355     store.register_removed("negate_unsigned", "cast a signed value instead");
 356     store.register_removed("raw_pointer_derive", "using derive with raw pointers is ok");
 357     // This was renamed to raw_pointer_derive, which was then removed,
 358     // so it is also considered removed
 359     store.register_removed("raw_pointer_deriving", "using derive with raw pointers is ok");
 360     store.register_removed("drop_with_repr_extern", "drop flags have been removed");
 361     store.register_removed("fat_ptr_transmutes", "was accidentally removed back in 2014");
 362     store.register_removed("deprecated_attr", "use `deprecated` instead");
 363     store.register_removed("transmute_from_fn_item_types",
 364         "always cast functions before transmuting them");
 365     store.register_removed("hr_lifetime_in_assoc_type",
 366         "converted into hard error, see https://github.com/rust-lang/rust/issues/33685");
 367     store.register_removed("inaccessible_extern_crate",
 368         "converted into hard error, see https://github.com/rust-lang/rust/issues/36886");
 369     store.register_removed("super_or_self_in_global_path",
 370         "converted into hard error, see https://github.com/rust-lang/rust/issues/36888");
 371     store.register_removed("overlapping_inherent_impls",
 372         "converted into hard error, see https://github.com/rust-lang/rust/issues/36889");
 373     store.register_removed("illegal_floating_point_constant_pattern",
 374         "converted into hard error, see https://github.com/rust-lang/rust/issues/36890");
 375     store.register_removed("illegal_struct_or_enum_constant_pattern",
 376         "converted into hard error, see https://github.com/rust-lang/rust/issues/36891");
 377     store.register_removed("lifetime_underscore",
 378         "converted into hard error, see https://github.com/rust-lang/rust/issues/36892");
 379     store.register_removed("extra_requirement_in_impl",
 380         "converted into hard error, see https://github.com/rust-lang/rust/issues/37166");
 381     store.register_removed("legacy_imports",
 382         "converted into hard error, see https://github.com/rust-lang/rust/issues/38260");
 383     store.register_removed("coerce_never",
 384         "converted into hard error, see https://github.com/rust-lang/rust/issues/48950");
 385     store.register_removed("resolve_trait_on_defaulted_unit",
 386         "converted into hard error, see https://github.com/rust-lang/rust/issues/48950");
 387 }