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 #![deny(bare_trait_objects)]
  23
  24 #![doc(html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
  25       html_favicon_url = "https://doc.rust-lang.org/favicon.ico",
  26       html_root_url = "https://doc.rust-lang.org/nightly/")]
  27
  28 #![cfg_attr(test, feature(test))]
  29 #![feature(box_patterns)]
  30 #![feature(box_syntax)]
  31 #![feature(macro_vis_matcher)]
  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::{BARE_TRAIT_OBJECTS, ABSOLUTE_PATHS_NOT_STARTING_WITH_CRATE,
  48                            ELIDED_LIFETIMES_IN_PATHS};
  49 use rustc::lint::builtin::MACRO_USE_EXTERN_CRATE;
  50 use rustc::session;
  51 use rustc::util;
  52 use rustc::hir;
  53
  54 use syntax::ast;
  55 use syntax_pos::Span;
  56
  57 use session::Session;
  58 use syntax::edition::Edition;
  59 use lint::LintId;
  60 use lint::FutureIncompatibleInfo;
  61
  62 mod bad_style;
  63 pub mod builtin;
  64 mod types;
  65 mod unused;
  66
  67 use bad_style::*;
  68 use builtin::*;
  69 use types::*;
  70 use unused::*;
  71
  72 /// Useful for other parts of the compiler.
  73 pub use builtin::SoftLints;
  74
  75 /// Tell the `LintStore` about all the built-in lints (the ones
  76 /// defined in this crate and the ones defined in
  77 /// `rustc::lint::builtin`).
  78 pub fn register_builtins(store: &mut lint::LintStore, sess: Option<&Session>) {
  79     macro_rules! add_early_builtin {
  80         ($sess:ident, $($name:ident),*,) => (
  81             {$(
  82                 store.register_early_pass($sess, false, box $name);
  83                 )*}
  84             )
  85     }
  86
  87     macro_rules! add_pre_expansion_builtin {
  88         ($sess:ident, $($name:ident),*,) => (
  89             {$(
  90                 store.register_early_pass($sess, false, box $name);
  91                 )*}
  92             )
  93     }
  94
  95     macro_rules! add_early_builtin_with_new {
  96         ($sess:ident, $($name:ident),*,) => (
  97             {$(
  98                 store.register_early_pass($sess, false, box $name::new());
  99                 )*}
 100             )
 101     }
 102
 103     macro_rules! add_lint_group {
 104         ($sess:ident, $name:expr, $($lint:ident),*) => (
 105             store.register_group($sess, false, $name, vec![$(LintId::of($lint)),*]);
 106             )
 107     }
 108
 109     add_pre_expansion_builtin!(sess,
 110         Async2018,
 111     );
 112
 113     add_early_builtin!(sess,
 114                        UnusedParens,
 115                        UnusedImportBraces,
 116                        AnonymousParameters,
 117                        UnusedDocComment,
 118                        BadRepr,
 119                        EllipsisInclusiveRangePatterns,
 120                        );
 121
 122     add_early_builtin_with_new!(sess,
 123                                 DeprecatedAttr,
 124                                 );
 125
 126     late_lint_methods!(declare_combined_late_lint_pass, [BuiltinCombinedLateLintPass, [
 127         HardwiredLints: HardwiredLints,
 128         WhileTrue: WhileTrue,
 129         ImproperCTypes: ImproperCTypes,
 130         VariantSizeDifferences: VariantSizeDifferences,
 131         BoxPointers: BoxPointers,
 132         UnusedAttributes: UnusedAttributes,
 133         PathStatements: PathStatements,
 134         UnusedResults: UnusedResults,
 135         NonCamelCaseTypes: NonCamelCaseTypes,
 136         NonSnakeCase: NonSnakeCase,
 137         NonUpperCaseGlobals: NonUpperCaseGlobals,
 138         NonShorthandFieldPatterns: NonShorthandFieldPatterns,
 139         UnsafeCode: UnsafeCode,
 140         UnusedAllocation: UnusedAllocation,
 141         MissingCopyImplementations: MissingCopyImplementations,
 142         UnstableFeatures: UnstableFeatures,
 143         UnconditionalRecursion: UnconditionalRecursion,
 144         InvalidNoMangleItems: InvalidNoMangleItems,
 145         PluginAsLibrary: PluginAsLibrary,
 146         MutableTransmutes: MutableTransmutes,
 147         UnionsWithDropFields: UnionsWithDropFields,
 148         UnreachablePub: UnreachablePub,
 149         UnnameableTestFunctions: UnnameableTestFunctions,
 150         TypeAliasBounds: TypeAliasBounds,
 151         UnusedBrokenConst: UnusedBrokenConst,
 152         TrivialConstraints: TrivialConstraints,
 153         TypeLimits: TypeLimits::new(),
 154         MissingDoc: MissingDoc::new(),
 155         MissingDebugImplementations: MissingDebugImplementations::new(),
 156     ]], ['tcx]);
 157
 158     store.register_late_pass(sess, false, box BuiltinCombinedLateLintPass::new());
 159
 160     add_lint_group!(sess,
 161                     "bad_style",
 162                     NON_CAMEL_CASE_TYPES,
 163                     NON_SNAKE_CASE,
 164                     NON_UPPER_CASE_GLOBALS);
 165
 166     add_lint_group!(sess,
 167                     "nonstandard_style",
 168                     NON_CAMEL_CASE_TYPES,
 169                     NON_SNAKE_CASE,
 170                     NON_UPPER_CASE_GLOBALS);
 171
 172     add_lint_group!(sess,
 173                     "unused",
 174                     UNUSED_IMPORTS,
 175                     UNUSED_VARIABLES,
 176                     UNUSED_ASSIGNMENTS,
 177                     DEAD_CODE,
 178                     UNUSED_MUT,
 179                     UNREACHABLE_CODE,
 180                     UNREACHABLE_PATTERNS,
 181                     UNUSED_MUST_USE,
 182                     UNUSED_UNSAFE,
 183                     PATH_STATEMENTS,
 184                     UNUSED_ATTRIBUTES,
 185                     UNUSED_MACROS,
 186                     UNUSED_ALLOCATION,
 187                     UNUSED_DOC_COMMENTS,
 188                     UNUSED_EXTERN_CRATES,
 189                     UNUSED_FEATURES,
 190                     UNUSED_LABELS,
 191                     UNUSED_PARENS);
 192
 193     add_lint_group!(sess,
 194                     "rust_2018_idioms",
 195                     BARE_TRAIT_OBJECTS,
 196                     UNREACHABLE_PUB,
 197                     UNUSED_EXTERN_CRATES,
 198                     MACRO_USE_EXTERN_CRATE,
 199                     ELIDED_LIFETIMES_IN_PATHS,
 200                     ELLIPSIS_INCLUSIVE_RANGE_PATTERNS);
 201
 202     // Guidelines for creating a future incompatibility lint:
 203     //
 204     // - Create a lint defaulting to warn as normal, with ideally the same error
 205     //   message you would normally give
 206     // - Add a suitable reference, typically an RFC or tracking issue. Go ahead
 207     //   and include the full URL, sort items in ascending order of issue numbers.
 208     // - Later, change lint to error
 209     // - Eventually, remove lint
 210     store.register_future_incompatible(sess,
 211                                        vec![
 212         FutureIncompatibleInfo {
 213             id: LintId::of(PRIVATE_IN_PUBLIC),
 214             reference: "issue #34537 <https://github.com/rust-lang/rust/issues/34537>",
 215             edition: None,
 216         },
 217         FutureIncompatibleInfo {
 218             id: LintId::of(PUB_USE_OF_PRIVATE_EXTERN_CRATE),
 219             reference: "issue #34537 <https://github.com/rust-lang/rust/issues/34537>",
 220             edition: None,
 221         },
 222         FutureIncompatibleInfo {
 223             id: LintId::of(PATTERNS_IN_FNS_WITHOUT_BODY),
 224             reference: "issue #35203 <https://github.com/rust-lang/rust/issues/35203>",
 225             edition: None,
 226         },
 227         FutureIncompatibleInfo {
 228             id: LintId::of(DUPLICATE_MACRO_EXPORTS),
 229             reference: "issue #35896 <https://github.com/rust-lang/rust/issues/35896>",
 230             edition: Some(Edition::Edition2018),
 231         },
 232         FutureIncompatibleInfo {
 233             id: LintId::of(ASYNC_IDENTS),
 234             reference: "issue #49716 <https://github.com/rust-lang/rust/issues/49716>",
 235             edition: Some(Edition::Edition2018),
 236         },
 237         FutureIncompatibleInfo {
 238             id: LintId::of(SAFE_EXTERN_STATICS),
 239             reference: "issue #36247 <https://github.com/rust-lang/rust/issues/36247>",
 240             edition: None,
 241         },
 242         FutureIncompatibleInfo {
 243             id: LintId::of(INVALID_TYPE_PARAM_DEFAULT),
 244             reference: "issue #36887 <https://github.com/rust-lang/rust/issues/36887>",
 245             edition: None,
 246         },
 247         FutureIncompatibleInfo {
 248             id: LintId::of(LEGACY_DIRECTORY_OWNERSHIP),
 249             reference: "issue #37872 <https://github.com/rust-lang/rust/issues/37872>",
 250             edition: None,
 251         },
 252         FutureIncompatibleInfo {
 253             id: LintId::of(LEGACY_CONSTRUCTOR_VISIBILITY),
 254             reference: "issue #39207 <https://github.com/rust-lang/rust/issues/39207>",
 255             edition: None,
 256         },
 257         FutureIncompatibleInfo {
 258             id: LintId::of(MISSING_FRAGMENT_SPECIFIER),
 259             reference: "issue #40107 <https://github.com/rust-lang/rust/issues/40107>",
 260             edition: None,
 261         },
 262         FutureIncompatibleInfo {
 263             id: LintId::of(ILLEGAL_FLOATING_POINT_LITERAL_PATTERN),
 264             reference: "issue #41620 <https://github.com/rust-lang/rust/issues/41620>",
 265             edition: None,
 266         },
 267         FutureIncompatibleInfo {
 268             id: LintId::of(ANONYMOUS_PARAMETERS),
 269             reference: "issue #41686 <https://github.com/rust-lang/rust/issues/41686>",
 270             edition: None,
 271         },
 272         FutureIncompatibleInfo {
 273             id: LintId::of(PARENTHESIZED_PARAMS_IN_TYPES_AND_MODULES),
 274             reference: "issue #42238 <https://github.com/rust-lang/rust/issues/42238>",
 275             edition: None,
 276         },
 277         FutureIncompatibleInfo {
 278             id: LintId::of(LATE_BOUND_LIFETIME_ARGUMENTS),
 279             reference: "issue #42868 <https://github.com/rust-lang/rust/issues/42868>",
 280             edition: None,
 281         },
 282         FutureIncompatibleInfo {
 283             id: LintId::of(SAFE_PACKED_BORROWS),
 284             reference: "issue #46043 <https://github.com/rust-lang/rust/issues/46043>",
 285             edition: None,
 286         },
 287         FutureIncompatibleInfo {
 288             id: LintId::of(INCOHERENT_FUNDAMENTAL_IMPLS),
 289             reference: "issue #46205 <https://github.com/rust-lang/rust/issues/46205>",
 290             edition: None,
 291         },
 292         FutureIncompatibleInfo {
 293             id: LintId::of(TYVAR_BEHIND_RAW_POINTER),
 294             reference: "issue #46906 <https://github.com/rust-lang/rust/issues/46906>",
 295             edition: Some(Edition::Edition2018),
 296         },
 297         FutureIncompatibleInfo {
 298             id: LintId::of(UNSTABLE_NAME_COLLISIONS),
 299             reference: "issue #48919 <https://github.com/rust-lang/rust/issues/48919>",
 300             edition: None,
 301             // Note: this item represents future incompatibility of all unstable functions in the
 302             //       standard library, and thus should never be removed or changed to an error.
 303         },
 304         FutureIncompatibleInfo {
 305             id: LintId::of(ABSOLUTE_PATHS_NOT_STARTING_WITH_CRATE),
 306             reference: "issue TBD",
 307             edition: Some(Edition::Edition2018),
 308         },
 309         FutureIncompatibleInfo {
 310             id: LintId::of(WHERE_CLAUSES_OBJECT_SAFETY),
 311             reference: "issue #51443 <https://github.com/rust-lang/rust/issues/51443>",
 312             edition: None,
 313         },
 314         FutureIncompatibleInfo {
 315             id: LintId::of(DUPLICATE_ASSOCIATED_TYPE_BINDINGS),
 316             reference: "issue #50589 <https://github.com/rust-lang/rust/issues/50589>",
 317             edition: None,
 318         },
 319         FutureIncompatibleInfo {
 320             id: LintId::of(PROC_MACRO_DERIVE_RESOLUTION_FALLBACK),
 321             reference: "issue #50504 <https://github.com/rust-lang/rust/issues/50504>",
 322             edition: None,
 323         },
 324         ]);
 325
 326     // Register renamed and removed lints
 327     store.register_renamed("single_use_lifetime", "single_use_lifetimes");
 328     store.register_renamed("elided_lifetime_in_path", "elided_lifetimes_in_paths");
 329     store.register_renamed("bare_trait_object", "bare_trait_objects");
 330     store.register_renamed("unstable_name_collision", "unstable_name_collisions");
 331     store.register_renamed("unused_doc_comment", "unused_doc_comments");
 332     store.register_renamed("unknown_features", "unused_features");
 333     store.register_removed("unsigned_negation", "replaced by negate_unsigned feature gate");
 334     store.register_removed("negate_unsigned", "cast a signed value instead");
 335     store.register_removed("raw_pointer_derive", "using derive with raw pointers is ok");
 336     // This was renamed to raw_pointer_derive, which was then removed,
 337     // so it is also considered removed
 338     store.register_removed("raw_pointer_deriving", "using derive with raw pointers is ok");
 339     store.register_removed("drop_with_repr_extern", "drop flags have been removed");
 340     store.register_removed("fat_ptr_transmutes", "was accidentally removed back in 2014");
 341     store.register_removed("deprecated_attr", "use `deprecated` instead");
 342     store.register_removed("transmute_from_fn_item_types",
 343         "always cast functions before transmuting them");
 344     store.register_removed("hr_lifetime_in_assoc_type",
 345         "converted into hard error, see https://github.com/rust-lang/rust/issues/33685");
 346     store.register_removed("inaccessible_extern_crate",
 347         "converted into hard error, see https://github.com/rust-lang/rust/issues/36886");
 348     store.register_removed("super_or_self_in_global_path",
 349         "converted into hard error, see https://github.com/rust-lang/rust/issues/36888");
 350     store.register_removed("overlapping_inherent_impls",
 351         "converted into hard error, see https://github.com/rust-lang/rust/issues/36889");
 352     store.register_removed("illegal_floating_point_constant_pattern",
 353         "converted into hard error, see https://github.com/rust-lang/rust/issues/36890");
 354     store.register_removed("illegal_struct_or_enum_constant_pattern",
 355         "converted into hard error, see https://github.com/rust-lang/rust/issues/36891");
 356     store.register_removed("lifetime_underscore",
 357         "converted into hard error, see https://github.com/rust-lang/rust/issues/36892");
 358     store.register_removed("extra_requirement_in_impl",
 359         "converted into hard error, see https://github.com/rust-lang/rust/issues/37166");
 360     store.register_removed("legacy_imports",
 361         "converted into hard error, see https://github.com/rust-lang/rust/issues/38260");
 362     store.register_removed("coerce_never",
 363         "converted into hard error, see https://github.com/rust-lang/rust/issues/48950");
 364     store.register_removed("resolve_trait_on_defaulted_unit",
 365         "converted into hard error, see https://github.com/rust-lang/rust/issues/48950");
 366 }