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 #![feature(quote)]
  32 #![feature(rustc_diagnostic_macros)]
  33 #![feature(macro_at_most_once_rep)]
  34
  35 #[macro_use]
  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 diagnostics;
  66 mod nonstandard_style;
  67 pub mod builtin;
  68 mod types;
  69 mod unused;
  70
  71 use nonstandard_style::*;
  72 use builtin::*;
  73 use types::*;
  74 use unused::*;
  75
  76 /// Useful for other parts of the compiler.
  77 pub use builtin::SoftLints;
  78
  79 /// Tell the `LintStore` about all the built-in lints (the ones
  80 /// defined in this crate and the ones defined in
  81 /// `rustc::lint::builtin`).
  82 pub fn register_builtins(store: &mut lint::LintStore, sess: Option<&Session>) {
  83     macro_rules! add_early_builtin {
  84         ($sess:ident, $($name:ident),*,) => (
  85             {$(
  86                 store.register_early_pass($sess, false, box $name);
  87                 )*}
  88             )
  89     }
  90
  91     macro_rules! add_pre_expansion_builtin {
  92         ($sess:ident, $($name:ident),*,) => (
  93             {$(
  94                 store.register_pre_expansion_pass($sess, box $name);
  95                 )*}
  96             )
  97     }
  98
  99     macro_rules! add_early_builtin_with_new {
 100         ($sess:ident, $($name:ident),*,) => (
 101             {$(
 102                 store.register_early_pass($sess, false, box $name::new());
 103                 )*}
 104             )
 105     }
 106
 107     macro_rules! add_lint_group {
 108         ($sess:ident, $name:expr, $($lint:ident),*) => (
 109             store.register_group($sess, false, $name, None, vec![$(LintId::of($lint)),*]);
 110             )
 111     }
 112
 113     add_pre_expansion_builtin!(sess,
 114         KeywordIdents,
 115     );
 116
 117     add_early_builtin!(sess,
 118                        UnusedParens,
 119                        UnusedImportBraces,
 120                        AnonymousParameters,
 121                        UnusedDocComment,
 122                        BadRepr,
 123                        EllipsisInclusiveRangePatterns,
 124                        );
 125
 126     add_early_builtin_with_new!(sess,
 127                                 DeprecatedAttr,
 128                                 );
 129
 130     late_lint_methods!(declare_combined_late_lint_pass, [BuiltinCombinedLateLintPass, [
 131         HardwiredLints: HardwiredLints,
 132         WhileTrue: WhileTrue,
 133         ImproperCTypes: ImproperCTypes,
 134         VariantSizeDifferences: VariantSizeDifferences,
 135         BoxPointers: BoxPointers,
 136         UnusedAttributes: UnusedAttributes,
 137         PathStatements: PathStatements,
 138         UnusedResults: UnusedResults,
 139         NonCamelCaseTypes: NonCamelCaseTypes,
 140         NonSnakeCase: NonSnakeCase,
 141         NonUpperCaseGlobals: NonUpperCaseGlobals,
 142         NonShorthandFieldPatterns: NonShorthandFieldPatterns,
 143         UnsafeCode: UnsafeCode,
 144         UnusedAllocation: UnusedAllocation,
 145         MissingCopyImplementations: MissingCopyImplementations,
 146         UnstableFeatures: UnstableFeatures,
 147         UnconditionalRecursion: UnconditionalRecursion,
 148         InvalidNoMangleItems: InvalidNoMangleItems,
 149         PluginAsLibrary: PluginAsLibrary,
 150         MutableTransmutes: MutableTransmutes,
 151         UnionsWithDropFields: UnionsWithDropFields,
 152         UnreachablePub: UnreachablePub,
 153         UnnameableTestItems: UnnameableTestItems::new(),
 154         TypeAliasBounds: TypeAliasBounds,
 155         UnusedBrokenConst: UnusedBrokenConst,
 156         TrivialConstraints: TrivialConstraints,
 157         TypeLimits: TypeLimits::new(),
 158         MissingDoc: MissingDoc::new(),
 159         MissingDebugImplementations: MissingDebugImplementations::new(),
 160     ]], ['tcx]);
 161
 162     store.register_late_pass(sess, false, box BuiltinCombinedLateLintPass::new());
 163
 164     add_lint_group!(sess,
 165                     "bad_style",
 166                     NON_CAMEL_CASE_TYPES,
 167                     NON_SNAKE_CASE,
 168                     NON_UPPER_CASE_GLOBALS);
 169
 170     add_lint_group!(sess,
 171                     "nonstandard_style",
 172                     NON_CAMEL_CASE_TYPES,
 173                     NON_SNAKE_CASE,
 174                     NON_UPPER_CASE_GLOBALS);
 175
 176     add_lint_group!(sess,
 177                     "unused",
 178                     UNUSED_IMPORTS,
 179                     UNUSED_VARIABLES,
 180                     UNUSED_ASSIGNMENTS,
 181                     DEAD_CODE,
 182                     UNUSED_MUT,
 183                     UNREACHABLE_CODE,
 184                     UNREACHABLE_PATTERNS,
 185                     UNUSED_MUST_USE,
 186                     UNUSED_UNSAFE,
 187                     PATH_STATEMENTS,
 188                     UNUSED_ATTRIBUTES,
 189                     UNUSED_MACROS,
 190                     UNUSED_ALLOCATION,
 191                     UNUSED_DOC_COMMENTS,
 192                     UNUSED_EXTERN_CRATES,
 193                     UNUSED_FEATURES,
 194                     UNUSED_LABELS,
 195                     UNUSED_PARENS);
 196
 197     add_lint_group!(sess,
 198                     "rust_2018_idioms",
 199                     BARE_TRAIT_OBJECTS,
 200                     UNUSED_EXTERN_CRATES,
 201                     ELLIPSIS_INCLUSIVE_RANGE_PATTERNS,
 202                     ELIDED_LIFETIMES_IN_PATHS
 203
 204                     // FIXME(#52665, #47816) not always applicable and not all
 205                     // macros are ready for this yet.
 206                     // UNREACHABLE_PUB,
 207
 208                     // FIXME macro crates are not up for this yet, too much
 209                     // breakage is seen if we try to encourage this lint.
 210                     // MACRO_USE_EXTERN_CRATE,
 211                     );
 212
 213     // Guidelines for creating a future incompatibility lint:
 214     //
 215     // - Create a lint defaulting to warn as normal, with ideally the same error
 216     //   message you would normally give
 217     // - Add a suitable reference, typically an RFC or tracking issue. Go ahead
 218     //   and include the full URL, sort items in ascending order of issue numbers.
 219     // - Later, change lint to error
 220     // - Eventually, remove lint
 221     store.register_future_incompatible(sess,
 222                                        vec![
 223         FutureIncompatibleInfo {
 224             id: LintId::of(PRIVATE_IN_PUBLIC),
 225             reference: "issue #34537 <https://github.com/rust-lang/rust/issues/34537>",
 226             edition: None,
 227         },
 228         FutureIncompatibleInfo {
 229             id: LintId::of(PUB_USE_OF_PRIVATE_EXTERN_CRATE),
 230             reference: "issue #34537 <https://github.com/rust-lang/rust/issues/34537>",
 231             edition: None,
 232         },
 233         FutureIncompatibleInfo {
 234             id: LintId::of(PATTERNS_IN_FNS_WITHOUT_BODY),
 235             reference: "issue #35203 <https://github.com/rust-lang/rust/issues/35203>",
 236             edition: None,
 237         },
 238         FutureIncompatibleInfo {
 239             id: LintId::of(DUPLICATE_MACRO_EXPORTS),
 240             reference: "issue #35896 <https://github.com/rust-lang/rust/issues/35896>",
 241             edition: Some(Edition::Edition2018),
 242         },
 243         FutureIncompatibleInfo {
 244             id: LintId::of(KEYWORD_IDENTS),
 245             reference: "issue #49716 <https://github.com/rust-lang/rust/issues/49716>",
 246             edition: Some(Edition::Edition2018),
 247         },
 248         FutureIncompatibleInfo {
 249             id: LintId::of(SAFE_EXTERN_STATICS),
 250             reference: "issue #36247 <https://github.com/rust-lang/rust/issues/36247>",
 251             edition: None,
 252         },
 253         FutureIncompatibleInfo {
 254             id: LintId::of(INVALID_TYPE_PARAM_DEFAULT),
 255             reference: "issue #36887 <https://github.com/rust-lang/rust/issues/36887>",
 256             edition: None,
 257         },
 258         FutureIncompatibleInfo {
 259             id: LintId::of(LEGACY_DIRECTORY_OWNERSHIP),
 260             reference: "issue #37872 <https://github.com/rust-lang/rust/issues/37872>",
 261             edition: None,
 262         },
 263         FutureIncompatibleInfo {
 264             id: LintId::of(LEGACY_CONSTRUCTOR_VISIBILITY),
 265             reference: "issue #39207 <https://github.com/rust-lang/rust/issues/39207>",
 266             edition: None,
 267         },
 268         FutureIncompatibleInfo {
 269             id: LintId::of(MISSING_FRAGMENT_SPECIFIER),
 270             reference: "issue #40107 <https://github.com/rust-lang/rust/issues/40107>",
 271             edition: None,
 272         },
 273         FutureIncompatibleInfo {
 274             id: LintId::of(ILLEGAL_FLOATING_POINT_LITERAL_PATTERN),
 275             reference: "issue #41620 <https://github.com/rust-lang/rust/issues/41620>",
 276             edition: None,
 277         },
 278         FutureIncompatibleInfo {
 279             id: LintId::of(ANONYMOUS_PARAMETERS),
 280             reference: "issue #41686 <https://github.com/rust-lang/rust/issues/41686>",
 281             edition: Some(Edition::Edition2018),
 282         },
 283         FutureIncompatibleInfo {
 284             id: LintId::of(PARENTHESIZED_PARAMS_IN_TYPES_AND_MODULES),
 285             reference: "issue #42238 <https://github.com/rust-lang/rust/issues/42238>",
 286             edition: None,
 287         },
 288         FutureIncompatibleInfo {
 289             id: LintId::of(LATE_BOUND_LIFETIME_ARGUMENTS),
 290             reference: "issue #42868 <https://github.com/rust-lang/rust/issues/42868>",
 291             edition: None,
 292         },
 293         FutureIncompatibleInfo {
 294             id: LintId::of(SAFE_PACKED_BORROWS),
 295             reference: "issue #46043 <https://github.com/rust-lang/rust/issues/46043>",
 296             edition: None,
 297         },
 298         FutureIncompatibleInfo {
 299             id: LintId::of(INCOHERENT_FUNDAMENTAL_IMPLS),
 300             reference: "issue #46205 <https://github.com/rust-lang/rust/issues/46205>",
 301             edition: None,
 302         },
 303         FutureIncompatibleInfo {
 304             id: LintId::of(TYVAR_BEHIND_RAW_POINTER),
 305             reference: "issue #46906 <https://github.com/rust-lang/rust/issues/46906>",
 306             edition: Some(Edition::Edition2018),
 307         },
 308         FutureIncompatibleInfo {
 309             id: LintId::of(UNSTABLE_NAME_COLLISIONS),
 310             reference: "issue #48919 <https://github.com/rust-lang/rust/issues/48919>",
 311             edition: None,
 312             // Note: this item represents future incompatibility of all unstable functions in the
 313             //       standard library, and thus should never be removed or changed to an error.
 314         },
 315         FutureIncompatibleInfo {
 316             id: LintId::of(ABSOLUTE_PATHS_NOT_STARTING_WITH_CRATE),
 317             reference: "issue TBD",
 318             edition: Some(Edition::Edition2018),
 319         },
 320         FutureIncompatibleInfo {
 321             id: LintId::of(WHERE_CLAUSES_OBJECT_SAFETY),
 322             reference: "issue #51443 <https://github.com/rust-lang/rust/issues/51443>",
 323             edition: None,
 324         },
 325         FutureIncompatibleInfo {
 326             id: LintId::of(DUPLICATE_ASSOCIATED_TYPE_BINDINGS),
 327             reference: "issue #50589 <https://github.com/rust-lang/rust/issues/50589>",
 328             edition: None,
 329         },
 330         FutureIncompatibleInfo {
 331             id: LintId::of(PROC_MACRO_DERIVE_RESOLUTION_FALLBACK),
 332             reference: "issue #50504 <https://github.com/rust-lang/rust/issues/50504>",
 333             edition: None,
 334         },
 335         FutureIncompatibleInfo {
 336             id: LintId::of(QUESTION_MARK_MACRO_SEP),
 337             reference: "issue #48075 <https://github.com/rust-lang/rust/issues/48075>",
 338             edition: Some(Edition::Edition2018),
 339         },
 340         FutureIncompatibleInfo {
 341             id: LintId::of(MACRO_EXPANDED_MACRO_EXPORTS_ACCESSED_BY_ABSOLUTE_PATHS),
 342             reference: "issue #52234 <https://github.com/rust-lang/rust/issues/52234>",
 343             edition: None,
 344         },
 345         ]);
 346
 347     // Register renamed and removed lints
 348     store.register_renamed("single_use_lifetime", "single_use_lifetimes");
 349     store.register_renamed("elided_lifetime_in_path", "elided_lifetimes_in_paths");
 350     store.register_renamed("bare_trait_object", "bare_trait_objects");
 351     store.register_renamed("unstable_name_collision", "unstable_name_collisions");
 352     store.register_renamed("unused_doc_comment", "unused_doc_comments");
 353     store.register_renamed("async_idents", "keyword_idents");
 354     store.register_removed("unknown_features", "replaced by an error");
 355     store.register_removed("unsigned_negation", "replaced by negate_unsigned feature gate");
 356     store.register_removed("negate_unsigned", "cast a signed value instead");
 357     store.register_removed("raw_pointer_derive", "using derive with raw pointers is ok");
 358     // This was renamed to raw_pointer_derive, which was then removed,
 359     // so it is also considered removed
 360     store.register_removed("raw_pointer_deriving", "using derive with raw pointers is ok");
 361     store.register_removed("drop_with_repr_extern", "drop flags have been removed");
 362     store.register_removed("fat_ptr_transmutes", "was accidentally removed back in 2014");
 363     store.register_removed("deprecated_attr", "use `deprecated` instead");
 364     store.register_removed("transmute_from_fn_item_types",
 365         "always cast functions before transmuting them");
 366     store.register_removed("hr_lifetime_in_assoc_type",
 367         "converted into hard error, see https://github.com/rust-lang/rust/issues/33685");
 368     store.register_removed("inaccessible_extern_crate",
 369         "converted into hard error, see https://github.com/rust-lang/rust/issues/36886");
 370     store.register_removed("super_or_self_in_global_path",
 371         "converted into hard error, see https://github.com/rust-lang/rust/issues/36888");
 372     store.register_removed("overlapping_inherent_impls",
 373         "converted into hard error, see https://github.com/rust-lang/rust/issues/36889");
 374     store.register_removed("illegal_floating_point_constant_pattern",
 375         "converted into hard error, see https://github.com/rust-lang/rust/issues/36890");
 376     store.register_removed("illegal_struct_or_enum_constant_pattern",
 377         "converted into hard error, see https://github.com/rust-lang/rust/issues/36891");
 378     store.register_removed("lifetime_underscore",
 379         "converted into hard error, see https://github.com/rust-lang/rust/issues/36892");
 380     store.register_removed("extra_requirement_in_impl",
 381         "converted into hard error, see https://github.com/rust-lang/rust/issues/37166");
 382     store.register_removed("legacy_imports",
 383         "converted into hard error, see https://github.com/rust-lang/rust/issues/38260");
 384     store.register_removed("coerce_never",
 385         "converted into hard error, see https://github.com/rust-lang/rust/issues/48950");
 386     store.register_removed("resolve_trait_on_defaulted_unit",
 387         "converted into hard error, see https://github.com/rust-lang/rust/issues/48950");
 388 }