crates/ide/src/diagnostics.rs

   1 //! Collects diagnostics & fixits  for a single file.
   2 //!
   3 //! The tricky bit here is that diagnostics are produced by hir in terms of
   4 //! macro-expanded files, but we need to present them to the users in terms of
   5 //! original files. So we need to map the ranges.
   6
   7 mod fixes;
   8 mod field_shorthand;
   9 mod unlinked_file;
  10
  11 use std::cell::RefCell;
  12
  13 use hir::{
  14     db::AstDatabase,
  15     diagnostics::{Diagnostic as _, DiagnosticCode, DiagnosticSinkBuilder},
  16     InFile, Semantics,
  17 };
  18 use ide_assists::AssistResolveStrategy;
  19 use ide_db::{base_db::SourceDatabase, RootDatabase};
  20 use itertools::Itertools;
  21 use rustc_hash::FxHashSet;
  22 use syntax::{
  23     ast::{self, AstNode},
  24     SyntaxNode, SyntaxNodePtr, TextRange, TextSize,
  25 };
  26 use text_edit::TextEdit;
  27 use unlinked_file::UnlinkedFile;
  28
  29 use crate::{Assist, AssistId, AssistKind, FileId, Label, SourceChange};
  30
  31 use self::fixes::DiagnosticWithFix;
  32
  33 #[derive(Debug)]
  34 pub struct Diagnostic {
  35     // pub name: Option<String>,
  36     pub message: String,
  37     pub range: TextRange,
  38     pub severity: Severity,
  39     pub fix: Option<Assist>,
  40     pub unused: bool,
  41     pub code: Option<DiagnosticCode>,
  42 }
  43
  44 impl Diagnostic {
  45     fn error(range: TextRange, message: String) -> Self {
  46         Self { message, range, severity: Severity::Error, fix: None, unused: false, code: None }
  47     }
  48
  49     fn hint(range: TextRange, message: String) -> Self {
  50         Self {
  51             message,
  52             range,
  53             severity: Severity::WeakWarning,
  54             fix: None,
  55             unused: false,
  56             code: None,
  57         }
  58     }
  59
  60     fn with_fix(self, fix: Option<Assist>) -> Self {
  61         Self { fix, ..self }
  62     }
  63
  64     fn with_unused(self, unused: bool) -> Self {
  65         Self { unused, ..self }
  66     }
  67
  68     fn with_code(self, code: Option<DiagnosticCode>) -> Self {
  69         Self { code, ..self }
  70     }
  71 }
  72
  73 #[derive(Debug, Copy, Clone)]
  74 pub enum Severity {
  75     Error,
  76     WeakWarning,
  77 }
  78
  79 #[derive(Default, Debug, Clone)]
  80 pub struct DiagnosticsConfig {
  81     pub disable_experimental: bool,
  82     pub disabled: FxHashSet<String>,
  83 }
  84
  85 pub(crate) fn diagnostics(
  86     db: &RootDatabase,
  87     config: &DiagnosticsConfig,
  88     resolve: &AssistResolveStrategy,
  89     file_id: FileId,
  90 ) -> Vec<Diagnostic> {
  91     let _p = profile::span("diagnostics");
  92     let sema = Semantics::new(db);
  93     let parse = db.parse(file_id);
  94     let mut res = Vec::new();
  95
  96     // [#34344] Only take first 128 errors to prevent slowing down editor/ide, the number 128 is chosen arbitrarily.
  97     res.extend(
  98         parse
  99             .errors()
 100             .iter()
 101             .take(128)
 102             .map(|err| Diagnostic::error(err.range(), format!("Syntax Error: {}", err))),
 103     );
 104
 105     for node in parse.tree().syntax().descendants() {
 106         check_unnecessary_braces_in_use_statement(&mut res, file_id, &node);
 107         field_shorthand::check(&mut res, file_id, &node);
 108     }
 109     let res = RefCell::new(res);
 110     let sink_builder = DiagnosticSinkBuilder::new()
 111         .on::<hir::diagnostics::UnresolvedModule, _>(|d| {
 112             res.borrow_mut().push(diagnostic_with_fix(d, &sema, resolve));
 113         })
 114         .on::<hir::diagnostics::MissingFields, _>(|d| {
 115             res.borrow_mut().push(diagnostic_with_fix(d, &sema, resolve));
 116         })
 117         .on::<hir::diagnostics::MissingOkOrSomeInTailExpr, _>(|d| {
 118             res.borrow_mut().push(diagnostic_with_fix(d, &sema, resolve));
 119         })
 120         .on::<hir::diagnostics::NoSuchField, _>(|d| {
 121             res.borrow_mut().push(diagnostic_with_fix(d, &sema, resolve));
 122         })
 123         .on::<hir::diagnostics::RemoveThisSemicolon, _>(|d| {
 124             res.borrow_mut().push(diagnostic_with_fix(d, &sema, resolve));
 125         })
 126         .on::<hir::diagnostics::IncorrectCase, _>(|d| {
 127             res.borrow_mut().push(warning_with_fix(d, &sema, resolve));
 128         })
 129         .on::<hir::diagnostics::ReplaceFilterMapNextWithFindMap, _>(|d| {
 130             res.borrow_mut().push(warning_with_fix(d, &sema, resolve));
 131         })
 132         .on::<hir::diagnostics::InactiveCode, _>(|d| {
 133             // If there's inactive code somewhere in a macro, don't propagate to the call-site.
 134             if d.display_source().file_id.expansion_info(db).is_some() {
 135                 return;
 136             }
 137
 138             // Override severity and mark as unused.
 139             res.borrow_mut().push(
 140                 Diagnostic::hint(
 141                     sema.diagnostics_display_range(d.display_source()).range,
 142                     d.message(),
 143                 )
 144                 .with_unused(true)
 145                 .with_code(Some(d.code())),
 146             );
 147         })
 148         .on::<UnlinkedFile, _>(|d| {
 149             // Limit diagnostic to the first few characters in the file. This matches how VS Code
 150             // renders it with the full span, but on other editors, and is less invasive.
 151             let range = sema.diagnostics_display_range(d.display_source()).range;
 152             let range = range.intersect(TextRange::up_to(TextSize::of("..."))).unwrap_or(range);
 153
 154             // Override severity and mark as unused.
 155             res.borrow_mut().push(
 156                 Diagnostic::hint(range, d.message())
 157                     .with_fix(d.fix(&sema, resolve))
 158                     .with_code(Some(d.code())),
 159             );
 160         })
 161         .on::<hir::diagnostics::UnresolvedProcMacro, _>(|d| {
 162             // Use more accurate position if available.
 163             let display_range = d
 164                 .precise_location
 165                 .unwrap_or_else(|| sema.diagnostics_display_range(d.display_source()).range);
 166
 167             // FIXME: it would be nice to tell the user whether proc macros are currently disabled
 168             res.borrow_mut()
 169                 .push(Diagnostic::hint(display_range, d.message()).with_code(Some(d.code())));
 170         })
 171         .on::<hir::diagnostics::UnresolvedMacroCall, _>(|d| {
 172             let last_path_segment = sema.db.parse_or_expand(d.file).and_then(|root| {
 173                 d.node
 174                     .to_node(&root)
 175                     .path()
 176                     .and_then(|it| it.segment())
 177                     .and_then(|it| it.name_ref())
 178                     .map(|it| InFile::new(d.file, SyntaxNodePtr::new(it.syntax())))
 179             });
 180             let diagnostics = last_path_segment.unwrap_or_else(|| d.display_source());
 181             let display_range = sema.diagnostics_display_range(diagnostics).range;
 182             res.borrow_mut()
 183                 .push(Diagnostic::error(display_range, d.message()).with_code(Some(d.code())));
 184         })
 185         // Only collect experimental diagnostics when they're enabled.
 186         .filter(|diag| !(diag.is_experimental() && config.disable_experimental))
 187         .filter(|diag| !config.disabled.contains(diag.code().as_str()));
 188
 189     // Finalize the `DiagnosticSink` building process.
 190     let mut sink = sink_builder
 191         // Diagnostics not handled above get no fix and default treatment.
 192         .build(|d| {
 193             res.borrow_mut().push(
 194                 Diagnostic::error(
 195                     sema.diagnostics_display_range(d.display_source()).range,
 196                     d.message(),
 197                 )
 198                 .with_code(Some(d.code())),
 199             );
 200         });
 201
 202     match sema.to_module_def(file_id) {
 203         Some(m) => m.diagnostics(db, &mut sink),
 204         None => {
 205             sink.push(UnlinkedFile { file_id, node: SyntaxNodePtr::new(&parse.tree().syntax()) });
 206         }
 207     }
 208
 209     drop(sink);
 210     res.into_inner()
 211 }
 212
 213 fn diagnostic_with_fix<D: DiagnosticWithFix>(
 214     d: &D,
 215     sema: &Semantics<RootDatabase>,
 216     resolve: &AssistResolveStrategy,
 217 ) -> Diagnostic {
 218     Diagnostic::error(sema.diagnostics_display_range(d.display_source()).range, d.message())
 219         .with_fix(d.fix(&sema, resolve))
 220         .with_code(Some(d.code()))
 221 }
 222
 223 fn warning_with_fix<D: DiagnosticWithFix>(
 224     d: &D,
 225     sema: &Semantics<RootDatabase>,
 226     resolve: &AssistResolveStrategy,
 227 ) -> Diagnostic {
 228     Diagnostic::hint(sema.diagnostics_display_range(d.display_source()).range, d.message())
 229         .with_fix(d.fix(&sema, resolve))
 230         .with_code(Some(d.code()))
 231 }
 232
 233 fn check_unnecessary_braces_in_use_statement(
 234     acc: &mut Vec<Diagnostic>,
 235     file_id: FileId,
 236     node: &SyntaxNode,
 237 ) -> Option<()> {
 238     let use_tree_list = ast::UseTreeList::cast(node.clone())?;
 239     if let Some((single_use_tree,)) = use_tree_list.use_trees().collect_tuple() {
 240         // If there is a comment inside the bracketed `use`,
 241         // assume it is a commented out module path and don't show diagnostic.
 242         if use_tree_list.has_inner_comment() {
 243             return Some(());
 244         }
 245
 246         let use_range = use_tree_list.syntax().text_range();
 247         let edit =
 248             text_edit_for_remove_unnecessary_braces_with_self_in_use_statement(&single_use_tree)
 249                 .unwrap_or_else(|| {
 250                     let to_replace = single_use_tree.syntax().text().to_string();
 251                     let mut edit_builder = TextEdit::builder();
 252                     edit_builder.delete(use_range);
 253                     edit_builder.insert(use_range.start(), to_replace);
 254                     edit_builder.finish()
 255                 });
 256
 257         acc.push(
 258             Diagnostic::hint(use_range, "Unnecessary braces in use statement".to_string())
 259                 .with_fix(Some(fix(
 260                     "remove_braces",
 261                     "Remove unnecessary braces",
 262                     SourceChange::from_text_edit(file_id, edit),
 263                     use_range,
 264                 ))),
 265         );
 266     }
 267
 268     Some(())
 269 }
 270
 271 fn text_edit_for_remove_unnecessary_braces_with_self_in_use_statement(
 272     single_use_tree: &ast::UseTree,
 273 ) -> Option<TextEdit> {
 274     let use_tree_list_node = single_use_tree.syntax().parent()?;
 275     if single_use_tree.path()?.segment()?.self_token().is_some() {
 276         let start = use_tree_list_node.prev_sibling_or_token()?.text_range().start();
 277         let end = use_tree_list_node.text_range().end();
 278         return Some(TextEdit::delete(TextRange::new(start, end)));
 279     }
 280     None
 281 }
 282
 283 fn fix(id: &'static str, label: &str, source_change: SourceChange, target: TextRange) -> Assist {
 284     let mut res = unresolved_fix(id, label, target);
 285     res.source_change = Some(source_change);
 286     res
 287 }
 288
 289 fn unresolved_fix(id: &'static str, label: &str, target: TextRange) -> Assist {
 290     assert!(!id.contains(' '));
 291     Assist {
 292         id: AssistId(id, AssistKind::QuickFix),
 293         label: Label::new(label),
 294         group: None,
 295         target,
 296         source_change: None,
 297     }
 298 }
 299
 300 #[cfg(test)]
 301 mod tests {
 302     use expect_test::{expect, Expect};
 303     use ide_assists::AssistResolveStrategy;
 304     use stdx::trim_indent;
 305     use test_utils::assert_eq_text;
 306
 307     use crate::{fixture, DiagnosticsConfig};
 308
 309     /// Takes a multi-file input fixture with annotated cursor positions,
 310     /// and checks that:
 311     ///  * a diagnostic is produced
 312     ///  * this diagnostic fix trigger range touches the input cursor position
 313     ///  * that the contents of the file containing the cursor match `after` after the diagnostic fix is applied
 314     pub(crate) fn check_fix(ra_fixture_before: &str, ra_fixture_after: &str) {
 315         let after = trim_indent(ra_fixture_after);
 316
 317         let (analysis, file_position) = fixture::position(ra_fixture_before);
 318         let diagnostic = analysis
 319             .diagnostics(
 320                 &DiagnosticsConfig::default(),
 321                 AssistResolveStrategy::All,
 322                 file_position.file_id,
 323             )
 324             .unwrap()
 325             .pop()
 326             .unwrap();
 327         let fix = diagnostic.fix.unwrap();
 328         let actual = {
 329             let source_change = fix.source_change.unwrap();
 330             let file_id = *source_change.source_file_edits.keys().next().unwrap();
 331             let mut actual = analysis.file_text(file_id).unwrap().to_string();
 332
 333             for edit in source_change.source_file_edits.values() {
 334                 edit.apply(&mut actual);
 335             }
 336             actual
 337         };
 338
 339         assert_eq_text!(&after, &actual);
 340         assert!(
 341             fix.target.contains_inclusive(file_position.offset),
 342             "diagnostic fix range {:?} does not touch cursor position {:?}",
 343             fix.target,
 344             file_position.offset
 345         );
 346     }
 347
 348     /// Checks that there's a diagnostic *without* fix at `$0`.
 349     fn check_no_fix(ra_fixture: &str) {
 350         let (analysis, file_position) = fixture::position(ra_fixture);
 351         let diagnostic = analysis
 352             .diagnostics(
 353                 &DiagnosticsConfig::default(),
 354                 AssistResolveStrategy::All,
 355                 file_position.file_id,
 356             )
 357             .unwrap()
 358             .pop()
 359             .unwrap();
 360         assert!(diagnostic.fix.is_none(), "got a fix when none was expected: {:?}", diagnostic);
 361     }
 362
 363     /// Takes a multi-file input fixture with annotated cursor position and checks that no diagnostics
 364     /// apply to the file containing the cursor.
 365     pub(crate) fn check_no_diagnostics(ra_fixture: &str) {
 366         let (analysis, files) = fixture::files(ra_fixture);
 367         let diagnostics = files
 368             .into_iter()
 369             .flat_map(|file_id| {
 370                 analysis
 371                     .diagnostics(&DiagnosticsConfig::default(), AssistResolveStrategy::All, file_id)
 372                     .unwrap()
 373             })
 374             .collect::<Vec<_>>();
 375         assert_eq!(diagnostics.len(), 0, "unexpected diagnostics:\n{:#?}", diagnostics);
 376     }
 377
 378     pub(crate) fn check_expect(ra_fixture: &str, expect: Expect) {
 379         let (analysis, file_id) = fixture::file(ra_fixture);
 380         let diagnostics = analysis
 381             .diagnostics(&DiagnosticsConfig::default(), AssistResolveStrategy::All, file_id)
 382             .unwrap();
 383         expect.assert_debug_eq(&diagnostics)
 384     }
 385
 386     #[test]
 387     fn test_unresolved_macro_range() {
 388         check_expect(
 389             r#"foo::bar!(92);"#,
 390             expect![[r#"
 391                 [
 392                     Diagnostic {
 393                         message: "unresolved macro `foo::bar!`",
 394                         range: 5..8,
 395                         severity: Error,
 396                         fix: None,
 397                         unused: false,
 398                         code: Some(
 399                             DiagnosticCode(
 400                                 "unresolved-macro-call",
 401                             ),
 402                         ),
 403                     },
 404                 ]
 405             "#]],
 406         );
 407     }
 408
 409     #[test]
 410     fn range_mapping_out_of_macros() {
 411         // FIXME: this is very wrong, but somewhat tricky to fix.
 412         check_fix(
 413             r#"
 414 fn some() {}
 415 fn items() {}
 416 fn here() {}
 417
 418 macro_rules! id { ($($tt:tt)*) => { $($tt)*}; }
 419
 420 fn main() {
 421     let _x = id![Foo { a: $042 }];
 422 }
 423
 424 pub struct Foo { pub a: i32, pub b: i32 }
 425 "#,
 426             r#"
 427 fn some(, b: () ) {}
 428 fn items() {}
 429 fn here() {}
 430
 431 macro_rules! id { ($($tt:tt)*) => { $($tt)*}; }
 432
 433 fn main() {
 434     let _x = id![Foo { a: 42 }];
 435 }
 436
 437 pub struct Foo { pub a: i32, pub b: i32 }
 438 "#,
 439         );
 440     }
 441
 442     #[test]
 443     fn test_check_unnecessary_braces_in_use_statement() {
 444         check_no_diagnostics(
 445             r#"
 446 use a;
 447 use a::{c, d::e};
 448
 449 mod a {
 450     mod c {}
 451     mod d {
 452         mod e {}
 453     }
 454 }
 455 "#,
 456         );
 457         check_no_diagnostics(
 458             r#"
 459 use a;
 460 use a::{
 461     c,
 462     // d::e
 463 };
 464
 465 mod a {
 466     mod c {}
 467     mod d {
 468         mod e {}
 469     }
 470 }
 471 "#,
 472         );
 473         check_fix(
 474             r"
 475             mod b {}
 476             use {$0b};
 477             ",
 478             r"
 479             mod b {}
 480             use b;
 481             ",
 482         );
 483         check_fix(
 484             r"
 485             mod b {}
 486             use {b$0};
 487             ",
 488             r"
 489             mod b {}
 490             use b;
 491             ",
 492         );
 493         check_fix(
 494             r"
 495             mod a { mod c {} }
 496             use a::{c$0};
 497             ",
 498             r"
 499             mod a { mod c {} }
 500             use a::c;
 501             ",
 502         );
 503         check_fix(
 504             r"
 505             mod a {}
 506             use a::{self$0};
 507             ",
 508             r"
 509             mod a {}
 510             use a;
 511             ",
 512         );
 513         check_fix(
 514             r"
 515             mod a { mod c {} mod d { mod e {} } }
 516             use a::{c, d::{e$0}};
 517             ",
 518             r"
 519             mod a { mod c {} mod d { mod e {} } }
 520             use a::{c, d::e};
 521             ",
 522         );
 523     }
 524
 525     #[test]
 526     fn test_disabled_diagnostics() {
 527         let mut config = DiagnosticsConfig::default();
 528         config.disabled.insert("unresolved-module".into());
 529
 530         let (analysis, file_id) = fixture::file(r#"mod foo;"#);
 531
 532         let diagnostics =
 533             analysis.diagnostics(&config, AssistResolveStrategy::All, file_id).unwrap();
 534         assert!(diagnostics.is_empty());
 535
 536         let diagnostics = analysis
 537             .diagnostics(&DiagnosticsConfig::default(), AssistResolveStrategy::All, file_id)
 538             .unwrap();
 539         assert!(!diagnostics.is_empty());
 540     }
 541
 542     #[test]
 543     fn unlinked_file_prepend_first_item() {
 544         cov_mark::check!(unlinked_file_prepend_before_first_item);
 545         check_fix(
 546             r#"
 547 //- /main.rs
 548 fn f() {}
 549 //- /foo.rs
 550 $0
 551 "#,
 552             r#"
 553 mod foo;
 554
 555 fn f() {}
 556 "#,
 557         );
 558     }
 559
 560     #[test]
 561     fn unlinked_file_append_mod() {
 562         cov_mark::check!(unlinked_file_append_to_existing_mods);
 563         check_fix(
 564             r#"
 565 //- /main.rs
 566 //! Comment on top
 567
 568 mod preexisting;
 569
 570 mod preexisting2;
 571
 572 struct S;
 573
 574 mod preexisting_bottom;)
 575 //- /foo.rs
 576 $0
 577 "#,
 578             r#"
 579 //! Comment on top
 580
 581 mod preexisting;
 582
 583 mod preexisting2;
 584 mod foo;
 585
 586 struct S;
 587
 588 mod preexisting_bottom;)
 589 "#,
 590         );
 591     }
 592
 593     #[test]
 594     fn unlinked_file_insert_in_empty_file() {
 595         cov_mark::check!(unlinked_file_empty_file);
 596         check_fix(
 597             r#"
 598 //- /main.rs
 599 //- /foo.rs
 600 $0
 601 "#,
 602             r#"
 603 mod foo;
 604 "#,
 605         );
 606     }
 607
 608     #[test]
 609     fn unlinked_file_old_style_modrs() {
 610         check_fix(
 611             r#"
 612 //- /main.rs
 613 mod submod;
 614 //- /submod/mod.rs
 615 // in mod.rs
 616 //- /submod/foo.rs
 617 $0
 618 "#,
 619             r#"
 620 // in mod.rs
 621 mod foo;
 622 "#,
 623         );
 624     }
 625
 626     #[test]
 627     fn unlinked_file_new_style_mod() {
 628         check_fix(
 629             r#"
 630 //- /main.rs
 631 mod submod;
 632 //- /submod.rs
 633 //- /submod/foo.rs
 634 $0
 635 "#,
 636             r#"
 637 mod foo;
 638 "#,
 639         );
 640     }
 641
 642     #[test]
 643     fn unlinked_file_with_cfg_off() {
 644         cov_mark::check!(unlinked_file_skip_fix_when_mod_already_exists);
 645         check_no_fix(
 646             r#"
 647 //- /main.rs
 648 #[cfg(never)]
 649 mod foo;
 650
 651 //- /foo.rs
 652 $0
 653 "#,
 654         );
 655     }
 656
 657     #[test]
 658     fn unlinked_file_with_cfg_on() {
 659         check_no_diagnostics(
 660             r#"
 661 //- /main.rs
 662 #[cfg(not(never))]
 663 mod foo;
 664
 665 //- /foo.rs
 666 "#,
 667         );
 668     }
 669 }