Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/hir-ty/src/diagnostics/expr.rs')
| -rw-r--r-- | crates/hir-ty/src/diagnostics/expr.rs | 60 |
1 files changed, 56 insertions, 4 deletions
diff --git a/crates/hir-ty/src/diagnostics/expr.rs b/crates/hir-ty/src/diagnostics/expr.rs index afb80e1f44..0c5d639961 100644 --- a/crates/hir-ty/src/diagnostics/expr.rs +++ b/crates/hir-ty/src/diagnostics/expr.rs @@ -12,6 +12,7 @@ use hir_expand::name; use itertools::Itertools; use rustc_hash::FxHashSet; use rustc_pattern_analysis::usefulness::{compute_match_usefulness, ValidityConstraint}; +use tracing::debug; use triomphe::Arc; use typed_arena::Arena; @@ -44,6 +45,10 @@ pub enum BodyValidationDiagnostic { match_expr: ExprId, uncovered_patterns: String, }, + NonExhaustiveLet { + pat: PatId, + uncovered_patterns: String, + }, RemoveTrailingReturn { return_expr: ExprId, }, @@ -68,7 +73,7 @@ struct ExprValidator { owner: DefWithBodyId, body: Arc<Body>, infer: Arc<InferenceResult>, - pub(super) diagnostics: Vec<BodyValidationDiagnostic>, + diagnostics: Vec<BodyValidationDiagnostic>, } impl ExprValidator { @@ -105,6 +110,9 @@ impl ExprValidator { Expr::If { .. } => { self.check_for_unnecessary_else(id, expr, &body); } + Expr::Block { .. } => { + self.validate_block(db, expr); + } _ => {} } } @@ -231,11 +239,55 @@ impl ExprValidator { if !witnesses.is_empty() { self.diagnostics.push(BodyValidationDiagnostic::MissingMatchArms { match_expr, - uncovered_patterns: missing_match_arms(&cx, scrut_ty, witnesses, arms), + uncovered_patterns: missing_match_arms(&cx, scrut_ty, witnesses, m_arms.is_empty()), }); } } + fn validate_block(&mut self, db: &dyn HirDatabase, expr: &Expr) { + let Expr::Block { statements, .. } = expr else { return }; + let pattern_arena = Arena::new(); + let cx = MatchCheckCtx::new(self.owner.module(db.upcast()), self.owner, db); + for stmt in &**statements { + let &Statement::Let { pat, initializer, else_branch: None, .. } = stmt else { + continue; + }; + let Some(initializer) = initializer else { continue }; + let ty = &self.infer[initializer]; + + let mut have_errors = false; + let deconstructed_pat = self.lower_pattern(&cx, pat, db, &mut have_errors); + let match_arm = rustc_pattern_analysis::MatchArm { + pat: pattern_arena.alloc(deconstructed_pat), + has_guard: false, + arm_data: (), + }; + if have_errors { + continue; + } + + let report = match compute_match_usefulness( + &cx, + &[match_arm], + ty.clone(), + ValidityConstraint::ValidOnly, + ) { + Ok(v) => v, + Err(e) => { + debug!(?e, "match usefulness error"); + continue; + } + }; + let witnesses = report.non_exhaustiveness_witnesses; + if !witnesses.is_empty() { + self.diagnostics.push(BodyValidationDiagnostic::NonExhaustiveLet { + pat, + uncovered_patterns: missing_match_arms(&cx, ty, witnesses, false), + }); + } + } + } + fn lower_pattern<'p>( &self, cx: &MatchCheckCtx<'p>, @@ -444,7 +496,7 @@ fn missing_match_arms<'p>( cx: &MatchCheckCtx<'p>, scrut_ty: &Ty, witnesses: Vec<WitnessPat<'p>>, - arms: &[MatchArm], + arms_is_empty: bool, ) -> String { struct DisplayWitness<'a, 'p>(&'a WitnessPat<'p>, &'a MatchCheckCtx<'p>); impl fmt::Display for DisplayWitness<'_, '_> { @@ -459,7 +511,7 @@ fn missing_match_arms<'p>( Some((AdtId::EnumId(e), _)) => !cx.db.enum_data(e).variants.is_empty(), _ => false, }; - if arms.is_empty() && !non_empty_enum { + if arms_is_empty && !non_empty_enum { format!("type `{}` is non-empty", scrut_ty.display(cx.db)) } else { let pat_display = |witness| DisplayWitness(witness, cx); |