diff options
3 files changed, 82 insertions, 64 deletions
diff --git a/compiler/rustc_mir_build/src/thir/pattern/check_match.rs b/compiler/rustc_mir_build/src/thir/pattern/check_match.rs index 0e218cd8788..c66a26123bc 100644 --- a/compiler/rustc_mir_build/src/thir/pattern/check_match.rs +++ b/compiler/rustc_mir_build/src/thir/pattern/check_match.rs @@ -58,7 +58,7 @@ fn create_e0004( struct_span_err!(sess, sp, E0004, "{}", &error_message) } -#[derive(PartialEq)] +#[derive(Copy, Clone, PartialEq)] enum RefutableFlag { Irrefutable, Refutable, @@ -197,32 +197,36 @@ impl<'p, 'tcx> MatchVisitor<'_, 'p, 'tcx> { self.let_source = old_let_source; } - fn with_lint_level(&mut self, new_lint_level: LintLevel, f: impl FnOnce(&mut Self)) { + fn with_lint_level<T>( + &mut self, + new_lint_level: LintLevel, + f: impl FnOnce(&mut Self) -> T, + ) -> T { if let LintLevel::Explicit(hir_id) = new_lint_level { let old_lint_level = self.lint_level; self.lint_level = hir_id; - f(self); + let ret = f(self); self.lint_level = old_lint_level; + ret } else { - f(self); + f(self) } } - fn check_patterns(&self, pat: &Pat<'tcx>, rf: RefutableFlag) { - pat.walk_always(|pat| check_borrow_conflicts_in_at_patterns(self, pat)); - check_for_bindings_named_same_as_variants(self, pat, rf); - } - fn lower_pattern( &mut self, cx: &MatchCheckCtxt<'p, 'tcx>, - pattern: &Pat<'tcx>, + pat: &Pat<'tcx>, ) -> Result<&'p DeconstructedPat<'p, 'tcx>, ErrorGuaranteed> { - if let Err(err) = pattern.pat_error_reported() { + if let Err(err) = pat.pat_error_reported() { self.error = Err(err); Err(err) } else { - Ok(cx.pattern_arena.alloc(DeconstructedPat::from_pat(cx, pattern))) + // Check the pattern for some things unrelated to exhaustiveness. + let refutable = if cx.refutable { Refutable } else { Irrefutable }; + pat.walk_always(|pat| check_borrow_conflicts_in_at_patterns(self, pat)); + pat.walk_always(|pat| check_for_bindings_named_same_as_variants(self, pat, refutable)); + Ok(cx.pattern_arena.alloc(DeconstructedPat::from_pat(cx, pat))) } } @@ -241,7 +245,6 @@ impl<'p, 'tcx> MatchVisitor<'_, 'p, 'tcx> { if let LetSource::None = source { return; } - self.check_patterns(pat, Refutable); let mut cx = self.new_cx(self.lint_level, true); let Ok(tpat) = self.lower_pattern(&cx, pat) else { return }; self.check_let_reachability(&mut cx, self.lint_level, source, tpat, span); @@ -258,18 +261,18 @@ impl<'p, 'tcx> MatchVisitor<'_, 'p, 'tcx> { let mut tarms = Vec::with_capacity(arms.len()); for &arm in arms { - // Check the arm for some things unrelated to exhaustiveness. let arm = &self.thir.arms[arm]; - self.with_lint_level(arm.lint_level, |this| { - this.check_patterns(&arm.pattern, Refutable); + let got_error = self.with_lint_level(arm.lint_level, |this| { + let Ok(pat) = this.lower_pattern(&mut cx, &arm.pattern) else { + return true; + }; + let arm = MatchArm { pat, hir_id: this.lint_level, has_guard: arm.guard.is_some() }; + tarms.push(arm); + false }); - let hir_id = match arm.lint_level { - LintLevel::Explicit(hir_id) => hir_id, - LintLevel::Inherited => self.lint_level, - }; - let Ok(pat) = self.lower_pattern(&mut cx, &arm.pattern) else { return }; - let arm = MatchArm { pat, hir_id, has_guard: arm.guard.is_some() }; - tarms.push(arm); + if got_error { + return; + } } let scrut = &self.thir[scrut]; @@ -458,7 +461,6 @@ impl<'p, 'tcx> MatchVisitor<'_, 'p, 'tcx> { let witnesses = report.non_exhaustiveness_witnesses; if witnesses.is_empty() { // The pattern is irrefutable. - self.check_patterns(pat, Irrefutable); return; } @@ -659,43 +661,41 @@ fn check_for_bindings_named_same_as_variants( pat: &Pat<'_>, rf: RefutableFlag, ) { - pat.walk_always(|p| { - if let PatKind::Binding { - name, - mode: BindingMode::ByValue, - mutability: Mutability::Not, - subpattern: None, - ty, - .. - } = p.kind - && let ty::Adt(edef, _) = ty.peel_refs().kind() - && edef.is_enum() - && edef - .variants() - .iter() - .any(|variant| variant.name == name && variant.ctor_kind() == Some(CtorKind::Const)) - { - let variant_count = edef.variants().len(); - let ty_path = with_no_trimmed_paths!(cx.tcx.def_path_str(edef.did())); - cx.tcx.emit_spanned_lint( - BINDINGS_WITH_VARIANT_NAME, - cx.lint_level, - p.span, - BindingsWithVariantName { - // If this is an irrefutable pattern, and there's > 1 variant, - // then we can't actually match on this. Applying the below - // suggestion would produce code that breaks on `check_irrefutable`. - suggestion: if rf == Refutable || variant_count == 1 { - Some(p.span) - } else { - None - }, - ty_path, - name, + if let PatKind::Binding { + name, + mode: BindingMode::ByValue, + mutability: Mutability::Not, + subpattern: None, + ty, + .. + } = pat.kind + && let ty::Adt(edef, _) = ty.peel_refs().kind() + && edef.is_enum() + && edef + .variants() + .iter() + .any(|variant| variant.name == name && variant.ctor_kind() == Some(CtorKind::Const)) + { + let variant_count = edef.variants().len(); + let ty_path = with_no_trimmed_paths!(cx.tcx.def_path_str(edef.did())); + cx.tcx.emit_spanned_lint( + BINDINGS_WITH_VARIANT_NAME, + cx.lint_level, + pat.span, + BindingsWithVariantName { + // If this is an irrefutable pattern, and there's > 1 variant, + // then we can't actually match on this. Applying the below + // suggestion would produce code that breaks on `check_irrefutable`. + suggestion: if rf == Refutable || variant_count == 1 { + Some(pat.span) + } else { + None }, - ) - } - }); + ty_path, + name, + }, + ) + } } fn irrefutable_let_patterns( diff --git a/tests/ui/pattern/usefulness/conflicting_bindings.rs b/tests/ui/pattern/usefulness/conflicting_bindings.rs index 1df4425c48b..0b3e7ce9e9a 100644 --- a/tests/ui/pattern/usefulness/conflicting_bindings.rs +++ b/tests/ui/pattern/usefulness/conflicting_bindings.rs @@ -9,9 +9,11 @@ fn main() { if let Some(ref mut y @ ref mut z) = x {} //~^ ERROR: mutable more than once if let Some(ref mut y @ ref mut z) = x && true {} + //~^ ERROR: mutable more than once while let Some(ref mut y @ ref mut z) = x {} //~^ ERROR: mutable more than once while let Some(ref mut y @ ref mut z) = x && true {} + //~^ ERROR: mutable more than once match x { ref mut y @ ref mut z => {} //~ ERROR: mutable more than once } diff --git a/tests/ui/pattern/usefulness/conflicting_bindings.stderr b/tests/ui/pattern/usefulness/conflicting_bindings.stderr index af20eece20c..679fc83e7f5 100644 --- a/tests/ui/pattern/usefulness/conflicting_bindings.stderr +++ b/tests/ui/pattern/usefulness/conflicting_bindings.stderr @@ -23,7 +23,15 @@ LL | if let Some(ref mut y @ ref mut z) = x {} | value is mutably borrowed by `y` here error: cannot borrow value as mutable more than once at a time - --> $DIR/conflicting_bindings.rs:12:20 + --> $DIR/conflicting_bindings.rs:11:17 + | +LL | if let Some(ref mut y @ ref mut z) = x && true {} + | ^^^^^^^^^ --------- value is mutably borrowed by `z` here + | | + | value is mutably borrowed by `y` here + +error: cannot borrow value as mutable more than once at a time + --> $DIR/conflicting_bindings.rs:13:20 | LL | while let Some(ref mut y @ ref mut z) = x {} | ^^^^^^^^^ --------- value is mutably borrowed by `z` here @@ -31,7 +39,15 @@ LL | while let Some(ref mut y @ ref mut z) = x {} | value is mutably borrowed by `y` here error: cannot borrow value as mutable more than once at a time - --> $DIR/conflicting_bindings.rs:16:9 + --> $DIR/conflicting_bindings.rs:15:20 + | +LL | while let Some(ref mut y @ ref mut z) = x && true {} + | ^^^^^^^^^ --------- value is mutably borrowed by `z` here + | | + | value is mutably borrowed by `y` here + +error: cannot borrow value as mutable more than once at a time + --> $DIR/conflicting_bindings.rs:18:9 | LL | ref mut y @ ref mut z => {} | ^^^^^^^^^ --------- value is mutably borrowed by `z` here @@ -39,12 +55,12 @@ LL | ref mut y @ ref mut z => {} | value is mutably borrowed by `y` here error: cannot borrow value as mutable more than once at a time - --> $DIR/conflicting_bindings.rs:19:24 + --> $DIR/conflicting_bindings.rs:21:24 | LL | () if let Some(ref mut y @ ref mut z) = x => {} | ^^^^^^^^^ --------- value is mutably borrowed by `z` here | | | value is mutably borrowed by `y` here -error: aborting due to 6 previous errors +error: aborting due to 8 previous errors |