diff options
| -rw-r--r-- | compiler/rustc_infer/src/infer/error_reporting/mod.rs | 10 | ||||
| -rw-r--r-- | compiler/rustc_middle/src/traits/mod.rs | 4 | ||||
| -rw-r--r-- | compiler/rustc_typeck/src/check/_match.rs | 16 | ||||
| -rw-r--r-- | src/test/ui/point-to-type-err-cause-on-impl-trait-return.rs | 35 | ||||
| -rw-r--r-- | src/test/ui/point-to-type-err-cause-on-impl-trait-return.stderr | 110 |
5 files changed, 156 insertions, 19 deletions
diff --git a/compiler/rustc_infer/src/infer/error_reporting/mod.rs b/compiler/rustc_infer/src/infer/error_reporting/mod.rs index ca6f4243c28..bcfcee23d13 100644 --- a/compiler/rustc_infer/src/infer/error_reporting/mod.rs +++ b/compiler/rustc_infer/src/infer/error_reporting/mod.rs @@ -617,14 +617,14 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> { ref prior_arms, last_ty, scrut_hir_id, - suggest_box, + opt_suggest_box_span, arm_span, .. }) => match source { hir::MatchSource::IfLetDesugar { .. } => { let msg = "`if let` arms have incompatible types"; err.span_label(cause.span, msg); - if let Some(ret_sp) = suggest_box { + if let Some(ret_sp) = opt_suggest_box_span { self.suggest_boxing_for_return_impl_trait( err, ret_sp, @@ -684,7 +684,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> { Applicability::MachineApplicable, ); } - if let Some(ret_sp) = suggest_box { + if let Some(ret_sp) = opt_suggest_box_span { // Get return type span and point to it. self.suggest_boxing_for_return_impl_trait( err, @@ -699,7 +699,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> { else_sp, outer, semicolon, - suggest_box, + opt_suggest_box_span, }) => { err.span_label(then, "expected because of this"); if let Some(sp) = outer { @@ -713,7 +713,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> { Applicability::MachineApplicable, ); } - if let Some(ret_sp) = suggest_box { + if let Some(ret_sp) = opt_suggest_box_span { self.suggest_boxing_for_return_impl_trait( err, ret_sp, diff --git a/compiler/rustc_middle/src/traits/mod.rs b/compiler/rustc_middle/src/traits/mod.rs index 71582b7ed73..9db3b57a5c2 100644 --- a/compiler/rustc_middle/src/traits/mod.rs +++ b/compiler/rustc_middle/src/traits/mod.rs @@ -350,7 +350,7 @@ pub struct MatchExpressionArmCause<'tcx> { pub prior_arms: Vec<Span>, pub last_ty: Ty<'tcx>, pub scrut_hir_id: hir::HirId, - pub suggest_box: Option<Span>, + pub opt_suggest_box_span: Option<Span>, } #[derive(Clone, Debug, PartialEq, Eq, Hash)] @@ -359,7 +359,7 @@ pub struct IfExpressionCause { pub else_sp: Span, pub outer: Option<Span>, pub semicolon: Option<Span>, - pub suggest_box: Option<Span>, + pub opt_suggest_box_span: Option<Span>, } #[derive(Clone, Debug, PartialEq, Eq, Hash, Lift)] diff --git a/compiler/rustc_typeck/src/check/_match.rs b/compiler/rustc_typeck/src/check/_match.rs index 98e53a25879..08cf178c813 100644 --- a/compiler/rustc_typeck/src/check/_match.rs +++ b/compiler/rustc_typeck/src/check/_match.rs @@ -119,13 +119,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { // When we have a `match` as a tail expression in a `fn` with a returned `impl Trait` // we check if the different arms would work with boxed trait objects instead and // provide a structured suggestion in that case. - let suggest_box = match ( + let opt_suggest_box_span = match ( orig_expected, - self.body_id - .owner - .to_def_id() - .as_local() - .and_then(|id| self.ret_coercion_impl_trait.map(|ty| (id, ty))), + self.ret_coercion_impl_trait.map(|ty| (self.body_id.owner, ty)), ) { (Expectation::ExpectHasType(expected), Some((id, ty))) if self.in_tail_expr && self.can_coerce(arm_ty, expected) => @@ -181,7 +177,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { &arm.body, then_ty, arm_ty, - suggest_box, + opt_suggest_box_span, ); coercion.coerce(self, &cause, &arm.body, arm_ty); } @@ -205,7 +201,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { prior_arms: other_arms.clone(), last_ty: prior_arm_ty.unwrap(), scrut_hir_id: scrut.hir_id, - suggest_box, + opt_suggest_box_span, }), ), }; @@ -330,7 +326,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { else_expr: &'tcx hir::Expr<'tcx>, then_ty: Ty<'tcx>, else_ty: Ty<'tcx>, - suggest_box: Option<Span>, + opt_suggest_box_span: Option<Span>, ) -> ObligationCause<'tcx> { let mut outer_sp = if self.tcx.sess.source_map().is_multiline(span) { // The `if`/`else` isn't in one line in the output, include some context to make it @@ -421,7 +417,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { else_sp: error_sp, outer: outer_sp, semicolon: remove_semicolon, - suggest_box, + opt_suggest_box_span, }), ) } diff --git a/src/test/ui/point-to-type-err-cause-on-impl-trait-return.rs b/src/test/ui/point-to-type-err-cause-on-impl-trait-return.rs index 1a477e5db99..fa7664a83ee 100644 --- a/src/test/ui/point-to-type-err-cause-on-impl-trait-return.rs +++ b/src/test/ui/point-to-type-err-cause-on-impl-trait-return.rs @@ -63,4 +63,39 @@ fn dog() -> impl std::fmt::Display { } } +fn hat() -> dyn std::fmt::Display { //~ ERROR return type cannot have an unboxed trait object + match 13 { + 0 => { + return 0i32; + } + _ => { + 1u32 + } + } +} + +fn pug() -> dyn std::fmt::Display { //~ ERROR return type cannot have an unboxed trait object + match 13 { + 0 => 0i32, + 1 => 1u32, //~ ERROR `match` arms have incompatible types + _ => 2u32, + } +} + +fn man() -> dyn std::fmt::Display { //~ ERROR return type cannot have an unboxed trait object + if false { + 0i32 + } else { + 1u32 //~ ERROR `if` and `else` have incompatible types + } +} + +fn apt() -> impl std::fmt::Display { + if let Some(42) = Some(42) { + 0i32 + } else { + 1u32 //~ ERROR `if` and `else` have incompatible types + } +} + fn main() {} diff --git a/src/test/ui/point-to-type-err-cause-on-impl-trait-return.stderr b/src/test/ui/point-to-type-err-cause-on-impl-trait-return.stderr index 4265381eb40..eb4dc45c8a9 100644 --- a/src/test/ui/point-to-type-err-cause-on-impl-trait-return.stderr +++ b/src/test/ui/point-to-type-err-cause-on-impl-trait-return.stderr @@ -207,6 +207,112 @@ LL | 0 => Box::new(0i32), LL | 1 => Box::new(1u32), | -error: aborting due to 8 previous errors +error[E0308]: `if` and `else` have incompatible types + --> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:97:9 + | +LL | / if let Some(42) = Some(42) { +LL | | 0i32 + | | ---- expected because of this +LL | | } else { +LL | | 1u32 + | | ^^^^ expected `i32`, found `u32` +LL | | } + | |_____- `if` and `else` have incompatible types + | +help: you could change the return type to be a boxed trait object + | +LL | fn apt() -> Box<dyn std::fmt::Display> { + | ^^^^^^^ ^ +help: if you change the return type to expect trait objects, box the returned expressions + | +LL | Box::new(0i32) +LL | } else { +LL | Box::new(1u32) + | + +error[E0746]: return type cannot have an unboxed trait object + --> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:66:13 + | +LL | fn hat() -> dyn std::fmt::Display { + | ^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time + | + = note: for information on trait objects, see <https://doc.rust-lang.org/book/ch17-02-trait-objects.html#using-trait-objects-that-allow-for-values-of-different-types> + = note: if all the returned values were of the same type you could use `impl std::fmt::Display` as the return type + = note: for information on `impl Trait`, see <https://doc.rust-lang.org/book/ch10-02-traits.html#returning-types-that-implement-traits> + = note: you can create a new `enum` with a variant for each returned type +help: return a boxed trait object instead + | +LL | fn hat() -> Box<dyn std::fmt::Display> { +LL | match 13 { +LL | 0 => { +LL | return Box::new(0i32); +LL | } +LL | _ => { + ... + +error[E0308]: `match` arms have incompatible types + --> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:80:14 + | +LL | / match 13 { +LL | | 0 => 0i32, + | | ---- this is found to be of type `i32` +LL | | 1 => 1u32, + | | ^^^^ expected `i32`, found `u32` +LL | | _ => 2u32, +LL | | } + | |_____- `match` arms have incompatible types + +error[E0746]: return type cannot have an unboxed trait object + --> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:77:13 + | +LL | fn pug() -> dyn std::fmt::Display { + | ^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time + | + = note: for information on trait objects, see <https://doc.rust-lang.org/book/ch17-02-trait-objects.html#using-trait-objects-that-allow-for-values-of-different-types> + = note: if all the returned values were of the same type you could use `impl std::fmt::Display` as the return type + = note: for information on `impl Trait`, see <https://doc.rust-lang.org/book/ch10-02-traits.html#returning-types-that-implement-traits> + = note: you can create a new `enum` with a variant for each returned type +help: return a boxed trait object instead + | +LL | fn pug() -> Box<dyn std::fmt::Display> { +LL | match 13 { +LL | 0 => Box::new(0i32), +LL | 1 => Box::new(1u32), +LL | _ => Box::new(2u32), + | + +error[E0308]: `if` and `else` have incompatible types + --> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:89:9 + | +LL | / if false { +LL | | 0i32 + | | ---- expected because of this +LL | | } else { +LL | | 1u32 + | | ^^^^ expected `i32`, found `u32` +LL | | } + | |_____- `if` and `else` have incompatible types + +error[E0746]: return type cannot have an unboxed trait object + --> $DIR/point-to-type-err-cause-on-impl-trait-return.rs:85:13 + | +LL | fn man() -> dyn std::fmt::Display { + | ^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time + | + = note: for information on trait objects, see <https://doc.rust-lang.org/book/ch17-02-trait-objects.html#using-trait-objects-that-allow-for-values-of-different-types> + = note: if all the returned values were of the same type you could use `impl std::fmt::Display` as the return type + = note: for information on `impl Trait`, see <https://doc.rust-lang.org/book/ch10-02-traits.html#returning-types-that-implement-traits> + = note: you can create a new `enum` with a variant for each returned type +help: return a boxed trait object instead + | +LL | fn man() -> Box<dyn std::fmt::Display> { +LL | if false { +LL | Box::new(0i32) +LL | } else { +LL | Box::new(1u32) + | + +error: aborting due to 14 previous errors -For more information about this error, try `rustc --explain E0308`. +Some errors have detailed explanations: E0308, E0746. +For more information about an error, try `rustc --explain E0308`. |