diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs index c920c80d1bba1..ead1f0126c465 100644 --- a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs +++ b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs @@ -1083,20 +1083,31 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> { let parent_node = hir.get_parent_node(obligation.cause.body_id); let node = hir.find(parent_node); if let Some(hir::Node::Item(hir::Item { kind: hir::ItemKind::Fn(sig, _, body_id), .. })) = node - && let body = hir.body(*body_id) - && let hir::ExprKind::Block(blk, _) = &body.value.kind + && let hir::ExprKind::Block(blk, _) = &hir.body(*body_id).value.kind && sig.decl.output.span().overlaps(span) && blk.expr.is_none() - && *trait_pred.self_ty().skip_binder().kind() == ty::Tuple(ty::List::empty()) - // FIXME(estebank): When encountering a method with a trait - // bound not satisfied in the return type with a body that has - // no return, suggest removal of semicolon on last statement. - // Once that is added, close #54771. + && trait_pred.self_ty().skip_binder().is_unit() && let Some(stmt) = blk.stmts.last() - && let hir::StmtKind::Semi(_) = stmt.kind + && let hir::StmtKind::Semi(expr) = stmt.kind + // Only suggest this if the expression behind the semicolon implements the predicate + && let Some(typeck_results) = self.in_progress_typeck_results + && let Some(ty) = typeck_results.borrow().expr_ty_opt(expr) + && self.predicate_may_hold(&self.mk_trait_obligation_with_new_self_ty(obligation.param_env, trait_pred, ty)) { - let sp = self.tcx.sess.source_map().end_point(stmt.span); - err.span_label(sp, "consider removing this semicolon"); + err.span_label( + expr.span, + &format!( + "this expression has type `{}`, which implements `{}`", + ty, + trait_pred.print_modifiers_and_trait_path() + ) + ); + err.span_suggestion( + self.tcx.sess.source_map().end_point(stmt.span), + "remove this semicolon", + String::new(), + Applicability::MachineApplicable + ); return true; } false diff --git a/compiler/rustc_typeck/src/check/fn_ctxt/checks.rs b/compiler/rustc_typeck/src/check/fn_ctxt/checks.rs index 1cc1460750a23..f6a5243274cd2 100644 --- a/compiler/rustc_typeck/src/check/fn_ctxt/checks.rs +++ b/compiler/rustc_typeck/src/check/fn_ctxt/checks.rs @@ -936,7 +936,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { } else { err.span_suggestion_short( span_semi, - "consider removing this semicolon", + "remove this semicolon", String::new(), Applicability::MachineApplicable, ); diff --git a/src/test/ui/block-result/consider-removing-last-semi.stderr b/src/test/ui/block-result/consider-removing-last-semi.stderr index 99a367bfccdcd..2412dcd32f79a 100644 --- a/src/test/ui/block-result/consider-removing-last-semi.stderr +++ b/src/test/ui/block-result/consider-removing-last-semi.stderr @@ -7,7 +7,7 @@ LL | pub fn f() -> String { | implicitly returns `()` as its body has no tail or `return` expression LL | 0u8; LL | "bla".to_string(); - | - help: consider removing this semicolon + | - help: remove this semicolon error[E0308]: mismatched types --> $DIR/consider-removing-last-semi.rs:8:15 @@ -18,7 +18,7 @@ LL | pub fn g() -> String { | implicitly returns `()` as its body has no tail or `return` expression LL | "this won't work".to_string(); LL | "removeme".to_string(); - | - help: consider removing this semicolon + | - help: remove this semicolon error[E0308]: mismatched types --> $DIR/consider-removing-last-semi.rs:13:25 @@ -29,7 +29,7 @@ LL | pub fn macro_tests() -> u32 { | implicitly returns `()` as its body has no tail or `return` expression ... LL | mac!(); - | - help: consider removing this semicolon + | - help: remove this semicolon error: aborting due to 3 previous errors diff --git a/src/test/ui/block-result/issue-11714.stderr b/src/test/ui/block-result/issue-11714.stderr index 61991643a4a56..5b8d96fd4ebe2 100644 --- a/src/test/ui/block-result/issue-11714.stderr +++ b/src/test/ui/block-result/issue-11714.stderr @@ -7,7 +7,7 @@ LL | fn blah() -> i32 { | implicitly returns `()` as its body has no tail or `return` expression ... LL | ; - | - help: consider removing this semicolon + | - help: remove this semicolon error: aborting due to previous error diff --git a/src/test/ui/block-result/issue-13428.stderr b/src/test/ui/block-result/issue-13428.stderr index 2f24679cc9591..a33448edff2bc 100644 --- a/src/test/ui/block-result/issue-13428.stderr +++ b/src/test/ui/block-result/issue-13428.stderr @@ -15,7 +15,7 @@ LL | fn bar() -> String { | implicitly returns `()` as its body has no tail or `return` expression LL | "foobar".to_string() LL | ; - | - help: consider removing this semicolon + | - help: remove this semicolon error: aborting due to 2 previous errors diff --git a/src/test/ui/closures/old-closure-expression-remove-semicolon.fixed b/src/test/ui/closures/old-closure-expression-remove-semicolon.fixed index 5629d4b6e6e5f..623e917da07e8 100644 --- a/src/test/ui/closures/old-closure-expression-remove-semicolon.fixed +++ b/src/test/ui/closures/old-closure-expression-remove-semicolon.fixed @@ -7,6 +7,6 @@ fn foo() -> i32 { fn main() { let _x: i32 = { //~^ ERROR mismatched types - foo() //~ HELP consider removing this semicolon + foo() //~ HELP remove this semicolon }; } diff --git a/src/test/ui/closures/old-closure-expression-remove-semicolon.rs b/src/test/ui/closures/old-closure-expression-remove-semicolon.rs index 33f11b50afca2..4974b08664945 100644 --- a/src/test/ui/closures/old-closure-expression-remove-semicolon.rs +++ b/src/test/ui/closures/old-closure-expression-remove-semicolon.rs @@ -7,6 +7,6 @@ fn foo() -> i32 { fn main() { let _x: i32 = { //~^ ERROR mismatched types - foo(); //~ HELP consider removing this semicolon + foo(); //~ HELP remove this semicolon }; } diff --git a/src/test/ui/closures/old-closure-expression-remove-semicolon.stderr b/src/test/ui/closures/old-closure-expression-remove-semicolon.stderr index ab7983dc9e487..9b73ce4fee346 100644 --- a/src/test/ui/closures/old-closure-expression-remove-semicolon.stderr +++ b/src/test/ui/closures/old-closure-expression-remove-semicolon.stderr @@ -5,7 +5,7 @@ LL | let _x: i32 = { | ___________________^ LL | | LL | | foo(); - | | - help: consider removing this semicolon + | | - help: remove this semicolon LL | | }; | |_____^ expected `i32`, found `()` diff --git a/src/test/ui/coercion/coercion-missing-tail-expected-type.stderr b/src/test/ui/coercion/coercion-missing-tail-expected-type.stderr index df1fb58e25a02..a4843bca58c99 100644 --- a/src/test/ui/coercion/coercion-missing-tail-expected-type.stderr +++ b/src/test/ui/coercion/coercion-missing-tail-expected-type.stderr @@ -6,7 +6,7 @@ LL | fn plus_one(x: i32) -> i32 { | | | implicitly returns `()` as its body has no tail or `return` expression LL | x + 1; - | - help: consider removing this semicolon + | - help: remove this semicolon error[E0308]: mismatched types --> $DIR/coercion-missing-tail-expected-type.rs:8:13 @@ -16,7 +16,7 @@ LL | fn foo() -> Result { | | | implicitly returns `()` as its body has no tail or `return` expression LL | Ok(1); - | - help: consider removing this semicolon + | - help: remove this semicolon | = note: expected enum `Result` found unit type `()` diff --git a/src/test/ui/issues/issue-6458-4.stderr b/src/test/ui/issues/issue-6458-4.stderr index 0cf82d37d5d0b..d6e74d10e03c9 100644 --- a/src/test/ui/issues/issue-6458-4.stderr +++ b/src/test/ui/issues/issue-6458-4.stderr @@ -6,7 +6,7 @@ LL | fn foo(b: bool) -> Result { | | | implicitly returns `()` as its body has no tail or `return` expression LL | Err("bar".to_string()); - | - help: consider removing this semicolon + | - help: remove this semicolon | = note: expected enum `Result` found unit type `()` diff --git a/src/test/ui/liveness/liveness-return-last-stmt-semi.stderr b/src/test/ui/liveness/liveness-return-last-stmt-semi.stderr index 0b33d8d0a2b23..82d136bd318d8 100644 --- a/src/test/ui/liveness/liveness-return-last-stmt-semi.stderr +++ b/src/test/ui/liveness/liveness-return-last-stmt-semi.stderr @@ -14,7 +14,7 @@ LL | fn bar(x: u32) -> u32 { | | | implicitly returns `()` as its body has no tail or `return` expression LL | x * 2; - | - help: consider removing this semicolon + | - help: remove this semicolon error[E0308]: mismatched types --> $DIR/liveness-return-last-stmt-semi.rs:13:19 diff --git a/src/test/ui/suggestions/impl-trait-return-trailing-semicolon.rs b/src/test/ui/suggestions/impl-trait-return-trailing-semicolon.rs index cad7d76c6ab5f..5a17c108ccc13 100644 --- a/src/test/ui/suggestions/impl-trait-return-trailing-semicolon.rs +++ b/src/test/ui/suggestions/impl-trait-return-trailing-semicolon.rs @@ -1,8 +1,25 @@ trait Bar {} -impl Bar for u8 {} + +impl Bar for i32 {} + +struct Qux; + +impl Bar for Qux {} + fn foo() -> impl Bar { - 5; //~^ ERROR the trait bound `(): Bar` is not satisfied + //~^ ERROR the trait bound `(): Bar` is not satisfied + //~| ERROR the trait bound `(): Bar` is not satisfied + //~| HELP the following other types implement trait `Bar`: + 5; + //~^ HELP remove this semicolon +} + +fn bar() -> impl Bar { + //~^ ERROR the trait bound `(): Bar` is not satisfied //~| ERROR the trait bound `(): Bar` is not satisfied + //~| HELP the following other types implement trait `Bar`: + //~| HELP the following other types implement trait `Bar`: + ""; } fn main() {} diff --git a/src/test/ui/suggestions/impl-trait-return-trailing-semicolon.stderr b/src/test/ui/suggestions/impl-trait-return-trailing-semicolon.stderr index 0de765588e5b7..43f8b7c66f07a 100644 --- a/src/test/ui/suggestions/impl-trait-return-trailing-semicolon.stderr +++ b/src/test/ui/suggestions/impl-trait-return-trailing-semicolon.stderr @@ -1,23 +1,58 @@ error[E0277]: the trait bound `(): Bar` is not satisfied - --> $DIR/impl-trait-return-trailing-semicolon.rs:3:13 + --> $DIR/impl-trait-return-trailing-semicolon.rs:9:13 | LL | fn foo() -> impl Bar { | ^^^^^^^^ the trait `Bar` is not implemented for `()` +... LL | 5; - | - consider removing this semicolon + | -- help: remove this semicolon + | | + | this expression has type `{integer}`, which implements `Bar` error[E0277]: the trait bound `(): Bar` is not satisfied - --> $DIR/impl-trait-return-trailing-semicolon.rs:3:22 + --> $DIR/impl-trait-return-trailing-semicolon.rs:9:22 | LL | fn foo() -> impl Bar { | ______________________^ +LL | | +LL | | +LL | | LL | | 5; LL | | LL | | } | |_^ the trait `Bar` is not implemented for `()` | - = help: the trait `Bar` is implemented for `u8` + = help: the following other types implement trait `Bar`: + Qux + i32 + +error[E0277]: the trait bound `(): Bar` is not satisfied + --> $DIR/impl-trait-return-trailing-semicolon.rs:17:13 + | +LL | fn bar() -> impl Bar { + | ^^^^^^^^ the trait `Bar` is not implemented for `()` + | + = help: the following other types implement trait `Bar`: + Qux + i32 + +error[E0277]: the trait bound `(): Bar` is not satisfied + --> $DIR/impl-trait-return-trailing-semicolon.rs:17:22 + | +LL | fn bar() -> impl Bar { + | ______________________^ +LL | | +LL | | +LL | | +LL | | +LL | | ""; +LL | | } + | |_^ the trait `Bar` is not implemented for `()` + | + = help: the following other types implement trait `Bar`: + Qux + i32 -error: aborting due to 2 previous errors +error: aborting due to 4 previous errors For more information about this error, try `rustc --explain E0277`. diff --git a/src/test/ui/suggestions/issue-81098.stderr b/src/test/ui/suggestions/issue-81098.stderr index d62526442e9af..8665f2e70a85c 100644 --- a/src/test/ui/suggestions/issue-81098.stderr +++ b/src/test/ui/suggestions/issue-81098.stderr @@ -27,7 +27,9 @@ LL | fn ok() -> impl core::fmt::Display { | ^^^^^^^^^^^^^^^^^^^^^^^ `()` cannot be formatted with the default formatter LL | LL | 1; - | - consider removing this semicolon + | -- help: remove this semicolon + | | + | this expression has type `{integer}`, which implements `std::fmt::Display` | = help: the trait `std::fmt::Display` is not implemented for `()` = note: in format strings you may be able to use `{:?}` (or {:#?} for pretty-print) instead diff --git a/src/test/ui/suggestions/match-with-different-arm-types-as-stmt-instead-of-expr.stderr b/src/test/ui/suggestions/match-with-different-arm-types-as-stmt-instead-of-expr.stderr index 7dce97468b6dd..60f423a116317 100644 --- a/src/test/ui/suggestions/match-with-different-arm-types-as-stmt-instead-of-expr.stderr +++ b/src/test/ui/suggestions/match-with-different-arm-types-as-stmt-instead-of-expr.stderr @@ -7,7 +7,7 @@ LL | fn not_all_paths(a: &str) -> u32 { | implicitly returns `()` as its body has no tail or `return` expression ... LL | }; - | - help: consider removing this semicolon + | - help: remove this semicolon error[E0308]: `match` arms have incompatible types --> $DIR/match-with-different-arm-types-as-stmt-instead-of-expr.rs:26:14