From fc816c37b734e594037f36114a2844d7e7b30f76 Mon Sep 17 00:00:00 2001 From: Michael Goulet Date: Mon, 15 Nov 2021 22:51:20 -0800 Subject: [PATCH] Fix await suggestion better --- .../src/infer/error_reporting/mod.rs | 45 +++++++----- .../ui/async-await/suggest-missing-await.rs | 28 ++++++++ .../async-await/suggest-missing-await.stderr | 70 ++++++++++++++++++- 3 files changed, 123 insertions(+), 20 deletions(-) diff --git a/compiler/rustc_infer/src/infer/error_reporting/mod.rs b/compiler/rustc_infer/src/infer/error_reporting/mod.rs index 7a0db820c9c99..c25ec1356e230 100644 --- a/compiler/rustc_infer/src/infer/error_reporting/mod.rs +++ b/compiler/rustc_infer/src/infer/error_reporting/mod.rs @@ -1794,31 +1794,38 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> { } }, (_, Some(ty)) if ty::TyS::same_type(exp_found.expected, ty) => { - let span = match cause.code { - // scrutinee's span - ObligationCauseCode::Pattern { span: Some(span), .. } => span, - _ => exp_span, - }; - diag.span_suggestion_verbose( - span.shrink_to_hi(), - "consider `await`ing on the `Future`", - ".await".to_string(), - Applicability::MaybeIncorrect, - ); - } - (Some(ty), _) if ty::TyS::same_type(ty, exp_found.found) => { - let span = match cause.code { - // scrutinee's span - ObligationCauseCode::Pattern { span: Some(span), .. } => span, - _ => exp_span, - }; diag.span_suggestion_verbose( - span.shrink_to_hi(), + exp_span.shrink_to_hi(), "consider `await`ing on the `Future`", ".await".to_string(), Applicability::MaybeIncorrect, ); } + (Some(ty), _) if ty::TyS::same_type(ty, exp_found.found) => match cause.code { + ObligationCauseCode::Pattern { span: Some(span), .. } + | ObligationCauseCode::IfExpression(box IfExpressionCause { then: span, .. }) => { + diag.span_suggestion_verbose( + span.shrink_to_hi(), + "consider `await`ing on the `Future`", + ".await".to_string(), + Applicability::MaybeIncorrect, + ); + } + ObligationCauseCode::MatchExpressionArm(box MatchExpressionArmCause { + ref prior_arms, + .. + }) => { + diag.multipart_suggestion_verbose( + "consider `await`ing on the `Future`", + prior_arms + .iter() + .map(|arm| (arm.shrink_to_hi(), ".await".to_string())) + .collect(), + Applicability::MaybeIncorrect, + ); + } + _ => {} + }, _ => {} } } diff --git a/src/test/ui/async-await/suggest-missing-await.rs b/src/test/ui/async-await/suggest-missing-await.rs index 352a88ac10cd5..df74df79d9f47 100644 --- a/src/test/ui/async-await/suggest-missing-await.rs +++ b/src/test/ui/async-await/suggest-missing-await.rs @@ -26,4 +26,32 @@ async fn suggest_await_in_async_fn_return() { //~| SUGGESTION .await } +#[allow(unused)] +async fn suggest_await_on_if() { + let _x = if true { + dummy() + //~^ HELP consider `await`ing on the `Future` + } else { + dummy().await + //~^ ERROR `if` and `else` have incompatible types [E0308] + }; +} + +#[allow(unused)] +async fn suggest_await_on_previous_match_arms() { + let _x = match 0usize { + 0 => dummy(), //~ HELP consider `await`ing on the `Future` + 1 => dummy(), + 2 => dummy().await, + //~^ `match` arms have incompatible types [E0308] + }; +} + +#[allow(unused)] +async fn suggest_await_on_match_expr() { + let _x = match dummy() { //~ HELP consider `await`ing on the `Future` + () => {} //~ ERROR mismatched types [E0308] + }; +} + fn main() {} diff --git a/src/test/ui/async-await/suggest-missing-await.stderr b/src/test/ui/async-await/suggest-missing-await.stderr index 08868a04657c4..aefe3096fd9b2 100644 --- a/src/test/ui/async-await/suggest-missing-await.stderr +++ b/src/test/ui/async-await/suggest-missing-await.stderr @@ -38,6 +38,74 @@ help: consider using a semicolon here LL | dummy(); | + -error: aborting due to 2 previous errors +error[E0308]: `if` and `else` have incompatible types + --> $DIR/suggest-missing-await.rs:35:9 + | +LL | let _x = if true { + | ______________- +LL | | dummy() + | | ------- expected because of this +LL | | +LL | | } else { +LL | | dummy().await + | | ^^^^^^^^^^^^^ expected opaque type, found `()` +LL | | +LL | | }; + | |_____- `if` and `else` have incompatible types + | + = note: expected type `impl Future` + found unit type `()` +help: consider `await`ing on the `Future` + | +LL | dummy().await + | ++++++ + +error[E0308]: `match` arms have incompatible types + --> $DIR/suggest-missing-await.rs:45:14 + | +LL | let _x = match 0usize { + | ______________- +LL | | 0 => dummy(), + | | ------- this is found to be of type `impl Future` +LL | | 1 => dummy(), + | | ------- this is found to be of type `impl Future` +LL | | 2 => dummy().await, + | | ^^^^^^^^^^^^^ expected opaque type, found `()` +LL | | +LL | | }; + | |_____- `match` arms have incompatible types + | +note: while checking the return type of the `async fn` + --> $DIR/suggest-missing-await.rs:18:18 + | +LL | async fn dummy() {} + | ^ checked the `Output` of this `async fn`, expected opaque type + = note: expected opaque type `impl Future` + found unit type `()` +help: consider `await`ing on the `Future` + | +LL ~ 0 => dummy().await, +LL ~ 1 => dummy().await, + | + +error[E0308]: mismatched types + --> $DIR/suggest-missing-await.rs:53:9 + | +LL | () => {} + | ^^ expected opaque type, found `()` + | +note: while checking the return type of the `async fn` + --> $DIR/suggest-missing-await.rs:18:18 + | +LL | async fn dummy() {} + | ^ checked the `Output` of this `async fn`, expected opaque type + = note: expected opaque type `impl Future` + found unit type `()` +help: consider `await`ing on the `Future` + | +LL | let _x = match dummy().await { + | ++++++ + +error: aborting due to 5 previous errors For more information about this error, try `rustc --explain E0308`.