diff options
4 files changed, 82 insertions, 2 deletions
diff --git a/src/librustc/infer/error_reporting/mod.rs b/src/librustc/infer/error_reporting/mod.rs index afc83771fe1..1377176bc7f 100644 --- a/src/librustc/infer/error_reporting/mod.rs +++ b/src/librustc/infer/error_reporting/mod.rs @@ -518,7 +518,17 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> { } else { err.span_label(arm_span, msg); } - } + }, + hir::MatchSource::TryDesugar => { // Issue #51632 + if let Ok(try_snippet) = self.tcx.sess.codemap().span_to_snippet(arm_span) { + err.span_suggestion_with_applicability( + arm_span, + "try wrapping with a success variant", + format!("Ok({})", try_snippet), + Applicability::MachineApplicable + ); + } + }, _ => { let msg = "match arm with an incompatible type"; if self.tcx.sess.codemap().is_multiline(arm_span) { @@ -1312,7 +1322,12 @@ impl<'tcx> ObligationCause<'tcx> { match self.code { CompareImplMethodObligation { .. } => Error0308("method not compatible with trait"), MatchExpressionArm { source, .. } => Error0308(match source { - hir::MatchSource::IfLetDesugar { .. } => "`if let` arms have incompatible types", + hir::MatchSource::IfLetDesugar { .. } => { + "`if let` arms have incompatible types" + }, + hir::MatchSource::TryDesugar => { + "try expression alternatives have incompatible types" + }, _ => "match arms have incompatible types", }), IfExpression => Error0308("if and else have incompatible types"), diff --git a/src/test/ui/issue-51632-try-desugar-incompatible-types.fixed b/src/test/ui/issue-51632-try-desugar-incompatible-types.fixed new file mode 100644 index 00000000000..016cff914bd --- /dev/null +++ b/src/test/ui/issue-51632-try-desugar-incompatible-types.fixed @@ -0,0 +1,25 @@ +// Copyright 2018 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or +// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license +// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +// run-rustfix + +#![allow(dead_code)] + +fn missing_discourses() -> Result<isize, ()> { + Ok(1) +} + +fn forbidden_narratives() -> Result<isize, ()> { + Ok(missing_discourses()?) + //~^ ERROR try expression alternatives have incompatible types + //~| HELP try wrapping with a success variant +} + +fn main() {} diff --git a/src/test/ui/issue-51632-try-desugar-incompatible-types.rs b/src/test/ui/issue-51632-try-desugar-incompatible-types.rs new file mode 100644 index 00000000000..315773a85f0 --- /dev/null +++ b/src/test/ui/issue-51632-try-desugar-incompatible-types.rs @@ -0,0 +1,25 @@ +// Copyright 2018 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or +// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license +// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +// run-rustfix + +#![allow(dead_code)] + +fn missing_discourses() -> Result<isize, ()> { + Ok(1) +} + +fn forbidden_narratives() -> Result<isize, ()> { + missing_discourses()? + //~^ ERROR try expression alternatives have incompatible types + //~| HELP try wrapping with a success variant +} + +fn main() {} diff --git a/src/test/ui/issue-51632-try-desugar-incompatible-types.stderr b/src/test/ui/issue-51632-try-desugar-incompatible-types.stderr new file mode 100644 index 00000000000..a50af5624c0 --- /dev/null +++ b/src/test/ui/issue-51632-try-desugar-incompatible-types.stderr @@ -0,0 +1,15 @@ +error[E0308]: try expression alternatives have incompatible types + --> $DIR/issue-51632-try-desugar-incompatible-types.rs:20:5 + | +LL | missing_discourses()? + | ^^^^^^^^^^^^^^^^^^^^^ + | | + | expected enum `std::result::Result`, found isize + | help: try wrapping with a success variant: `Ok(missing_discourses()?)` + | + = note: expected type `std::result::Result<isize, ()>` + found type `isize` + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0308`. |