rebase blessing

WaffleLapkin · WaffleLapkin · commit ea98e42bfd7e · 2024-06-13T14:43:16.000+02:00
diff --git a/compiler/rustc_hir_typeck/src/fallback.rs b/compiler/rustc_hir_typeck/src/fallback.rs
@@ -477,7 +477,7 @@ impl<'tcx> FnCtxt<'_, 'tcx> {
         behavior: DivergingFallbackBehavior,
         diverging_vids: &[ty::TyVid],
     ) {
-        let DivergingFallbackBehavior::FallbackToUnit = behavior else { return };
+        let DivergingFallbackBehavior::ToUnit = behavior else { return };
 
         // Fallback happens if and only if there are diverging variables
         if diverging_vids.is_empty() {
diff --git a/tests/ui/editions/never-type-fallback-breaking.e2021.stderr b/tests/ui/editions/never-type-fallback-breaking.e2021.stderr
@@ -0,0 +1,23 @@
+warning: this function depends on never type fallback being `()`
+  --> $DIR/never-type-fallback-breaking.rs:15:1
+   |
+LL | fn m() {
+   | ^^^^^^
+   |
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #123748 <https://github.com/rust-lang/rust/issues/123748>
+   = help: specify the types explicitly
+   = note: `#[warn(dependency_on_unit_never_type_fallback)]` on by default
+
+warning: this function depends on never type fallback being `()`
+  --> $DIR/never-type-fallback-breaking.rs:27:1
+   |
+LL | fn q() -> Option<()> {
+   | ^^^^^^^^^^^^^^^^^^^^
+   |
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #123748 <https://github.com/rust-lang/rust/issues/123748>
+   = help: specify the types explicitly
+
+warning: 2 warnings emitted
+
diff --git a/tests/ui/editions/never-type-fallback-breaking.e2024.stderr b/tests/ui/editions/never-type-fallback-breaking.e2024.stderr
@@ -1,5 +1,5 @@
 error[E0277]: the trait bound `!: Default` is not satisfied
-  --> $DIR/never-type-fallback-breaking.rs:17:17
+  --> $DIR/never-type-fallback-breaking.rs:19:17
    |
 LL |         true => Default::default(),
    |                 ^^^^^^^^^^^^^^^^^^ the trait `Default` is not implemented for `!`
@@ -8,15 +8,15 @@ LL |         true => Default::default(),
    = help: did you intend to use the type `()` here instead?
 
 error[E0277]: the trait bound `!: Default` is not satisfied
-  --> $DIR/never-type-fallback-breaking.rs:30:5
+  --> $DIR/never-type-fallback-breaking.rs:34:5
    |
 LL |     deserialize()?;
    |     ^^^^^^^^^^^^^ the trait `Default` is not implemented for `!`
    |
    = note: this error might have been caused by changes to Rust's type-inference algorithm (see issue #48950 <https://github.com/rust-lang/rust/issues/48950> for more information)
    = help: did you intend to use the type `()` here instead?
 note: required by a bound in `deserialize`
-  --> $DIR/never-type-fallback-breaking.rs:26:23
+  --> $DIR/never-type-fallback-breaking.rs:30:23
    |
 LL |     fn deserialize<T: Default>() -> Option<T> {
    |                       ^^^^^^^ required by this bound in `deserialize`
diff --git a/tests/ui/editions/never-type-fallback-breaking.rs b/tests/ui/editions/never-type-fallback-breaking.rs
@@ -13,6 +13,8 @@ fn main() {
 }
 
 fn m() {
+    //[e2021]~^ this function depends on never type fallback being `()`
+    //[e2021]~| this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
     let x = match true {
         true => Default::default(),
         //[e2024]~^ error: the trait bound `!: Default` is not satisfied
@@ -23,6 +25,8 @@ fn m() {
 }
 
 fn q() -> Option<()> {
+    //[e2021]~^ this function depends on never type fallback being `()`
+    //[e2021]~| this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
     fn deserialize<T: Default>() -> Option<T> {
         Some(T::default())
     }

Original file line number	Diff line number	Diff line change
`@@ -1,5 +1,5 @@`
`1`	`1`	error[E0277]: the trait bound `!: Default` is not satisfied
`2`		`- --> $DIR/never-type-fallback-breaking.rs:17:17`
	`2`	`+ --> $DIR/never-type-fallback-breaking.rs:19:17`
`3`	`3`	`\|`
`4`	`4`	`LL \| true => Default::default(),`
`5`	`5`	\| ^^^^^^^^^^^^^^^^^^ the trait `Default` is not implemented for `!`
`@@ -8,15 +8,15 @@ LL \| true => Default::default(),`
`8`	`8`	= help: did you intend to use the type `()` here instead?
`9`	`9`
`10`	`10`	error[E0277]: the trait bound `!: Default` is not satisfied
`11`		`- --> $DIR/never-type-fallback-breaking.rs:30:5`
	`11`	`+ --> $DIR/never-type-fallback-breaking.rs:34:5`
`12`	`12`	`\|`
`13`	`13`	`LL \| deserialize()?;`
`14`	`14`	\| ^^^^^^^^^^^^^ the trait `Default` is not implemented for `!`
`15`	`15`	`\|`
`16`	`16`	`= note: this error might have been caused by changes to Rust's type-inference algorithm (see issue #48950 <https://github.com/rust-lang/rust/issues/48950> for more information)`
`17`	`17`	= help: did you intend to use the type `()` here instead?
`18`	`18`	note: required by a bound in `deserialize`
`19`		`- --> $DIR/never-type-fallback-breaking.rs:26:23`
	`19`	`+ --> $DIR/never-type-fallback-breaking.rs:30:23`
`20`	`20`	`\|`
`21`	`21`	`LL \| fn deserialize<T: Default>() -> Option<T> {`
`22`	`22`	\| ^^^^^^^ required by this bound in `deserialize`
Original file line number	Diff line number	Diff line change
`@@ -13,6 +13,8 @@ fn main() {`
`13`	`13`	`}`
`14`	`14`
`15`	`15`	`fn m() {`
	`16`	+ //[e2021]~^ this function depends on never type fallback being `()`
	`17`	`+ //[e2021]~\| this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!`
`16`	`18`	`let x = match true {`
`17`	`19`	`true => Default::default(),`
`18`	`20`	//[e2024]~^ error: the trait bound `!: Default` is not satisfied
`@@ -23,6 +25,8 @@ fn m() {`
`23`	`25`	`}`
`24`	`26`
`25`	`27`	`fn q() -> Option<()> {`
	`28`	+ //[e2021]~^ this function depends on never type fallback being `()`
	`29`	`+ //[e2021]~\| this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!`
`26`	`30`	`fn deserialize<T: Default>() -> Option<T> {`
`27`	`31`	`Some(T::default())`
`28`	`32`	`}`