Revert "Remove #![feature(never_type)] from tests."

This reverts commit 8f6197f.

src/test/codegen/enum-debug-niche-2.rs

@@ -12,6 +12,8 @@
 // CHECK: {{.*}}DIDerivedType{{.*}}tag: DW_TAG_member,{{.*}}name: "Placeholder",{{.*}}extraData: i64 4294967295{{[,)].*}}
 // CHECK: {{.*}}DIDerivedType{{.*}}tag: DW_TAG_member,{{.*}}name: "Error",{{.*}}extraData: i64 0{{[,)].*}}
 
+#![feature(never_type)]
+
 #[derive(Copy, Clone)]
 pub struct Entity {
     private: std::num::NonZeroU32,

src/test/mir-opt/uninhabited-enum.rs

@@ -1,3 +1,5 @@
+#![feature(never_type)]
+
 pub enum Void {}
 
 #[no_mangle]

src/test/ui/binding/empty-types-in-patterns.rs

@@ -1,5 +1,5 @@
 // run-pass
-#![feature(never_type_fallback)]
+#![feature(never_type, never_type_fallback)]
 #![feature(exhaustive_patterns)]
 #![feature(slice_patterns)]
 #![allow(unreachable_patterns)]

src/test/ui/borrowck/assign-never-type.rs

@@ -2,6 +2,8 @@
 
 // check-pass
 
+#![feature(never_type)]
+
 pub fn main() {
     loop {
         match None {

src/test/ui/break-while-condition.rs

@@ -1,3 +1,5 @@
+#![feature(never_type)]
+
 fn main() {
     // The `if false` expressions are simply to
     // make sure we don't avoid checking everything

src/test/ui/break-while-condition.stderr

@@ -1,5 +1,5 @@
 error[E0308]: mismatched types
-  --> $DIR/break-while-condition.rs:7:20
+  --> $DIR/break-while-condition.rs:9:20
    |
 LL |           let _: ! = {
    |  ____________________^
@@ -11,7 +11,7 @@ LL | |         };
            found unit type `()`
 
 error[E0308]: mismatched types
-  --> $DIR/break-while-condition.rs:14:13
+  --> $DIR/break-while-condition.rs:16:13
    |
 LL | /             while false {
 LL | |                 break
@@ -22,7 +22,7 @@ LL | |             }
            found unit type `()`
 
 error[E0308]: mismatched types
-  --> $DIR/break-while-condition.rs:22:13
+  --> $DIR/break-while-condition.rs:24:13
    |
 LL | /             while false {
 LL | |                 return

src/test/ui/coercion/coerce-issue-49593-box-never.rs

@@ -1,5 +1,5 @@
 // check-pass
-#![feature(never_type_fallback)]
+#![feature(never_type, never_type_fallback)]
 #![allow(unreachable_code)]
 
 use std::error::Error;

src/test/ui/coercion/coerce-to-bang-cast.rs

@@ -1,3 +1,5 @@
+#![feature(never_type)]
+
 fn foo(x: usize, y: !, z: usize) { }
 
 fn cast_a() {

src/test/ui/coercion/coerce-to-bang-cast.stderr

@@ -1,13 +1,13 @@
 error[E0605]: non-primitive cast: `i32` as `!`
-  --> $DIR/coerce-to-bang-cast.rs:4:13
+  --> $DIR/coerce-to-bang-cast.rs:6:13
    |
 LL |     let y = {return; 22} as !;
    |             ^^^^^^^^^^^^^^^^^
    |
    = note: an `as` expression can only be used to convert between primitive types. Consider using the `From` trait
 
 error[E0605]: non-primitive cast: `i32` as `!`
-  --> $DIR/coerce-to-bang-cast.rs:9:13
+  --> $DIR/coerce-to-bang-cast.rs:11:13
    |
 LL |     let y = 22 as !;
    |             ^^^^^^^

src/test/ui/coercion/coerce-to-bang.rs

@@ -1,3 +1,5 @@
+#![feature(never_type)]
+
 fn foo(x: usize, y: !, z: usize) { }
 
 fn call_foo_a() {

src/test/ui/coercion/coerce-to-bang.stderr

@@ -1,5 +1,5 @@
 error[E0308]: mismatched types
-  --> $DIR/coerce-to-bang.rs:4:17
+  --> $DIR/coerce-to-bang.rs:6:17
    |
 LL |     foo(return, 22, 44);
    |                 ^^ expected `!`, found integer
@@ -8,7 +8,7 @@ LL |     foo(return, 22, 44);
               found type `{integer}`
 
 error[E0308]: mismatched types
-  --> $DIR/coerce-to-bang.rs:16:13
+  --> $DIR/coerce-to-bang.rs:18:13
    |
 LL |     foo(22, 44, return);
    |             ^^ expected `!`, found integer
@@ -17,7 +17,7 @@ LL |     foo(22, 44, return);
               found type `{integer}`
 
 error[E0308]: mismatched types
-  --> $DIR/coerce-to-bang.rs:24:12
+  --> $DIR/coerce-to-bang.rs:26:12
    |
 LL |     foo(a, b, c); // ... and hence a reference to `a` is expected to diverge.
    |            ^ expected `!`, found integer
@@ -26,7 +26,7 @@ LL |     foo(a, b, c); // ... and hence a reference to `a` is expected to diverg
               found type `{integer}`
 
 error[E0308]: mismatched types
-  --> $DIR/coerce-to-bang.rs:34:12
+  --> $DIR/coerce-to-bang.rs:36:12
    |
 LL |     foo(a, b, c);
    |            ^ expected `!`, found integer
@@ -35,7 +35,7 @@ LL |     foo(a, b, c);
               found type `{integer}`
 
 error[E0308]: mismatched types
-  --> $DIR/coerce-to-bang.rs:43:12
+  --> $DIR/coerce-to-bang.rs:45:12
    |
 LL |     foo(a, b, c);
    |            ^ expected `!`, found integer
@@ -44,7 +44,7 @@ LL |     foo(a, b, c);
               found type `{integer}`
 
 error[E0308]: mismatched types
-  --> $DIR/coerce-to-bang.rs:48:21
+  --> $DIR/coerce-to-bang.rs:50:21
    |
 LL |     let x: [!; 2] = [return, 22];
    |            ------   ^^^^^^^^^^^^ expected `!`, found integer
@@ -55,7 +55,7 @@ LL |     let x: [!; 2] = [return, 22];
               found array `[{integer}; 2]`
 
 error[E0308]: mismatched types
-  --> $DIR/coerce-to-bang.rs:53:22
+  --> $DIR/coerce-to-bang.rs:55:22
    |
 LL |     let x: [!; 2] = [22, return];
    |                      ^^ expected `!`, found integer
@@ -64,7 +64,7 @@ LL |     let x: [!; 2] = [22, return];
               found type `{integer}`
 
 error[E0308]: mismatched types
-  --> $DIR/coerce-to-bang.rs:58:37
+  --> $DIR/coerce-to-bang.rs:60:37
    |
 LL |     let x: (usize, !, usize) = (22, 44, 66);
    |                                     ^^ expected `!`, found integer
@@ -73,7 +73,7 @@ LL |     let x: (usize, !, usize) = (22, 44, 66);
               found type `{integer}`
 
 error[E0308]: mismatched types
-  --> $DIR/coerce-to-bang.rs:63:41
+  --> $DIR/coerce-to-bang.rs:65:41
    |
 LL |     let x: (usize, !, usize) = (return, 44, 66);
    |                                         ^^ expected `!`, found integer
@@ -82,7 +82,7 @@ LL |     let x: (usize, !, usize) = (return, 44, 66);
               found type `{integer}`
 
 error[E0308]: mismatched types
-  --> $DIR/coerce-to-bang.rs:74:37
+  --> $DIR/coerce-to-bang.rs:76:37
    |
 LL |     let x: (usize, !, usize) = (22, 44, return);
    |                                     ^^ expected `!`, found integer

src/test/ui/consts/validate_never_arrays.rs

@@ -1,4 +1,4 @@
-#![feature(const_raw_ptr_deref)]
+#![feature(const_raw_ptr_deref, never_type)]
 
 const FOO: &[!; 1] = unsafe { &*(1_usize as *const [!; 1]) }; //~ ERROR undefined behavior
 

src/test/ui/empty/empty-never-array.rs

@@ -1,3 +1,5 @@
+#![feature(never_type)]
+
 enum Helper<T, U> {
     T(T, [!; 0]),
     #[allow(dead_code)]

src/test/ui/empty/empty-never-array.stderr

@@ -1,5 +1,5 @@
 error[E0005]: refutable pattern in local binding: `T(_, _)` not covered
-  --> $DIR/empty-never-array.rs:8:9
+  --> $DIR/empty-never-array.rs:10:9
    |
 LL | / enum Helper<T, U> {
 LL | |     T(T, [!; 0]),
@@ -20,7 +20,7 @@ LL |     if let Helper::U(u) = Helper::T(t, []) { /* */ }
    |
 
 error[E0381]: use of possibly-uninitialized variable: `u`
-  --> $DIR/empty-never-array.rs:10:5
+  --> $DIR/empty-never-array.rs:12:5
    |
 LL |     u
    |     ^ use of possibly-uninitialized `u`

src/test/ui/feature-gates/feature-gate-exhaustive-patterns.rs

@@ -1,3 +1,5 @@
+#![feature(never_type)]
+
 fn foo() -> Result<u32, !> {
     Ok(123)
 }

src/test/ui/feature-gates/feature-gate-exhaustive-patterns.stderr

@@ -1,5 +1,5 @@
 error[E0005]: refutable pattern in local binding: `Err(_)` not covered
-  --> $DIR/feature-gate-exhaustive-patterns.rs:6:9
+  --> $DIR/feature-gate-exhaustive-patterns.rs:8:9
    |
 LL |     let Ok(_x) = foo();
    |         ^^^^^^ pattern `Err(_)` not covered

src/test/ui/feature-gates/feature-gate-never_type.rs

@@ -0,0 +1,17 @@
+// Test that ! errors when used in illegal positions with feature(never_type) disabled
+
+trait Foo {
+    type Wub;
+}
+
+type Ma = (u32, !, i32); //~ ERROR type is experimental
+type Meeshka = Vec<!>; //~ ERROR type is experimental
+type Mow = &'static fn(!) -> !; //~ ERROR type is experimental
+type Skwoz = &'static mut !; //~ ERROR type is experimental
+
+impl Foo for Meeshka {
+    type Wub = !; //~ ERROR type is experimental
+}
+
+fn main() {
+}

src/test/ui/feature-gates/feature-gate-never_type.stderr

@@ -0,0 +1,48 @@
+error[E0658]: The `!` type is experimental
+  --> $DIR/feature-gate-never_type.rs:7:17
+   |
+LL | type Ma = (u32, !, i32);
+   |                 ^
+   |
+   = note: for more information, see https://github.com/rust-lang/rust/issues/35121
+   = help: add `#![feature(never_type)]` to the crate attributes to enable
+
+error[E0658]: The `!` type is experimental
+  --> $DIR/feature-gate-never_type.rs:8:20
+   |
+LL | type Meeshka = Vec<!>;
+   |                    ^
+   |
+   = note: for more information, see https://github.com/rust-lang/rust/issues/35121
+   = help: add `#![feature(never_type)]` to the crate attributes to enable
+
+error[E0658]: The `!` type is experimental
+  --> $DIR/feature-gate-never_type.rs:9:24
+   |
+LL | type Mow = &'static fn(!) -> !;
+   |                        ^
+   |
+   = note: for more information, see https://github.com/rust-lang/rust/issues/35121
+   = help: add `#![feature(never_type)]` to the crate attributes to enable
+
+error[E0658]: The `!` type is experimental
+  --> $DIR/feature-gate-never_type.rs:10:27
+   |
+LL | type Skwoz = &'static mut !;
+   |                           ^
+   |
+   = note: for more information, see https://github.com/rust-lang/rust/issues/35121
+   = help: add `#![feature(never_type)]` to the crate attributes to enable
+
+error[E0658]: The `!` type is experimental
+  --> $DIR/feature-gate-never_type.rs:13:16
+   |
+LL |     type Wub = !;
+   |                ^
+   |
+   = note: for more information, see https://github.com/rust-lang/rust/issues/35121
+   = help: add `#![feature(never_type)]` to the crate attributes to enable
+
+error: aborting due to 5 previous errors
+
+For more information about this error, try `rustc --explain E0658`.

src/test/ui/for-loop-while/loop-break-value.rs

@@ -1,6 +1,7 @@
 // run-pass
 
 #![allow(unreachable_code)]
+#![feature(never_type)]
 
 #[allow(unused)]
 fn never_returns() {

src/test/ui/lint/must_use-unit.rs

@@ -1,3 +1,4 @@
+#![feature(never_type)]
 #![deny(unused_must_use)]
 
 #[must_use]

src/test/ui/lint/must_use-unit.stderr

@@ -1,17 +1,17 @@
 error: unused return value of `foo` that must be used
-  --> $DIR/must_use-unit.rs:12:5
+  --> $DIR/must_use-unit.rs:13:5
    |
 LL |     foo();
    |     ^^^^^^
    |
 note: lint level defined here
-  --> $DIR/must_use-unit.rs:1:9
+  --> $DIR/must_use-unit.rs:2:9
    |
 LL | #![deny(unused_must_use)]
    |         ^^^^^^^^^^^^^^^
 
 error: unused return value of `bar` that must be used
-  --> $DIR/must_use-unit.rs:14:5
+  --> $DIR/must_use-unit.rs:15:5
    |
 LL |     bar();
    |     ^^^^^^

src/test/ui/lint/uninitialized-zeroed.rs

@@ -2,7 +2,7 @@
 // This test checks that calling `mem::{uninitialized,zeroed}` with certain types results
 // in a lint.
 
-#![feature(rustc_attrs)]
+#![feature(never_type, rustc_attrs)]
 #![allow(deprecated)]
 #![deny(invalid_value)]
 

src/test/ui/loops/loop-break-value.rs

@@ -1,3 +1,5 @@
+#![feature(never_type)]
+
 fn main() {
     let val: ! = loop { break break; };
     //~^ ERROR mismatched types