Move /src/test to /tests

29 files changed, 1023 insertions, 0 deletions

diff --git a/tests/ui/empty/auxiliary/empty-struct.rs b/tests/ui/empty/auxiliary/empty-struct.rs
new file mode 100644
index 00000000000..3fb40f6bfa9
--- /dev/null
+++ b/tests/ui/empty/auxiliary/empty-struct.rs
@@ -0,0 +1,9 @@
+pub struct XEmpty1 {}
+pub struct XEmpty2;
+pub struct XEmpty6();
+
+pub enum XE {
+    XEmpty3 {},
+    XEmpty4,
+    XEmpty5(),
+}
diff --git a/tests/ui/empty/auxiliary/two_macros.rs b/tests/ui/empty/auxiliary/two_macros.rs
new file mode 100644
index 00000000000..2330c75c8e0
--- /dev/null
+++ b/tests/ui/empty/auxiliary/two_macros.rs
@@ -0,0 +1,5 @@
+#[macro_export]
+macro_rules! macro_one { () => ("one") }
+
+#[macro_export]
+macro_rules! macro_two { () => ("two") }
diff --git a/tests/ui/empty/empty-attributes.rs b/tests/ui/empty/empty-attributes.rs
new file mode 100644
index 00000000000..d319227b217
--- /dev/null
+++ b/tests/ui/empty/empty-attributes.rs
@@ -0,0 +1,17 @@
+#![feature(lint_reasons)]
+
+#![deny(unused_attributes)]
+#![allow()] //~ ERROR unused attribute
+#![expect()] //~ ERROR unused attribute
+#![warn()] //~ ERROR unused attribute
+#![deny()] //~ ERROR unused attribute
+#![forbid()] //~ ERROR unused attribute
+#![feature()] //~ ERROR unused attribute
+
+#[repr()] //~ ERROR unused attribute
+pub struct S;
+
+#[target_feature()] //~ ERROR unused attribute
+pub unsafe fn foo() {}
+
+fn main() {}
diff --git a/tests/ui/empty/empty-attributes.stderr b/tests/ui/empty/empty-attributes.stderr
new file mode 100644
index 00000000000..01d0d5a6b48
--- /dev/null
+++ b/tests/ui/empty/empty-attributes.stderr
@@ -0,0 +1,71 @@
+error: unused attribute
+  --> $DIR/empty-attributes.rs:11:1
+   |
+LL | #[repr()]
+   | ^^^^^^^^^ help: remove this attribute
+   |
+   = note: attribute `repr` with an empty list has no effect
+note: the lint level is defined here
+  --> $DIR/empty-attributes.rs:3:9
+   |
+LL | #![deny(unused_attributes)]
+   |         ^^^^^^^^^^^^^^^^^
+
+error: unused attribute
+  --> $DIR/empty-attributes.rs:14:1
+   |
+LL | #[target_feature()]
+   | ^^^^^^^^^^^^^^^^^^^ help: remove this attribute
+   |
+   = note: attribute `target_feature` with an empty list has no effect
+
+error: unused attribute
+  --> $DIR/empty-attributes.rs:4:1
+   |
+LL | #![allow()]
+   | ^^^^^^^^^^^ help: remove this attribute
+   |
+   = note: attribute `allow` with an empty list has no effect
+
+error: unused attribute
+  --> $DIR/empty-attributes.rs:5:1
+   |
+LL | #![expect()]
+   | ^^^^^^^^^^^^ help: remove this attribute
+   |
+   = note: attribute `expect` with an empty list has no effect
+
+error: unused attribute
+  --> $DIR/empty-attributes.rs:6:1
+   |
+LL | #![warn()]
+   | ^^^^^^^^^^ help: remove this attribute
+   |
+   = note: attribute `warn` with an empty list has no effect
+
+error: unused attribute
+  --> $DIR/empty-attributes.rs:7:1
+   |
+LL | #![deny()]
+   | ^^^^^^^^^^ help: remove this attribute
+   |
+   = note: attribute `deny` with an empty list has no effect
+
+error: unused attribute
+  --> $DIR/empty-attributes.rs:8:1
+   |
+LL | #![forbid()]
+   | ^^^^^^^^^^^^ help: remove this attribute
+   |
+   = note: attribute `forbid` with an empty list has no effect
+
+error: unused attribute
+  --> $DIR/empty-attributes.rs:9:1
+   |
+LL | #![feature()]
+   | ^^^^^^^^^^^^^ help: remove this attribute
+   |
+   = note: attribute `feature` with an empty list has no effect
+
+error: aborting due to 8 previous errors
+
diff --git a/tests/ui/empty/empty-comment.rs b/tests/ui/empty/empty-comment.rs
new file mode 100644
index 00000000000..174274d28b0
--- /dev/null
+++ b/tests/ui/empty/empty-comment.rs
@@ -0,0 +1,11 @@
+// `/**/` was previously regarded as a doc comment because it starts with `/**` and ends with `*/`.
+// This could break some internal logic that assumes the length of a doc comment is at least 5,
+// leading to an ICE.
+
+macro_rules! one_arg_macro {
+    ($fmt:expr) => (print!(concat!($fmt, "\n")));
+}
+
+fn main() {
+    one_arg_macro!(/**/); //~ ERROR unexpected end
+}
diff --git a/tests/ui/empty/empty-comment.stderr b/tests/ui/empty/empty-comment.stderr
new file mode 100644
index 00000000000..7cc8d8fe922
--- /dev/null
+++ b/tests/ui/empty/empty-comment.stderr
@@ -0,0 +1,17 @@
+error: unexpected end of macro invocation
+  --> $DIR/empty-comment.rs:10:5
+   |
+LL | macro_rules! one_arg_macro {
+   | -------------------------- when calling this macro
+...
+LL |     one_arg_macro!(/**/);
+   |     ^^^^^^^^^^^^^^^^^^^^ missing tokens in macro arguments
+   |
+note: while trying to match meta-variable `$fmt:expr`
+  --> $DIR/empty-comment.rs:6:6
+   |
+LL |     ($fmt:expr) => (print!(concat!($fmt, "\n")));
+   |      ^^^^^^^^^
+
+error: aborting due to previous error
+
diff --git a/tests/ui/empty/empty-linkname.rs b/tests/ui/empty/empty-linkname.rs
new file mode 100644
index 00000000000..7113d913cd0
--- /dev/null
+++ b/tests/ui/empty/empty-linkname.rs
@@ -0,0 +1,4 @@
+#[link(name = "")] //~ ERROR: link name must not be empty
+extern "C" {}
+
+fn main() {}
diff --git a/tests/ui/empty/empty-linkname.stderr b/tests/ui/empty/empty-linkname.stderr
new file mode 100644
index 00000000000..adcf3670d1d
--- /dev/null
+++ b/tests/ui/empty/empty-linkname.stderr
@@ -0,0 +1,9 @@
+error[E0454]: link name must not be empty
+  --> $DIR/empty-linkname.rs:1:15
+   |
+LL | #[link(name = "")]
+   |               ^^ empty link name
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0454`.
diff --git a/tests/ui/empty/empty-macro-use.rs b/tests/ui/empty/empty-macro-use.rs
new file mode 100644
index 00000000000..846004e661d
--- /dev/null
+++ b/tests/ui/empty/empty-macro-use.rs
@@ -0,0 +1,9 @@
+// aux-build:two_macros.rs
+
+#[macro_use()]
+extern crate two_macros;
+
+pub fn main() {
+    macro_two!();
+    //~^ ERROR cannot find macro
+}
diff --git a/tests/ui/empty/empty-macro-use.stderr b/tests/ui/empty/empty-macro-use.stderr
new file mode 100644
index 00000000000..700f6616af4
--- /dev/null
+++ b/tests/ui/empty/empty-macro-use.stderr
@@ -0,0 +1,11 @@
+error: cannot find macro `macro_two` in this scope
+  --> $DIR/empty-macro-use.rs:7:5
+   |
+LL |     macro_two!();
+   |     ^^^^^^^^^
+   |
+   = note: consider importing this macro:
+           two_macros::macro_two
+
+error: aborting due to previous error
+
diff --git a/tests/ui/empty/empty-never-array.rs b/tests/ui/empty/empty-never-array.rs
new file mode 100644
index 00000000000..3de2b1a78a3
--- /dev/null
+++ b/tests/ui/empty/empty-never-array.rs
@@ -0,0 +1,17 @@
+#![feature(never_type)]
+
+enum Helper<T, U> {
+    T(T, [!; 0]),
+    #[allow(dead_code)]
+    U(U),
+}
+
+fn transmute<T, U>(t: T) -> U {
+    let Helper::U(u) = Helper::T(t, []);
+    //~^ ERROR refutable pattern in local binding: `Helper::T(_, _)` not covered
+    u
+}
+
+fn main() {
+    println!("{:?}", transmute::<&str, (*const u8, u64)>("type safety"));
+}
diff --git a/tests/ui/empty/empty-never-array.stderr b/tests/ui/empty/empty-never-array.stderr
new file mode 100644
index 00000000000..adf78274368
--- /dev/null
+++ b/tests/ui/empty/empty-never-array.stderr
@@ -0,0 +1,28 @@
+error[E0005]: refutable pattern in local binding: `Helper::T(_, _)` not covered
+  --> $DIR/empty-never-array.rs:10:9
+   |
+LL |     let Helper::U(u) = Helper::T(t, []);
+   |         ^^^^^^^^^^^^ pattern `Helper::T(_, _)` not covered
+   |
+   = note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant
+   = note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html
+note: `Helper<T, U>` defined here
+  --> $DIR/empty-never-array.rs:4:5
+   |
+LL | enum Helper<T, U> {
+   |      ------
+LL |     T(T, [!; 0]),
+   |     ^ not covered
+   = note: the matched value is of type `Helper<T, U>`
+help: you might want to use `if let` to ignore the variant that isn't matched
+   |
+LL |     let u = if let Helper::U(u) = Helper::T(t, []) { u } else { todo!() };
+   |     ++++++++++                                     ++++++++++++++++++++++
+help: alternatively, you might want to use let else to handle the variant that isn't matched
+   |
+LL |     let Helper::U(u) = Helper::T(t, []) else { todo!() };
+   |                                         ++++++++++++++++
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0005`.
diff --git a/tests/ui/empty/empty-struct-braces-expr.rs b/tests/ui/empty/empty-struct-braces-expr.rs
new file mode 100644
index 00000000000..2aab3e7772c
--- /dev/null
+++ b/tests/ui/empty/empty-struct-braces-expr.rs
@@ -0,0 +1,29 @@
+// Can't use empty braced struct as constant or constructor function
+
+// aux-build:empty-struct.rs
+
+extern crate empty_struct;
+use empty_struct::*;
+
+struct Empty1 {}
+
+enum E {
+    Empty3 {}
+}
+
+fn main() {
+    let e1 = Empty1; //~ ERROR expected value, found struct `Empty1`
+    let e1 = Empty1();
+    //~^ ERROR expected function, tuple struct or tuple variant, found struct `Empty1`
+    let e3 = E::Empty3; //~ ERROR expected value, found struct variant `E::Empty3`
+    let e3 = E::Empty3();
+    //~^ ERROR expected value, found struct variant `E::Empty3`
+
+    let xe1 = XEmpty1; //~ ERROR expected value, found struct `XEmpty1`
+    let xe1 = XEmpty1();
+    //~^ ERROR expected function, tuple struct or tuple variant, found struct `XEmpty1`
+    let xe3 = XE::Empty3; //~ ERROR no variant or associated item named `Empty3` found for enum
+    let xe3 = XE::Empty3(); //~ ERROR no variant or associated item named `Empty3` found for enum
+
+    XE::Empty1 {}; //~ ERROR no variant named `Empty1` found for enum `empty_struct::XE`
+}
diff --git a/tests/ui/empty/empty-struct-braces-expr.stderr b/tests/ui/empty/empty-struct-braces-expr.stderr
new file mode 100644
index 00000000000..0e580aedeaa
--- /dev/null
+++ b/tests/ui/empty/empty-struct-braces-expr.stderr
@@ -0,0 +1,130 @@
+error[E0423]: expected value, found struct `Empty1`
+  --> $DIR/empty-struct-braces-expr.rs:15:14
+   |
+LL | struct Empty1 {}
+   | ---------------- `Empty1` defined here
+...
+LL |     let e1 = Empty1;
+   |              ^^^^^^
+   |
+  ::: $DIR/auxiliary/empty-struct.rs:2:1
+   |
+LL | pub struct XEmpty2;
+   | ------------------ similarly named unit struct `XEmpty2` defined here
+   |
+help: use struct literal syntax instead
+   |
+LL |     let e1 = Empty1 {};
+   |              ~~~~~~~~~
+help: a unit struct with a similar name exists
+   |
+LL |     let e1 = XEmpty2;
+   |              ~~~~~~~
+
+error[E0423]: expected value, found struct `XEmpty1`
+  --> $DIR/empty-struct-braces-expr.rs:22:15
+   |
+LL |     let xe1 = XEmpty1;
+   |               ^^^^^^^
+   |
+  ::: $DIR/auxiliary/empty-struct.rs:1:1
+   |
+LL | pub struct XEmpty1 {}
+   | ------------------ `XEmpty1` defined here
+LL | pub struct XEmpty2;
+   | ------------------ similarly named unit struct `XEmpty2` defined here
+   |
+help: use struct literal syntax instead
+   |
+LL |     let xe1 = XEmpty1 {};
+   |               ~~~~~~~~~~
+help: a unit struct with a similar name exists
+   |
+LL |     let xe1 = XEmpty2;
+   |               ~~~~~~~
+
+error[E0423]: expected function, tuple struct or tuple variant, found struct `Empty1`
+  --> $DIR/empty-struct-braces-expr.rs:16:14
+   |
+LL | struct Empty1 {}
+   | ---------------- `Empty1` defined here
+...
+LL |     let e1 = Empty1();
+   |              ^^^^^^^^
+   |
+  ::: $DIR/auxiliary/empty-struct.rs:2:1
+   |
+LL | pub struct XEmpty2;
+   | ------------------ similarly named unit struct `XEmpty2` defined here
+   |
+help: use struct literal syntax instead
+   |
+LL |     let e1 = Empty1 {};
+   |              ~~~~~~~~~
+help: a unit struct with a similar name exists
+   |
+LL |     let e1 = XEmpty2();
+   |              ~~~~~~~
+
+error[E0533]: expected value, found struct variant `E::Empty3`
+  --> $DIR/empty-struct-braces-expr.rs:18:14
+   |
+LL |     let e3 = E::Empty3;
+   |              ^^^^^^^^^ not a value
+
+error[E0533]: expected value, found struct variant `E::Empty3`
+  --> $DIR/empty-struct-braces-expr.rs:19:14
+   |
+LL |     let e3 = E::Empty3();
+   |              ^^^^^^^^^ not a value
+
+error[E0423]: expected function, tuple struct or tuple variant, found struct `XEmpty1`
+  --> $DIR/empty-struct-braces-expr.rs:23:15
+   |
+LL |     let xe1 = XEmpty1();
+   |               ^^^^^^^^^
+   |
+  ::: $DIR/auxiliary/empty-struct.rs:1:1
+   |
+LL | pub struct XEmpty1 {}
+   | ------------------ `XEmpty1` defined here
+LL | pub struct XEmpty2;
+   | ------------------ similarly named unit struct `XEmpty2` defined here
+   |
+help: use struct literal syntax instead
+   |
+LL |     let xe1 = XEmpty1 {};
+   |               ~~~~~~~~~~
+help: a unit struct with a similar name exists
+   |
+LL |     let xe1 = XEmpty2();
+   |               ~~~~~~~
+
+error[E0599]: no variant or associated item named `Empty3` found for enum `XE` in the current scope
+  --> $DIR/empty-struct-braces-expr.rs:25:19
+   |
+LL |     let xe3 = XE::Empty3;
+   |                   ^^^^^^
+   |                   |
+   |                   variant or associated item not found in `XE`
+   |                   help: there is a variant with a similar name: `XEmpty3`
+
+error[E0599]: no variant or associated item named `Empty3` found for enum `XE` in the current scope
+  --> $DIR/empty-struct-braces-expr.rs:26:19
+   |
+LL |     let xe3 = XE::Empty3();
+   |                   ^^^^^^
+   |                   |
+   |                   variant or associated item not found in `XE`
+   |                   help: there is a variant with a similar name: `XEmpty3`
+
+error[E0599]: no variant named `Empty1` found for enum `empty_struct::XE`
+  --> $DIR/empty-struct-braces-expr.rs:28:9
+   |
+LL |     XE::Empty1 {};
+   |         ^^^^^^ help: there is a variant with a similar name: `XEmpty3`
+
+error: aborting due to 9 previous errors
+
+Some errors have detailed explanations: E0423, E0533, E0599.
+For more information about an error, try `rustc --explain E0423`.
diff --git a/tests/ui/empty/empty-struct-braces-pat-1.rs b/tests/ui/empty/empty-struct-braces-pat-1.rs
new file mode 100644
index 00000000000..9bed93f9c15
--- /dev/null
+++ b/tests/ui/empty/empty-struct-braces-pat-1.rs
@@ -0,0 +1,34 @@
+// Can't use empty braced struct as constant pattern
+
+// aux-build:empty-struct.rs
+
+extern crate empty_struct;
+use empty_struct::*;
+
+struct Empty1 {}
+
+enum E {
+    Empty3 {}
+}
+
+fn main() {
+    let e1 = Empty1 {};
+    let e3 = E::Empty3 {};
+    let xe1 = XEmpty1 {};
+    let xe3 = XE::XEmpty3 {};
+
+    match e1 {
+        Empty1 => () // Not an error, `Empty1` is interpreted as a new binding
+    }
+    match e3 {
+        E::Empty3 => ()
+        //~^ ERROR expected unit struct, unit variant or constant, found struct variant `E::Empty3`
+    }
+    match xe1 {
+        XEmpty1 => () // Not an error, `XEmpty1` is interpreted as a new binding
+    }
+    match xe3 {
+        XE::XEmpty3 => ()
+    //~^ ERROR expected unit struct, unit variant or constant, found struct variant `XE::XEmpty3`
+    }
+}
diff --git a/tests/ui/empty/empty-struct-braces-pat-1.stderr b/tests/ui/empty/empty-struct-braces-pat-1.stderr
new file mode 100644
index 00000000000..14e09fc27a0
--- /dev/null
+++ b/tests/ui/empty/empty-struct-braces-pat-1.stderr
@@ -0,0 +1,15 @@
+error[E0533]: expected unit struct, unit variant or constant, found struct variant `E::Empty3`
+  --> $DIR/empty-struct-braces-pat-1.rs:24:9
+   |
+LL |         E::Empty3 => ()
+   |         ^^^^^^^^^ not a unit struct, unit variant or constant
+
+error[E0533]: expected unit struct, unit variant or constant, found struct variant `XE::XEmpty3`
+  --> $DIR/empty-struct-braces-pat-1.rs:31:9
+   |
+LL |         XE::XEmpty3 => ()
+   |         ^^^^^^^^^^^ not a unit struct, unit variant or constant
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0533`.
diff --git a/tests/ui/empty/empty-struct-braces-pat-2.rs b/tests/ui/empty/empty-struct-braces-pat-2.rs
new file mode 100644
index 00000000000..cfe4641f356
--- /dev/null
+++ b/tests/ui/empty/empty-struct-braces-pat-2.rs
@@ -0,0 +1,26 @@
+// Can't use empty braced struct as enum pattern
+
+// aux-build:empty-struct.rs
+
+extern crate empty_struct;
+use empty_struct::*;
+
+struct Empty1 {}
+
+fn main() {
+    let e1 = Empty1 {};
+    let xe1 = XEmpty1 {};
+
+    match e1 {
+        Empty1() => () //~ ERROR expected tuple struct or tuple variant, found struct `Empty1`
+    }
+    match xe1 {
+        XEmpty1() => () //~ ERROR expected tuple struct or tuple variant, found struct `XEmpty1`
+    }
+    match e1 {
+        Empty1(..) => () //~ ERROR expected tuple struct or tuple variant, found struct `Empty1`
+    }
+    match xe1 {
+        XEmpty1(..) => () //~ ERROR expected tuple struct or tuple variant, found struct `XEmpty1`
+    }
+}
diff --git a/tests/ui/empty/empty-struct-braces-pat-2.stderr b/tests/ui/empty/empty-struct-braces-pat-2.stderr
new file mode 100644
index 00000000000..7fb5cb2034a
--- /dev/null
+++ b/tests/ui/empty/empty-struct-braces-pat-2.stderr
@@ -0,0 +1,95 @@
+error[E0532]: expected tuple struct or tuple variant, found struct `Empty1`
+  --> $DIR/empty-struct-braces-pat-2.rs:15:9
+   |
+LL | struct Empty1 {}
+   | ---------------- `Empty1` defined here
+...
+LL |         Empty1() => ()
+   |         ^^^^^^^^
+   |
+  ::: $DIR/auxiliary/empty-struct.rs:3:1
+   |
+LL | pub struct XEmpty6();
+   | ------------------ similarly named tuple struct `XEmpty6` defined here
+   |
+help: use struct pattern syntax instead
+   |
+LL |         Empty1 {} => ()
+   |         ~~~~~~~~~
+help: a tuple struct with a similar name exists
+   |
+LL |         XEmpty6() => ()
+   |         ~~~~~~~
+
+error[E0532]: expected tuple struct or tuple variant, found struct `XEmpty1`
+  --> $DIR/empty-struct-braces-pat-2.rs:18:9
+   |
+LL |         XEmpty1() => ()
+   |         ^^^^^^^^^
+   |
+  ::: $DIR/auxiliary/empty-struct.rs:1:1
+   |
+LL | pub struct XEmpty1 {}
+   | ------------------ `XEmpty1` defined here
+LL | pub struct XEmpty2;
+LL | pub struct XEmpty6();
+   | ------------------ similarly named tuple struct `XEmpty6` defined here
+   |
+help: use struct pattern syntax instead
+   |
+LL |         XEmpty1 {} => ()
+   |         ~~~~~~~~~~
+help: a tuple struct with a similar name exists
+   |
+LL |         XEmpty6() => ()
+   |         ~~~~~~~
+
+error[E0532]: expected tuple struct or tuple variant, found struct `Empty1`
+  --> $DIR/empty-struct-braces-pat-2.rs:21:9
+   |
+LL | struct Empty1 {}
+   | ---------------- `Empty1` defined here
+...
+LL |         Empty1(..) => ()
+   |         ^^^^^^^^^^
+   |
+  ::: $DIR/auxiliary/empty-struct.rs:3:1
+   |
+LL | pub struct XEmpty6();
+   | ------------------ similarly named tuple struct `XEmpty6` defined here
+   |
+help: use struct pattern syntax instead
+   |
+LL |         Empty1 {} => ()
+   |         ~~~~~~~~~
+help: a tuple struct with a similar name exists
+   |
+LL |         XEmpty6(..) => ()
+   |         ~~~~~~~
+
+error[E0532]: expected tuple struct or tuple variant, found struct `XEmpty1`
+  --> $DIR/empty-struct-braces-pat-2.rs:24:9
+   |
+LL |         XEmpty1(..) => ()
+   |         ^^^^^^^^^^^
+   |
+  ::: $DIR/auxiliary/empty-struct.rs:1:1
+   |
+LL | pub struct XEmpty1 {}
+   | ------------------ `XEmpty1` defined here
+LL | pub struct XEmpty2;
+LL | pub struct XEmpty6();
+   | ------------------ similarly named tuple struct `XEmpty6` defined here
+   |
+help: use struct pattern syntax instead
+   |
+LL |         XEmpty1 {} => ()
+   |         ~~~~~~~~~~
+help: a tuple struct with a similar name exists
+   |
+LL |         XEmpty6(..) => ()
+   |         ~~~~~~~
+
+error: aborting due to 4 previous errors
+
+For more information about this error, try `rustc --explain E0532`.
diff --git a/tests/ui/empty/empty-struct-braces-pat-3.rs b/tests/ui/empty/empty-struct-braces-pat-3.rs
new file mode 100644
index 00000000000..54d547eefcc
--- /dev/null
+++ b/tests/ui/empty/empty-struct-braces-pat-3.rs
@@ -0,0 +1,32 @@
+// Can't use empty braced struct as enum pattern
+
+// aux-build:empty-struct.rs
+
+extern crate empty_struct;
+use empty_struct::*;
+
+enum E {
+    Empty3 {}
+}
+
+fn main() {
+    let e3 = E::Empty3 {};
+    let xe3 = XE::XEmpty3 {};
+
+    match e3 {
+        E::Empty3() => ()
+        //~^ ERROR expected tuple struct or tuple variant, found struct variant `E::Empty3`
+    }
+    match xe3 {
+        XE::XEmpty3() => ()
+        //~^ ERROR expected tuple struct or tuple variant, found struct variant `XE::XEmpty3`
+    }
+    match e3 {
+        E::Empty3(..) => ()
+        //~^ ERROR expected tuple struct or tuple variant, found struct variant `E::Empty3`
+    }
+    match xe3 {
+        XE::XEmpty3(..) => ()
+        //~^ ERROR expected tuple struct or tuple variant, found struct variant `XE::XEmpty3
+    }
+}
diff --git a/tests/ui/empty/empty-struct-braces-pat-3.stderr b/tests/ui/empty/empty-struct-braces-pat-3.stderr
new file mode 100644
index 00000000000..00c8b12e6f9
--- /dev/null
+++ b/tests/ui/empty/empty-struct-braces-pat-3.stderr
@@ -0,0 +1,27 @@
+error[E0164]: expected tuple struct or tuple variant, found struct variant `E::Empty3`
+  --> $DIR/empty-struct-braces-pat-3.rs:17:9
+   |
+LL |         E::Empty3() => ()
+   |         ^^^^^^^^^^^ not a tuple struct or tuple variant
+
+error[E0164]: expected tuple struct or tuple variant, found struct variant `XE::XEmpty3`
+  --> $DIR/empty-struct-braces-pat-3.rs:21:9
+   |
+LL |         XE::XEmpty3() => ()
+   |         ^^^^^^^^^^^^^ not a tuple struct or tuple variant
+
+error[E0164]: expected tuple struct or tuple variant, found struct variant `E::Empty3`
+  --> $DIR/empty-struct-braces-pat-3.rs:25:9
+   |
+LL |         E::Empty3(..) => ()
+   |         ^^^^^^^^^^^^^ not a tuple struct or tuple variant
+
+error[E0164]: expected tuple struct or tuple variant, found struct variant `XE::XEmpty3`
+  --> $DIR/empty-struct-braces-pat-3.rs:29:9
+   |
+LL |         XE::XEmpty3(..) => ()
+   |         ^^^^^^^^^^^^^^^ not a tuple struct or tuple variant
+
+error: aborting due to 4 previous errors
+
+For more information about this error, try `rustc --explain E0164`.
diff --git a/tests/ui/empty/empty-struct-tuple-pat.rs b/tests/ui/empty/empty-struct-tuple-pat.rs
new file mode 100644
index 00000000000..47da8a306a4
--- /dev/null
+++ b/tests/ui/empty/empty-struct-tuple-pat.rs
@@ -0,0 +1,37 @@
+// Can't use unit struct as enum pattern
+
+// aux-build:empty-struct.rs
+
+extern crate empty_struct;
+use empty_struct::*;
+
+struct Empty2();
+
+enum E {
+    Empty4()
+}
+
+// remove attribute after warning cycle and promoting warnings to errors
+fn main() {
+    let e2 = Empty2();
+    let e4 = E::Empty4();
+    let xe6 = XEmpty6();
+    let xe5 = XE::XEmpty5();
+
+    match e2 {
+        Empty2 => () //~ ERROR match bindings cannot shadow tuple structs
+    }
+    match xe6 {
+        XEmpty6 => () //~ ERROR match bindings cannot shadow tuple structs
+    }
+
+    match e4 {
+        E::Empty4 => ()
+        //~^ ERROR expected unit struct, unit variant or constant, found tuple variant `E::Empty4`
+    }
+    match xe5 {
+        XE::XEmpty5 => (),
+        //~^ ERROR expected unit struct, unit variant or constant, found tuple variant `XE::XEmpty5`
+        _ => {},
+    }
+}
diff --git a/tests/ui/empty/empty-struct-tuple-pat.stderr b/tests/ui/empty/empty-struct-tuple-pat.stderr
new file mode 100644
index 00000000000..8d0f75d204c
--- /dev/null
+++ b/tests/ui/empty/empty-struct-tuple-pat.stderr
@@ -0,0 +1,59 @@
+error[E0530]: match bindings cannot shadow tuple structs
+  --> $DIR/empty-struct-tuple-pat.rs:22:9
+   |
+LL | struct Empty2();
+   | ---------------- the tuple struct `Empty2` is defined here
+...
+LL |         Empty2 => ()
+   |         ^^^^^^
+   |         |
+   |         cannot be named the same as a tuple struct
+   |         help: try specify the pattern arguments: `Empty2(..)`
+
+error[E0530]: match bindings cannot shadow tuple structs
+  --> $DIR/empty-struct-tuple-pat.rs:25:9
+   |
+LL | use empty_struct::*;
+   |     --------------- the tuple struct `XEmpty6` is imported here
+...
+LL |         XEmpty6 => ()
+   |         ^^^^^^^
+   |         |
+   |         cannot be named the same as a tuple struct
+   |         help: try specify the pattern arguments: `XEmpty6(..)`
+
+error[E0532]: expected unit struct, unit variant or constant, found tuple variant `E::Empty4`
+  --> $DIR/empty-struct-tuple-pat.rs:29:9
+   |
+LL |     Empty4()
+   |     -------- `E::Empty4` defined here
+...
+LL |         E::Empty4 => ()
+   |         ^^^^^^^^^ help: use the tuple variant pattern syntax instead: `E::Empty4()`
+
+error[E0532]: expected unit struct, unit variant or constant, found tuple variant `XE::XEmpty5`
+  --> $DIR/empty-struct-tuple-pat.rs:33:9
+   |
+LL |         XE::XEmpty5 => (),
+   |         ^^^^^^^^^^^
+   |
+  ::: $DIR/auxiliary/empty-struct.rs:7:5
+   |
+LL |     XEmpty4,
+   |     ------- similarly named unit variant `XEmpty4` defined here
+LL |     XEmpty5(),
+   |     ------- `XE::XEmpty5` defined here
+   |
+help: use the tuple variant pattern syntax instead
+   |
+LL |         XE::XEmpty5(/* fields */) => (),
+   |         ~~~~~~~~~~~~~~~~~~~~~~~~~
+help: a unit variant with a similar name exists
+   |
+LL |         XE::XEmpty4 => (),
+   |             ~~~~~~~
+
+error: aborting due to 4 previous errors
+
+Some errors have detailed explanations: E0530, E0532.
+For more information about an error, try `rustc --explain E0530`.
diff --git a/tests/ui/empty/empty-struct-unit-expr.rs b/tests/ui/empty/empty-struct-unit-expr.rs
new file mode 100644
index 00000000000..8f3688a2a07
--- /dev/null
+++ b/tests/ui/empty/empty-struct-unit-expr.rs
@@ -0,0 +1,21 @@
+// Can't use unit struct as constructor function
+
+// aux-build:empty-struct.rs
+
+extern crate empty_struct;
+use empty_struct::*;
+
+struct Empty2;
+
+enum E {
+    Empty4
+}
+
+fn main() {
+    let e2 = Empty2(); //~ ERROR expected function, found struct `Empty2`
+    let e4 = E::Empty4();
+    //~^ ERROR expected function, found enum variant `E::Empty4` [E0618]
+    let xe2 = XEmpty2(); //~ ERROR expected function, found struct `XEmpty2`
+    let xe4 = XE::XEmpty4();
+    //~^ ERROR expected function, found enum variant `XE::XEmpty4` [E0618]
+}
diff --git a/tests/ui/empty/empty-struct-unit-expr.stderr b/tests/ui/empty/empty-struct-unit-expr.stderr
new file mode 100644
index 00000000000..e97209527fe
--- /dev/null
+++ b/tests/ui/empty/empty-struct-unit-expr.stderr
@@ -0,0 +1,65 @@
+error[E0618]: expected function, found struct `Empty2`
+  --> $DIR/empty-struct-unit-expr.rs:15:14
+   |
+LL | struct Empty2;
+   | ------------- struct `Empty2` defined here
+...
+LL |     let e2 = Empty2();
+   |              ^^^^^^--
+   |              |
+   |              call expression requires function
+   |
+help: `Empty2` is a unit struct, and does not take parentheses to be constructed
+   |
+LL -     let e2 = Empty2();
+LL +     let e2 = Empty2;
+   |
+
+error[E0618]: expected function, found enum variant `E::Empty4`
+  --> $DIR/empty-struct-unit-expr.rs:16:14
+   |
+LL |     Empty4
+   |     ------ enum variant `E::Empty4` defined here
+...
+LL |     let e4 = E::Empty4();
+   |              ^^^^^^^^^--
+   |              |
+   |              call expression requires function
+   |
+help: `E::Empty4` is a unit enum variant, and does not take parentheses to be constructed
+   |
+LL -     let e4 = E::Empty4();
+LL +     let e4 = E::Empty4;
+   |
+
+error[E0618]: expected function, found struct `XEmpty2`
+  --> $DIR/empty-struct-unit-expr.rs:18:15
+   |
+LL |     let xe2 = XEmpty2();
+   |               ^^^^^^^--
+   |               |
+   |               call expression requires function
+   |
+help: `XEmpty2` is a unit struct, and does not take parentheses to be constructed
+   |
+LL -     let xe2 = XEmpty2();
+LL +     let xe2 = XEmpty2;
+   |
+
+error[E0618]: expected function, found enum variant `XE::XEmpty4`
+  --> $DIR/empty-struct-unit-expr.rs:19:15
+   |
+LL |     let xe4 = XE::XEmpty4();
+   |               ^^^^^^^^^^^--
+   |               |
+   |               call expression requires function
+   |
+help: `XE::XEmpty4` is a unit enum variant, and does not take parentheses to be constructed
+   |
+LL -     let xe4 = XE::XEmpty4();
+LL +     let xe4 = XE::XEmpty4;
+   |
+
+error: aborting due to 4 previous errors
+
+For more information about this error, try `rustc --explain E0618`.
diff --git a/tests/ui/empty/empty-struct-unit-pat.rs b/tests/ui/empty/empty-struct-unit-pat.rs
new file mode 100644
index 00000000000..44a1e9e3d93
--- /dev/null
+++ b/tests/ui/empty/empty-struct-unit-pat.rs
@@ -0,0 +1,54 @@
+// Can't use unit struct as tuple struct pattern
+
+// aux-build:empty-struct.rs
+
+extern crate empty_struct;
+use empty_struct::*;
+
+struct Empty2;
+
+enum E {
+    Empty4
+}
+
+fn main() {
+    let e2 = Empty2;
+    let e4 = E::Empty4;
+    let xe2 = XEmpty2;
+    let xe4 = XE::XEmpty4;
+
+    match e2 {
+        Empty2() => () //~ ERROR expected tuple struct or tuple variant, found unit struct `Empty2`
+    }
+    match xe2 {
+        XEmpty2() => ()
+        //~^ ERROR expected tuple struct or tuple variant, found unit struct `XEmpty2`
+    }
+    match e2 {
+        Empty2(..) => ()
+        //~^ ERROR expected tuple struct or tuple variant, found unit struct `Empty2`
+    }
+    match xe2 {
+        XEmpty2(..) => ()
+        //~^ ERROR expected tuple struct or tuple variant, found unit struct `XEmpty2`
+    }
+
+    match e4 {
+        E::Empty4() => ()
+        //~^ ERROR expected tuple struct or tuple variant, found unit variant `E::Empty4`
+    }
+    match xe4 {
+        XE::XEmpty4() => (),
+        //~^ ERROR expected tuple struct or tuple variant, found unit variant `XE::XEmpty4`
+        _ => {},
+    }
+    match e4 {
+        E::Empty4(..) => ()
+        //~^ ERROR expected tuple struct or tuple variant, found unit variant `E::Empty4`
+    }
+    match xe4 {
+        XE::XEmpty4(..) => (),
+        //~^ ERROR expected tuple struct or tuple variant, found unit variant `XE::XEmpty4`
+        _ => {},
+    }
+}
diff --git a/tests/ui/empty/empty-struct-unit-pat.stderr b/tests/ui/empty/empty-struct-unit-pat.stderr
new file mode 100644
index 00000000000..5c0b4cffa94
--- /dev/null
+++ b/tests/ui/empty/empty-struct-unit-pat.stderr
@@ -0,0 +1,155 @@
+error[E0532]: expected tuple struct or tuple variant, found unit struct `Empty2`
+  --> $DIR/empty-struct-unit-pat.rs:21:9
+   |
+LL | struct Empty2;
+   | -------------- `Empty2` defined here
+...
+LL |         Empty2() => ()
+   |         ^^^^^^^^
+   |
+  ::: $DIR/auxiliary/empty-struct.rs:3:1
+   |
+LL | pub struct XEmpty6();
+   | ------------------ similarly named tuple struct `XEmpty6` defined here
+   |
+help: use this syntax instead
+   |
+LL |         Empty2 => ()
+   |         ~~~~~~
+help: a tuple struct with a similar name exists
+   |
+LL |         XEmpty6() => ()
+   |         ~~~~~~~
+
+error[E0532]: expected tuple struct or tuple variant, found unit struct `XEmpty2`
+  --> $DIR/empty-struct-unit-pat.rs:24:9
+   |
+LL |         XEmpty2() => ()
+   |         ^^^^^^^^^
+   |
+  ::: $DIR/auxiliary/empty-struct.rs:2:1
+   |
+LL | pub struct XEmpty2;
+   | ------------------ `XEmpty2` defined here
+LL | pub struct XEmpty6();
+   | ------------------ similarly named tuple struct `XEmpty6` defined here
+   |
+help: use this syntax instead
+   |
+LL |         XEmpty2 => ()
+   |         ~~~~~~~
+help: a tuple struct with a similar name exists
+   |
+LL |         XEmpty6() => ()
+   |         ~~~~~~~
+
+error[E0532]: expected tuple struct or tuple variant, found unit struct `Empty2`
+  --> $DIR/empty-struct-unit-pat.rs:28:9
+   |
+LL | struct Empty2;
+   | -------------- `Empty2` defined here
+...
+LL |         Empty2(..) => ()
+   |         ^^^^^^^^^^
+   |
+  ::: $DIR/auxiliary/empty-struct.rs:3:1
+   |
+LL | pub struct XEmpty6();
+   | ------------------ similarly named tuple struct `XEmpty6` defined here
+   |
+help: use this syntax instead
+   |
+LL |         Empty2 => ()
+   |         ~~~~~~
+help: a tuple struct with a similar name exists
+   |
+LL |         XEmpty6(..) => ()
+   |         ~~~~~~~
+
+error[E0532]: expected tuple struct or tuple variant, found unit struct `XEmpty2`
+  --> $DIR/empty-struct-unit-pat.rs:32:9
+   |
+LL |         XEmpty2(..) => ()
+   |         ^^^^^^^^^^^
+   |
+  ::: $DIR/auxiliary/empty-struct.rs:2:1
+   |
+LL | pub struct XEmpty2;
+   | ------------------ `XEmpty2` defined here
+LL | pub struct XEmpty6();
+   | ------------------ similarly named tuple struct `XEmpty6` defined here
+   |
+help: use this syntax instead
+   |
+LL |         XEmpty2 => ()
+   |         ~~~~~~~
+help: a tuple struct with a similar name exists
+   |
+LL |         XEmpty6(..) => ()
+   |         ~~~~~~~
+
+error[E0532]: expected tuple struct or tuple variant, found unit variant `E::Empty4`
+  --> $DIR/empty-struct-unit-pat.rs:37:9
+   |
+LL |     Empty4
+   |     ------ `E::Empty4` defined here
+...
+LL |         E::Empty4() => ()
+   |         ^^^^^^^^^^^ help: use this syntax instead: `E::Empty4`
+
+error[E0532]: expected tuple struct or tuple variant, found unit variant `XE::XEmpty4`
+  --> $DIR/empty-struct-unit-pat.rs:41:9
+   |
+LL |         XE::XEmpty4() => (),
+   |         ^^^^^^^^^^^^^
+   |
+  ::: $DIR/auxiliary/empty-struct.rs:7:5
+   |
+LL |     XEmpty4,
+   |     ------- `XE::XEmpty4` defined here
+LL |     XEmpty5(),
+   |     ------- similarly named tuple variant `XEmpty5` defined here
+   |
+help: use this syntax instead
+   |
+LL |         XE::XEmpty4 => (),
+   |         ~~~~~~~~~~~
+help: a tuple variant with a similar name exists
+   |
+LL |         XE::XEmpty5() => (),
+   |             ~~~~~~~
+
+error[E0532]: expected tuple struct or tuple variant, found unit variant `E::Empty4`
+  --> $DIR/empty-struct-unit-pat.rs:46:9
+   |
+LL |     Empty4
+   |     ------ `E::Empty4` defined here
+...
+LL |         E::Empty4(..) => ()
+   |         ^^^^^^^^^^^^^ help: use this syntax instead: `E::Empty4`
+
+error[E0532]: expected tuple struct or tuple variant, found unit variant `XE::XEmpty4`
+  --> $DIR/empty-struct-unit-pat.rs:50:9
+   |
+LL |         XE::XEmpty4(..) => (),
+   |         ^^^^^^^^^^^^^^^
+   |
+  ::: $DIR/auxiliary/empty-struct.rs:7:5
+   |
+LL |     XEmpty4,
+   |     ------- `XE::XEmpty4` defined here
+LL |     XEmpty5(),
+   |     ------- similarly named tuple variant `XEmpty5` defined here
+   |
+help: use this syntax instead
+   |
+LL |         XE::XEmpty4 => (),
+   |         ~~~~~~~~~~~
+help: a tuple variant with a similar name exists
+   |
+LL |         XE::XEmpty5(..) => (),
+   |             ~~~~~~~
+
+error: aborting due to 8 previous errors
+
+For more information about this error, try `rustc --explain E0532`.
diff --git a/tests/ui/empty/issue-37026.rs b/tests/ui/empty/issue-37026.rs
new file mode 100644
index 00000000000..fd678a717d0
--- /dev/null
+++ b/tests/ui/empty/issue-37026.rs
@@ -0,0 +1,8 @@
+// aux-build:empty-struct.rs
+
+extern crate empty_struct;
+
+fn main() {
+    let empty_struct::XEmpty2 = (); //~ ERROR mismatched types
+    let empty_struct::XEmpty6(..) = (); //~ ERROR mismatched types
+}
diff --git a/tests/ui/empty/issue-37026.stderr b/tests/ui/empty/issue-37026.stderr
new file mode 100644
index 00000000000..48a4a5bcad2
--- /dev/null
+++ b/tests/ui/empty/issue-37026.stderr
@@ -0,0 +1,19 @@
+error[E0308]: mismatched types
+  --> $DIR/issue-37026.rs:6:9
+   |
+LL |     let empty_struct::XEmpty2 = ();
+   |         ^^^^^^^^^^^^^^^^^^^^^   -- this expression has type `()`
+   |         |
+   |         expected `()`, found struct `XEmpty2`
+
+error[E0308]: mismatched types
+  --> $DIR/issue-37026.rs:7:9
+   |
+LL |     let empty_struct::XEmpty6(..) = ();
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^   -- this expression has type `()`
+   |         |
+   |         expected `()`, found struct `XEmpty6`
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0308`.
diff --git a/tests/ui/empty/no-link.rs b/tests/ui/empty/no-link.rs
new file mode 100644
index 00000000000..c80e61b4511
--- /dev/null
+++ b/tests/ui/empty/no-link.rs
@@ -0,0 +1,9 @@
+// check-pass
+// aux-build:empty-struct.rs
+
+#[no_link]
+extern crate empty_struct;
+
+fn main() {
+    empty_struct::XEmpty1 {};
+}