6 files changed, 101 insertions, 0 deletions
diff --git a/tests/ui/explicit-tail-calls/become-outside.array.stderr b/tests/ui/explicit-tail-calls/become-outside.array.stderr
new file mode 100644
index 000000000..839c20509
--- /dev/null
+++ b/tests/ui/explicit-tail-calls/become-outside.array.stderr
@@ -0,0 +1,9 @@
+error[E0572]: become statement outside of function body
+  --> $DIR/become-outside.rs:11:17
+   |
+LL | struct Bad([(); become f()]);
+   |                 ^^^^^^^^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0572`.
diff --git a/tests/ui/explicit-tail-calls/become-outside.constant.stderr b/tests/ui/explicit-tail-calls/become-outside.constant.stderr
new file mode 100644
index 000000000..9b67f08af
--- /dev/null
+++ b/tests/ui/explicit-tail-calls/become-outside.constant.stderr
@@ -0,0 +1,9 @@
+error[E0572]: become statement outside of function body
+  --> $DIR/become-outside.rs:7:5
+   |
+LL |     become f();
+   |     ^^^^^^^^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0572`.
diff --git a/tests/ui/explicit-tail-calls/become-outside.rs b/tests/ui/explicit-tail-calls/become-outside.rs
new file mode 100644
index 000000000..51b4389c8
--- /dev/null
+++ b/tests/ui/explicit-tail-calls/become-outside.rs
@@ -0,0 +1,15 @@
+// revisions: constant array
+#![allow(incomplete_features)]
+#![feature(explicit_tail_calls)]
+
+#[cfg(constant)]
+const _: () = {
+    become f(); //[constant]~ error: become statement outside of function body
+};
+
+#[cfg(array)]
+struct Bad([(); become f()]); //[array]~ error: become statement outside of function body
+
+fn f() {}
+
+fn main() {}
diff --git a/tests/ui/explicit-tail-calls/return-lifetime-sub.rs b/tests/ui/explicit-tail-calls/return-lifetime-sub.rs
new file mode 100644
index 000000000..8a3f43d4b
--- /dev/null
+++ b/tests/ui/explicit-tail-calls/return-lifetime-sub.rs
@@ -0,0 +1,13 @@
+// check-pass
+#![allow(incomplete_features)]
+#![feature(explicit_tail_calls)]
+
+fn _f<'a>() -> &'a [u8] {
+    become _g();
+}
+
+fn _g() -> &'static [u8] {
+    &[0, 1, 2, 3]
+}
+
+fn main() {}
diff --git a/tests/ui/explicit-tail-calls/return-mismatches.rs b/tests/ui/explicit-tail-calls/return-mismatches.rs
new file mode 100644
index 000000000..935a1a1d2
--- /dev/null
+++ b/tests/ui/explicit-tail-calls/return-mismatches.rs
@@ -0,0 +1,28 @@
+#![allow(incomplete_features)]
+#![feature(explicit_tail_calls)]
+
+fn _f0<'a>() -> &'static [u8] {
+    become _g0(); //~ error: mismatched types
+}
+
+fn _g0() -> &'static [u8; 1] {
+    &[0]
+}
+
+fn _f1() {
+    become _g1(); //~ error: mismatched types
+}
+
+fn _g1() -> ! {
+    become _g1();
+}
+
+fn _f2() -> u32 {
+    become _g2(); //~ error: mismatched types
+}
+
+fn _g2() -> u16 {
+    0
+}
+
+fn main() {}
diff --git a/tests/ui/explicit-tail-calls/return-mismatches.stderr b/tests/ui/explicit-tail-calls/return-mismatches.stderr
new file mode 100644
index 000000000..1dcc35797
--- /dev/null
+++ b/tests/ui/explicit-tail-calls/return-mismatches.stderr
@@ -0,0 +1,27 @@
+error[E0308]: mismatched types
+  --> $DIR/return-mismatches.rs:5:5
+   |
+LL |     become _g0();
+   |     ^^^^^^^^^^^^ expected `&[u8]`, found `&[u8; 1]`
+   |
+   = note: expected reference `&'static [u8]`
+              found reference `&'static [u8; 1]`
+
+error[E0308]: mismatched types
+  --> $DIR/return-mismatches.rs:13:5
+   |
+LL |     become _g1();
+   |     ^^^^^^^^^^^^ expected `()`, found `!`
+   |
+   = note: expected unit type `()`
+                   found type `!`
+
+error[E0308]: mismatched types
+  --> $DIR/return-mismatches.rs:21:5
+   |
+LL |     become _g2();
+   |     ^^^^^^^^^^^^ expected `u32`, found `u16`
+
+error: aborting due to 3 previous errors
+
+For more information about this error, try `rustc --explain E0308`.