9 files changed, 115 insertions, 0 deletions
diff --git a/tests/ui/indexing/index-bot.rs b/tests/ui/indexing/index-bot.rs
new file mode 100644
index 00000000000..e69c4019f61
--- /dev/null
+++ b/tests/ui/indexing/index-bot.rs
@@ -0,0 +1,3 @@
+fn main() {
+    (return)[0]; //~ ERROR cannot index into a value of type `!`
+}
diff --git a/tests/ui/indexing/index-bot.stderr b/tests/ui/indexing/index-bot.stderr
new file mode 100644
index 00000000000..bf231c92cad
--- /dev/null
+++ b/tests/ui/indexing/index-bot.stderr
@@ -0,0 +1,9 @@
+error[E0608]: cannot index into a value of type `!`
+  --> $DIR/index-bot.rs:2:13
+   |
+LL |     (return)[0];
+   |             ^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0608`.
diff --git a/tests/ui/indexing/index-help.rs b/tests/ui/indexing/index-help.rs
new file mode 100644
index 00000000000..66571ec41a0
--- /dev/null
+++ b/tests/ui/indexing/index-help.rs
@@ -0,0 +1,4 @@
+fn main() {
+    let x = vec![1];
+    x[0i32]; //~ ERROR E0277
+}
diff --git a/tests/ui/indexing/index-help.stderr b/tests/ui/indexing/index-help.stderr
new file mode 100644
index 00000000000..e020d029875
--- /dev/null
+++ b/tests/ui/indexing/index-help.stderr
@@ -0,0 +1,13 @@
+error[E0277]: the type `[{integer}]` cannot be indexed by `i32`
+  --> $DIR/index-help.rs:3:7
+   |
+LL |     x[0i32];
+   |       ^^^^ slice indices are of type `usize` or ranges of `usize`
+   |
+   = help: the trait `SliceIndex<[{integer}]>` is not implemented for `i32`
+   = help: the trait `SliceIndex<[T]>` is implemented for `usize`
+   = note: required for `Vec<{integer}>` to implement `Index<i32>`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/indexing/index_message.rs b/tests/ui/indexing/index_message.rs
new file mode 100644
index 00000000000..88b848d6f85
--- /dev/null
+++ b/tests/ui/indexing/index_message.rs
@@ -0,0 +1,4 @@
+fn main() {
+    let z = (10,);
+    let _ = z[0]; //~ ERROR cannot index into a value of type `({integer},)`
+}
diff --git a/tests/ui/indexing/index_message.stderr b/tests/ui/indexing/index_message.stderr
new file mode 100644
index 00000000000..80f2bd52314
--- /dev/null
+++ b/tests/ui/indexing/index_message.stderr
@@ -0,0 +1,9 @@
+error[E0608]: cannot index into a value of type `({integer},)`
+  --> $DIR/index_message.rs:3:14
+   |
+LL |     let _ = z[0];
+   |              ^^^ help: to access tuple elements, use: `.0`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0608`.
diff --git a/tests/ui/indexing/indexing-requires-a-uint.rs b/tests/ui/indexing/indexing-requires-a-uint.rs
new file mode 100644
index 00000000000..dbe9b44a138
--- /dev/null
+++ b/tests/ui/indexing/indexing-requires-a-uint.rs
@@ -0,0 +1,14 @@
+// Make sure that indexing an array is only valid with a `usize`, not any other
+// integral type.
+
+fn main() {
+    fn bar<T>(_: T) {}
+    [0][0u8]; //~ ERROR: the type `[{integer}]` cannot be indexed by `u8`
+
+    [0][0]; // should infer to be a usize
+
+    let i = 0;      // i is an IntVar
+    [0][i];         // i should be locked to usize
+    bar::<isize>(i);  // i should not be re-coerced back to an isize
+    //~^ ERROR: mismatched types
+}
diff --git a/tests/ui/indexing/indexing-requires-a-uint.stderr b/tests/ui/indexing/indexing-requires-a-uint.stderr
new file mode 100644
index 00000000000..7a741cfc7de
--- /dev/null
+++ b/tests/ui/indexing/indexing-requires-a-uint.stderr
@@ -0,0 +1,32 @@
+error[E0277]: the type `[{integer}]` cannot be indexed by `u8`
+  --> $DIR/indexing-requires-a-uint.rs:6:9
+   |
+LL |     [0][0u8];
+   |         ^^^ slice indices are of type `usize` or ranges of `usize`
+   |
+   = help: the trait `SliceIndex<[{integer}]>` is not implemented for `u8`
+   = help: the trait `SliceIndex<[T]>` is implemented for `usize`
+   = note: required for `[{integer}]` to implement `Index<u8>`
+
+error[E0308]: mismatched types
+  --> $DIR/indexing-requires-a-uint.rs:12:18
+   |
+LL |     bar::<isize>(i);  // i should not be re-coerced back to an isize
+   |     ------------ ^ expected `isize`, found `usize`
+   |     |
+   |     arguments to this function are incorrect
+   |
+note: function defined here
+  --> $DIR/indexing-requires-a-uint.rs:5:8
+   |
+LL |     fn bar<T>(_: T) {}
+   |        ^^^    ----
+help: you can convert a `usize` to an `isize` and panic if the converted value doesn't fit
+   |
+LL |     bar::<isize>(i.try_into().unwrap());  // i should not be re-coerced back to an isize
+   |                   ++++++++++++++++++++
+
+error: aborting due to 2 previous errors
+
+Some errors have detailed explanations: E0277, E0308.
+For more information about an error, try `rustc --explain E0277`.
diff --git a/tests/ui/indexing/indexing-spans-caller-location.rs b/tests/ui/indexing/indexing-spans-caller-location.rs
new file mode 100644
index 00000000000..2652f00211d
--- /dev/null
+++ b/tests/ui/indexing/indexing-spans-caller-location.rs
@@ -0,0 +1,27 @@
+// run-pass
+
+// Regression test for https://github.com/rust-lang/rust/issues/114388
+
+#[track_caller]
+fn caller_line() -> u32 {
+    std::panic::Location::caller().line()
+}
+
+fn main() {
+    let prev_line = caller_line(); // first line
+    (A { prev_line }) // second line
+    [0]; // third line
+}
+
+struct A {
+    prev_line: u32,
+}
+impl std::ops::Index<usize> for A {
+    type Output = ();
+
+    fn index(&self, _idx: usize) -> &() {
+        // Use the relative number to make it resistent to header changes.
+        assert_eq!(caller_line(), self.prev_line + 2);
+        &()
+    }
+}