2 files changed, 20 insertions, 0 deletions
diff --git a/src/test/ui/attributes/issue-100631.rs b/src/test/ui/attributes/issue-100631.rs
new file mode 100644
index 00000000000..0fefcf83fd5
--- /dev/null
+++ b/src/test/ui/attributes/issue-100631.rs
@@ -0,0 +1,8 @@
+// issue #100631, make sure `TyCtxt::get_attr` only called by case that compiler
+// can reasonably deal with multiple attributes.
+// `repr` will use `TyCtxt::get_attrs` since it's `DuplicatesOk`.
+#[repr(C)] //~ ERROR: unsupported representation for zero-variant enum [E0084]
+#[repr(C)]
+enum Foo {}
+
+fn main() {}
diff --git a/src/test/ui/attributes/issue-100631.stderr b/src/test/ui/attributes/issue-100631.stderr
new file mode 100644
index 00000000000..caa5351ddc7
--- /dev/null
+++ b/src/test/ui/attributes/issue-100631.stderr
@@ -0,0 +1,12 @@
+error[E0084]: unsupported representation for zero-variant enum
+  --> $DIR/issue-100631.rs:4:1
+   |
+LL | #[repr(C)]
+   | ^^^^^^^^^^
+LL | #[repr(C)]
+LL | enum Foo {}
+   | -------- zero-variant enum
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0084`.