cleaned up some tests

2 files changed, 43 insertions, 0 deletions

diff --git a/tests/ui/statics/static-generic-param-soundness.rs b/tests/ui/statics/static-generic-param-soundness.rs
new file mode 100644
index 00000000000..aabcca514d3
--- /dev/null
+++ b/tests/ui/statics/static-generic-param-soundness.rs
@@ -0,0 +1,20 @@
+//! Originally, inner statics in generic functions were generated only once, causing the same
+//! static to be shared across all generic instantiations. This created a soundness hole where
+//! different types could be coerced through thread-local storage in safe code.
+//!
+//! This test checks that generic parameters from outer scopes cannot be used in inner statics,
+//! preventing this soundness issue.
+//!
+//! See https://github.com/rust-lang/rust/issues/9186
+
+enum Bar<T> {
+    //~^ ERROR parameter `T` is never used
+    What,
+}
+
+fn foo<T>() {
+    static a: Bar<T> = Bar::What;
+    //~^ ERROR can't use generic parameters from outer item
+}
+
+fn main() {}
diff --git a/tests/ui/statics/static-generic-param-soundness.stderr b/tests/ui/statics/static-generic-param-soundness.stderr
new file mode 100644
index 00000000000..47554c7fcb0
--- /dev/null
+++ b/tests/ui/statics/static-generic-param-soundness.stderr
@@ -0,0 +1,23 @@
+error[E0401]: can't use generic parameters from outer item
+  --> $DIR/static-generic-param-soundness.rs:16:19
+   |
+LL | fn foo<T>() {
+   |        - type parameter from outer item
+LL |     static a: Bar<T> = Bar::What;
+   |                   ^ use of generic parameter from outer item
+   |
+   = note: a `static` is a separate item from the item that contains it
+
+error[E0392]: type parameter `T` is never used
+  --> $DIR/static-generic-param-soundness.rs:10:10
+   |
+LL | enum Bar<T> {
+   |          ^ unused type parameter
+   |
+   = help: consider removing `T`, referring to it in a field, or using a marker such as `PhantomData`
+   = help: if you intended `T` to be a const parameter, use `const T: /* Type */` instead
+
+error: aborting due to 2 previous errors
+
+Some errors have detailed explanations: E0392, E0401.
+For more information about an error, try `rustc --explain E0392`.