1 files changed, 161 insertions, 0 deletions
diff --git a/src/test/ui/polymorphization/type_parameters/closures.rs b/src/test/ui/polymorphization/type_parameters/closures.rs
new file mode 100644
index 000000000..07ab1355a
--- /dev/null
+++ b/src/test/ui/polymorphization/type_parameters/closures.rs
@@ -0,0 +1,161 @@
+// build-fail
+// compile-flags:-Zpolymorphize=on
+#![feature(stmt_expr_attributes, rustc_attrs)]
+
+// This test checks that the polymorphization analysis correctly detects unused type
+// parameters in closures.
+
+// Function doesn't have any generic parameters to be unused.
+#[rustc_polymorphize_error]
+pub fn no_parameters() {
+    let _ = || {};
+}
+
+// Function has an unused generic parameter in parent and closure.
+#[rustc_polymorphize_error]
+pub fn unused<T>() -> u32 {
+    //~^ ERROR item has unused generic parameters
+
+    let add_one = |x: u32| x + 1;
+    //~^ ERROR item has unused generic parameters
+    add_one(3)
+}
+
+// Function has an unused generic parameter in closure, but not in parent.
+#[rustc_polymorphize_error]
+pub fn used_parent<T: Default>() -> u32 {
+    let _: T = Default::default();
+    let add_one = |x: u32| x + 1;
+    //~^ ERROR item has unused generic parameters
+    add_one(3)
+}
+
+// Function uses generic parameter in value of a binding in closure.
+#[rustc_polymorphize_error]
+pub fn used_binding_value<T: Default>() -> T {
+    let x = || {
+        let y: T = Default::default();
+        y
+    };
+
+    x()
+}
+
+// Function uses generic parameter in generic of a binding in closure.
+#[rustc_polymorphize_error]
+pub fn used_binding_generic<T>() -> Option<T> {
+    let x = || {
+        let y: Option<T> = None;
+        y
+    };
+
+    x()
+}
+
+// Function and closure uses generic parameter in argument.
+#[rustc_polymorphize_error]
+pub fn used_argument<T>(t: T) -> u32 {
+    let x = |_: T| 3;
+    x(t)
+}
+
+// Closure uses generic parameter in argument.
+#[rustc_polymorphize_error]
+pub fn used_argument_closure<T: Default>() -> u32 {
+    let t: T = Default::default();
+
+    let x = |_: T| 3;
+    x(t)
+}
+
+// Closure uses generic parameter as upvar.
+#[rustc_polymorphize_error]
+pub fn used_upvar<T: Default>() -> T {
+    let x: T = Default::default();
+
+    let y = || x;
+    y()
+}
+
+// Closure uses generic parameter in substitutions to another function.
+#[rustc_polymorphize_error]
+pub fn used_substs<T>() -> u32 {
+    let x = || unused::<T>();
+    x()
+}
+
+struct Foo<F>(F);
+
+impl<F: Default> Foo<F> {
+    // Function has an unused generic parameter from impl and fn.
+    #[rustc_polymorphize_error]
+    pub fn unused_all<G: Default>() -> u32 {
+        //~^ ERROR item has unused generic parameters
+        let add_one = |x: u32| x + 1;
+        //~^ ERROR item has unused generic parameters
+        add_one(3)
+    }
+
+    // Function uses generic parameter from impl and fn in closure.
+    #[rustc_polymorphize_error]
+    pub fn used_both<G: Default>() -> u32 {
+        let add_one = |x: u32| {
+            let _: F = Default::default();
+            let _: G = Default::default();
+            x + 1
+        };
+
+        add_one(3)
+    }
+
+    // Function uses generic parameter from fn in closure.
+    #[rustc_polymorphize_error]
+    pub fn used_fn<G: Default>() -> u32 {
+        //~^ ERROR item has unused generic parameters
+        let add_one = |x: u32| {
+            //~^ ERROR item has unused generic parameters
+            let _: G = Default::default();
+            x + 1
+        };
+
+        add_one(3)
+    }
+
+    // Function uses generic parameter from impl in closure.
+    #[rustc_polymorphize_error]
+    pub fn used_impl<G: Default>() -> u32 {
+        //~^ ERROR item has unused generic parameters
+        let add_one = |x: u32| {
+            //~^ ERROR item has unused generic parameters
+            let _: F = Default::default();
+            x + 1
+        };
+
+        add_one(3)
+    }
+
+    // Closure uses generic parameter in substitutions to another function.
+    #[rustc_polymorphize_error]
+    pub fn used_substs() -> u32 {
+        let x = || unused::<F>();
+        x()
+    }
+}
+
+fn main() {
+    no_parameters();
+    let _ = unused::<u32>();
+    let _ = used_parent::<u32>();
+    let _ = used_binding_value::<u32>();
+    let _ = used_binding_generic::<u32>();
+    let _ = used_argument(3u32);
+    let _ = used_argument_closure::<u32>();
+    let _ = used_upvar::<u32>();
+    let _ = used_substs::<u32>();
+
+    let _ = Foo::<u32>::unused_all::<u32>();
+    let _ = Foo::<u32>::used_both::<u32>();
+    let _ = Foo::<u32>::used_impl::<u32>();
+    let _ = Foo::<u32>::used_fn::<u32>();
+    let _ = Foo::<u32>::used_substs();
+}