1 files changed, 61 insertions, 0 deletions
diff --git a/src/test/ui/dep-graph/dep-graph-trait-impl.rs b/src/test/ui/dep-graph/dep-graph-trait-impl.rs
new file mode 100644
index 000000000..19002965b
--- /dev/null
+++ b/src/test/ui/dep-graph/dep-graph-trait-impl.rs
@@ -0,0 +1,61 @@
+// Test that when a trait impl changes, fns whose body uses that trait
+// must also be recompiled.
+
+// incremental
+// compile-flags: -Z query-dep-graph
+
+#![feature(rustc_attrs)]
+#![allow(warnings)]
+
+fn main() { }
+
+pub trait Foo: Sized {
+    fn method(self) { }
+}
+
+mod x {
+    use Foo;
+
+    #[rustc_if_this_changed]
+    impl Foo for char { }
+
+    impl Foo for u32 { }
+}
+
+mod y {
+    use Foo;
+
+    #[rustc_then_this_would_need(typeck)] //~ ERROR OK
+    pub fn with_char() {
+        char::method('a');
+    }
+
+    #[rustc_then_this_would_need(typeck)] //~ ERROR OK
+    pub fn take_foo_with_char() {
+        take_foo::<char>('a');
+    }
+
+    #[rustc_then_this_would_need(typeck)] //~ ERROR OK
+    pub fn with_u32() {
+        u32::method(22);
+    }
+
+    #[rustc_then_this_would_need(typeck)] //~ ERROR OK
+    pub fn take_foo_with_u32() {
+        take_foo::<u32>(22);
+    }
+
+    pub fn take_foo<T:Foo>(t: T) { }
+}
+
+mod z {
+    use y;
+
+    // These are expected to yield errors, because changes to `x`
+    // affect the BODY of `y`, but not its signature.
+    #[rustc_then_this_would_need(typeck)] //~ ERROR no path
+    pub fn z() {
+        y::with_char();
+        y::with_u32();
+    }
+}