Rollup merge of rust-lang#37919 - nikomatsakis:incremental-36168, r=mw

add regression test for rust-lang#36168

Fixes rust-lang#36168

r? @michaelwoerister

Author: dns2utf8

src/test/incremental/add_private_fn_at_krate_root_cc/auxiliary/point.rs

@@ -0,0 +1,28 @@
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+pub struct Point {
+    pub x: f32,
+    pub y: f32,
+}
+
+#[cfg(rpass2)]
+fn unused_helper() {
+}
+
+pub fn distance_squared(this: &Point) -> f32 {
+    return this.x * this.x + this.y * this.y;
+}
+
+impl Point {
+    pub fn distance_from_origin(&self) -> f32 {
+        distance_squared(self).sqrt()
+    }
+}

src/test/incremental/add_private_fn_at_krate_root_cc/struct_point.rs

@@ -0,0 +1,84 @@
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// Test where we add a private item into the root of an external.
+// crate. This should not cause anything we use to be invalidated.
+// Regression test for #36168.
+
+// revisions:rpass1 rpass2
+// compile-flags: -Z query-dep-graph
+// aux-build:point.rs
+
+#![feature(rustc_attrs)]
+#![feature(stmt_expr_attributes)]
+#![allow(dead_code)]
+
+#![rustc_partition_reused(module="struct_point-fn_calls_methods_in_same_impl", cfg="rpass2")]
+#![rustc_partition_reused(module="struct_point-fn_calls_free_fn", cfg="rpass2")]
+#![rustc_partition_reused(module="struct_point-fn_read_field", cfg="rpass2")]
+#![rustc_partition_reused(module="struct_point-fn_write_field", cfg="rpass2")]
+#![rustc_partition_reused(module="struct_point-fn_make_struct", cfg="rpass2")]
+
+extern crate point;
+
+/// A fn item that calls (public) methods on `Point` from the same impl
+mod fn_calls_methods_in_same_impl {
+    use point::Point;
+
+    #[rustc_clean(label="TypeckItemBody", cfg="rpass2")]
+    pub fn check() {
+        let x = Point { x: 2.0, y: 2.0 };
+        x.distance_from_origin();
+    }
+}
+
+/// A fn item that calls (public) methods on `Point` from another impl
+mod fn_calls_free_fn {
+    use point::{self, Point};
+
+    #[rustc_clean(label="TypeckItemBody", cfg="rpass2")]
+    pub fn check() {
+        let x = Point { x: 2.0, y: 2.0 };
+        point::distance_squared(&x);
+    }
+}
+
+/// A fn item that makes an instance of `Point` but does not invoke methods
+mod fn_make_struct {
+    use point::Point;
+
+    #[rustc_clean(label="TypeckItemBody", cfg="rpass2")]
+    pub fn make_origin() -> Point {
+        Point { x: 2.0, y: 2.0 }
+    }
+}
+
+/// A fn item that reads fields from `Point` but does not invoke methods
+mod fn_read_field {
+    use point::Point;
+
+    #[rustc_clean(label="TypeckItemBody", cfg="rpass2")]
+    pub fn get_x(p: Point) -> f32 {
+        p.x
+    }
+}
+
+/// A fn item that writes to a field of `Point` but does not invoke methods
+mod fn_write_field {
+    use point::Point;
+
+    #[rustc_clean(label="TypeckItemBody", cfg="rpass2")]
+    pub fn inc_x(p: &mut Point) {
+        p.x += 1.0;
+    }
+}
+
+fn main() {
+}