Rollup merge of #34513 - ollie27:rustdoc_stripped, r=alexcrichton

rustdoc: Fix a few stripping issues

We need to recurse into stripped modules to strip things like impl methods
but when doing so we must not add any items to the `retained` set.

For example this removes [`core::num::ParseFloatError::__description`](https://doc.rust-lang.org/nightly/core/num/struct.ParseFloatError.html#method.__description) and [`impl Clone for ThreadRng`](https://doc.rust-lang.org/nightly/std/clone/trait.Clone.html).

2 files changed, 66 insertions, 0 deletions

diff --git a/src/test/rustdoc/hidden-impls.rs b/src/test/rustdoc/hidden-impls.rs
new file mode 100644
index 00000000000..203c56e9e2e
--- /dev/null
+++ b/src/test/rustdoc/hidden-impls.rs
@@ -0,0 +1,27 @@
+// Copyright 2016 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.
+
+#![crate_name = "foo"]
+
+mod hidden {
+    #[derive(Clone)]
+    pub struct Foo;
+}
+
+#[doc(hidden)]
+pub mod __hidden {
+    pub use hidden::Foo;
+}
+
+// @has foo/trait.Clone.html
+// @!has - 'Foo'
+// @has implementors/foo/trait.Clone.js
+// @!has - 'Foo'
+pub use std::clone::Clone;
diff --git a/src/test/rustdoc/hidden-methods.rs b/src/test/rustdoc/hidden-methods.rs
new file mode 100644
index 00000000000..18f5f086cd1
--- /dev/null
+++ b/src/test/rustdoc/hidden-methods.rs
@@ -0,0 +1,39 @@
+// Copyright 2016 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.
+
+#![crate_name = "foo"]
+
+#[doc(hidden)]
+pub mod hidden {
+    pub struct Foo;
+
+    impl Foo {
+        #[doc(hidden)]
+        pub fn this_should_be_hidden() {}
+    }
+
+    pub struct Bar;
+
+    impl Bar {
+        fn this_should_be_hidden() {}
+    }
+}
+
+// @has foo/struct.Foo.html
+// @!has - 'Methods'
+// @!has - 'impl Foo'
+// @!has - 'this_should_be_hidden'
+pub use hidden::Foo;
+
+// @has foo/struct.Bar.html
+// @!has - 'Methods'
+// @!has - 'impl Bar'
+// @!has - 'this_should_be_hidden'
+pub use hidden::Bar;