Auto merge of #33002 - mitaa:rdoc-cross-impls, r=alexcrichton

rustdoc: refine cross-crate impl inlining

This changes the current rule that impls within `doc(hidden)` modules aren't inlined, to only inlining impls where the implemented trait and type are reachable in documentation.

fixes #14586
fixes #31948

.. and also applies the reachability checking to cross-crate links.

fixes #28480

r? @alexcrichton

src/test/auxiliary/rustdoc-hidden-sig.rs

@@ -0,0 +1,22 @@
+// 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.
+
+pub struct Bar;
+
+impl Bar {
+    pub fn bar(_: u8) -> hidden::Hidden {
+        hidden::Hidden
+    }
+}
+
+#[doc(hidden)]
+pub mod hidden {
+    pub struct Hidden;
+}

src/test/auxiliary/rustdoc-nonreachable-impls.rs

@@ -0,0 +1,44 @@
+// 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.
+
+pub struct Foo;
+
+pub trait Woof {}
+pub trait Bark {}
+
+mod private {
+    // should be shown
+    impl ::Woof for ::Foo {}
+
+    pub trait Bar {}
+    pub struct Wibble;
+
+    // these should not be shown
+    impl Bar for ::Foo {}
+    impl Bar for Wibble {}
+    impl ::Bark for Wibble {}
+    impl ::Woof for Wibble {}
+}
+
+#[doc(hidden)]
+pub mod hidden {
+    // should be shown
+    impl ::Bark for ::Foo {}
+
+    pub trait Qux {}
+    pub struct Wobble;
+
+
+    // these should only be shown if they're reexported correctly
+    impl Qux for ::Foo {}
+    impl Qux for Wobble {}
+    impl ::Bark for Wobble {}
+    impl ::Woof for Wobble {}
+}

src/test/rustdoc/inline_cross/issue-28480.rs

@@ -0,0 +1,23 @@
+// 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.
+
+// aux-build:rustdoc-hidden-sig.rs
+// build-aux-docs
+// ignore-cross-compile
+
+// @has rustdoc_hidden_sig/struct.Bar.html
+// @!has -  '//a/@title' 'Hidden'
+// @has -  '//a' 'u8'
+extern crate rustdoc_hidden_sig;
+
+// @has issue_28480/struct.Bar.html
+// @!has -  '//a/@title' 'Hidden'
+// @has -  '//a' 'u8'
+pub use rustdoc_hidden_sig::Bar;

src/test/rustdoc/inline_cross/issue-31948-1.rs

@@ -0,0 +1,37 @@
+// 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.
+
+// aux-build:rustdoc-nonreachable-impls.rs
+// build-aux-docs
+// ignore-cross-compile
+
+extern crate rustdoc_nonreachable_impls;
+
+// @has issue_31948_1/struct.Wobble.html
+// @has - '//*[@class="impl"]//code' 'Bark for'
+// @has - '//*[@class="impl"]//code' 'Woof for'
+// @!has - '//*[@class="impl"]//code' 'Bar for'
+// @!has - '//*[@class="impl"]//code' 'Qux for'
+pub use rustdoc_nonreachable_impls::hidden::Wobble;
+
+// @has issue_31948_1/trait.Bark.html
+// FIXME(33025): has - '//code' 'for Foo'
+// @has - '//code' 'for Wobble'
+// @!has - '//code' 'for Wibble'
+pub use rustdoc_nonreachable_impls::Bark;
+
+// @has issue_31948_1/trait.Woof.html
+// FIXME(33025): has - '//code' 'for Foo'
+// @has - '//code' 'for Wobble'
+// @!has - '//code' 'for Wibble'
+pub use rustdoc_nonreachable_impls::Woof;
+
+// @!has issue_31948_1/trait.Bar.html
+// @!has issue_31948_1/trait.Qux.html

src/test/rustdoc/inline_cross/issue-31948-2.rs

@@ -0,0 +1,31 @@
+// 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.
+
+// aux-build:rustdoc-nonreachable-impls.rs
+// build-aux-docs
+// ignore-cross-compile
+
+extern crate rustdoc_nonreachable_impls;
+
+// @has issue_31948_2/struct.Wobble.html
+// @has - '//*[@class="impl"]//code' 'Qux for'
+// @has - '//*[@class="impl"]//code' 'Bark for'
+// @has - '//*[@class="impl"]//code' 'Woof for'
+// @!has - '//*[@class="impl"]//code' 'Bar for'
+pub use rustdoc_nonreachable_impls::hidden::Wobble;
+
+// @has issue_31948_2/trait.Qux.html
+// FIXME(33025): has - '//code' 'for Foo'
+// @has - '//code' 'for Wobble'
+pub use rustdoc_nonreachable_impls::hidden::Qux;
+
+// @!has issue_31948_2/trait.Bar.html
+// @!has issue_31948_2/trait.Woof.html
+// @!has issue_31948_2/trait.Bark.html

src/test/rustdoc/inline_cross/issue-31948.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.
+
+// aux-build:rustdoc-nonreachable-impls.rs
+// build-aux-docs
+// ignore-cross-compile
+
+extern crate rustdoc_nonreachable_impls;
+
+// @has issue_31948/struct.Foo.html
+// @has - '//*[@class="impl"]//code' 'Bark for'
+// @has - '//*[@class="impl"]//code' 'Woof for'
+// @!has - '//*[@class="impl"]//code' 'Bar for'
+// @!has - '//*[@class="impl"]//code' 'Qux for'
+pub use rustdoc_nonreachable_impls::Foo;
+
+// @has issue_31948/trait.Bark.html
+// @has - '//code' 'for Foo'
+// @!has - '//code' 'for Wibble'
+// @!has - '//code' 'for Wobble'
+pub use rustdoc_nonreachable_impls::Bark;
+
+// @has issue_31948/trait.Woof.html
+// @has - '//code' 'for Foo'
+// @!has - '//code' 'for Wibble'
+// @!has - '//code' 'for Wobble'
+pub use rustdoc_nonreachable_impls::Woof;
+
+// @!has issue_31948/trait.Bar.html
+// @!has issue_31948/trait.Qux.html
+// @!has issue_31948/struct.Wibble.html
+// @!has issue_31948/struct.Wobble.html