Auto merge of #23265 - eddyb:meth-ast-refactor, r=nikomatsakis

The end result is that common fields (id, name, attributes, etc.) are stored in now-structures `ImplItem` and `TraitItem`.
The signature of a method is no longer duplicated between methods with a body (default/impl) and those without, they now share `MethodSig`.

This is also a [breaking-change] because of minor bugfixes and changes to syntax extensions:
* `pub fn` methods in a trait no longer parse - remove the `pub`, it has no meaning anymore
* `MacResult::make_methods` is now `make_impl_items` and the return type has changed accordingly
* `quote_method` is gone, because `P<ast::Method>` doesn't exist and it couldn't represent a full method anyways - could be replaced by `quote_impl_item`/`quote_trait_item` in the future, but I do hope we realize how silly that combinatorial macro expansion is and settle on a single `quote` macro + some type hints - or just no types at all (only token-trees)

r? @nikomatsakis This is necessary (hopefully also sufficient) for associated constants.

3 files changed, 31 insertions, 1 deletions

diff --git a/src/test/parse-fail/issue-21153.rs b/src/test/parse-fail/issue-21153.rs
index e2b6deb0ad9..6496ffebbc8 100644
--- a/src/test/parse-fail/issue-21153.rs
+++ b/src/test/parse-fail/issue-21153.rs
@@ -9,5 +9,5 @@
 // except according to those terms.
 
 trait MyTrait<T>: Iterator {
-    Item = T; //~ ERROR expected one of `extern`, `fn`, `pub`, `type`, or `unsafe`, found `Item`
+    Item = T; //~ ERROR expected one of `extern`, `fn`, `type`, or `unsafe`, found `Item`
 }
diff --git a/src/test/parse-fail/trait-pub-assoc-ty.rs b/src/test/parse-fail/trait-pub-assoc-ty.rs
new file mode 100644
index 00000000000..02d76234d4e
--- /dev/null
+++ b/src/test/parse-fail/trait-pub-assoc-ty.rs
@@ -0,0 +1,15 @@
+// Copyright 2015 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.
+
+trait Foo {
+    pub type Foo; //~ ERROR expected one of `extern`, `fn`, `type`, or `unsafe`, found `pub`
+}
+
+fn main() {}
diff --git a/src/test/parse-fail/trait-pub-method.rs b/src/test/parse-fail/trait-pub-method.rs
new file mode 100644
index 00000000000..e76802d2ea0
--- /dev/null
+++ b/src/test/parse-fail/trait-pub-method.rs
@@ -0,0 +1,15 @@
+// Copyright 2015 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.
+
+trait Foo {
+    pub fn foo(); //~ ERROR expected one of `extern`, `fn`, `type`, or `unsafe`, found `pub`
+}
+
+fn main() {}