Auto merge of #47013 - topecongiro:issue-46655, r=petrochenkov

Do not expand a derive invocation when derive is not allowed

Closes #46655.

The first commit is what actually closes #46655. The second one is just a refactoring I have done while waiting on a test.

3 files changed, 28 insertions, 3 deletions

diff --git a/src/test/compile-fail/derive-on-trait-item-or-impl-item.rs b/src/test/compile-fail/derive-on-trait-item-or-impl-item.rs
new file mode 100644
index 00000000000..9ff1c14f54c
--- /dev/null
+++ b/src/test/compile-fail/derive-on-trait-item-or-impl-item.rs
@@ -0,0 +1,23 @@
+// Copyright 2017 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 {
+    #[derive(Clone)]
+    //~^ ERROR `derive` may only be applied to structs, enums and unions
+    type Bar;
+}
+
+impl Bar {
+    #[derive(Clone)]
+    //~^ ERROR `derive` may only be applied to structs, enums and unions
+    fn bar(&self) {}
+}
+
+fn main() {}
diff --git a/src/test/run-pass-fulldeps/auxiliary/custom_derive_plugin_attr.rs b/src/test/run-pass-fulldeps/auxiliary/custom_derive_plugin_attr.rs
index 1a9358f22bf..0f90cb3752c 100644
--- a/src/test/run-pass-fulldeps/auxiliary/custom_derive_plugin_attr.rs
+++ b/src/test/run-pass-fulldeps/auxiliary/custom_derive_plugin_attr.rs
@@ -21,6 +21,7 @@ extern crate rustc;
 extern crate rustc_plugin;
 
 use syntax::ast;
+use syntax::attr;
 use syntax::ext::base::{MultiDecorator, ExtCtxt, Annotatable};
 use syntax::ext::build::AstBuilder;
 use syntax::symbol::Symbol;
@@ -80,7 +81,7 @@ fn totalsum_substructure(cx: &mut ExtCtxt, trait_span: Span,
     };
 
     fields.iter().fold(cx.expr_isize(trait_span, 0), |acc, ref item| {
-        if item.attrs.iter().find(|a| a.check_name("ignore")).is_some() {
+        if attr::contains_name(&item.attrs, "ignore") {
             acc
         } else {
             cx.expr_binary(item.span, ast::BinOpKind::Add, acc,
diff --git a/src/test/run-pass-fulldeps/proc-macro/auxiliary/issue-40001-plugin.rs b/src/test/run-pass-fulldeps/proc-macro/auxiliary/issue-40001-plugin.rs
index 29b6cc012b3..0433b11f7c1 100644
--- a/src/test/run-pass-fulldeps/proc-macro/auxiliary/issue-40001-plugin.rs
+++ b/src/test/run-pass-fulldeps/proc-macro/auxiliary/issue-40001-plugin.rs
@@ -17,6 +17,7 @@ extern crate rustc_plugin;
 extern crate syntax;
 
 use rustc_plugin::Registry;
+use syntax::attr;
 use syntax::ext::base::*;
 use syntax::feature_gate::AttributeType::Whitelisted;
 use syntax::symbol::Symbol;
@@ -59,9 +60,9 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MissingWhitelistedAttrPass {
             _ => cx.tcx.hir.expect_item(cx.tcx.hir.get_parent(id)),
         };
 
-        if !item.attrs.iter().any(|a| a.check_name("whitelisted_attr")) {
+        if !attr::contains_name(&item.attrs, "whitelisted_attr") {
             cx.span_lint(MISSING_WHITELISTED_ATTR, span,
-                         "Missing 'whitelited_attr' attribute");
+                         "Missing 'whitelisted_attr' attribute");
         }
     }
 }