in region, treat current (and future) item-likes alike

src/librustc/middle/region.rs

@@ -1066,7 +1066,11 @@ fn resolve_local<'a, 'tcx>(visitor: &mut RegionResolutionVisitor<'tcx, 'a>,
     }
 }
 
-fn resolve_item<'a, 'tcx>(visitor: &mut RegionResolutionVisitor<'tcx, 'a>, item: &'tcx hir::Item) {
+fn resolve_item_like<'a, 'tcx, F>(visitor: &mut RegionResolutionVisitor<'tcx, 'a>,
+                                  id: ast::NodeId,
+                                  walk: F)
+    where F: FnOnce(&mut RegionResolutionVisitor<'tcx, 'a>)
+{
     // Items create a new outer block scope as far as we're concerned.
     let prev_cx = visitor.cx;
     let prev_ts = mem::replace(&mut visitor.terminating_scopes, NodeSet());
@@ -1075,8 +1079,8 @@ fn resolve_item<'a, 'tcx>(visitor: &mut RegionResolutionVisitor<'tcx, 'a>, item:
         var_parent: ROOT_CODE_EXTENT,
         parent: ROOT_CODE_EXTENT
     };
-    intravisit::walk_item(visitor, item);
-    visitor.create_item_scope_if_needed(item.id);
+    walk(visitor);
+    visitor.create_item_scope_if_needed(id);
     visitor.cx = prev_cx;
     visitor.terminating_scopes = prev_ts;
 }
@@ -1179,17 +1183,15 @@ impl<'ast, 'a> Visitor<'ast> for RegionResolutionVisitor<'ast, 'a> {
     }
 
     fn visit_item(&mut self, i: &'ast Item) {
-        resolve_item(self, i);
+        resolve_item_like(self, i.id, |this| intravisit::walk_item(this, i));
     }
 
     fn visit_impl_item(&mut self, ii: &'ast hir::ImplItem) {
-        intravisit::walk_impl_item(self, ii);
-        self.create_item_scope_if_needed(ii.id);
+        resolve_item_like(self, ii.id, |this| intravisit::walk_impl_item(this, ii));
     }
 
     fn visit_trait_item(&mut self, ti: &'ast hir::TraitItem) {
-        intravisit::walk_trait_item(self, ti);
-        self.create_item_scope_if_needed(ti.id);
+        resolve_item_like(self, ti.id, |this| intravisit::walk_trait_item(this, ti));
     }
 
     fn visit_fn(&mut self, fk: FnKind<'ast>, fd: &'ast FnDecl,

src/test/run-pass-fulldeps/issue-37290/auxiliary/lint.rs

@@ -0,0 +1,68 @@
+// Copyright 2012-2014 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.
+
+// This flag is needed for plugins to work:
+// compile-flags: -C prefer-dynamic
+
+#![feature(plugin_registrar, rustc_private)]
+#![crate_type = "dylib"]
+#![deny(region_hierarchy)]
+
+extern crate syntax;
+#[macro_use]
+extern crate rustc;
+extern crate rustc_plugin;
+
+use rustc::lint::{LateContext, LintPass, LateLintPass, LintArray, LintContext};
+use rustc::hir;
+use rustc::hir::intravisit::FnKind;
+use rustc::middle::region::CodeExtent;
+use rustc::util::nodemap::FxHashMap;
+
+use syntax::ast::{self, NodeId};
+use syntax::codemap::Span;
+
+declare_lint!(REGION_HIERARCHY, Warn, "warn about bogus region hierarchy");
+
+struct Pass {
+    map: FxHashMap<CodeExtent, NodeId>
+}
+
+impl LintPass for Pass {
+    fn get_lints(&self) -> LintArray { lint_array!(REGION_HIERARCHY) }
+}
+
+impl LateLintPass for Pass {
+    fn check_fn(&mut self, cx: &LateContext,
+                fk: FnKind, _: &hir::FnDecl, expr: &hir::Expr,
+                span: Span, node: ast::NodeId)
+    {
+        if let FnKind::Closure(..) = fk { return }
+
+        let mut extent = cx.tcx.region_maps.node_extent(expr.id);
+        while let Some(parent) = cx.tcx.region_maps.opt_encl_scope(extent) {
+            extent = parent;
+        }
+        if let Some(other) = self.map.insert(extent, node) {
+            cx.span_lint(REGION_HIERARCHY, span, &format!(
+                "different fns {:?}, {:?} with the same root extent {:?}",
+                cx.tcx.map.local_def_id(other),
+                cx.tcx.map.local_def_id(node),
+                extent));
+        }
+    }
+}
+
+#[plugin_registrar]
+pub fn plugin_registrar(reg: &mut ::rustc_plugin::Registry) {
+    reg.register_late_lint_pass(Box::new(
+        Pass { map: FxHashMap() }
+    ));
+}

src/test/run-pass-fulldeps/issue-37290/main.rs

@@ -0,0 +1,30 @@
+// Copyright 2012-2014 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.
+
+// aux-build:lint.rs
+
+#![feature(plugin)]
+#![plugin(lint)]
+
+struct Foo {
+}
+
+impl Foo {
+    fn bar(&self) -> usize {
+    22
+    }
+
+    fn baz(&self) -> usize {
+    22
+    }
+}
+
+fn main() { }
+