test for #37290 using lint

src/test/run-pass/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/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() { }
+