Use the most recent redecl to decide if it is needed.

This fixes pr14691, which I think is a regression from r168519.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@171077 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 18 insertions, 1 deletions

diff --git a/lib/Sema/Sema.cpp b/lib/Sema/Sema.cpp
index e195bbfff3..e444f3c357 100644
--- a/lib/Sema/Sema.cpp
+++ b/lib/Sema/Sema.cpp
@@ -328,7 +328,7 @@ CastKind Sema::ScalarTypeToBooleanCastKind(QualType ScalarTy) {
 
 /// \brief Used to prune the decls of Sema's UnusedFileScopedDecls vector.
 static bool ShouldRemoveFromUnused(Sema *SemaRef, const DeclaratorDecl *D) {
-  if (D->isUsed())
+  if (D->getMostRecentDecl()->isUsed())
     return true;
 
   if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
diff --git a/test/SemaCXX/warn-func-not-needed.cpp b/test/SemaCXX/warn-func-not-needed.cpp
new file mode 100644
index 0000000000..437a428664
--- /dev/null
+++ b/test/SemaCXX/warn-func-not-needed.cpp
@@ -0,0 +1,17 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -Wall %s
+
+namespace test1 {
+  static void f() {} // expected-warning {{is not needed and will not be emitted}}
+  static void f();
+  template <typename T>
+  void foo() {
+    f();
+  }
+}
+
+namespace test2 {
+  static void f() {}
+  static void f();
+  static void g() { f(); }
+  void h() { g(); }
+}