Index: lib/Sema/SemaDeclAttr.cpp
===================================================================
--- lib/Sema/SemaDeclAttr.cpp
+++ lib/Sema/SemaDeclAttr.cpp
@@ -3024,15 +3024,18 @@
              << Unsupported << None << CurFeature;
   }
 
-  return true;
+  return false;
 }
 
 static void handleTargetAttr(Sema &S, Decl *D, const AttributeList &AL) {
   StringRef Str;
   SourceLocation LiteralLoc;
   if (!S.checkStringLiteralArgumentAttr(AL, 0, Str, &LiteralLoc) ||
-      !S.checkTargetAttr(LiteralLoc, Str))
+      S.checkTargetAttr(LiteralLoc, Str)) {
+    S.Diag(AL.getLoc(), diag::warn_attribute_ignored) << AL.getName();
     return;
+  }
+
   unsigned Index = AL.getAttributeSpellingListIndex();
   TargetAttr *NewAttr =
       ::new (S.Context) TargetAttr(AL.getRange(), S.Context, Str, Index);
Index: test/Sema/attr-target-ast.c
===================================================================
--- test/Sema/attr-target-ast.c
+++ test/Sema/attr-target-ast.c
@@ -0,0 +1,5 @@
+// RUN: %clang_cc1 -triple x86_64-linux-gnu -ast-dump %s | FileCheck %s
+
+int __attribute__((target("arch=hiss,arch=woof"))) pine_tree() { return 4; }
+// CHECK-NOT: arch=hiss
+// CHECK-NOT: arch=woof
Index: test/Sema/attr-target.c
===================================================================
--- test/Sema/attr-target.c
+++ test/Sema/attr-target.c
@@ -2,12 +2,18 @@
 
 int __attribute__((target("avx,sse4.2,arch=ivybridge"))) foo() { return 4; }
 int __attribute__((target())) bar() { return 4; } //expected-error {{'target' attribute takes one argument}}
+// expected-warning@+1 {{'target' attribute ignored}}
 int __attribute__((target("tune=sandybridge"))) baz() { return 4; } //expected-warning {{ignoring unsupported 'tune=' in the target attribute string}}
+// expected-warning@+1 {{'target' attribute ignored}}
 int __attribute__((target("fpmath=387"))) walrus() { return 4; } //expected-warning {{ignoring unsupported 'fpmath=' in the target attribute string}}
+// expected-warning@+1 {{'target' attribute ignored}}
 int __attribute__((target("avx,sse4.2,arch=hiss"))) meow() {  return 4; }//expected-warning {{ignoring unsupported architecture 'hiss' in the target attribute string}}
+// expected-warning@+1 {{'target' attribute ignored}}
 int __attribute__((target("woof"))) bark() {  return 4; }//expected-warning {{ignoring unsupported 'woof' in the target attribute string}}
 int __attribute__((target("arch="))) turtle() { return 4; } // no warning, same as saying 'nothing'.
+// expected-warning@+1 {{'target' attribute ignored}}
 int __attribute__((target("arch=hiss,arch=woof"))) pine_tree() { return 4; } //expected-warning {{ignoring unsupported architecture 'hiss' in the target attribute string}}
+// expected-warning@+1 {{'target' attribute ignored}}
 int __attribute__((target("arch=ivybridge,arch=haswell"))) oak_tree() { return 4; } //expected-warning {{ignoring duplicate 'arch=' in the target attribute string}}
 
 
Index: test/SemaCXX/attr-target-mv.cpp
===================================================================
--- test/SemaCXX/attr-target-mv.cpp
+++ test/SemaCXX/attr-target-mv.cpp
@@ -1,7 +1,8 @@
 // RUN: %clang_cc1 -triple x86_64-linux-gnu  -fsyntax-only -verify -fexceptions -fcxx-exceptions %s -std=c++14
 void __attribute__((target("default"))) invalid_features(void);
-//expected-error@+2 {{function multiversioning doesn't support feature 'hello_world'}}
-//expected-warning@+1 {{ignoring unsupported 'hello_world' in the target attribute string}}
+//expected-error@+3 {{function declaration is missing 'target' attribute in a multiversioned function}}
+//expected-warning@+2 {{ignoring unsupported 'hello_world' in the target attribute string}}
+//expected-warning@+1 {{'target' attribute ignored}}
 void __attribute__((target("hello_world"))) invalid_features(void);
 //expected-error@+1 {{function multiversioning doesn't support feature 'no-sse4.2'}}
 void __attribute__((target("no-sse4.2"))) invalid_features(void);