Index: lib/Driver/ToolChains.h
===================================================================
--- lib/Driver/ToolChains.h
+++ lib/Driver/ToolChains.h
@@ -496,6 +496,8 @@
     return TargetVersion < VersionTuple(V0, V1, V2);
   }
 
+  StringRef getOSLibraryNameSuffix() const;
+
 public:
   /// }
   /// @name ToolChain Implementation
Index: lib/Driver/ToolChains.cpp
===================================================================
--- lib/Driver/ToolChains.cpp
+++ lib/Driver/ToolChains.cpp
@@ -319,6 +319,25 @@
   }
 }
 
+StringRef Darwin::getOSLibraryNameSuffix() const {
+  if (isTargetMacOS())
+    return "osx";
+  if (isTargetWatchOSSimulator())
+    return "watchossim";
+  if (isTargetWatchOS())
+    return "watchos";
+  if (isTargetIOSSimulator())
+    return "iossim";
+  if (isTargetIPhoneOS())
+    return "ios";
+  if (isTargetTvOSSimulator())
+    return "tvossim";
+  if (isTargetTvOS())
+    return "tvos";
+
+  llvm_unreachable("Unsuported OS");
+}
+
 void Darwin::addProfileRTLibs(const ArgList &Args,
                               ArgStringList &CmdArgs) const {
   if (!needsProfileRT(Args)) return;
@@ -363,12 +382,11 @@
     // Sanitizer runtime libraries requires C++.
     AddCXXStdlibLibArgs(Args, CmdArgs);
   }
-  // ASan is not supported on watchOS.
-  assert(isTargetMacOS() || isTargetIOSSimulator());
-  StringRef OS = isTargetMacOS() ? "osx" : "iossim";
+
   AddLinkRuntimeLib(
       Args, CmdArgs,
-      (Twine("libclang_rt.") + Sanitizer + "_" + OS + "_dynamic.dylib").str(),
+      (Twine("libclang_rt.") + Sanitizer + "_" +
+       getOSLibraryNameSuffix() + "_dynamic.dylib").str(),
       /*AlwaysLink*/ true, /*IsEmbedded*/ false,
       /*AddRPath*/ true);
 
@@ -1220,8 +1238,7 @@
 
 SanitizerMask Darwin::getSupportedSanitizers() const {
   SanitizerMask Res = ToolChain::getSupportedSanitizers();
-  if (isTargetMacOS() || isTargetIOSSimulator())
-    Res |= SanitizerKind::Address;
+  Res |= SanitizerKind::Address;
   if (isTargetMacOS()) {
     if (!isMacosxVersionLT(10, 9))
       Res |= SanitizerKind::Vptr;
Index: test/Driver/fsanitize.c
===================================================================
--- test/Driver/fsanitize.c
+++ test/Driver/fsanitize.c
@@ -230,7 +230,7 @@
 // CHECK-VPTR-DARWIN-NEW: -fsanitize=alignment,vptr
 
 // RUN: %clang -target armv7-apple-ios7 -miphoneos-version-min=7.0 -fsanitize=address %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-ASAN-IOS
-// CHECK-ASAN-IOS: unsupported option '-fsanitize=address' for target 'arm-apple-ios7'
+// CHECK-ASAN-IOS: -fsanitize=address
 
 // RUN: %clang -target i386-pc-openbsd -fsanitize=address %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-ASAN-OPENBSD
 // CHECK-ASAN-OPENBSD: unsupported option '-fsanitize=address' for target 'i386-pc-openbsd'