Index: cfe/trunk/include/clang/Driver/SanitizerArgs.h
===================================================================
--- cfe/trunk/include/clang/Driver/SanitizerArgs.h
+++ cfe/trunk/include/clang/Driver/SanitizerArgs.h
@@ -38,6 +38,7 @@
   bool AsanGlobalsDeadStripping = false;
   bool LinkCXXRuntimes = false;
   bool NeedPIE = false;
+  bool SafeStackRuntime = false;
   bool Stats = false;
   bool TsanMemoryAccess = true;
   bool TsanFuncEntryExit = true;
@@ -58,9 +59,7 @@
   }
   bool needsUbsanRt() const;
   bool needsDfsanRt() const { return Sanitizers.has(SanitizerKind::DataFlow); }
-  bool needsSafeStackRt() const {
-    return Sanitizers.has(SanitizerKind::SafeStack);
-  }
+  bool needsSafeStackRt() const { return SafeStackRuntime; }
   bool needsCfiRt() const;
   bool needsCfiDiagRt() const;
   bool needsStatsRt() const { return Stats; }
Index: cfe/trunk/lib/Driver/SanitizerArgs.cpp
===================================================================
--- cfe/trunk/lib/Driver/SanitizerArgs.cpp
+++ cfe/trunk/lib/Driver/SanitizerArgs.cpp
@@ -605,6 +605,11 @@
     AsanUseAfterScope = false;
   }
 
+  if (AllAddedKinds & SafeStack) {
+    // SafeStack runtime is built into the system on Fuchsia.
+    SafeStackRuntime = !TC.getTriple().isOSFuchsia();
+  }
+
   // Parse -link-cxx-sanitizer flag.
   LinkCXXRuntimes =
       Args.hasArg(options::OPT_fsanitize_link_cxx_runtime) || D.CCCIsCXX();
Index: cfe/trunk/test/Driver/fuchsia.c
===================================================================
--- cfe/trunk/test/Driver/fuchsia.c
+++ cfe/trunk/test/Driver/fuchsia.c
@@ -45,6 +45,8 @@
 // RUN:     -fsanitize=safe-stack 2>&1 \
 // RUN:     | FileCheck %s -check-prefix=CHECK-SAFESTACK
 // CHECK-SAFESTACK: "-fsanitize=safe-stack"
+// CHECK-SAFESTACK-NOT: "{{.*[/\\]}}libclang_rt.safestack-x86_64.a"
+// CHECK-SAFESTACK-NOT: "__safestack_init"
 
 // RUN: %clang %s -### --target=x86_64-unknown-fuchsia \
 // RUN:     -fsanitize=address 2>&1 \