Index: lib/Driver/Tools.cpp
===================================================================
--- lib/Driver/Tools.cpp
+++ lib/Driver/Tools.cpp
@@ -4767,7 +4767,20 @@
 
   if (Args.hasFlag(options::OPT_fxray_instrument,
                    options::OPT_fnoxray_instrument, false)) {
-    CmdArgs.push_back("-fxray-instrument");
+    const char* const XRayInstrumentOption = "-fxray-instrument";
+    switch(getToolChain().getArch()) {
+    case llvm::Triple::arm:
+    case llvm::Triple::x86_64:
+      break;
+    default:
+    {
+      std::string Feature(XRayInstrumentOption);
+      Feature += " on ";
+      Feature += Triple.getArchName().data();
+      D.Diag(diag::err_drv_clang_unsupported) << Feature;
+      break;
+    } }
+    CmdArgs.push_back(XRayInstrumentOption);
     if (const Arg *A =
             Args.getLastArg(options::OPT_fxray_instruction_threshold_,
                             options::OPT_fxray_instruction_threshold_EQ)) {
Index: test/Driver/xray-instrument.c
===================================================================
--- test/Driver/xray-instrument.c
+++ test/Driver/xray-instrument.c
@@ -0,0 +1,2 @@
+// RUN: %clang -fxray-instrument %s
+// XFAIL: armeb,aarch64,aarch64_be,avr,bpfel,bpfeb,hexagon,mips,mipsel,mips64,mips64el,msp430,ppc,ppc64,ppc64le,r600,amdgcn,sparc,sparcv9,sparcel,systemz,tce,thumb,thumbeb,x86,xcore,nvptx,nvptx64,le32,le64,amdil,amdil64,hsail,hsail64,spir,spir64,kalimba,shave,lanai,wasm32,wasm64,renderscript32,renderscript64