Index: cfe/trunk/include/clang/Basic/XRayLists.h
===================================================================
--- cfe/trunk/include/clang/Basic/XRayLists.h
+++ cfe/trunk/include/clang/Basic/XRayLists.h
@@ -37,6 +37,7 @@
     NONE,
     ALWAYS,
     NEVER,
+    ALWAYS_ARG1,
   };
 
   ImbueAttribute shouldImbueFunction(StringRef FunctionName) const;
Index: cfe/trunk/lib/Basic/XRayLists.cpp
===================================================================
--- cfe/trunk/lib/Basic/XRayLists.cpp
+++ cfe/trunk/lib/Basic/XRayLists.cpp
@@ -26,6 +26,8 @@
 XRayFunctionFilter::shouldImbueFunction(StringRef FunctionName) const {
   // First apply the always instrument list, than if it isn't an "always" see
   // whether it's treated as a "never" instrument function.
+  if (AlwaysInstrument->inSection("fun", FunctionName, "arg1"))
+    return ImbueAttribute::ALWAYS_ARG1;
   if (AlwaysInstrument->inSection("fun", FunctionName))
     return ImbueAttribute::ALWAYS;
   if (NeverInstrument->inSection("fun", FunctionName))
Index: cfe/trunk/lib/CodeGen/CodeGenModule.cpp
===================================================================
--- cfe/trunk/lib/CodeGen/CodeGenModule.cpp
+++ cfe/trunk/lib/CodeGen/CodeGenModule.cpp
@@ -1508,6 +1508,10 @@
   case ImbueAttr::ALWAYS:
     Fn->addFnAttr("function-instrument", "xray-always");
     break;
+  case ImbueAttr::ALWAYS_ARG1:
+    Fn->addFnAttr("function-instrument", "xray-always");
+    Fn->addFnAttr("xray-log-args", "1");
+    break;
   case ImbueAttr::NEVER:
     Fn->addFnAttr("function-instrument", "xray-never");
     break;
Index: cfe/trunk/test/CodeGen/xray-imbue-arg1.cpp
===================================================================
--- cfe/trunk/test/CodeGen/xray-imbue-arg1.cpp
+++ cfe/trunk/test/CodeGen/xray-imbue-arg1.cpp
@@ -0,0 +1,12 @@
+// RUN: echo "fun:*arg1*=arg1" >> %t.always-instrument
+// RUN: %clang_cc1 -fxray-instrument -x c++ -std=c++11 -fxray-always-instrument=%t.always-instrument -emit-llvm -o - %s -triple x86_64-unknown-linux-gnu | FileCheck %s
+
+void foo() {}
+
+void arg1(void*) {}
+
+// CHECK: define void @_Z3foov() #[[FOO:[0-9]+]] {
+// CHECK: define void {{.*}}arg1{{.*}} #[[ALWAYSARG1:[0-9]+]] {
+
+// CHECK: attributes #[[FOO]] = {{.*}}
+// CHECK: attributes #[[ALWAYSARG1]] = {{.*}} "function-instrument"="xray-always" {{.*}} "xray-log-args"="1"