Index: lib/CodeGen/CGCall.cpp
===================================================================
--- lib/CodeGen/CGCall.cpp
+++ lib/CodeGen/CGCall.cpp
@@ -4398,10 +4398,23 @@
 
     // Strip away the noreturn attribute to better diagnose unreachable UB.
     if (SanOpts.has(SanitizerKind::Unreachable)) {
+      // Also remove from function since CI->hasFnAttr(..) also checks attributes
+      // of the called function.
       if (auto *F = CI->getCalledFunction())
         F->removeFnAttr(llvm::Attribute::NoReturn);
       CI->removeAttribute(llvm::AttributeList::FunctionIndex,
                           llvm::Attribute::NoReturn);
+
+      // Avoid incompatibility with ASan which relies on the `noreturn`
+      // attribute to insert handler calls.
+      if (SanOpts.has(SanitizerKind::Address)) {
+        SanitizerScope SanScope(this);
+        Builder.SetInsertPoint(CI);
+        auto *FnType = llvm::FunctionType::get(CGM.VoidTy, /*isVarArg=*/false);
+        auto *Fn = CGM.CreateRuntimeFunction(FnType, "__asan_handle_no_return");
+        EmitNounwindRuntimeCall(Fn);
+        Builder.SetInsertPoint(CI->getParent());
+      }
     }
 
     EmitUnreachable(Loc);
Index: lib/CodeGen/CodeGenFunction.h
===================================================================
--- lib/CodeGen/CodeGenFunction.h
+++ lib/CodeGen/CodeGenFunction.h
@@ -4084,8 +4084,8 @@
   /// passing to a runtime sanitizer handler.
   llvm::Constant *EmitCheckSourceLocation(SourceLocation Loc);
 
-  /// Create a basic block that will call a handler function in a
-  /// sanitizer runtime with the provided arguments, and create a conditional
+  /// Create a basic block that will either trap or call a handler function in
+  /// the UBSan runtime with the provided arguments, and create a conditional
   /// branch to it.
   void EmitCheck(ArrayRef<std::pair<llvm::Value *, SanitizerMask>> Checked,
                  SanitizerHandler Check, ArrayRef<llvm::Constant *> StaticArgs,
Index: test/CodeGen/ubsan-asan-noreturn.c
===================================================================
--- test/CodeGen/ubsan-asan-noreturn.c
+++ test/CodeGen/ubsan-asan-noreturn.c
@@ -0,0 +1,21 @@
+// Ensure compatiblity of UBSan unreachable with ASan in the presence of
+// noreturn functions.
+// RUN: %clang_cc1 -fsanitize=unreachable,address -triple x86_64-linux -emit-llvm -o - %s | FileCheck %s
+
+void my_longjmp(void) __attribute__((noreturn));
+
+// CHECK-LABEL: define void @calls_noreturn()
+void calls_noreturn() {
+  my_longjmp();
+  // CHECK:      @__asan_handle_no_return{{.*}} !nosanitize
+  // CHECK-NEXT: @my_longjmp(){{[^#]*}}
+  // CHECK:      @__asan_handle_no_return()
+  // CHECK-NEXT: @__ubsan_handle_builtin_unreachable{{.*}} !nosanitize
+  // CHECK-NEXT: unreachable
+}
+
+// CHECK: declare void @my_longjmp() [[FN_ATTR:#[0-9]+]]
+// CHECK: declare void @__asan_handle_no_return()
+
+// CHECK-LABEL: attributes
+// CHECK-NOT: [[FN_ATTR]] = { {{.*noreturn.*}} }
Index: test/CodeGenCXX/ubsan-unreachable.cpp
===================================================================
--- test/CodeGenCXX/ubsan-unreachable.cpp
+++ test/CodeGenCXX/ubsan-unreachable.cpp
@@ -1,39 +1,37 @@
 // RUN: %clang_cc1 -triple x86_64-apple-darwin10 -emit-llvm -o - %s -fsanitize=unreachable | FileCheck %s
 
-extern void __attribute__((noreturn)) abort();
+void abort() __attribute__((noreturn));
 
-// CHECK-LABEL: define void @_Z14calls_noreturnv
+// CHECK-LABEL: define void @_Z14calls_noreturnv()
 void calls_noreturn() {
+  // Check absence ([^#]*) of call site attributes (including noreturn)
+  // CHECK: call void @_Z5abortv(){{[^#]*}}
   abort();
 
-  // Check that there are no attributes on the call site.
-  // CHECK-NOT: call void @_Z5abortv{{.*}}#
-
   // CHECK: __ubsan_handle_builtin_unreachable
   // CHECK: unreachable
 }
 
 struct A {
-  // CHECK: declare void @_Z5abortv{{.*}} [[ABORT_ATTR:#[0-9]+]]
+  // CHECK: declare void @_Z5abortv() [[EXTERN_FN_ATTR:#[0-9]+]]
 
   // CHECK-LABEL: define linkonce_odr void @_ZN1A5call1Ev
   void call1() {
-    // CHECK-NOT: call void @_ZN1A16does_not_return2Ev{{.*}}#
+    // CHECK: call void @_ZN1A16does_not_return2Ev({{.*}}){{[^#]*}}
     does_not_return2();
 
     // CHECK: __ubsan_handle_builtin_unreachable
     // CHECK: unreachable
   }
 
-  // Test static members.
-  static void __attribute__((noreturn)) does_not_return1() {
-    // CHECK-NOT: call void @_Z5abortv{{.*}}#
+  // Test static members. Checks are below after `struct A` scope ends.
+  static void does_not_return1() __attribute__((noreturn)) {
     abort();
   }
 
   // CHECK-LABEL: define linkonce_odr void @_ZN1A5call2Ev
   void call2() {
-    // CHECK-NOT: call void @_ZN1A16does_not_return1Ev{{.*}}#
+    // CHECK: call void @_ZN1A16does_not_return1Ev(){{[^#]*}}
     does_not_return1();
 
     // CHECK: __ubsan_handle_builtin_unreachable
@@ -41,23 +39,23 @@
   }
 
   // Test calls through pointers to non-static member functions.
-  typedef void __attribute__((noreturn)) (A::*MemFn)();
+  typedef void (A::*MemFn)() __attribute__((noreturn));
 
   // CHECK-LABEL: define linkonce_odr void @_ZN1A5call3Ev
   void call3() {
     MemFn MF = &A::does_not_return2;
+    // CHECK: call void %{{[0-9]+\(.*}}){{[^#]*}}
     (this->*MF)();
 
-    // CHECK-NOT: call void %{{.*}}#
     // CHECK: __ubsan_handle_builtin_unreachable
     // CHECK: unreachable
   }
 
   // Test regular members.
   // CHECK-LABEL: define linkonce_odr void @_ZN1A16does_not_return2Ev({{.*}})
-  // CHECK-SAME: [[DOES_NOT_RETURN_ATTR:#[0-9]+]]
-  void __attribute__((noreturn)) does_not_return2() {
-    // CHECK-NOT: call void @_Z5abortv(){{.*}}#
+  // CHECK-SAME: [[USER_FN_ATTR:#[0-9]+]]
+  void does_not_return2() __attribute__((noreturn)) {
+    // CHECK: call void @_Z5abortv(){{[^#]*}}
     abort();
 
     // CHECK: call void @__ubsan_handle_builtin_unreachable
@@ -68,7 +66,9 @@
   }
 };
 
-// CHECK: define linkonce_odr void @_ZN1A16does_not_return1Ev() [[DOES_NOT_RETURN_ATTR]]
+// CHECK-LABEL: define linkonce_odr void @_ZN1A16does_not_return1Ev()
+// CHECK-SAME: [[USER_FN_ATTR]]
+// CHECK: call void @_Z5abortv(){{[^#]*}}
 
 void force_irgen() {
   A a;
@@ -77,5 +77,7 @@
   a.call3();
 }
 
-// CHECK-NOT: [[ABORT_ATTR]] = {{[^}]+}}noreturn
-// CHECK-NOT: [[DOES_NOT_RETURN_ATTR]] = {{[^}]+}}noreturn
+// `noreturn` should be removed from functions and call sites
+// CHECK-LABEL: attributes
+// CHECK-NOT: [[USER_FN_ATTR]] = { {{.*noreturn.*}} }
+// CHECK-NOT: [[EXTERN_FN_ATTR]] = { {{.*noreturn.*}} }