diff --git a/cmake/modules/OmrDetectSystemInformation.cmake b/cmake/modules/OmrDetectSystemInformation.cmake
index 55bc8e37d7d..d73f0639b07 100644
--- a/cmake/modules/OmrDetectSystemInformation.cmake
+++ b/cmake/modules/OmrDetectSystemInformation.cmake
@@ -193,10 +193,14 @@ macro(omr_detect_system_information)
 			if("${CMAKE_C_SIMULATE_ID}" STREQUAL "MSVC" OR "${CMAKE_CXX_SIMULATE_ID}" STREQUAL "MSVC")
 				# clang on Windows mimics MSVC
 				set(_OMR_TOOLCONFIG "msvc")
-			else()
-				# For openxl, CMAKE_C_COMPILER_ID "Clang 17.x.x" 
+			elseif(CMAKE_C_COMPILER_ID MATCHES "^Clang$")
+				# OpenXL17 uses CMAKE_C_COMPILER_ID "Clang" 
 				set(_OMR_TOOLCONFIG "openxl")
-				set(CMAKE_C_COMPILER_IS_OPENXL TRUE CACHE BOOL "OpenXL is the C compiler")
+				set(CMAKE_C_COMPILER_IS_OPENXL TRUE CACHE BOOL "OpenXL is the C compiler"i)
+			else()
+				# TODO we don't actually have a clang config
+				# just use GNU config
+				set(_OMR_TOOLCONFIG "gnu")
 			endif()
 		elseif(CMAKE_C_COMPILER_ID MATCHES "^XL(Clang)?$" OR CMAKE_C_COMPILER_ID STREQUAL "zOS")
 			# In CMake 3.14 and prior, XLClang uses CMAKE_C_COMPILER_ID "XL"
diff --git a/compiler/compile/OSRData.cpp b/compiler/compile/OSRData.cpp
index 93ae51ba4e0..c4d2346c85a 100644
--- a/compiler/compile/OSRData.cpp
+++ b/compiler/compile/OSRData.cpp
@@ -1515,7 +1515,7 @@ bool TR_OSRCompilationData::TR_ScratchBufferInfo::operator==(const TR_ScratchBuf
 
 #if (defined(TR_HOST_POWER) && defined(TR_TARGET_POWER)                       \
            || defined(TR_HOST_S390) && defined(TR_TARGET_S390))               \
-        && defined(__IBMCPP__)
+        && (defined(__IBMCPP__) || defined(__open_xl__) && defined(__cplusplus))
 __attribute__((__noinline__))
 //This tiny function when inlined by xlC 12 or later at -O3 breaks java -version
 //on Power and causes intermittent crashes on z/OS with xlC 2.1.1
diff --git a/compiler/control/OptimizationPlan.hpp b/compiler/control/OptimizationPlan.hpp
index 0db9e8bd475..49830a1b9ea 100644
--- a/compiler/control/OptimizationPlan.hpp
+++ b/compiler/control/OptimizationPlan.hpp
@@ -39,7 +39,7 @@ namespace TR { class Recompilation; }
 namespace TR { class Monitor; }
 struct TR_MethodToBeCompiled;
 
-#if defined(__IBMCPP__)
+#if defined(__IBMCPP__) || defined(__open_xl__) && defined(__cplusplus)
 // GCC (and other compilers) may assume that operator new cannot return null
 // unless a nothrow specification is provided. For other reasons, we build
 // Testarossa with -qnoeh / -fnoeh to disable exceptions. This is all fine,
diff --git a/compiler/cs2/bitmanip.h b/compiler/cs2/bitmanip.h
index b721afe1964..e071153ae04 100644
--- a/compiler/cs2/bitmanip.h
+++ b/compiler/cs2/bitmanip.h
@@ -29,7 +29,7 @@
 #ifndef CSBITMANIP_H
 #define CSBITMANIP_H
 
-#if defined(__IBMCPP__) && defined (__PPC__)
+#if (defined(__IBMCPP__) || defined(__open_xl__) && defined(__cplusplus)) && defined (__PPC__)
 // to __cntlz4 and related routines
 # include "builtins.h"
 #endif
diff --git a/compiler/env/defines.h b/compiler/env/defines.h
index 5b4d561bc32..8a7ca966f88 100644
--- a/compiler/env/defines.h
+++ b/compiler/env/defines.h
@@ -165,7 +165,7 @@
 /* Compiler macros */
 #if defined(__GNUC__)
 #  define HOST_COMPILER COMPILER_GCC
-#elif defined(__IBMC__) || defined(__IBMCPP__)
+#elif defined(__IBMC__) || defined(__IBMCPP__) || defined(__open_xl__)
 #  define HOST_COMPILER COMPILER_XLC
 #elif defined(_MSC_VER)
 #  define HOST_COMPILER COMPILER_MSVC
diff --git a/compiler/env/jittypes.h b/compiler/env/jittypes.h
index 607e01900f3..3546b01b346 100644
--- a/compiler/env/jittypes.h
+++ b/compiler/env/jittypes.h
@@ -139,7 +139,7 @@ typedef struct TR_InlinedCallSite
       #define FLUSH_MEMORY(smp)
    #endif
 #else
-   #if defined(__IBMC__) || defined(__IBMCPP__)
+   #if defined(__IBMC__) || defined(__IBMCPP__) || defined(__open_xl__)
       #if defined(__cplusplus)
       #include <builtins.h>
       #endif /* __cplusplus */
diff --git a/compiler/infra/Annotations.hpp b/compiler/infra/Annotations.hpp
index 7bc9e08fe0b..c5d598a6cb0 100644
--- a/compiler/infra/Annotations.hpp
+++ b/compiler/infra/Annotations.hpp
@@ -64,7 +64,7 @@
 #define OMR_NORETURN _declspec(noreturn)
 #elif defined(__GNUC__)
 #define OMR_NORETURN __attribute__ ((noreturn))
-#elif defined(__IBMCPP__)
+#elif defined(__IBMCPP__) || defined(__open_xl__) && defined(__cplusplus)
 #define OMR_NORETURN __attribute__ ((noreturn))
 #else
 #warning "Noreturn attribute undefined for this platform."
diff --git a/compiler/p/runtime/PPCCodeSync.inc b/compiler/p/runtime/PPCCodeSync.inc
index 93dd59955bd..0cf4a741654 100644
--- a/compiler/p/runtime/PPCCodeSync.inc
+++ b/compiler/p/runtime/PPCCodeSync.inc
@@ -25,7 +25,7 @@
 extern "C" void *getCodeSync();
 
 #if defined(TR_HOST_POWER)
-#if defined(__IBMC__) || defined(__IBMCPP__)
+#if defined(__IBMC__) || defined(__IBMCPP__) || defined(__open_xl__)
 
 #if defined(__cplusplus)
 #include <builtins.h>
@@ -35,7 +35,7 @@ extern "C" void *getCodeSync();
 #define sync() __sync()
 #define isync() __isync()
 
-#else /* defined(__IBMC__) || defined(__IBMCPP__) */
+#else /* defined(__IBMC__) || defined(__IBMCPP__) || defined(__open_xl__) */
 
 static inline void dcbf(unsigned char *addr)
    {
@@ -55,7 +55,7 @@ static inline void isync()
    __asm__("isync");
    }
 
-#endif /* defined(__IBMC__) || defined(__IBMCPP__) */
+#endif /* defined(__IBMC__) || defined(__IBMCPP__) || defined(__open_xl__) */
 
 static inline void icbi(unsigned char *addr)
    {
diff --git a/compiler/runtime/OMRRuntimeAssumptions.cpp b/compiler/runtime/OMRRuntimeAssumptions.cpp
index 8709188a155..a7ff0248773 100644
--- a/compiler/runtime/OMRRuntimeAssumptions.cpp
+++ b/compiler/runtime/OMRRuntimeAssumptions.cpp
@@ -22,7 +22,7 @@
 #include "runtime/OMRRuntimeAssumptions.hpp"
 #include "env/jittypes.h"
 
-#if defined(__IBMCPP__) && !defined(AIXPPC) && !defined(LINUXPPC)
+#if (defined(__IBMCPP__) || defined(__open_xl__) && defined(__cplusplus)) && !defined(AIXPPC) && !defined(LINUXPPC)
 #define ASM_CALL __cdecl
 #else
 #define ASM_CALL
diff --git a/compiler/runtime/Runtime.cpp b/compiler/runtime/Runtime.cpp
index ab0dfe842a9..1dfbd1297b8 100644
--- a/compiler/runtime/Runtime.cpp
+++ b/compiler/runtime/Runtime.cpp
@@ -23,7 +23,7 @@
 
 TR_RuntimeHelperTable runtimeHelpers;
 
-#if (defined(__IBMCPP__) || defined(__IBMC__) && !defined(MVS)) && !defined(LINUXPPC64)
+#if (defined(__IBMCPP__) || defined(__IBMC__) && !defined(MVS)) && !defined(LINUXPPC64) || defined(__open_xl__)
  #if defined(AIXPPC)
   #define JIT_HELPER(x) extern "C" void *x
  #else
diff --git a/include_core/omrcomp.h b/include_core/omrcomp.h
index a4c6d44c7dc..b0b5a6bb373 100644
--- a/include_core/omrcomp.h
+++ b/include_core/omrcomp.h
@@ -603,7 +603,7 @@ typedef struct U_128 {
 
 #if defined(_MSC_VER) && (1900 > _MSC_VER) /* MSVC versions prior to Visual Studio 2015 (14.0) */
 #define OMR_ALIGNOF(x) __alignof(x)
-#elif defined(__IBMC__) || defined(__IBMCPP__) /* XL C/C++ versions prior to xlclang/xlclang++ */
+#elif defined(__IBMC__) || defined(__IBMCPP__) || defined(__open_xl__) /* XL C/C++ versions prior to xlclang/xlclang++ */
 #define OMR_ALIGNOF(x) __alignof__(x)
 #else /* All other compilers that support C11 and C++11 */
 #define OMR_ALIGNOF(x) alignof(x)
diff --git a/third_party/gtest-1.8.0/include/gtest/internal/gtest-port.h b/third_party/gtest-1.8.0/include/gtest/internal/gtest-port.h
index 79559f29b2e..21e72261efe 100644
--- a/third_party/gtest-1.8.0/include/gtest/internal/gtest-port.h
+++ b/third_party/gtest-1.8.0/include/gtest/internal/gtest-port.h
@@ -478,7 +478,7 @@ struct _RTL_CRITICAL_SECTION;
 // detecting whether they are enabled or not.  Therefore, we assume that
 // they are enabled unless the user tells us otherwise.
 #  define GTEST_HAS_EXCEPTIONS 1
-# elif defined(__IBMCPP__) && __EXCEPTIONS
+# elif (defined(__IBMCPP__) || defined(__open_xl__) && defined(__cplusplus)) && __EXCEPTIONS
 // xlC defines __EXCEPTIONS to 1 iff exceptions are enabled.
 #  define GTEST_HAS_EXCEPTIONS 1
 # elif defined(__HP_aCC)
@@ -570,7 +570,7 @@ struct _RTL_CRITICAL_SECTION;
 
 // Starting with version 9.0 IBM Visual Age defines __RTTI_ALL__ to 1 if
 // both the typeid and dynamic_cast features are present.
-# elif defined(__IBMCPP__) && (__IBMCPP__ >= 900)
+# elif defined(__IBMCPP__) && (__IBMCPP__ >= 900) || defined(__open_xl__) && defined(__cplusplus)
 
 #  ifdef __RTTI_ALL__
 #   define GTEST_HAS_RTTI 1
@@ -821,7 +821,7 @@ using ::std::tuple_size;
 // Typed tests need <typeinfo> and variadic macros, which GCC, VC++ 8.0,
 // Sun Pro CC, IBM Visual Age, and HP aCC support.
 #if defined(__GNUC__) || (_MSC_VER >= 1400) || defined(__SUNPRO_CC) || \
-    defined(__IBMCPP__) || defined(__HP_aCC)
+    defined(__IBMCPP__) || defined(__HP_aCC) || defined(__open_xl__) && defined(__cplusplus)
 # define GTEST_HAS_TYPED_TEST 1
 # define GTEST_HAS_TYPED_TEST_P 1
 #endif
@@ -2200,7 +2200,7 @@ GTEST_API_ size_t GetThreadCount();
 // for objects passed through ellipsis (...), failing for uncopyable
 // objects.  We define this to ensure that only POD is passed through
 // ellipsis on these systems.
-#if defined(__SYMBIAN32__) || defined(__IBMCPP__) || defined(__SUNPRO_CC)
+#if defined(__SYMBIAN32__) || defined(__IBMCPP__) || defined(__SUNPRO_CC) || defined(__open_xl__) && defined(__cplusplus)
 // We lose support for NULL detection where the compiler doesn't like
 // passing non-POD classes through ellipsis (...).
 # define GTEST_ELLIPSIS_NEEDS_POD_ 1
@@ -2212,7 +2212,7 @@ GTEST_API_ size_t GetThreadCount();
 // const T& and const T* in a function template.  These compilers
 // _can_ decide between class template specializations for T and T*,
 // so a tr1::type_traits-like is_pointer works.
-#if defined(__SYMBIAN32__) || defined(__IBMCPP__)
+#if defined(__SYMBIAN32__) || defined(__IBMCPP__) || defined(__open_xl__) && defined(__cplusplus)
 # define GTEST_NEEDS_IS_POINTER_ 1
 #endif