diff --git a/include/dxc/Support/WinAdapter.h b/include/dxc/Support/WinAdapter.h
index ac96f63b0c..be36410515 100644
--- a/include/dxc/Support/WinAdapter.h
+++ b/include/dxc/Support/WinAdapter.h
@@ -50,15 +50,9 @@
 #define _countof(a) (sizeof(a) / sizeof(*(a)))
 
 // If it is GCC, there is no UUID support and we must emulate it.
-#ifdef __APPLE__
-#define __EMULATE_UUID 1
-#else // __APPLE__
-#ifdef __GNUC__
 #ifndef __clang__
 #define __EMULATE_UUID 1
-#endif // __GNUC__
 #endif // __clang__
-#endif // __APPLE__
 
 #ifdef __EMULATE_UUID
 #define __declspec(x)
@@ -452,15 +446,14 @@ typedef GUID CLSID;
 typedef const GUID &REFGUID;
 typedef const GUID &REFCLSID;
 
-#ifdef __EMULATE_UUID
-typedef const void *REFIID;
-#define IsEqualIID(a, b) a == b
-#define IsEqualCLSID(a, b) !memcmp(&a, &b, sizeof(GUID))
-#else  // __EMULATE_UUID
 typedef GUID IID;
 typedef IID *LPIID;
 typedef const IID &REFIID;
 inline bool IsEqualGUID(REFGUID rguid1, REFGUID rguid2) {
+  // Optimization:
+  if (&rguid1 == &rguid2)
+    return true;
+
   return !memcmp(&rguid1, &rguid2, sizeof(GUID));
 }
 
@@ -479,7 +472,6 @@ inline bool IsEqualIID(REFIID riid1, REFIID riid2) {
 inline bool IsEqualCLSID(REFCLSID rclsid1, REFCLSID rclsid2) {
   return IsEqualGUID(rclsid1, rclsid2);
 }
-#endif // __EMULATE_UUID
 
 //===--------------------- Struct Types -----------------------------------===//
 
@@ -559,27 +551,63 @@ enum tagSTATFLAG {
 
 #ifdef __EMULATE_UUID
 
-size_t UuidStrHash(const char* k);
-
 // The following macros are defined to facilitate the lack of 'uuid' on Linux.
-#define DECLARE_CROSS_PLATFORM_UUIDOF(T)                                       \
-public:                                                                        \
-  static REFIID uuidof() { return reinterpret_cast<REFIID>(T##_ID); }          \
-                                                                               \
-private:                                                                       \
-  __attribute__((visibility("default"))) static const size_t T##_ID;
-
-#define DEFINE_CROSS_PLATFORM_UUIDOF(T)                                        \
-  __attribute__((visibility("default"))) const size_t T::T##_ID =              \
-      UuidStrHash(#T);
-#define __uuidof(T) T::uuidof()
+
+constexpr uint8_t nybble_from_hex(char c) {
+  return ((c >= '0' && c <= '9')
+              ? (c - '0')
+              : ((c >= 'a' && c <= 'f')
+                     ? (c - 'a' + 10)
+                     : ((c >= 'A' && c <= 'F') ? (c - 'A' + 10)
+                                               : /* Should be an error */ -1)));
+}
+
+constexpr uint8_t byte_from_hex(char c1, char c2) {
+  return nybble_from_hex(c1) << 4 | nybble_from_hex(c2);
+}
+
+constexpr uint8_t byte_from_hexstr(const char str[2]) {
+  return nybble_from_hex(str[0]) << 4 | nybble_from_hex(str[1]);
+}
+
+constexpr GUID guid_from_string(const char str[37]) {
+  return GUID{static_cast<uint32_t>(byte_from_hexstr(str)) << 24 |
+                  static_cast<uint32_t>(byte_from_hexstr(str + 2)) << 16 |
+                  static_cast<uint32_t>(byte_from_hexstr(str + 4)) << 8 |
+                  byte_from_hexstr(str + 6),
+              static_cast<uint16_t>(
+                  static_cast<uint16_t>(byte_from_hexstr(str + 9)) << 8 |
+                  byte_from_hexstr(str + 11)),
+              static_cast<uint16_t>(
+                  static_cast<uint16_t>(byte_from_hexstr(str + 14)) << 8 |
+                  byte_from_hexstr(str + 16)),
+              {byte_from_hexstr(str + 19), byte_from_hexstr(str + 21),
+               byte_from_hexstr(str + 24), byte_from_hexstr(str + 26),
+               byte_from_hexstr(str + 28), byte_from_hexstr(str + 30),
+               byte_from_hexstr(str + 32), byte_from_hexstr(str + 34)}};
+}
+
+template <typename interface> inline GUID __emulated_uuidof();
+
+#define CROSS_PLATFORM_UUIDOF(interface, spec)                                 \
+  struct interface;                                                            \
+  template <> inline GUID __emulated_uuidof<interface>() {                     \
+    static const IID _IID = guid_from_string(spec);                            \
+    return _IID;                                                               \
+  }
+
+#define __uuidof(T) __emulated_uuidof<typename std::decay<T>::type>()
+
 #define IID_PPV_ARGS(ppType)                                                   \
-  (**(ppType)).uuidof(), reinterpret_cast<void **>(ppType)
+  __uuidof(decltype(**(ppType))), reinterpret_cast<void **>(ppType)
 
 #else // __EMULATE_UUID
 
-#define DECLARE_CROSS_PLATFORM_UUIDOF(T)
-#define DEFINE_CROSS_PLATFORM_UUIDOF(T)
+#ifndef CROSS_PLATFORM_UUIDOF
+// Warning: This macro exists in dxcapi.h as well
+#define CROSS_PLATFORM_UUIDOF(interface, spec)                                 \
+  struct __declspec(uuid(spec)) interface;
+#endif
 
 template <typename T> inline void **IID_PPV_ARGS_Helper(T **pp) {
   return reinterpret_cast<void **>(pp);
@@ -590,8 +618,9 @@ template <typename T> inline void **IID_PPV_ARGS_Helper(T **pp) {
 
 //===--------------------- COM Interfaces ---------------------------------===//
 
-struct __declspec(uuid("00000000-0000-0000-C000-000000000046")) IUnknown {
-  IUnknown() : m_count(0){};
+CROSS_PLATFORM_UUIDOF(IUnknown, "00000000-0000-0000-C000-000000000046")
+struct IUnknown {
+  IUnknown() : m_count(0) {};
   virtual HRESULT QueryInterface(REFIID riid, void **ppvObject) = 0;
   virtual ULONG AddRef();
   virtual ULONG Release();
@@ -602,33 +631,27 @@ struct __declspec(uuid("00000000-0000-0000-C000-000000000046")) IUnknown {
 
 private:
   std::atomic<unsigned long> m_count;
-
-  DECLARE_CROSS_PLATFORM_UUIDOF(IUnknown)
 };
 
-struct __declspec(uuid("ECC8691B-C1DB-4DC0-855E-65F6C551AF49")) INoMarshal
-    : public IUnknown {
-  DECLARE_CROSS_PLATFORM_UUIDOF(INoMarshal)
-};
+CROSS_PLATFORM_UUIDOF(INoMarshal, "ECC8691B-C1DB-4DC0-855E-65F6C551AF49")
+struct INoMarshal : public IUnknown {};
 
-struct __declspec(uuid("00000002-0000-0000-C000-000000000046")) IMalloc
-    : public IUnknown {
+CROSS_PLATFORM_UUIDOF(IMalloc, "00000002-0000-0000-C000-000000000046")
+struct IMalloc : public IUnknown {
   virtual void *Alloc(size_t size);
   virtual void *Realloc(void *ptr, size_t size);
   virtual void Free(void *ptr);
   virtual HRESULT QueryInterface(REFIID riid, void **ppvObject);
 };
 
-struct __declspec(uuid("0C733A30-2A1C-11CE-ADE5-00AA0044773D"))
-    ISequentialStream : public IUnknown {
+CROSS_PLATFORM_UUIDOF(ISequentialStream, "0C733A30-2A1C-11CE-ADE5-00AA0044773D")
+struct ISequentialStream : public IUnknown {
   virtual HRESULT Read(void *pv, ULONG cb, ULONG *pcbRead) = 0;
   virtual HRESULT Write(const void *pv, ULONG cb, ULONG *pcbWritten) = 0;
-
-  DECLARE_CROSS_PLATFORM_UUIDOF(ISequentialStream)
 };
 
-struct __declspec(uuid("0000000c-0000-0000-C000-000000000046")) IStream
-    : public ISequentialStream {
+CROSS_PLATFORM_UUIDOF(IStream, "0000000c-0000-0000-C000-000000000046")
+struct IStream : public ISequentialStream {
   virtual HRESULT Seek(LARGE_INTEGER dlibMove, DWORD dwOrigin,
                        ULARGE_INTEGER *plibNewPosition) = 0;
   virtual HRESULT SetSize(ULARGE_INTEGER libNewSize) = 0;
@@ -649,8 +672,6 @@ struct __declspec(uuid("0000000c-0000-0000-C000-000000000046")) IStream
   virtual HRESULT Stat(STATSTG *pstatstg, DWORD grfStatFlag) = 0;
 
   virtual HRESULT Clone(IStream **ppstm) = 0;
-
-  DECLARE_CROSS_PLATFORM_UUIDOF(IStream)
 };
 
 //===--------------------- COM Pointer Types ------------------------------===//
diff --git a/include/dxc/dxcapi.h b/include/dxc/dxcapi.h
index 897368c07b..e02418732d 100644
--- a/include/dxc/dxcapi.h
+++ b/include/dxc/dxcapi.h
@@ -24,9 +24,15 @@
 #endif
 
 #ifdef _WIN32
-#define DECLARE_CROSS_PLATFORM_UUIDOF(T)
-#define DEFINE_CROSS_PLATFORM_UUIDOF(T)
+
+#ifndef CROSS_PLATFORM_UUIDOF
+// Warning: This macro exists in WinAdapter.h as well
+#define CROSS_PLATFORM_UUIDOF(interface, spec)                                 \
+  struct __declspec(uuid(spec)) interface;
+#endif
+
 #else
+
 #include <dlfcn.h>
 #include "dxc/Support/WinAdapter.h"
 #endif
@@ -133,22 +139,18 @@ typedef struct DxcShaderHash {
 #define DXC_ARG_DEBUG_NAME_FOR_BINARY L"-Zsb"
 
 // IDxcBlob is an alias of ID3D10Blob and ID3DBlob
-struct __declspec(uuid("8BA5FB08-5195-40e2-AC58-0D989C3A0102"))
-IDxcBlob : public IUnknown {
+CROSS_PLATFORM_UUIDOF(IDxcBlob, "8BA5FB08-5195-40e2-AC58-0D989C3A0102")
+struct IDxcBlob : public IUnknown {
 public:
   virtual LPVOID STDMETHODCALLTYPE GetBufferPointer(void) = 0;
   virtual SIZE_T STDMETHODCALLTYPE GetBufferSize(void) = 0;
-
-  DECLARE_CROSS_PLATFORM_UUIDOF(IDxcBlob)
 };
 
-struct __declspec(uuid("7241d424-2646-4191-97c0-98e96e42fc68"))
-IDxcBlobEncoding : public IDxcBlob {
+CROSS_PLATFORM_UUIDOF(IDxcBlobEncoding, "7241d424-2646-4191-97c0-98e96e42fc68")
+struct IDxcBlobEncoding : public IDxcBlob {
 public:
   virtual HRESULT STDMETHODCALLTYPE GetEncoding(_Out_ BOOL *pKnown,
                                                 _Out_ UINT32 *pCodePage) = 0;
-
-  DECLARE_CROSS_PLATFORM_UUIDOF(IDxcBlobEncoding)
 };
 
 // Notes on IDxcBlobUtf16 and IDxcBlobUtf8
@@ -160,31 +162,25 @@ IDxcBlobEncoding : public IDxcBlob {
 // on the -encoding option.
 
 // The API will use this interface for output name strings
-struct __declspec(uuid("A3F84EAB-0FAA-497E-A39C-EE6ED60B2D84"))
-IDxcBlobUtf16 : public IDxcBlobEncoding {
+CROSS_PLATFORM_UUIDOF(IDxcBlobUtf16, "A3F84EAB-0FAA-497E-A39C-EE6ED60B2D84")
+struct IDxcBlobUtf16 : public IDxcBlobEncoding {
 public:
   virtual LPCWSTR STDMETHODCALLTYPE GetStringPointer(void) = 0;
   virtual SIZE_T STDMETHODCALLTYPE GetStringLength(void) = 0;
-
-  DECLARE_CROSS_PLATFORM_UUIDOF(IDxcBlobUtf16)
 };
-struct __declspec(uuid("3DA636C9-BA71-4024-A301-30CBF125305B"))
-IDxcBlobUtf8 : public IDxcBlobEncoding {
+CROSS_PLATFORM_UUIDOF(IDxcBlobUtf8, "3DA636C9-BA71-4024-A301-30CBF125305B")
+struct IDxcBlobUtf8 : public IDxcBlobEncoding {
 public:
   virtual LPCSTR STDMETHODCALLTYPE GetStringPointer(void) = 0;
   virtual SIZE_T STDMETHODCALLTYPE GetStringLength(void) = 0;
-
-  DECLARE_CROSS_PLATFORM_UUIDOF(IDxcBlobUtf8)
 };
 
-struct __declspec(uuid("7f61fc7d-950d-467f-b3e3-3c02fb49187c"))
-IDxcIncludeHandler : public IUnknown {
+CROSS_PLATFORM_UUIDOF(IDxcIncludeHandler, "7f61fc7d-950d-467f-b3e3-3c02fb49187c")
+struct IDxcIncludeHandler : public IUnknown {
   virtual HRESULT STDMETHODCALLTYPE LoadSource(
     _In_z_ LPCWSTR pFilename,                                 // Candidate filename.
     _COM_Outptr_result_maybenull_ IDxcBlob **ppIncludeSource  // Resultant source object for included file, nullptr if not found.
     ) = 0;
-
-  DECLARE_CROSS_PLATFORM_UUIDOF(IDxcIncludeHandler)
 };
 
 // Structure for supplying bytes or text input to Dxc APIs.
@@ -200,8 +196,8 @@ struct DxcDefine {
   _Maybenull_ LPCWSTR Value;
 };
 
-struct __declspec(uuid("73EFFE2A-70DC-45F8-9690-EFF64C02429D"))
-IDxcCompilerArgs : public IUnknown {
+CROSS_PLATFORM_UUIDOF(IDxcCompilerArgs, "73EFFE2A-70DC-45F8-9690-EFF64C02429D")
+struct IDxcCompilerArgs : public IUnknown {
   // Pass GetArguments() and GetCount() to Compile
   virtual LPCWSTR* STDMETHODCALLTYPE GetArguments() = 0;
   virtual UINT32 STDMETHODCALLTYPE GetCount() = 0;
@@ -219,8 +215,6 @@ IDxcCompilerArgs : public IUnknown {
       _In_count_(defineCount) const DxcDefine *pDefines, // Array of defines
       _In_ UINT32 defineCount                            // Number of defines
   ) = 0;
-
-  DECLARE_CROSS_PLATFORM_UUIDOF(IDxcCompilerArgs)
 };
 
 //////////////////////////
@@ -228,8 +222,8 @@ IDxcCompilerArgs : public IUnknown {
 /////////////////////////
 
 // NOTE: IDxcUtils replaces IDxcLibrary
-struct __declspec(uuid("e5204dc7-d18c-4c3c-bdfb-851673980fe7"))
-IDxcLibrary : public IUnknown {
+CROSS_PLATFORM_UUIDOF(IDxcLibrary, "e5204dc7-d18c-4c3c-bdfb-851673980fe7")
+struct IDxcLibrary : public IUnknown {
   virtual HRESULT STDMETHODCALLTYPE SetMalloc(_In_opt_ IMalloc *pMalloc) = 0;
   virtual HRESULT STDMETHODCALLTYPE CreateBlobFromBlob(
     _In_ IDxcBlob *pBlob, UINT32 offset, UINT32 length, _COM_Outptr_ IDxcBlob **ppResult) = 0;
@@ -253,13 +247,11 @@ IDxcLibrary : public IUnknown {
     _In_ IDxcBlob *pBlob, _COM_Outptr_ IDxcBlobEncoding **pBlobEncoding) = 0;
   virtual HRESULT STDMETHODCALLTYPE GetBlobAsUtf16(
     _In_ IDxcBlob *pBlob, _COM_Outptr_ IDxcBlobEncoding **pBlobEncoding) = 0;
-
-  DECLARE_CROSS_PLATFORM_UUIDOF(IDxcLibrary)
 };
 
 // NOTE: IDxcResult replaces IDxcOperationResult
-struct __declspec(uuid("CEDB484A-D4E9-445A-B991-CA21CA157DC2"))
-IDxcOperationResult : public IUnknown {
+CROSS_PLATFORM_UUIDOF(IDxcOperationResult, "CEDB484A-D4E9-445A-B991-CA21CA157DC2")
+struct IDxcOperationResult : public IUnknown {
   virtual HRESULT STDMETHODCALLTYPE GetStatus(_Out_ HRESULT *pStatus) = 0;
 
   // GetResult returns the main result of the operation.
@@ -272,13 +264,11 @@ IDxcOperationResult : public IUnknown {
 
   // GetErrorBuffer Corresponds to DXC_OUT_ERRORS.
   virtual HRESULT STDMETHODCALLTYPE GetErrorBuffer(_COM_Outptr_result_maybenull_ IDxcBlobEncoding **ppErrors) = 0;
-
-  DECLARE_CROSS_PLATFORM_UUIDOF(IDxcOperationResult)
 };
 
 // NOTE: IDxcCompiler3 replaces IDxcCompiler and IDxcCompiler2
-struct __declspec(uuid("8c210bf3-011f-4422-8d70-6f9acb8db617"))
-IDxcCompiler : public IUnknown {
+CROSS_PLATFORM_UUIDOF(IDxcCompiler, "8c210bf3-011f-4422-8d70-6f9acb8db617")
+struct IDxcCompiler : public IUnknown {
   // Compile a single entry point to the target shader model
   virtual HRESULT STDMETHODCALLTYPE Compile(
     _In_ IDxcBlob *pSource,                       // Source text to compile
@@ -312,13 +302,11 @@ IDxcCompiler : public IUnknown {
     _In_ IDxcBlob *pSource,                         // Program to disassemble.
     _COM_Outptr_ IDxcBlobEncoding **ppDisassembly   // Disassembly text.
     ) = 0;
-
-  DECLARE_CROSS_PLATFORM_UUIDOF(IDxcCompiler)
 };
 
 // NOTE: IDxcCompiler3 replaces IDxcCompiler and IDxcCompiler2
-struct __declspec(uuid("A005A9D9-B8BB-4594-B5C9-0E633BEC4D37"))
-IDxcCompiler2 : public IDxcCompiler {
+CROSS_PLATFORM_UUIDOF(IDxcCompiler2, "A005A9D9-B8BB-4594-B5C9-0E633BEC4D37")
+struct IDxcCompiler2 : public IDxcCompiler {
   // Compile a single entry point to the target shader model with debug information.
   virtual HRESULT STDMETHODCALLTYPE CompileWithDebug(
     _In_ IDxcBlob *pSource,                       // Source text to compile
@@ -335,12 +323,10 @@ IDxcCompiler2 : public IDxcCompiler {
     _Outptr_opt_result_z_ LPWSTR *ppDebugBlobName,// Suggested file name for debug blob. (Must be HeapFree()'d!)
     _COM_Outptr_opt_ IDxcBlob **ppDebugBlob       // Debug blob
   ) = 0;
-
-  DECLARE_CROSS_PLATFORM_UUIDOF(IDxcCompiler2)
 };
 
-struct __declspec(uuid("F1B5BE2A-62DD-4327-A1C2-42AC1E1E78E6"))
-IDxcLinker : public IUnknown {
+CROSS_PLATFORM_UUIDOF(IDxcLinker, "F1B5BE2A-62DD-4327-A1C2-42AC1E1E78E6")
+struct IDxcLinker : public IUnknown {
 public:
   // Register a library with name to ref it later.
   virtual HRESULT RegisterLibrary(
@@ -361,8 +347,6 @@ IDxcLinker : public IUnknown {
     _COM_Outptr_
         IDxcOperationResult **ppResult  // Linker output status, buffer, and errors
   ) = 0;
-
-  DECLARE_CROSS_PLATFORM_UUIDOF(IDxcLinker)
 };
 
 /////////////////////////
@@ -370,8 +354,8 @@ IDxcLinker : public IUnknown {
 ////////////////////////
 
 // NOTE: IDxcUtils replaces IDxcLibrary
-struct __declspec(uuid("4605C4CB-2019-492A-ADA4-65F20BB7D67F"))
-IDxcUtils : public IUnknown {
+CROSS_PLATFORM_UUIDOF(IDxcUtils, "4605C4CB-2019-492A-ADA4-65F20BB7D67F")
+struct IDxcUtils : public IUnknown {
   // Create a sub-blob that holds a reference to the outer blob and points to its memory.
   virtual HRESULT STDMETHODCALLTYPE CreateBlobFromBlob(
     _In_ IDxcBlob *pBlob, UINT32 offset, UINT32 length, _COM_Outptr_ IDxcBlob **ppResult) = 0;
@@ -444,8 +428,6 @@ IDxcUtils : public IUnknown {
   // Takes the shader PDB and returns the hash and the container inside it
   virtual HRESULT STDMETHODCALLTYPE GetPDBContents(
     _In_ IDxcBlob *pPDBBlob, _COM_Outptr_ IDxcBlob **ppHash, _COM_Outptr_ IDxcBlob **ppContainer) = 0;
-
-  DECLARE_CROSS_PLATFORM_UUIDOF(IDxcUtils)
 };
 
 // For use with IDxcResult::[Has|Get]Output dxcOutKind argument
@@ -466,8 +448,8 @@ typedef enum DXC_OUT_KIND {
   DXC_OUT_FORCE_DWORD = 0xFFFFFFFF
 } DXC_OUT_KIND;
 
-struct __declspec(uuid("58346CDA-DDE7-4497-9461-6F87AF5E0659"))
-IDxcResult : public IDxcOperationResult {
+CROSS_PLATFORM_UUIDOF(IDxcResult, "58346CDA-DDE7-4497-9461-6F87AF5E0659")
+struct IDxcResult : public IDxcOperationResult {
   virtual BOOL STDMETHODCALLTYPE HasOutput(_In_ DXC_OUT_KIND dxcOutKind) = 0;
   virtual HRESULT STDMETHODCALLTYPE GetOutput(_In_ DXC_OUT_KIND dxcOutKind,
     _In_ REFIID iid, _COM_Outptr_opt_result_maybenull_ void **ppvObject,
@@ -476,28 +458,24 @@ IDxcResult : public IDxcOperationResult {
   virtual UINT32 GetNumOutputs() = 0;
   virtual DXC_OUT_KIND GetOutputByIndex(UINT32 Index) = 0;
   virtual DXC_OUT_KIND PrimaryOutput() = 0;
-
-  DECLARE_CROSS_PLATFORM_UUIDOF(IDxcResult)
 };
 
 // Special names for extra output that should get written to specific streams
 #define DXC_EXTRA_OUTPUT_NAME_STDOUT L"*stdout*"
 #define DXC_EXTRA_OUTPUT_NAME_STDERR L"*stderr*"
 
-struct __declspec(uuid("319b37a2-a5c2-494a-a5de-4801b2faf989"))
-IDxcExtraOutputs : public IUnknown {
+CROSS_PLATFORM_UUIDOF(IDxcExtraOutputs, "319b37a2-a5c2-494a-a5de-4801b2faf989")
+struct IDxcExtraOutputs : public IUnknown {
 
   virtual UINT32 STDMETHODCALLTYPE GetOutputCount() = 0;
   virtual HRESULT STDMETHODCALLTYPE GetOutput(_In_ UINT32 uIndex,
     _In_ REFIID iid, _COM_Outptr_opt_result_maybenull_ void **ppvObject,
     _COM_Outptr_opt_result_maybenull_ IDxcBlobUtf16 **ppOutputType,
     _COM_Outptr_opt_result_maybenull_ IDxcBlobUtf16 **ppOutputName) = 0;
-
-  DECLARE_CROSS_PLATFORM_UUIDOF(IDxcExtraOutputs)
 };
 
-struct __declspec(uuid("228B4687-5A6A-4730-900C-9702B2203F54"))
-IDxcCompiler3 : public IUnknown {
+CROSS_PLATFORM_UUIDOF(IDxcCompiler3, "228B4687-5A6A-4730-900C-9702B2203F54")
+struct IDxcCompiler3 : public IUnknown {
   // Compile a single entry point to the target shader model,
   // Compile a library to a library target (-T lib_*),
   // Compile a root signature (-T rootsig_*), or
@@ -515,8 +493,6 @@ IDxcCompiler3 : public IUnknown {
     _In_ const DxcBuffer *pObject,                // Program to disassemble: dxil container or bitcode.
     _In_ REFIID riid, _Out_ LPVOID *ppResult      // IDxcResult: status, disassembly text, and errors
     ) = 0;
-
-  DECLARE_CROSS_PLATFORM_UUIDOF(IDxcCompiler3)
 };
 
 static const UINT32 DxcValidatorFlags_Default = 0;
@@ -525,91 +501,75 @@ static const UINT32 DxcValidatorFlags_RootSignatureOnly = 2;
 static const UINT32 DxcValidatorFlags_ModuleOnly = 4;
 static const UINT32 DxcValidatorFlags_ValidMask = 0x7;
 
-struct __declspec(uuid("A6E82BD2-1FD7-4826-9811-2857E797F49A"))
-IDxcValidator : public IUnknown {
+CROSS_PLATFORM_UUIDOF(IDxcValidator, "A6E82BD2-1FD7-4826-9811-2857E797F49A")
+struct IDxcValidator : public IUnknown {
   // Validate a shader.
   virtual HRESULT STDMETHODCALLTYPE Validate(
     _In_ IDxcBlob *pShader,                       // Shader to validate.
     _In_ UINT32 Flags,                            // Validation flags.
     _COM_Outptr_ IDxcOperationResult **ppResult   // Validation output status, buffer, and errors
     ) = 0;
-
-  DECLARE_CROSS_PLATFORM_UUIDOF(IDxcValidator)
 };
 
-struct __declspec(uuid("334b1f50-2292-4b35-99a1-25588d8c17fe"))
-IDxcContainerBuilder : public IUnknown {
+CROSS_PLATFORM_UUIDOF(IDxcContainerBuilder, "334b1f50-2292-4b35-99a1-25588d8c17fe")
+struct IDxcContainerBuilder : public IUnknown {
   virtual HRESULT STDMETHODCALLTYPE Load(_In_ IDxcBlob *pDxilContainerHeader) = 0;                // Loads DxilContainer to the builder
   virtual HRESULT STDMETHODCALLTYPE AddPart(_In_ UINT32 fourCC, _In_ IDxcBlob *pSource) = 0;      // Part to add to the container
   virtual HRESULT STDMETHODCALLTYPE RemovePart(_In_ UINT32 fourCC) = 0;                           // Remove the part with fourCC
   virtual HRESULT STDMETHODCALLTYPE SerializeContainer(_Out_ IDxcOperationResult **ppResult) = 0; // Builds a container of the given container builder state
-
-  DECLARE_CROSS_PLATFORM_UUIDOF(IDxcContainerBuilder)
 };
 
-struct __declspec(uuid("091f7a26-1c1f-4948-904b-e6e3a8a771d5"))
-IDxcAssembler : public IUnknown {
+CROSS_PLATFORM_UUIDOF(IDxcAssembler, "091f7a26-1c1f-4948-904b-e6e3a8a771d5")
+struct IDxcAssembler : public IUnknown {
   // Assemble dxil in ll or llvm bitcode to DXIL container.
   virtual HRESULT STDMETHODCALLTYPE AssembleToContainer(
     _In_ IDxcBlob *pShader,                       // Shader to assemble.
     _COM_Outptr_ IDxcOperationResult **ppResult   // Assembly output status, buffer, and errors
     ) = 0;
-
-  DECLARE_CROSS_PLATFORM_UUIDOF(IDxcAssembler)
 };
 
-struct __declspec(uuid("d2c21b26-8350-4bdc-976a-331ce6f4c54c"))
-IDxcContainerReflection : public IUnknown {
+CROSS_PLATFORM_UUIDOF(IDxcContainerReflection, "d2c21b26-8350-4bdc-976a-331ce6f4c54c")
+struct IDxcContainerReflection : public IUnknown {
   virtual HRESULT STDMETHODCALLTYPE Load(_In_ IDxcBlob *pContainer) = 0; // Container to load.
   virtual HRESULT STDMETHODCALLTYPE GetPartCount(_Out_ UINT32 *pResult) = 0;
   virtual HRESULT STDMETHODCALLTYPE GetPartKind(UINT32 idx, _Out_ UINT32 *pResult) = 0;
   virtual HRESULT STDMETHODCALLTYPE GetPartContent(UINT32 idx, _COM_Outptr_ IDxcBlob **ppResult) = 0;
   virtual HRESULT STDMETHODCALLTYPE FindFirstPartKind(UINT32 kind, _Out_ UINT32 *pResult) = 0;
   virtual HRESULT STDMETHODCALLTYPE GetPartReflection(UINT32 idx, REFIID iid, void **ppvObject) = 0;
-
-  DECLARE_CROSS_PLATFORM_UUIDOF(IDxcContainerReflection)
 };
 
-struct __declspec(uuid("AE2CD79F-CC22-453F-9B6B-B124E7A5204C"))
-IDxcOptimizerPass : public IUnknown {
+CROSS_PLATFORM_UUIDOF(IDxcOptimizerPass, "AE2CD79F-CC22-453F-9B6B-B124E7A5204C")
+struct IDxcOptimizerPass : public IUnknown {
   virtual HRESULT STDMETHODCALLTYPE GetOptionName(_COM_Outptr_ LPWSTR *ppResult) = 0;
   virtual HRESULT STDMETHODCALLTYPE GetDescription(_COM_Outptr_ LPWSTR *ppResult) = 0;
   virtual HRESULT STDMETHODCALLTYPE GetOptionArgCount(_Out_ UINT32 *pCount) = 0;
   virtual HRESULT STDMETHODCALLTYPE GetOptionArgName(UINT32 argIndex, _COM_Outptr_ LPWSTR *ppResult) = 0;
   virtual HRESULT STDMETHODCALLTYPE GetOptionArgDescription(UINT32 argIndex, _COM_Outptr_ LPWSTR *ppResult) = 0;
-
-  DECLARE_CROSS_PLATFORM_UUIDOF(IDxcOptimizerPass)
 };
 
-struct __declspec(uuid("25740E2E-9CBA-401B-9119-4FB42F39F270"))
-IDxcOptimizer : public IUnknown {
+CROSS_PLATFORM_UUIDOF(IDxcOptimizer, "25740E2E-9CBA-401B-9119-4FB42F39F270")
+struct IDxcOptimizer : public IUnknown {
   virtual HRESULT STDMETHODCALLTYPE GetAvailablePassCount(_Out_ UINT32 *pCount) = 0;
   virtual HRESULT STDMETHODCALLTYPE GetAvailablePass(UINT32 index, _COM_Outptr_ IDxcOptimizerPass** ppResult) = 0;
   virtual HRESULT STDMETHODCALLTYPE RunOptimizer(IDxcBlob *pBlob,
     _In_count_(optionCount) LPCWSTR *ppOptions, UINT32 optionCount,
     _COM_Outptr_ IDxcBlob **pOutputModule,
     _COM_Outptr_opt_ IDxcBlobEncoding **ppOutputText) = 0;
-
-  DECLARE_CROSS_PLATFORM_UUIDOF(IDxcOptimizer)
 };
 
 static const UINT32 DxcVersionInfoFlags_None = 0;
 static const UINT32 DxcVersionInfoFlags_Debug = 1; // Matches VS_FF_DEBUG
 static const UINT32 DxcVersionInfoFlags_Internal = 2; // Internal Validator (non-signing)
 
-struct __declspec(uuid("b04f5b50-2059-4f12-a8ff-a1e0cde1cc7e"))
-IDxcVersionInfo : public IUnknown {
+CROSS_PLATFORM_UUIDOF(IDxcVersionInfo, "b04f5b50-2059-4f12-a8ff-a1e0cde1cc7e")
+struct IDxcVersionInfo : public IUnknown {
   virtual HRESULT STDMETHODCALLTYPE GetVersion(_Out_ UINT32 *pMajor, _Out_ UINT32 *pMinor) = 0;
   virtual HRESULT STDMETHODCALLTYPE GetFlags(_Out_ UINT32 *pFlags) = 0;
-
-  DECLARE_CROSS_PLATFORM_UUIDOF(IDxcVersionInfo)
 };
 
-struct __declspec(uuid("fb6904c4-42f0-4b62-9c46-983af7da7c83"))
-IDxcVersionInfo2 : public IDxcVersionInfo {
+CROSS_PLATFORM_UUIDOF(IDxcVersionInfo2, "fb6904c4-42f0-4b62-9c46-983af7da7c83")
+struct IDxcVersionInfo2 : public IDxcVersionInfo {
   virtual HRESULT STDMETHODCALLTYPE GetCommitInfo(_Out_ UINT32 *pCommitCount, _Out_ char **pCommitHash) = 0;
-
-  DECLARE_CROSS_PLATFORM_UUIDOF(IDxcVersionInfo2)
 };
 
 // Note: __declspec(selectany) requires 'extern'
diff --git a/include/dxc/dxcapi.internal.h b/include/dxc/dxcapi.internal.h
index 2acabebcf8..9bc19cd59d 100644
--- a/include/dxc/dxcapi.internal.h
+++ b/include/dxc/dxcapi.internal.h
@@ -126,8 +126,8 @@ struct HLSL_INTRINSIC {
 
 ///////////////////////////////////////////////////////////////////////////////
 // Interfaces.
-struct __declspec(uuid("f0d4da3f-f863-4660-b8b4-dfd94ded6215"))
-IDxcIntrinsicTable : public IUnknown
+CROSS_PLATFORM_UUIDOF(IDxcIntrinsicTable, "f0d4da3f-f863-4660-b8b4-dfd94ded6215")
+struct IDxcIntrinsicTable : public IUnknown
 {
 public:
   virtual HRESULT STDMETHODCALLTYPE GetTableName(_Outptr_ LPCSTR *pTableName) = 0;
@@ -153,15 +153,15 @@ IDxcIntrinsicTable : public IUnknown
   virtual HRESULT STDMETHODCALLTYPE GetDxilOpCode(UINT opcode, UINT *pDxilOpcode) = 0;
 };
 
-struct __declspec(uuid("1d063e4f-515a-4d57-a12a-431f6a44cfb9"))
-IDxcSemanticDefineValidator : public IUnknown
+CROSS_PLATFORM_UUIDOF(IDxcSemanticDefineValidator, "1d063e4f-515a-4d57-a12a-431f6a44cfb9")
+struct IDxcSemanticDefineValidator : public IUnknown
 {
 public:
   virtual HRESULT STDMETHODCALLTYPE GetSemanticDefineWarningsAndErrors(LPCSTR pName, LPCSTR pValue, IDxcBlobEncoding **ppWarningBlob, IDxcBlobEncoding **ppErrorBlob) = 0;
 };
 
-struct __declspec(uuid("282a56b4-3f56-4360-98c7-9ea04a752272"))
-IDxcLangExtensions : public IUnknown
+CROSS_PLATFORM_UUIDOF(IDxcLangExtensions, "282a56b4-3f56-4360-98c7-9ea04a752272")
+struct IDxcLangExtensions : public IUnknown
 {
 public:
   /// <summary>
@@ -181,19 +181,16 @@ IDxcLangExtensions : public IUnknown
   virtual HRESULT STDMETHODCALLTYPE SetSemanticDefineValidator(_In_ IDxcSemanticDefineValidator* pValidator) = 0;
   /// <summary>Sets the name for the root metadata node used in DXIL to hold the semantic defines.</summary>
   virtual HRESULT STDMETHODCALLTYPE SetSemanticDefineMetaDataName(LPCSTR name) = 0;
-
-  DECLARE_CROSS_PLATFORM_UUIDOF(IDxcLangExtensions)
 };
 
-struct __declspec(uuid("2490C368-89EE-4491-A4B2-C6547B6C9381"))
-IDxcLangExtensions2 : public IDxcLangExtensions {
+CROSS_PLATFORM_UUIDOF(IDxcLangExtensions2, "2490C368-89EE-4491-A4B2-C6547B6C9381")
+struct IDxcLangExtensions2 : public IDxcLangExtensions {
 public:
   virtual HRESULT STDMETHODCALLTYPE SetTargetTriple(LPCSTR name) = 0;
-  DECLARE_CROSS_PLATFORM_UUIDOF(IDxcLangExtensions2)
 };
 
-struct __declspec(uuid("454b764f-3549-475b-958c-a7a6fcd05fbc"))
-IDxcSystemAccess : public IUnknown
+CROSS_PLATFORM_UUIDOF(IDxcSystemAccess, "454b764f-3549-475b-958c-a7a6fcd05fbc")
+struct IDxcSystemAccess : public IUnknown
 {
 public:
   virtual HRESULT STDMETHODCALLTYPE EnumFiles(LPCWSTR fileName, IEnumSTATSTG** pResult) = 0;
@@ -237,15 +234,15 @@ IDxcSystemAccess : public IUnknown
   virtual HRESULT STDMETHODCALLTYPE GetStreamDisplay(_COM_Outptr_result_maybenull_ ITextFont** textFont, _Out_ unsigned* columnCount) = 0;
 };
 
-struct __declspec(uuid("e991ca8d-2045-413c-a8b8-788b2c06e14d"))
-IDxcContainerEventsHandler : public IUnknown
+CROSS_PLATFORM_UUIDOF(IDxcContainerEventsHandler, "e991ca8d-2045-413c-a8b8-788b2c06e14d")
+struct IDxcContainerEventsHandler : public IUnknown
 {
 public:
   virtual HRESULT STDMETHODCALLTYPE OnDxilContainerBuilt(_In_ IDxcBlob *pSource, _Out_ IDxcBlob **ppTarget) = 0;
 };
 
-struct __declspec(uuid("0cfc5058-342b-4ff2-83f7-04c12aad3d01"))
-IDxcContainerEvent : public IUnknown
+CROSS_PLATFORM_UUIDOF(IDxcContainerEvent, "0cfc5058-342b-4ff2-83f7-04c12aad3d01")
+struct IDxcContainerEvent : public IUnknown
 {
 public:
   virtual HRESULT STDMETHODCALLTYPE RegisterDxilContainerEventHandler(IDxcContainerEventsHandler *pHandler, UINT64 *pCookie) = 0;
diff --git a/include/dxc/dxcisense.h b/include/dxc/dxcisense.h
index c9e55a7199..1b7dc0c7c6 100644
--- a/include/dxc/dxcisense.h
+++ b/include/dxc/dxcisense.h
@@ -613,8 +613,8 @@ struct IDxcCodeCompleteResults;
 struct IDxcCompletionResult;
 struct IDxcCompletionString;
 
-struct __declspec(uuid("1467b985-288d-4d2a-80c1-ef89c42c40bc"))
-IDxcCursor : public IUnknown
+CROSS_PLATFORM_UUIDOF(IDxcCursor, "1467b985-288d-4d2a-80c1-ef89c42c40bc")
+struct IDxcCursor : public IUnknown
 {
   virtual HRESULT STDMETHODCALLTYPE GetExtent(_Outptr_result_nullonfailure_ IDxcSourceRange** pRange) = 0;
   virtual HRESULT STDMETHODCALLTYPE GetLocation(_Outptr_result_nullonfailure_ IDxcSourceLocation** pResult) = 0;
@@ -652,8 +652,8 @@ IDxcCursor : public IUnknown
   virtual HRESULT STDMETHODCALLTYPE GetSnappedChild(_In_ IDxcSourceLocation* location, _Outptr_result_maybenull_ IDxcCursor** pResult) = 0;
 };
 
-struct __declspec(uuid("4f76b234-3659-4d33-99b0-3b0db994b564"))
-IDxcDiagnostic : public IUnknown
+CROSS_PLATFORM_UUIDOF(IDxcDiagnostic, "4f76b234-3659-4d33-99b0-3b0db994b564")
+struct IDxcDiagnostic : public IUnknown
 {
   virtual HRESULT STDMETHODCALLTYPE FormatDiagnostic(
     DxcDiagnosticDisplayOptions options,
@@ -669,8 +669,8 @@ IDxcDiagnostic : public IUnknown
     _Outptr_result_nullonfailure_ IDxcSourceRange** pReplacementRange, _Outptr_result_maybenull_ LPSTR* pText) = 0;
 };
 
-struct __declspec(uuid("bb2fca9e-1478-47ba-b08c-2c502ada4895"))
-IDxcFile : public IUnknown
+CROSS_PLATFORM_UUIDOF(IDxcFile, "bb2fca9e-1478-47ba-b08c-2c502ada4895")
+struct IDxcFile : public IUnknown
 {
   /// <summary>Gets the file name for this file.</summary>
   virtual HRESULT STDMETHODCALLTYPE GetName(_Outptr_result_maybenull_ LPSTR* pResult) = 0;
@@ -678,16 +678,16 @@ IDxcFile : public IUnknown
   virtual HRESULT STDMETHODCALLTYPE IsEqualTo(_In_ IDxcFile* other, _Out_ BOOL* pResult) = 0;
 };
 
-struct __declspec(uuid("0c364d65-df44-4412-888e-4e552fc5e3d6"))
-IDxcInclusion : public IUnknown
+CROSS_PLATFORM_UUIDOF(IDxcInclusion, "0c364d65-df44-4412-888e-4e552fc5e3d6")
+struct IDxcInclusion : public IUnknown
 {
   virtual HRESULT STDMETHODCALLTYPE GetIncludedFile(_Outptr_result_nullonfailure_ IDxcFile** pResult) = 0;
   virtual HRESULT STDMETHODCALLTYPE GetStackLength(_Out_ unsigned *pResult) = 0;
   virtual HRESULT STDMETHODCALLTYPE GetStackItem(unsigned index, _Outptr_result_nullonfailure_ IDxcSourceLocation **pResult) = 0;
 };
 
-struct __declspec(uuid("b1f99513-46d6-4112-8169-dd0d6053f17d"))
-IDxcIntelliSense : public IUnknown
+CROSS_PLATFORM_UUIDOF(IDxcIntelliSense, "b1f99513-46d6-4112-8169-dd0d6053f17d")
+struct IDxcIntelliSense : public IUnknown
 {
   virtual HRESULT STDMETHODCALLTYPE CreateIndex(_Outptr_result_nullonfailure_ IDxcIndex** index) = 0;
   virtual HRESULT STDMETHODCALLTYPE GetNullLocation(_Outptr_result_nullonfailure_ IDxcSourceLocation** location) = 0;
@@ -700,12 +700,10 @@ IDxcIntelliSense : public IUnknown
     _Out_ DxcDiagnosticDisplayOptions* pValue) = 0;
   virtual HRESULT STDMETHODCALLTYPE GetDefaultEditingTUOptions(_Out_ DxcTranslationUnitFlags* pValue) = 0;
   virtual HRESULT STDMETHODCALLTYPE CreateUnsavedFile(_In_ LPCSTR fileName, _In_ LPCSTR contents, unsigned contentLength, _Outptr_result_nullonfailure_ IDxcUnsavedFile** pResult) = 0;
-
-  DECLARE_CROSS_PLATFORM_UUIDOF(IDxcIntelliSense)
 };
 
-struct __declspec(uuid("937824a0-7f5a-4815-9ba7-7fc0424f4173"))
-IDxcIndex : public IUnknown
+CROSS_PLATFORM_UUIDOF(IDxcIndex, "937824a0-7f5a-4815-9ba7-7fc0424f4173")
+struct IDxcIndex : public IUnknown
 {
   virtual HRESULT STDMETHODCALLTYPE SetGlobalOptions(DxcGlobalOptions options) = 0;
   virtual HRESULT STDMETHODCALLTYPE GetGlobalOptions(_Out_ DxcGlobalOptions* options) = 0;
@@ -719,8 +717,8 @@ IDxcIndex : public IUnknown
       _Out_ IDxcTranslationUnit** pTranslationUnit) = 0;
 };
 
-struct __declspec(uuid("8e7ddf1c-d7d3-4d69-b286-85fccba1e0cf"))
-IDxcSourceLocation : public IUnknown
+CROSS_PLATFORM_UUIDOF(IDxcSourceLocation, "8e7ddf1c-d7d3-4d69-b286-85fccba1e0cf")
+struct IDxcSourceLocation : public IUnknown
 {
   virtual HRESULT STDMETHODCALLTYPE IsEqualTo(_In_ IDxcSourceLocation* other, _Out_ BOOL* pResult) = 0;
   virtual HRESULT STDMETHODCALLTYPE GetSpellingLocation(
@@ -735,8 +733,8 @@ IDxcSourceLocation : public IUnknown
     _Out_opt_ unsigned* pCol) = 0;
 };
 
-struct __declspec(uuid("f1359b36-a53f-4e81-b514-b6b84122a13f"))
-IDxcSourceRange : public IUnknown
+CROSS_PLATFORM_UUIDOF(IDxcSourceRange, "f1359b36-a53f-4e81-b514-b6b84122a13f")
+struct IDxcSourceRange : public IUnknown
 {
   virtual HRESULT STDMETHODCALLTYPE IsNull(_Out_ BOOL* pValue) = 0;
   virtual HRESULT STDMETHODCALLTYPE GetStart(_Out_ IDxcSourceLocation** pValue) = 0;
@@ -744,8 +742,8 @@ IDxcSourceRange : public IUnknown
   virtual HRESULT STDMETHODCALLTYPE GetOffsets(_Out_ unsigned* startOffset, _Out_ unsigned* endOffset) = 0;
 };
 
-struct __declspec(uuid("7f90b9ff-a275-4932-97d8-3cfd234482a2"))
-IDxcToken : public IUnknown
+CROSS_PLATFORM_UUIDOF(IDxcToken, "7f90b9ff-a275-4932-97d8-3cfd234482a2")
+struct IDxcToken : public IUnknown
 {
   virtual HRESULT STDMETHODCALLTYPE GetKind(_Out_ DxcTokenKind* pValue) = 0;
   virtual HRESULT STDMETHODCALLTYPE GetLocation(_Out_ IDxcSourceLocation** pValue) = 0;
@@ -753,8 +751,8 @@ IDxcToken : public IUnknown
   virtual HRESULT STDMETHODCALLTYPE GetSpelling(_Out_ LPSTR* pValue) = 0;
 };
 
-struct __declspec(uuid("9677dee0-c0e5-46a1-8b40-3db3168be63d"))
-IDxcTranslationUnit : public IUnknown
+CROSS_PLATFORM_UUIDOF(IDxcTranslationUnit, "9677dee0-c0e5-46a1-8b40-3db3168be63d")
+struct IDxcTranslationUnit : public IUnknown
 {
   virtual HRESULT STDMETHODCALLTYPE GetCursor(_Out_ IDxcCursor** pCursor) = 0;
   virtual HRESULT STDMETHODCALLTYPE Tokenize(
@@ -791,16 +789,16 @@ IDxcTranslationUnit : public IUnknown
       _Outptr_result_nullonfailure_ IDxcCodeCompleteResults **pResult) = 0;
 };
 
-struct __declspec(uuid("2ec912fd-b144-4a15-ad0d-1c5439c81e46"))
-IDxcType : public IUnknown
+CROSS_PLATFORM_UUIDOF(IDxcType, "2ec912fd-b144-4a15-ad0d-1c5439c81e46")
+struct IDxcType : public IUnknown
 {
   virtual HRESULT STDMETHODCALLTYPE GetSpelling(_Outptr_result_z_ LPSTR* pResult) = 0;
   virtual HRESULT STDMETHODCALLTYPE IsEqualTo(_In_ IDxcType* other, _Out_ BOOL* pResult) = 0;
   virtual HRESULT STDMETHODCALLTYPE GetKind(_Out_ DxcTypeKind* pResult) = 0;
 };
 
-struct __declspec(uuid("8ec00f98-07d0-4e60-9d7c-5a50b5b0017f"))
-IDxcUnsavedFile : public IUnknown
+CROSS_PLATFORM_UUIDOF(IDxcUnsavedFile, "8ec00f98-07d0-4e60-9d7c-5a50b5b0017f")
+struct IDxcUnsavedFile : public IUnknown
 {
   virtual HRESULT STDMETHODCALLTYPE GetFileName(_Outptr_result_z_ LPSTR* pFileName) = 0;
   virtual HRESULT STDMETHODCALLTYPE GetContents(_Outptr_result_z_ LPSTR* pContents) = 0;
@@ -808,22 +806,22 @@ IDxcUnsavedFile : public IUnknown
 };
 
 
-struct __declspec(uuid("1E06466A-FD8B-45F3-A78F-8A3F76EBB552"))
-IDxcCodeCompleteResults : public IUnknown
+CROSS_PLATFORM_UUIDOF(IDxcCodeCompleteResults, "1E06466A-FD8B-45F3-A78F-8A3F76EBB552")
+struct IDxcCodeCompleteResults : public IUnknown
 {
   virtual HRESULT STDMETHODCALLTYPE GetNumResults(_Out_ unsigned* pResult) = 0;
   virtual HRESULT STDMETHODCALLTYPE GetResultAt(unsigned index, _Outptr_result_nullonfailure_ IDxcCompletionResult** pResult) = 0;
 };
 
-struct __declspec(uuid("943C0588-22D0-4784-86FC-701F802AC2B6"))
-IDxcCompletionResult : public IUnknown
+CROSS_PLATFORM_UUIDOF(IDxcCompletionResult, "943C0588-22D0-4784-86FC-701F802AC2B6")
+struct IDxcCompletionResult : public IUnknown
 {
   virtual HRESULT STDMETHODCALLTYPE GetCursorKind(_Out_ DxcCursorKind* pResult) = 0;
   virtual HRESULT STDMETHODCALLTYPE GetCompletionString(_Outptr_result_nullonfailure_ IDxcCompletionString** pResult) = 0;
 };
 
-struct __declspec(uuid("06B51E0F-A605-4C69-A110-CD6E14B58EEC"))
-IDxcCompletionString : public IUnknown
+CROSS_PLATFORM_UUIDOF(IDxcCompletionString, "06B51E0F-A605-4C69-A110-CD6E14B58EEC")
+struct IDxcCompletionString : public IUnknown
 {
   virtual HRESULT STDMETHODCALLTYPE GetNumCompletionChunks(_Out_ unsigned* pResult) = 0;
   virtual HRESULT STDMETHODCALLTYPE GetCompletionChunkKind(unsigned chunkNumber, _Out_ DxcCompletionChunkKind* pResult) = 0;
diff --git a/include/dxc/dxctools.h b/include/dxc/dxctools.h
index 49a2830f51..59527b163c 100644
--- a/include/dxc/dxctools.h
+++ b/include/dxc/dxctools.h
@@ -22,8 +22,8 @@ enum RewriterOptionMask {
   KeepUserMacro = 8,
 };
 
-struct __declspec(uuid("c012115b-8893-4eb9-9c5a-111456ea1c45"))
-IDxcRewriter : public IUnknown {
+CROSS_PLATFORM_UUIDOF(IDxcRewriter, "c012115b-8893-4eb9-9c5a-111456ea1c45")
+struct IDxcRewriter : public IUnknown {
 
   virtual HRESULT STDMETHODCALLTYPE RemoveUnusedGlobals(_In_ IDxcBlobEncoding *pSource,
                                                         _In_z_ LPCWSTR entryPoint,
@@ -46,8 +46,6 @@ IDxcRewriter : public IUnknown {
                                                      _In_opt_ IDxcIncludeHandler *pIncludeHandler,
                                                      _In_ UINT32  rewriteOption,
                                                      _COM_Outptr_ IDxcOperationResult **ppResult) = 0;
-
-  DECLARE_CROSS_PLATFORM_UUIDOF(IDxcRewriter)
 };
 
 #ifdef _MSC_VER
@@ -63,8 +61,8 @@ CLSID_SCOPE const CLSID
                          0x40b3,
                          {0x96, 0x8d, 0x93, 0xe1, 0x24, 0x73, 0x4d, 0xa4}};
 
-struct __declspec(uuid("261afca1-0609-4ec6-a77f-d98c7035194e"))
-IDxcRewriter2 : public IDxcRewriter {
+CROSS_PLATFORM_UUIDOF(IDxcRewriter2, "261afca1-0609-4ec6-a77f-d98c7035194e")
+struct IDxcRewriter2 : public IDxcRewriter {
 
   virtual HRESULT STDMETHODCALLTYPE RewriteWithOptions(_In_ IDxcBlobEncoding *pSource,
                                                      // Optional file name for pSource. Used in errors and include handlers.
@@ -76,8 +74,6 @@ IDxcRewriter2 : public IDxcRewriter {
                                                      // user-provided interface to handle #include directives (optional)
                                                      _In_opt_ IDxcIncludeHandler *pIncludeHandler,
                                                      _COM_Outptr_ IDxcOperationResult **ppResult) = 0;
-
-  DECLARE_CROSS_PLATFORM_UUIDOF(IDxcRewriter2)
 };
 
 #endif
diff --git a/lib/DxcSupport/WinAdapter.cpp b/lib/DxcSupport/WinAdapter.cpp
index dcc6303cc6..27bd7c3c7e 100644
--- a/lib/DxcSupport/WinAdapter.cpp
+++ b/lib/DxcSupport/WinAdapter.cpp
@@ -12,29 +12,6 @@
 #include "dxc/Support/WinAdapter.h"
 #include "dxc/Support/WinFunctions.h"
 
-//===--------------------- UUID Related Macros ----------------------------===//
-
-#ifdef __EMULATE_UUID
-
-size_t UuidStrHash(const char* k) {
-    long h = 0;
-    while (*k) {
-        h = (h << 4) + *(k++);
-        long g = h & 0xF0000000L;
-        if (g != 0)
-            h ^= g >> 24;
-        h &= ~g;
-    }
-    return h;
-}
-
-#endif // __EMULATE_UUID
-
-DEFINE_CROSS_PLATFORM_UUIDOF(IUnknown)
-DEFINE_CROSS_PLATFORM_UUIDOF(INoMarshal)
-DEFINE_CROSS_PLATFORM_UUIDOF(IStream)
-DEFINE_CROSS_PLATFORM_UUIDOF(ISequentialStream)
-
 //===--------------------------- IUnknown ---------------------------------===//
 
 ULONG IUnknown::AddRef() {
diff --git a/lib/HLSL/DxilContainerReflection.cpp b/lib/HLSL/DxilContainerReflection.cpp
index 5235a9a9c3..997a5f7267 100644
--- a/lib/HLSL/DxilContainerReflection.cpp
+++ b/lib/HLSL/DxilContainerReflection.cpp
@@ -2762,7 +2762,4 @@ void hlsl::CreateDxcContainerReflection(IDxcContainerReflection **ppResult) {
   *ppResult = nullptr;
 }
 
-DEFINE_CROSS_PLATFORM_UUIDOF(IDxcContainerReflection)
-
 #endif // LLVM_ON_WIN32
-
diff --git a/tools/clang/tools/dxcompiler/dxcapi.cpp b/tools/clang/tools/dxcompiler/dxcapi.cpp
index 7fc8fb1988..ec80ca7d1c 100644
--- a/tools/clang/tools/dxcompiler/dxcapi.cpp
+++ b/tools/clang/tools/dxcompiler/dxcapi.cpp
@@ -27,33 +27,6 @@
 #include "dxc/DxilContainer/DxcContainerBuilder.h"
 #include <memory>
 
-// Initialize the UUID for the interfaces.
-DEFINE_CROSS_PLATFORM_UUIDOF(IDxcLibrary)
-DEFINE_CROSS_PLATFORM_UUIDOF(IDxcBlobEncoding)
-DEFINE_CROSS_PLATFORM_UUIDOF(IDxcOperationResult)
-DEFINE_CROSS_PLATFORM_UUIDOF(IDxcAssembler)
-DEFINE_CROSS_PLATFORM_UUIDOF(IDxcBlob)
-DEFINE_CROSS_PLATFORM_UUIDOF(IDxcIncludeHandler)
-DEFINE_CROSS_PLATFORM_UUIDOF(IDxcCompiler)
-DEFINE_CROSS_PLATFORM_UUIDOF(IDxcCompiler2)
-DEFINE_CROSS_PLATFORM_UUIDOF(IDxcVersionInfo)
-DEFINE_CROSS_PLATFORM_UUIDOF(IDxcVersionInfo2)
-DEFINE_CROSS_PLATFORM_UUIDOF(IDxcValidator)
-DEFINE_CROSS_PLATFORM_UUIDOF(IDxcContainerBuilder)
-DEFINE_CROSS_PLATFORM_UUIDOF(IDxcOptimizerPass)
-DEFINE_CROSS_PLATFORM_UUIDOF(IDxcOptimizer)
-DEFINE_CROSS_PLATFORM_UUIDOF(IDxcRewriter)
-DEFINE_CROSS_PLATFORM_UUIDOF(IDxcRewriter2)
-DEFINE_CROSS_PLATFORM_UUIDOF(IDxcIntelliSense)
-DEFINE_CROSS_PLATFORM_UUIDOF(IDxcLinker)
-DEFINE_CROSS_PLATFORM_UUIDOF(IDxcBlobUtf16)
-DEFINE_CROSS_PLATFORM_UUIDOF(IDxcBlobUtf8)
-DEFINE_CROSS_PLATFORM_UUIDOF(IDxcCompilerArgs)
-DEFINE_CROSS_PLATFORM_UUIDOF(IDxcUtils)
-DEFINE_CROSS_PLATFORM_UUIDOF(IDxcResult)
-DEFINE_CROSS_PLATFORM_UUIDOF(IDxcExtraOutputs)
-DEFINE_CROSS_PLATFORM_UUIDOF(IDxcCompiler3)
-
 HRESULT CreateDxcCompiler(_In_ REFIID riid, _Out_ LPVOID *ppv);
 HRESULT CreateDxcDiaDataSource(_In_ REFIID riid, _Out_ LPVOID *ppv);
 HRESULT CreateDxcIntelliSense(_In_ REFIID riid, _Out_ LPVOID *ppv);
diff --git a/tools/clang/tools/dxcompiler/dxcompilerobj.cpp b/tools/clang/tools/dxcompiler/dxcompilerobj.cpp
index 53c3147b48..c66f1a7b12 100644
--- a/tools/clang/tools/dxcompiler/dxcompilerobj.cpp
+++ b/tools/clang/tools/dxcompiler/dxcompilerobj.cpp
@@ -67,9 +67,6 @@ using namespace clang;
 using namespace hlsl;
 using std::string;
 
-DEFINE_CROSS_PLATFORM_UUIDOF(IDxcLangExtensions)
-DEFINE_CROSS_PLATFORM_UUIDOF(IDxcLangExtensions2)
-
 // This declaration is used for the locally-linked validator.
 HRESULT CreateDxcValidator(_In_ REFIID riid, _Out_ LPVOID *ppv);