diff -r 38800d479cd4 -r e86049631677 ucx/cx/common.h
--- a/ucx/cx/common.h	Tue Dec 30 21:39:38 2025 +0100
+++ b/ucx/cx/common.h	Wed Dec 31 16:41:16 2025 +0100
@@ -133,27 +133,27 @@
 /**
  * Inform the compiler that falling through a switch case is intentional.
  */
-#define cx_attr_fallthrough __attribute__((__fallthrough__))
+#define CX_FALLTHROUGH __attribute__((__fallthrough__))
 
 /**
  * All pointer arguments must be non-NULL.
  */
-#define cx_attr_nonnull __attribute__((__nonnull__))
+#define CX_NONNULL __attribute__((__nonnull__))
 
 /**
  * The specified pointer arguments must be non-NULL.
  */
-#define cx_attr_nonnull_arg(...) __attribute__((__nonnull__(__VA_ARGS__)))
+#define CX_NONNULL_ARG(...) __attribute__((__nonnull__(__VA_ARGS__)))
 
 /**
  * The returned value is guaranteed to be non-NULL.
  */
-#define cx_attr_returns_nonnull __attribute__((__returns_nonnull__))
+#define CX_RETURNS_NONNULL __attribute__((__returns_nonnull__))
 
 /**
  * The attributed function always returns freshly allocated memory.
  */
-#define cx_attr_malloc __attribute__((__malloc__))
+#define CX_MALLOC __attribute__((__malloc__))
 
 #if !defined(__clang__) && __GNUC__ >= 11
 /**
@@ -163,59 +163,59 @@
  * @param freefunc the function that shall be used to free the memory
  * @param freefunc_arg the index of the pointer argument in @p freefunc
  */
-#define cx_attr_dealloc(freefunc, freefunc_arg) \
+#define CX_DEALLOC(freefunc, freefunc_arg) \
     __attribute__((__malloc__(freefunc, freefunc_arg)))
 #else
 /**
  * Not supported in clang.
  */
-#define cx_attr_dealloc(...)
+#define CX_DEALLOC(...)
 #endif // __clang__
 
 /**
  * Shortcut to specify #cxFree() as deallocator.
  */
-#define cx_attr_dealloc_ucx cx_attr_dealloc(cxFree, 2)
+#define CX_DEALLOC_UCX CX_DEALLOC(cxFree, 2)
 
 /**
  * Specifies the parameters from which the allocation size is calculated.
  */
-#define cx_attr_allocsize(...) __attribute__((__alloc_size__(__VA_ARGS__)))
+#define CX_ALLOCSIZE(...) __attribute__((__alloc_size__(__VA_ARGS__)))
 
 
 #ifdef __clang__
 /**
  * No support for @c null_terminated_string_arg in clang or GCC below 14.
  */
-#define cx_attr_cstr_arg(idx)
+#define CX_CSTR_ARG(idx)
 /**
  * No support for the access attribute in clang.
  */
-#define cx_attr_access(mode, ...)
+#define CX_ACCESS(mode, ...)
 #else
 #if __GNUC__ < 10
 /**
  * No support for access attribute in GCC < 10.
  */
-#define cx_attr_access(mode, ...)
+#define CX_ACCESS(mode, ...)
 #else
 /**
  * Helper macro to define access macros.
  */
-#define cx_attr_access(mode, ...) __attribute__((__access__(mode, __VA_ARGS__)))
+#define CX_ACCESS(mode, ...) __attribute__((__access__(mode, __VA_ARGS__)))
 #endif // __GNUC__ < 10
 #if __GNUC__ < 14
 /**
  * No support for @c null_terminated_string_arg in clang or GCC below 14.
  */
-#define cx_attr_cstr_arg(idx)
+#define CX_CSTR_ARG(idx)
 #else
 /**
  * The specified argument is expected to be a zero-terminated string.
  *
  * @param idx the index of the argument
  */
-#define cx_attr_cstr_arg(idx) \
+#define CX_CSTR_ARG(idx) \
     __attribute__((__null_terminated_string_arg__(idx)))
 #endif // __GNUC__ < 14
 #endif // __clang__
@@ -227,7 +227,7 @@
  * Takes one or two arguments: the index of the pointer and (optionally) the
  * index of another argument specifying the maximum number of accessed bytes.
  */
-#define cx_attr_access_r(...) cx_attr_access(__read_only__, __VA_ARGS__)
+#define CX_ACCESS_R(...) CX_ACCESS(__read_only__, __VA_ARGS__)
 
 /**
  * Specifies that the function will read and write through the given pointer.
@@ -235,7 +235,7 @@
  * Takes one or two arguments: the index of the pointer and (optionally) the
  * index of another argument specifying the maximum number of accessed bytes.
  */
-#define cx_attr_access_rw(...) cx_attr_access(__read_write__, __VA_ARGS__)
+#define CX_ACCESS_RW(...) CX_ACCESS(__read_write__, __VA_ARGS__)
 
 /**
  * Specifies that the function will only write through the given pointer.
@@ -243,27 +243,38 @@
  * Takes one or two arguments: the index of the pointer and (optionally) the
  * index of another argument specifying the maximum number of accessed bytes.
  */
-#define cx_attr_access_w(...) cx_attr_access(__write_only__, __VA_ARGS__)
+#define CX_ACCESS_W(...) CX_ACCESS(__write_only__, __VA_ARGS__)
 
 /**
  * Do not warn about unused variable.
  */
-#define cx_attr_unused __attribute__((__unused__))
+#define CX_UNUSED __attribute__((__unused__))
 
 /**
  * Warn about discarded return value.
  */
-#define cx_attr_nodiscard __attribute__((__warn_unused_result__))
+#define CX_NODISCARD __attribute__((__warn_unused_result__))
 
 
 // ---------------------------------------------------------------------------
-//       MSVC specifics
+//       Support for thread_local
 // ---------------------------------------------------------------------------
 
+#ifdef __cplusplus
+#define cx_thread_local thread_local
+#else // ! __cplusplus
 #ifdef _MSC_VER
-// fix missing _Thread_local support
-#define _Thread_local __declspec(thread)
+#define cx_thread_local __declspec(thread)
+#else // ! _MSC_VER
+#if !defined __STDC_VERSION__ || __STDC_VERSION__ < 202300L
+/** Platform independent thread-local macro. */
+#define cx_thread_local _Thread_local
+#else // C23 or newer
+/** Platform independent thread-local macro. */
+#define cx_thread_local thread_local
+#endif // C23
 #endif // _MSC_VER
+#endif // __cplusplus
 
 // ---------------------------------------------------------------------------
 //       Exported and inlined functions
@@ -278,6 +289,16 @@
 #define CX_EXPORT
 #endif // CX_WINDLL / CX_WINDLL_EXPORT
 
+#ifdef __cplusplus
+#define CX_EXTERN extern "C" CX_EXPORT
+#define CX_FPTR extern "C" typedef
+#else
+/** Declares a function with external linkage. */
+#define CX_EXTERN CX_EXPORT
+/** Defines a function pointer. */
+#define CX_FPTR typedef
+#endif
+
 #ifdef __GNUC__
 /**
  * Declares a function to be inlined.
@@ -355,10 +376,8 @@
  * @retval zero success
  * @retval non-zero the multiplication would overflow
  */
-#if __cplusplus
-extern "C"
-#endif
-CX_EXPORT int cx_szmul_impl(size_t a, size_t b, size_t *result);
+CX_EXTERN
+int cx_szmul_impl(size_t a, size_t b, size_t *result);
 #endif // cx_szmul
 
 #endif // UCX_COMMON_H