move XXH_FALLTHROUGH into a generic include file

Move XXH_FALLTHROUGH in c.h, and rename it to FALLTHROUGH

diff --git a/include/c.h b/include/c.h
index dcb2d683c70eb262b5860565a997d9456840280c..e0148e019c5e81aa1d7bb9282af56dd23480d8c1 100644 (file)
--- a/include/c.h
+++ b/include/c.h
@@ -82,6 +82,39 @@
 # endif
 #endif
 
+#ifdef __has_attribute
+# define UL_HAS_ATTRIBUTE(x) __has_attribute(x)
+#else
+# define UL_HAS_ATTRIBUTE(x) 0
+#endif
+
+/* C-language Attributes are added in C23. */
+#if defined(__STDC_VERSION__) && (__STDC_VERSION__ > 201710L) && defined(__has_c_attribute)
+# define UL_HAS_C_ATTRIBUTE(x) __has_c_attribute(x)
+#else
+# define UL_HAS_C_ATTRIBUTE(x) 0
+#endif
+
+#if defined(__cplusplus) && defined(__has_cpp_attribute)
+# define UL_HAS_CPP_ATTRIBUTE(x) __has_cpp_attribute(x)
+#else
+# define UL_HAS_CPP_ATTRIBUTE(x) 0
+#endif
+
+/*
+Define FALLTHROUGH macro for annotating switch case with the 'fallthrough' attribute
+introduced in CPP17 and C23.
+CPP17 : https://en.cppreference.com/w/cpp/language/attributes/fallthrough
+C23   : https://en.cppreference.com/w/c/language/attributes/fallthrough
+*/
+#if UL_HAS_C_ATTRIBUTE(fallthrough) || UL_HAS_CPP_ATTRIBUTE(fallthrough)
+# define FALLTHROUGH [[fallthrough]]
+#elif UL_HAS_ATTRIBUTE(__fallthrough__)
+# define FALLTHROUGH __attribute__ ((__fallthrough__))
+#else
+# define FALLTHROUGH /* fallthrough */
+#endif
+
 
 /*
  * It evaluates to 1 if the attribute/feature is supported by the current

diff --git a/include/xxhash.h b/include/xxhash.h
index c17521f99f37b426be80dc656e77ac7ddbd65a03..5a581b8884479147c1dfaa673b82cc70393041bf 100644 (file)
--- a/include/xxhash.h
+++ b/include/xxhash.h
@@ -605,39 +605,10 @@ XXH_PUBLIC_API void XXH32_canonicalFromHash(XXH32_canonical_t* dst, XXH32_hash_t
  */
 XXH_PUBLIC_API XXH32_hash_t XXH32_hashFromCanonical(const XXH32_canonical_t* src);
 
+/* Reuse FALLTHROUGH macro from c.h */
+#include "c.h"
 
-#ifdef __has_attribute
-# define XXH_HAS_ATTRIBUTE(x) __has_attribute(x)
-#else
-# define XXH_HAS_ATTRIBUTE(x) 0
-#endif
-
-/* C-language Attributes are added in C23. */
-#if defined(__STDC_VERSION__) && (__STDC_VERSION__ > 201710L) && defined(__has_c_attribute)
-# define XXH_HAS_C_ATTRIBUTE(x) __has_c_attribute(x)
-#else
-# define XXH_HAS_C_ATTRIBUTE(x) 0
-#endif
-
-#if defined(__cplusplus) && defined(__has_cpp_attribute)
-# define XXH_HAS_CPP_ATTRIBUTE(x) __has_cpp_attribute(x)
-#else
-# define XXH_HAS_CPP_ATTRIBUTE(x) 0
-#endif
-
-/*
-Define XXH_FALLTHROUGH macro for annotating switch case with the 'fallthrough' attribute
-introduced in CPP17 and C23.
-CPP17 : https://en.cppreference.com/w/cpp/language/attributes/fallthrough
-C23   : https://en.cppreference.com/w/c/language/attributes/fallthrough
-*/
-#if XXH_HAS_C_ATTRIBUTE(fallthrough) || XXH_HAS_CPP_ATTRIBUTE(fallthrough)
-# define XXH_FALLTHROUGH [[fallthrough]]
-#elif XXH_HAS_ATTRIBUTE(__fallthrough__)
-# define XXH_FALLTHROUGH __attribute__ ((__fallthrough__))
-#else
-# define XXH_FALLTHROUGH /* fallthrough */
-#endif
+#define XXH_FALLTHROUGH FALLTHROUGH
 
 /*!
  * @}