try to fix the fallthrough warning

1 files changed, 19 insertions, 10 deletions

diff --git a/uthash.h b/uthash.h
index d6b54e9..02f6e0a 100644
--- a/uthash.h
+++ b/uthash.h
@@ -423,6 +423,15 @@ do {
   c -= a; c -= b; c ^= ( b >> 15 );                                              \
 } while (0)
 
+#if defined __has_cpp_attribute
+    #if __has_cpp_attribute(fallthrough)
+      #define fallthrough ([[fallthrough]];)
+    #endif
+#endif
+#ifndef fallthrough
+#define fallthrough /* FALL-THRU */
+#endif
+
 #define HASH_JEN(key,keylen,num_bkts,hashv,bkt)                                  \
 do {                                                                             \
   unsigned _hj_i,_hj_j,_hj_k;                                                    \
@@ -449,25 +458,25 @@ do {
   hashv += keylen;                                                               \
   switch ( _hj_k ) {                                                             \
      case 11: hashv += ( (unsigned)_hj_key[10] << 24 );                          \
-     [[fallthrough]];                                                            \
+     fallthrough                                                                 \
      case 10: hashv += ( (unsigned)_hj_key[9] << 16 );                           \
-     [[fallthrough]];                                                            \
+     fallthrough                                                                 \
      case 9:  hashv += ( (unsigned)_hj_key[8] << 8 );                            \
-     [[fallthrough]];                                                            \
+     fallthrough                                                                 \
      case 8:  _hj_j += ( (unsigned)_hj_key[7] << 24 );                           \
-     [[fallthrough]];                                                            \
+     fallthrough                                                                 \
      case 7:  _hj_j += ( (unsigned)_hj_key[6] << 16 );                           \
-     [[fallthrough]];                                                            \
+     fallthrough                                                                 \
      case 6:  _hj_j += ( (unsigned)_hj_key[5] << 8 );                            \
-     [[fallthrough]];                                                            \
+     fallthrough                                                                 \
      case 5:  _hj_j += _hj_key[4];                                               \
-     [[fallthrough]];                                                            \
+     fallthrough                                                                 \
      case 4:  _hj_i += ( (unsigned)_hj_key[3] << 24 );                           \
-     [[fallthrough]];                                                            \
+     fallthrough                                                                 \
      case 3:  _hj_i += ( (unsigned)_hj_key[2] << 16 );                           \
-     [[fallthrough]];                                                            \
+     fallthrough                                                                 \
      case 2:  _hj_i += ( (unsigned)_hj_key[1] << 8 );                            \
-     [[fallthrough]];                                                            \
+     fallthrough                                                                 \
      case 1:  _hj_i += _hj_key[0];                                               \
   }                                                                              \
   HASH_JEN_MIX(_hj_i, _hj_j, hashv);                                             \