Bug#53445: Build with -Wall and fix warnings that it generates

Fix various mismatches between function's language linkage. Any
particular function that is declared in C++ but should be callable
from C must have C linkage. Note that function types with different
linkages are also distinct. Thus, if a function type is declared in
C code, it will have C linkage (same if declared in a extern "C"
block).

1 files changed, 8 insertions, 4 deletions

diff --git a/sql/item_sum.cc b/sql/item_sum.cc
index 917acb0e908..15927c4b11e 100644
--- a/sql/item_sum.cc
+++ b/sql/item_sum.cc
@@ -2827,6 +2827,7 @@ String *Item_sum_udf_str::val_str(String *str)
   @retval  1 : key1 > key2 
 */
 
+extern "C"
 int group_concat_key_cmp_with_distinct(void* arg, const void* key1, 
                                        const void* key2)
 {
@@ -2861,6 +2862,7 @@ int group_concat_key_cmp_with_distinct(void* arg, const void* key1,
   function of sort for syntax: GROUP_CONCAT(expr,... ORDER BY col,... )
 */
 
+extern "C"
 int group_concat_key_cmp_with_order(void* arg, const void* key1, 
                                     const void* key2)
 {
@@ -2905,13 +2907,16 @@ int group_concat_key_cmp_with_order(void* arg, const void* key1,
   Append data from current leaf to item->result.
 */
 
-int dump_leaf_key(uchar* key, element_count count __attribute__((unused)),
-                  Item_func_group_concat *item)
+extern "C"
+int dump_leaf_key(void* key_arg, element_count count __attribute__((unused)),
+                  void* item_arg)
 {
+  Item_func_group_concat *item= (Item_func_group_concat *) item_arg;
   TABLE *table= item->table;
   String tmp((char *)table->record[1], table->s->reclength,
              default_charset_info);
   String tmp2;
+  uchar *key= (uchar *) key_arg;
   String *result= &item->result;
   Item **arg= item->args, **arg_end= item->args + item->arg_count_field;
   uint old_length= result->length();
@@ -3385,8 +3390,7 @@ String* Item_func_group_concat::val_str(String* str)
     return 0;
   if (no_appended && tree)
     /* Tree is used for sorting as in ORDER BY */
-    tree_walk(tree, (tree_walk_action)&dump_leaf_key, (void*)this,
-              left_root_right);
+    tree_walk(tree, &dump_leaf_key, this, left_root_right);
   return &result;
 }