MDEV-4243 [PATCH] Warnings/errors while compiling with clang

fix the code to compile with clang. fix warnings too.

include/probes_mysql_nodtrace.h:
  clang++ doesn't like numeric _constants_ being used in ||
  (it suspects that the intention was | ). Boolean constants are ok.
sql/hostname.cc:
  only used in DBUG_ASSERT
sql/item.cc:
  str_to_time and str_to_datetime return bool, not MYSQL_TIMESTAMP_xxx
sql/item_func.cc:
  str_to_datetime_with_warn() returns bool, not MYSQL_TIMESTAMP_xxx
storage/cassandra/CMakeLists.txt:
  CMAKE_CXX_FLAGS can be empty
storage/connect/odbconn.cpp:
  HWND is void*
storage/connect/user_connect.h:
  deprecated on FreeBSD and unused anyway
storage/connect/value.cpp:
  bad characters inside. unused.
storage/spider/spd_trx.cc:
  clang++ warns that memset will also overwrite vtbl. it might be as well a good idea,
  as it asserts that the object will only be used as a storage.
  silence the warning.

7 files changed, 8 insertions, 12 deletions

diff --git a/sql/filesort.cc b/sql/filesort.cc
index 8783aa96739..2b0a91bf5d0 100644
--- a/sql/filesort.cc
+++ b/sql/filesort.cc
@@ -1215,13 +1215,13 @@ bool check_if_pq_applicable(Sort_param *param,
   if (param->max_rows == HA_POS_ERROR)
   {
     DBUG_PRINT("info", ("No LIMIT"));
-    DBUG_RETURN(NULL);
+    DBUG_RETURN(false);
   }
 
   if (param->max_rows + 2 >= UINT_MAX)
   {
     DBUG_PRINT("info", ("Too large LIMIT"));
-    DBUG_RETURN(NULL);
+    DBUG_RETURN(false);
   }
 
   ulong num_available_keys=
diff --git a/sql/hostname.cc b/sql/hostname.cc
index 6c3c70aa7ea..1200dd2c185 100644
--- a/sql/hostname.cc
+++ b/sql/hostname.cc
@@ -415,7 +415,7 @@ int ip_to_hostname(struct sockaddr_storage *ip_storage,
 {
   const struct sockaddr *ip= (const sockaddr *) ip_storage;
   int err_code;
-  bool err_status;
+  bool err_status __attribute__((unused));
   Host_errors errors;
 
   DBUG_ENTER("ip_to_hostname");
diff --git a/sql/item.cc b/sql/item.cc
index 248b0899026..38f5ed6bf5c 100644
--- a/sql/item.cc
+++ b/sql/item.cc
@@ -585,12 +585,11 @@ uint Item::temporal_precision(enum_field_types type)
     MYSQL_TIME_STATUS status;
     DBUG_ASSERT(fixed);
     if ((tmp= val_str(&buf)) &&
-        (type == MYSQL_TYPE_TIME ?
+        !(type == MYSQL_TYPE_TIME ?
          str_to_time(tmp->charset(), tmp->ptr(), tmp->length(),
                      &ltime, TIME_TIME_ONLY, &status) :
          str_to_datetime(tmp->charset(), tmp->ptr(), tmp->length(),
-                         &ltime, TIME_FUZZY_DATES, &status)) >
-        MYSQL_TIMESTAMP_ERROR)
+                         &ltime, TIME_FUZZY_DATES, &status)))
       return MY_MIN(status.precision, TIME_SECOND_PART_DIGITS);
   }
   return MY_MIN(decimals, TIME_SECOND_PART_DIGITS);
diff --git a/sql/item_func.cc b/sql/item_func.cc
index 1f516724a5f..36edc3aee55 100644
--- a/sql/item_func.cc
+++ b/sql/item_func.cc
@@ -1135,7 +1135,7 @@ bool Item_func_hybrid_result_type::get_date(MYSQL_TIME *ltime,
     String tmp(buff,sizeof(buff), &my_charset_bin),*res;
     if (!(res= str_op(&tmp)) ||
         str_to_datetime_with_warn(res->charset(), res->ptr(), res->length(),
-                                  ltime, fuzzydate) <= MYSQL_TIMESTAMP_ERROR)
+                                  ltime, fuzzydate))
       goto err;
     break;
      break;
diff --git a/sql/item_subselect.cc b/sql/item_subselect.cc
index 35e040cad3a..81c4f0f51e5 100644
--- a/sql/item_subselect.cc
+++ b/sql/item_subselect.cc
@@ -1333,8 +1333,6 @@ Item_exists_subselect::Item_exists_subselect(st_select_lex *select_lex):
   emb_on_expr_nest(NULL), optimizer(0), exists_transformed(0)
 {
   DBUG_ENTER("Item_exists_subselect::Item_exists_subselect");
-  bool val_bool();
-
   init(select_lex, new select_exists_subselect(this));
   max_columns= UINT_MAX;
   null_value= FALSE; //can't be NULL
diff --git a/sql/item_xmlfunc.h b/sql/item_xmlfunc.h
index 800cf6ed760..e818a6da408 100644
--- a/sql/item_xmlfunc.h
+++ b/sql/item_xmlfunc.h
@@ -21,7 +21,7 @@
 /* This file defines all XML functions */
 
 
-#ifdef __GNUC__
+#ifdef USE_PRAGMA_INTERFACE
 #pragma interface			/* gcc class implementation */
 #endif
 
diff --git a/sql/slave.cc b/sql/slave.cc
index 2b584365828..0912d77e070 100644
--- a/sql/slave.cc
+++ b/sql/slave.cc
@@ -6005,10 +6005,9 @@ static Log_event* next_event(rpl_group_info *rgi, ulonglong *event_size)
   IO_CACHE* cur_log = rli->cur_log;
   mysql_mutex_t *log_lock = rli->relay_log.get_log_lock();
   const char* errmsg=0;
-  THD *thd = rgi->thd;
   DBUG_ENTER("next_event");
 
-  DBUG_ASSERT(thd != 0 && thd == rli->sql_driver_thd);
+  DBUG_ASSERT(rgi->thd != 0 && rgi->thd == rli->sql_driver_thd);
   *event_size= 0;
 
 #ifndef DBUG_OFF