Remove compiler warnings

- Remove unused variables
- Mark variables unused
- Fix wrong types
- Add no-strict-aliasing to BUILD scripts

BUILD/SETUP.sh

@@ -140,7 +140,7 @@ elif [ "x$warning_mode" = "xmaintainer" ]; then
   debug_extra_cflags="-g3"
 else
 # Both C and C++ warnings
-  warnings="-Wall -Wextra -Wunused -Wwrite-strings -Wno-uninitialized"
+  warnings="-Wall -Wextra -Wunused -Wwrite-strings -Wno-uninitialized -Wno-strict-aliasing"
 
 # For more warnings, uncomment the following line
 # warnings="$warnings -Wshadow"

extra/mariabackup/xtrabackup.cc

@@ -3036,7 +3036,7 @@ static dberr_t xb_assign_undo_space_start()
 	byte*		page;
 	bool		ret;
 	dberr_t		error = DB_SUCCESS;
-	ulint		space, page_no;
+	ulint		space, page_no __attribute__((unused));
 
 	if (srv_undo_tablespaces == 0) {
 		return error;

sql/item_jsonfunc.cc

@@ -2615,7 +2615,7 @@ String *Item_func_json_remove::val_str(String *str)
   {
     uint array_counters[JSON_DEPTH_LIMIT];
     json_path_with_flags *c_path= paths + n_path;
-    const char *rem_start, *rem_end;
+    const char *rem_start= 0, *rem_end;
     const json_path_step_t *lp;
     uint n_item= 0;
 

sql/item_sum.cc

@@ -2456,7 +2456,7 @@ Item *Item_sum_max::copy_or_same(THD* thd)
 
 bool Item_sum_max::add()
 {
-  Item *tmp_item;
+  Item * UNINIT_VAR(tmp_item);
   DBUG_ENTER("Item_sum_max::add");
   DBUG_PRINT("enter", ("this: %p", this));
 
@@ -2661,7 +2661,7 @@ void Item_sum_num::reset_field()
 
 void Item_sum_hybrid::reset_field()
 {
-  Item *tmp_item, *arg0;
+  Item *UNINIT_VAR(tmp_item), *arg0;
   DBUG_ENTER("Item_sum_hybrid::reset_field");
 
   arg0= args[0];
@@ -3018,7 +3018,7 @@ Item *Item_sum_avg::result_item(THD *thd, Field *field)
 void Item_sum_hybrid::update_field()
 {
   DBUG_ENTER("Item_sum_hybrid::update_field");
-  Item *tmp_item;
+  Item *UNINIT_VAR(tmp_item);
   if (unlikely(direct_added))
   {
     tmp_item= args[0];

sql/opt_split.cc

@@ -862,7 +862,7 @@ SplM_plan_info * JOIN_TAB::choose_best_splitting(double record_count,
   table_map tables_usable_for_splitting=
               spl_opt_info->tables_usable_for_splitting;
   KEYUSE_EXT *keyuse_ext= &join->ext_keyuses_for_splitting->at(0);
-  KEYUSE_EXT *best_key_keyuse_ext_start;
+  KEYUSE_EXT *UNINIT_VAR(best_key_keyuse_ext_start);
   TABLE *best_table= 0;
   double best_rec_per_key= DBL_MAX;
   SplM_plan_info *spl_plan= 0;

sql/rpl_rli.cc

@@ -1520,7 +1520,7 @@ scan_one_gtid_slave_pos_table(THD *thd, HASH *hash, DYNAMIC_ARRAY *array,
                               LEX_CSTRING *tablename, void **out_hton)
 {
   TABLE_LIST tlist;
-  TABLE *table;
+  TABLE *UNINIT_VAR(table);
   bool table_opened= false;
   bool table_scanned= false;
   struct gtid_pos_element tmp_entry, *entry;

sql/slave.cc

@@ -356,7 +356,7 @@ end:
 static void
 handle_gtid_pos_auto_create_request(THD *thd, void *hton)
 {
-  int err;
+  int UNINIT_VAR(err);
   plugin_ref engine= NULL, *auto_engines;
   rpl_slave_state::gtid_pos_table *entry;
   StringBuffer<FN_REFLEN> loc_table_name;
@@ -6069,7 +6069,7 @@ static int queue_event(Master_info* mi,const char* buf, ulong event_len)
 {
   int error= 0;
   StringBuffer<1024> error_msg;
-  ulonglong inc_pos;
+  ulonglong inc_pos= 0;
   ulonglong event_pos;
   Relay_log_info *rli= &mi->rli;
   mysql_mutex_t *log_lock= rli->relay_log.get_log_lock();

sql/sql_base.cc

@@ -6548,7 +6548,7 @@ mark_common_columns(THD *thd, TABLE_LIST *table_ref_1, TABLE_LIST *table_ref_2,
   Query_arena *arena, backup;
   bool result= TRUE;
   bool first_outer_loop= TRUE;
-  Field *field_1, *field_2;
+  Field *field_1;
   field_visibility_t field_1_invisible, field_2_invisible;
   /*
     Leaf table references to which new natural join columns are added
@@ -6572,6 +6572,8 @@ mark_common_columns(THD *thd, TABLE_LIST *table_ref_1, TABLE_LIST *table_ref_2,
   {
     bool found= FALSE;
     const LEX_CSTRING *field_name_1;
+    Field *field_2= 0;
+
     /* true if field_name_1 is a member of using_fields */
     bool is_using_column_1;
     if (!(nj_col_1= it_1.get_or_create_column_ref(thd, leaf_1)))

sql/sql_parse.cc

@@ -4891,7 +4891,7 @@ end_with_restore_list:
     unit->set_limit(select_lex);
 
     MYSQL_DELETE_START(thd->query());
-    Protocol *save_protocol;
+    Protocol * UNINIT_VAR(save_protocol);
     bool replaced_protocol= false;
 
     if (!select_lex->item_list.is_empty())

storage/innobase/buf/buf0buf.cc

@@ -1188,7 +1188,6 @@ buf_madvise_do_dump()
 {
 	int ret= 0;
 	buf_pool_t*	buf_pool;
-	ulint		n;
 	buf_chunk_t*	chunk;
 
 	/* mirrors allocation in log_sys_init() */
@@ -1207,7 +1206,7 @@ buf_madvise_do_dump()
 
 	buf_pool_mutex_enter_all();
 
-	for (int i= 0; i < srv_buf_pool_instances; i++)
+	for (ulong i= 0; i < srv_buf_pool_instances; i++)
 	{
 		buf_pool = buf_pool_from_array(i);
 		chunk = buf_pool->chunks;

storage/innobase/buf/buf0flu.cc

@@ -967,7 +967,7 @@ buf_flush_init_for_writing(
 		}
 	}
 
-	uint32_t checksum;
+	uint32_t checksum= 0;
 
 	switch (srv_checksum_algorithm_t(srv_checksum_algorithm)) {
 	case SRV_CHECKSUM_ALGORITHM_INNODB:

storage/innobase/rem/rem0rec.cc

@@ -322,7 +322,7 @@ rec_init_offsets_comp_ordinary(
 	      || dict_table_is_comp(index->table));
 	ut_ad(format != REC_LEAF_TEMP_COLUMNS_ADDED
 	      || index->n_fields == rec_offs_n_fields(offsets));
-	ut_d(ulint n_null);
+	ut_d(ulint n_null= 0);
 
 	switch (format) {
 	case REC_LEAF_TEMP:
@@ -1447,10 +1447,10 @@ rec_convert_dtuple_to_rec_comp(
 	byte*		end;
 	byte*		nulls = temp
 		? rec - 1 : rec - (REC_N_NEW_EXTRA_BYTES + 1);
-	byte*		lens;
+	byte*		UNINIT_VAR(lens);
 	ulint		len;
 	ulint		i;
-	ulint		n_node_ptr_field;
+	ulint		UNINIT_VAR(n_node_ptr_field);
 	ulint		fixed_len;
 	ulint		null_mask	= 1;
 
@@ -1835,7 +1835,7 @@ rec_copy_prefix_to_buf(
 	ulint*			buf_size)	/*!< in/out: buffer size */
 {
 	const byte*	nulls;
-	const byte*	lens;
+	const byte*	UNINIT_VAR(lens);
 	ulint		i;
 	ulint		prefix_len;
 	ulint		null_mask;
@@ -2129,7 +2129,7 @@ rec_print_comp(
 	ulint	i;
 
 	for (i = 0; i < rec_offs_n_fields(offsets); i++) {
-		const byte*	data;
+          const byte*	UNINIT_VAR(data);
 		ulint		len;
 
 		if (rec_offs_nth_default(offsets, i)) {

storage/innobase/row/row0sel.cc

@@ -4177,7 +4177,7 @@ row_search_mvcc(
 	trx_t*		trx		= prebuilt->trx;
 	dict_index_t*	clust_index;
 	que_thr_t*	thr;
-	const rec_t*	rec;
+	const rec_t*	UNINIT_VAR(rec);
 	const dtuple_t*	vrow = NULL;
 	const rec_t*	result_rec = NULL;
 	const rec_t*	clust_rec;

storage/maria/ha_maria.cc

@@ -3091,7 +3091,7 @@ int ha_maria::create(const char *name, register TABLE *table_arg,
                      HA_CREATE_INFO *ha_create_info)
 {
   int error;
-  uint create_flags= 0, record_count, i;
+  uint create_flags= 0, record_count= 0, i;
   char buff[FN_REFLEN];
   MARIA_KEYDEF *keydef;
   MARIA_COLUMNDEF *recinfo;

storage/spider/spd_trx.cc

@@ -2811,7 +2811,7 @@ int spider_internal_xa_commit_by_xid(
   SPIDER_TRX *trx,
   XID* xid
 ) {
-  TABLE *table_xa, *table_xa_member;
+  TABLE *table_xa, *table_xa_member= 0;
   int error_num;
   char xa_key[MAX_KEY_LENGTH];
   char xa_member_key[MAX_KEY_LENGTH];
@@ -3046,7 +3046,7 @@ int spider_internal_xa_rollback_by_xid(
   SPIDER_TRX *trx,
   XID* xid
 ) {
-  TABLE *table_xa, *table_xa_member;
+  TABLE *table_xa, *table_xa_member= 0;
   int error_num;
   char xa_key[MAX_KEY_LENGTH];
   char xa_member_key[MAX_KEY_LENGTH];