From 53b8829682307224a8b5a9de814019926eea9bd7 Mon Sep 17 00:00:00 2001 From: Davi Arnaut Date: Thu, 10 Jun 2010 17:45:22 -0300 Subject: Bug#42733: Type-punning warnings when compiling MySQL -- strict aliasing violations. One somewhat major source of strict-aliasing violations and related warnings is the SQL_LIST structure. For example, consider its member function `link_in_list` which takes a pointer to pointer of type T (any type) as a pointer to pointer to unsigned char. Dereferencing this pointer, which is done to reset the next field, violates strict-aliasing rules and might cause problems for surrounding code that uses the next field of the object being added to the list. The solution is to use templates to parametrize the SQL_LIST structure in order to deference the pointers with compatible types. As a side bonus, it becomes possible to remove quite a few casts related to acessing data members of SQL_LIST. --- sql/sql_lex.h | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-) (limited to 'sql/sql_lex.h') diff --git a/sql/sql_lex.h b/sql/sql_lex.h index 54eefa22a59..fb011f05f08 100644 --- a/sql/sql_lex.h +++ b/sql/sql_lex.h @@ -587,8 +587,8 @@ public: st_lex *parent_lex; enum olap_type olap; /* FROM clause - points to the beginning of the TABLE_LIST::next_local list. */ - SQL_LIST table_list; - SQL_LIST group_list; /* GROUP BY clause. */ + SQL_I_List table_list; + SQL_I_List group_list; /* GROUP BY clause. */ List item_list; /* list of fields & expressions */ List interval_list; bool is_item_list_lookup; @@ -610,8 +610,8 @@ public: TABLE_LIST *leaf_tables; const char *type; /* type of select for EXPLAIN */ - SQL_LIST order_list; /* ORDER clause */ - SQL_LIST *gorder_list; + SQL_I_List order_list; /* ORDER clause */ + SQL_I_List *gorder_list; Item *select_limit, *offset_limit; /* LIMIT clause parameters */ // Arrays of pointers to top elements of all_fields list Item **ref_pointer_array; @@ -774,7 +774,7 @@ public: { order_list.elements= 0; order_list.first= 0; - order_list.next= (uchar**) &order_list.first; + order_list.next= &order_list.first; } /* This method created for reiniting LEX in mysql_admin_table() and can be @@ -953,6 +953,8 @@ enum xa_option_words {XA_NONE, XA_JOIN, XA_RESUME, XA_ONE_PHASE, XA_SUSPEND, XA_FOR_MIGRATE}; +struct Sroutine_hash_entry; + /* Class representing list of all tables used by statement. It also contains information about stored functions used by statement @@ -993,9 +995,9 @@ public: We use these two members for restoring of 'sroutines_list' to the state in which it was right after query parsing. */ - SQL_LIST sroutines_list; - uchar **sroutines_list_own_last; - uint sroutines_list_own_elements; + SQL_I_List sroutines_list; + Sroutine_hash_entry **sroutines_list_own_last; + uint sroutines_list_own_elements; /* These constructor and destructor serve for creation/destruction @@ -1599,7 +1601,8 @@ typedef struct st_lex : public Query_tables_list */ List context_stack; - SQL_LIST proc_list, auxiliary_table_list, save_list; + SQL_I_List proc_list; + SQL_I_List auxiliary_table_list, save_list; Create_field *last_field; Item_sum *in_sum_func; udf_func udf; @@ -1721,7 +1724,7 @@ typedef struct st_lex : public Query_tables_list fields to TABLE object at table open (altough for latter pointer to table being opened is probably enough). */ - SQL_LIST trg_table_fields; + SQL_I_List trg_table_fields; /* stmt_definition_begin is intended to point to the next word after -- cgit v1.2.1