/* Copyright 2000-2008 MySQL AB, 2008 Sun Microsystems, Inc. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; version 2 of the License. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ /** @defgroup Semantic_Analysis Semantic Analysis */ #ifndef SQL_LEX_INCLUDED #define SQL_LEX_INCLUDED #include "violite.h" /* SSL_type */ #include "sql_trigger.h" #include "item.h" /* From item_subselect.h: subselect_union_engine */ #include "thr_lock.h" /* thr_lock_type, TL_UNLOCK */ /* YACC and LEX Definitions */ /* These may not be declared yet */ class Table_ident; class sql_exchange; class LEX_COLUMN; class sp_head; class sp_name; class sp_instr; class sp_pcontext; class st_alter_tablespace; class partition_info; class Event_parse_data; class set_var_base; class sys_var; class Item_func_match; class Alter_drop; class Alter_column; class Key; class File_parser; class Key_part_spec; #ifdef MYSQL_SERVER /* There are 8 different type of table access so there is no more than combinations 2^8 = 256: . STMT_READS_TRANS_TABLE . STMT_READS_NON_TRANS_TABLE . STMT_READS_TEMP_TRANS_TABLE . STMT_READS_TEMP_NON_TRANS_TABLE . STMT_WRITES_TRANS_TABLE . STMT_WRITES_NON_TRANS_TABLE . STMT_WRITES_TEMP_TRANS_TABLE . STMT_WRITES_TEMP_NON_TRANS_TABLE The unsafe conditions for each combination is represented within a byte and stores the status of the option --binlog-direct-non-trans-updates, whether the trx-cache is empty or not, and whether the isolation level is lower than ISO_REPEATABLE_READ: . option (OFF/ON) . trx-cache (empty/not empty) . isolation (>= ISO_REPEATABLE_READ / < ISO_REPEATABLE_READ) bits 0 : . OFF, . empty, . >= ISO_REPEATABLE_READ bits 1 : . OFF, . empty, . < ISO_REPEATABLE_READ bits 2 : . OFF, . not empty, . >= ISO_REPEATABLE_READ bits 3 : . OFF, . not empty, . < ISO_REPEATABLE_READ bits 4 : . ON, . empty, . >= ISO_REPEATABLE_READ bits 5 : . ON, . empty, . < ISO_REPEATABLE_READ bits 6 : . ON, . not empty, . >= ISO_REPEATABLE_READ bits 7 : . ON, . not empty, . < ISO_REPEATABLE_READ */ extern uint binlog_unsafe_map[256]; /* Initializes the array with unsafe combinations and its respective conditions. */ void binlog_unsafe_map_init(); #endif /** used by the parser to store internal variable name */ struct sys_var_with_base { sys_var *var; LEX_STRING base_name; }; #ifdef MYSQL_SERVER /* The following hack is needed because mysql_yacc.cc does not define YYSTYPE before including this file */ #ifdef MYSQL_YACC #define LEX_YYSTYPE void * #else #include "lex_symbol.h" #if MYSQL_LEX #include "item_func.h" /* Cast_target used in sql_yacc.h */ #include "sql_yacc.h" #define LEX_YYSTYPE YYSTYPE * #else #define LEX_YYSTYPE void * #endif #endif #endif /* When a command is added here, be sure it's also added in mysqld.cc in "struct show_var_st status_vars[]= {" ... If the command returns a result set or is not allowed in stored functions or triggers, please also make sure that sp_get_flags_for_command (sp_head.cc) returns proper flags for the added SQLCOM_. */ enum enum_sql_command { SQLCOM_SELECT, SQLCOM_CREATE_TABLE, SQLCOM_CREATE_INDEX, SQLCOM_ALTER_TABLE, SQLCOM_UPDATE, SQLCOM_INSERT, SQLCOM_INSERT_SELECT, SQLCOM_DELETE, SQLCOM_TRUNCATE, SQLCOM_DROP_TABLE, SQLCOM_DROP_INDEX, SQLCOM_SHOW_DATABASES, SQLCOM_SHOW_TABLES, SQLCOM_SHOW_FIELDS, SQLCOM_SHOW_KEYS, SQLCOM_SHOW_VARIABLES, SQLCOM_SHOW_STATUS, SQLCOM_SHOW_ENGINE_LOGS, SQLCOM_SHOW_ENGINE_STATUS, SQLCOM_SHOW_ENGINE_MUTEX, SQLCOM_SHOW_PROCESSLIST, SQLCOM_SHOW_MASTER_STAT, SQLCOM_SHOW_SLAVE_STAT, SQLCOM_SHOW_GRANTS, SQLCOM_SHOW_CREATE, SQLCOM_SHOW_CHARSETS, SQLCOM_SHOW_COLLATIONS, SQLCOM_SHOW_CREATE_DB, SQLCOM_SHOW_TABLE_STATUS, SQLCOM_SHOW_TRIGGERS, SQLCOM_LOAD,SQLCOM_SET_OPTION,SQLCOM_LOCK_TABLES,SQLCOM_UNLOCK_TABLES, SQLCOM_GRANT, SQLCOM_CHANGE_DB, SQLCOM_CREATE_DB, SQLCOM_DROP_DB, SQLCOM_ALTER_DB, SQLCOM_REPAIR, SQLCOM_REPLACE, SQLCOM_REPLACE_SELECT, SQLCOM_CREATE_FUNCTION, SQLCOM_DROP_FUNCTION, SQLCOM_REVOKE,SQLCOM_OPTIMIZE, SQLCOM_CHECK, SQLCOM_ASSIGN_TO_KEYCACHE, SQLCOM_PRELOAD_KEYS, SQLCOM_FLUSH, SQLCOM_KILL, SQLCOM_ANALYZE, SQLCOM_ROLLBACK, SQLCOM_ROLLBACK_TO_SAVEPOINT, SQLCOM_COMMIT, SQLCOM_SAVEPOINT, SQLCOM_RELEASE_SAVEPOINT, SQLCOM_SLAVE_START, SQLCOM_SLAVE_STOP, SQLCOM_BEGIN, SQLCOM_CHANGE_MASTER, SQLCOM_RENAME_TABLE, SQLCOM_RESET, SQLCOM_PURGE, SQLCOM_PURGE_BEFORE, SQLCOM_SHOW_BINLOGS, SQLCOM_SHOW_OPEN_TABLES, SQLCOM_HA_OPEN, SQLCOM_HA_CLOSE, SQLCOM_HA_READ, SQLCOM_SHOW_SLAVE_HOSTS, SQLCOM_DELETE_MULTI, SQLCOM_UPDATE_MULTI, SQLCOM_SHOW_BINLOG_EVENTS, SQLCOM_DO, SQLCOM_SHOW_WARNS, SQLCOM_EMPTY_QUERY, SQLCOM_SHOW_ERRORS, SQLCOM_SHOW_STORAGE_ENGINES, SQLCOM_SHOW_PRIVILEGES, SQLCOM_HELP, SQLCOM_CREATE_USER, SQLCOM_DROP_USER, SQLCOM_RENAME_USER, SQLCOM_REVOKE_ALL, SQLCOM_CHECKSUM, SQLCOM_CREATE_PROCEDURE, SQLCOM_CREATE_SPFUNCTION, SQLCOM_CALL, SQLCOM_DROP_PROCEDURE, SQLCOM_ALTER_PROCEDURE,SQLCOM_ALTER_FUNCTION, SQLCOM_SHOW_CREATE_PROC, SQLCOM_SHOW_CREATE_FUNC, SQLCOM_SHOW_STATUS_PROC, SQLCOM_SHOW_STATUS_FUNC, SQLCOM_PREPARE, SQLCOM_EXECUTE, SQLCOM_DEALLOCATE_PREPARE, SQLCOM_CREATE_VIEW, SQLCOM_DROP_VIEW, SQLCOM_CREATE_TRIGGER, SQLCOM_DROP_TRIGGER, SQLCOM_XA_START, SQLCOM_XA_END, SQLCOM_XA_PREPARE, SQLCOM_XA_COMMIT, SQLCOM_XA_ROLLBACK, SQLCOM_XA_RECOVER, SQLCOM_SHOW_PROC_CODE, SQLCOM_SHOW_FUNC_CODE, SQLCOM_ALTER_TABLESPACE, SQLCOM_INSTALL_PLUGIN, SQLCOM_UNINSTALL_PLUGIN, SQLCOM_SHOW_AUTHORS, SQLCOM_BINLOG_BASE64_EVENT, SQLCOM_SHOW_PLUGINS, SQLCOM_SHOW_CONTRIBUTORS, SQLCOM_CREATE_SERVER, SQLCOM_DROP_SERVER, SQLCOM_ALTER_SERVER, SQLCOM_CREATE_EVENT, SQLCOM_ALTER_EVENT, SQLCOM_DROP_EVENT, SQLCOM_SHOW_CREATE_EVENT, SQLCOM_SHOW_EVENTS, SQLCOM_SHOW_CREATE_TRIGGER, SQLCOM_ALTER_DB_UPGRADE, SQLCOM_SHOW_PROFILE, SQLCOM_SHOW_PROFILES, SQLCOM_SIGNAL, SQLCOM_RESIGNAL, SQLCOM_SHOW_RELAYLOG_EVENTS, /* When a command is added here, be sure it's also added in mysqld.cc in "struct show_var_st status_vars[]= {" ... */ /* This should be the last !!! */ SQLCOM_END }; // describe/explain types #define DESCRIBE_NORMAL 1 #define DESCRIBE_EXTENDED 2 /* This is not within #ifdef because we want "EXPLAIN PARTITIONS ..." to produce additional "partitions" column even if partitioning is not compiled in. */ #define DESCRIBE_PARTITIONS 4 #ifdef MYSQL_SERVER enum enum_sp_suid_behaviour { SP_IS_DEFAULT_SUID= 0, SP_IS_NOT_SUID, SP_IS_SUID }; enum enum_sp_data_access { SP_DEFAULT_ACCESS= 0, SP_CONTAINS_SQL, SP_NO_SQL, SP_READS_SQL_DATA, SP_MODIFIES_SQL_DATA }; const LEX_STRING sp_data_access_name[]= { { C_STRING_WITH_LEN("") }, { C_STRING_WITH_LEN("CONTAINS SQL") }, { C_STRING_WITH_LEN("NO SQL") }, { C_STRING_WITH_LEN("READS SQL DATA") }, { C_STRING_WITH_LEN("MODIFIES SQL DATA") } }; #define DERIVED_SUBQUERY 1 #define DERIVED_VIEW 2 enum enum_view_create_mode { VIEW_CREATE_NEW, // check that there are not such VIEW/table VIEW_ALTER, // check that VIEW .frm with such name exists VIEW_CREATE_OR_REPLACE // check only that there are not such table }; enum enum_drop_mode { DROP_DEFAULT, // mode is not specified DROP_CASCADE, // CASCADE option DROP_RESTRICT // RESTRICT option }; /* Options to add_table_to_list() */ #define TL_OPTION_UPDATING 1 #define TL_OPTION_FORCE_INDEX 2 #define TL_OPTION_IGNORE_LEAVES 4 #define TL_OPTION_ALIAS 8 typedef List List_item; /* SERVERS CACHE CHANGES */ typedef struct st_lex_server_options { long port; uint server_name_length; char *server_name, *host, *db, *username, *password, *scheme, *socket, *owner; } LEX_SERVER_OPTIONS; /** Structure to hold parameters for CHANGE MASTER, START SLAVE, and STOP SLAVE. Remark: this should not be confused with Master_info (and perhaps would better be renamed to st_lex_replication_info). Some fields, e.g., delay, are saved in Relay_log_info, not in Master_info. */ typedef struct st_lex_master_info { char *host, *user, *password, *log_file_name; uint port, connect_retry; float heartbeat_period; ulonglong pos; ulong server_id; /* Enum is used for making it possible to detect if the user changed variable or if it should be left at old value */ enum {LEX_MI_UNCHANGED, LEX_MI_DISABLE, LEX_MI_ENABLE} ssl, ssl_verify_server_cert, heartbeat_opt, repl_ignore_server_ids_opt; char *ssl_key, *ssl_cert, *ssl_ca, *ssl_capath, *ssl_cipher; char *relay_log_name; ulong relay_log_pos; DYNAMIC_ARRAY repl_ignore_server_ids; } LEX_MASTER_INFO; enum sub_select_type { UNSPECIFIED_TYPE,UNION_TYPE, INTERSECT_TYPE, EXCEPT_TYPE, GLOBAL_OPTIONS_TYPE, DERIVED_TABLE_TYPE, OLAP_TYPE }; enum olap_type { UNSPECIFIED_OLAP_TYPE, CUBE_TYPE, ROLLUP_TYPE }; enum tablespace_op_type { NO_TABLESPACE_OP, DISCARD_TABLESPACE, IMPORT_TABLESPACE }; /* String names used to print a statement with index hints. Keep in sync with index_hint_type. */ extern const char * index_hint_type_name[]; typedef uchar index_clause_map; /* Bits in index_clause_map : one for each possible FOR clause in USE/FORCE/IGNORE INDEX index hint specification */ #define INDEX_HINT_MASK_JOIN (1) #define INDEX_HINT_MASK_GROUP (1 << 1) #define INDEX_HINT_MASK_ORDER (1 << 2) #define INDEX_HINT_MASK_ALL (INDEX_HINT_MASK_JOIN | INDEX_HINT_MASK_GROUP | \ INDEX_HINT_MASK_ORDER) /* Single element of an USE/FORCE/IGNORE INDEX list specified as a SQL hint */ class Index_hint : public Sql_alloc { public: /* The type of the hint : USE/FORCE/IGNORE */ enum index_hint_type type; /* Where the hit applies to. A bitmask of INDEX_HINT_MASK_ values */ index_clause_map clause; /* The index name. Empty (str=NULL) name represents an empty list USE INDEX () clause */ LEX_STRING key_name; Index_hint (enum index_hint_type type_arg, index_clause_map clause_arg, char *str, uint length) : type(type_arg), clause(clause_arg) { key_name.str= str; key_name.length= length; } void print(THD *thd, String *str); }; /* The state of the lex parsing for selects master and slaves are pointers to select_lex. master is pointer to upper level node. slave is pointer to lower level node select_lex is a SELECT without union unit is container of either - One SELECT - UNION of selects select_lex and unit are both inherited form select_lex_node neighbors are two select_lex or units on the same level All select describing structures linked with following pointers: - list of neighbors (next/prev) (prev of first element point to slave pointer of upper structure) - For select this is a list of UNION's (or one element list) - For units this is a list of sub queries for the upper level select - pointer to master (master), which is If this is a unit - pointer to outer select_lex If this is a select_lex - pointer to outer unit structure for select - pointer to slave (slave), which is either: If this is a unit: - first SELECT that belong to this unit If this is a select_lex - first unit that belong to this SELECT (subquries or derived tables) - list of all select_lex (link_next/link_prev) This is to be used for things like derived tables creation, where we go through this list and create the derived tables. If unit contain several selects (UNION now, INTERSECT etc later) then it have special select_lex called fake_select_lex. It used for storing global parameters (like ORDER BY, LIMIT) and executing union. Subqueries used in global ORDER BY clause will be attached to this fake_select_lex, which will allow them correctly resolve fields of 'upper' UNION and outer selects. For example for following query: select * from table1 where table1.field IN (select * from table1_1_1 union select * from table1_1_2) union select * from table2 where table2.field=(select (select f1 from table2_1_1_1_1 where table2_1_1_1_1.f2=table2_1_1.f3) from table2_1_1 where table2_1_1.f1=table2.f2) union select * from table3; we will have following structure: select1: (select * from table1 ...) select2: (select * from table2 ...) select3: (select * from table3) select1.1.1: (select * from table1_1_1) ... main unit fake0 select1 select2 select3 |^^ |^ s||| ||master l||| |+---------------------------------+ a||| +---------------------------------+| v|||master slave || e||+-------------------------+ || V| neighbor | V| unit1.1<+==================>unit1.2 unit2.1 fake1.1 select1.1.1 select 1.1.2 select1.2.1 select2.1.1 |^ || V| unit2.1.1.1 select2.1.1.1.1 relation in main unit will be following: (bigger picture for: main unit fake0 select1 select2 select3 in the above picture) main unit |^^^^|fake_select_lex |||||+--------------------------------------------+ ||||+--------------------------------------------+| |||+------------------------------+ || ||+--------------+ | || slave||master | | || V| neighbor | neighbor | master|V select1<========>select2<========>select3 fake0 list of all select_lex will be following (as it will be constructed by parser): select1->select2->select3->select2.1.1->select 2.1.2->select2.1.1.1.1-+ | +---------------------------------------------------------------------+ | +->select1.1.1->select1.1.2 */ /* Base class for st_select_lex (SELECT_LEX) & st_select_lex_unit (SELECT_LEX_UNIT) */ struct LEX; class st_select_lex; class st_select_lex_unit; class st_select_lex_node { protected: st_select_lex_node *next, **prev, /* neighbor list */ *master, *slave, /* vertical links */ *link_next, **link_prev; /* list of whole SELECT_LEX */ public: ulonglong options; /* In sql_cache we store SQL_CACHE flag as specified by user to be able to restore SELECT statement from internal structures. */ enum e_sql_cache { SQL_CACHE_UNSPECIFIED, SQL_NO_CACHE, SQL_CACHE }; e_sql_cache sql_cache; /* result of this query can't be cached, bit field, can be : UNCACHEABLE_DEPENDENT UNCACHEABLE_RAND UNCACHEABLE_SIDEEFFECT UNCACHEABLE_EXPLAIN UNCACHEABLE_PREPARE */ uint8 uncacheable; enum sub_select_type linkage; bool no_table_names_allowed; /* used for global order by */ bool no_error; /* suppress error message (convert it to warnings) */ static void *operator new(size_t size) throw () { return sql_alloc(size); } static void *operator new(size_t size, MEM_ROOT *mem_root) throw () { return (void*) alloc_root(mem_root, (uint) size); } static void operator delete(void *ptr,size_t size) { TRASH(ptr, size); } static void operator delete(void *ptr, MEM_ROOT *mem_root) {} // Ensures that at least all members used during cleanup() are initialized. st_select_lex_node() : next(NULL), prev(NULL), master(NULL), slave(NULL), link_next(NULL), link_prev(NULL), linkage(UNSPECIFIED_TYPE) { } virtual ~st_select_lex_node() {} inline st_select_lex_node* get_master() { return master; } virtual void init_query(); virtual void init_select(); void include_down(st_select_lex_node *upper); void include_neighbour(st_select_lex_node *before); void include_standalone(st_select_lex_node *sel, st_select_lex_node **ref); void include_global(st_select_lex_node **plink); void exclude(); virtual st_select_lex_unit* master_unit()= 0; virtual st_select_lex* outer_select()= 0; virtual st_select_lex* return_after_parsing()= 0; virtual bool set_braces(bool value); virtual bool inc_in_sum_expr(); virtual uint get_in_sum_expr(); virtual TABLE_LIST* get_table_list(); virtual List* get_item_list(); virtual ulong get_table_join_options(); virtual TABLE_LIST *add_table_to_list(THD *thd, Table_ident *table, LEX_STRING *alias, ulong table_options, thr_lock_type flags= TL_UNLOCK, enum_mdl_type mdl_type= MDL_SHARED_READ, List *hints= 0, LEX_STRING *option= 0); virtual void set_lock_for_tables(thr_lock_type lock_type) {} friend class st_select_lex_unit; friend bool mysql_new_select(LEX *lex, bool move_down); friend bool mysql_make_view(THD *thd, File_parser *parser, TABLE_LIST *table, uint flags); private: void fast_exclude(); }; typedef class st_select_lex_node SELECT_LEX_NODE; /* SELECT_LEX_UNIT - unit of selects (UNION, INTERSECT, ...) group SELECT_LEXs */ class THD; class select_result; class JOIN; class select_union; class Procedure; class st_select_lex_unit: public st_select_lex_node { protected: TABLE_LIST result_table_list; select_union *union_result; TABLE *table; /* temporary table using for appending UNION results */ select_result *result; ulonglong found_rows_for_union; bool saved_error; public: // Ensures that at least all members used during cleanup() are initialized. st_select_lex_unit() : union_result(NULL), table(NULL), result(NULL), cleaned(false), fake_select_lex(NULL) { } bool prepared, // prepare phase already performed for UNION (unit) optimized, // optimize phase already performed for UNION (unit) executed, // already executed cleaned; // list of fields which points to temporary table for union List item_list; /* list of types of items inside union (used for union & derived tables) Item_type_holders from which this list consist may have pointers to Field, pointers is valid only after preparing SELECTS of this unit and before any SELECT of this unit execution */ List types; /* Pointer to 'last' select or pointer to unit where stored global parameters for union */ st_select_lex *global_parameters; //node on wich we should return current_select pointer after parsing subquery st_select_lex *return_to; /* LIMIT clause runtime counters */ ha_rows select_limit_cnt, offset_limit_cnt; /* not NULL if unit used in subselect, point to subselect item */ Item_subselect *item; /* thread handler */ THD *thd; /* SELECT_LEX for hidden SELECT in onion which process global ORDER BY and LIMIT */ st_select_lex *fake_select_lex; st_select_lex *union_distinct; /* pointer to the last UNION DISTINCT */ bool describe; /* union exec() called for EXPLAIN */ Procedure *last_procedure; /* Pointer to procedure, if such exists */ void init_query(); st_select_lex_unit* master_unit(); st_select_lex* outer_select(); st_select_lex* first_select() { return reinterpret_cast(slave); } st_select_lex_unit* next_unit() { return reinterpret_cast(next); } st_select_lex* return_after_parsing() { return return_to; } void exclude_level(); void exclude_tree(); /* UNION methods */ bool prepare(THD *thd, select_result *result, ulong additional_options); bool exec(); bool cleanup(); inline void unclean() { cleaned= 0; } void reinit_exec_mechanism(); void print(String *str, enum_query_type query_type); bool add_fake_select_lex(THD *thd); void init_prepare_fake_select_lex(THD *thd); inline bool is_prepared() { return prepared; } bool change_result(select_subselect *result, select_subselect *old_result); void set_limit(st_select_lex *values); void set_thd(THD *thd_arg) { thd= thd_arg; } inline bool is_union (); friend void lex_start(THD *thd); friend int subselect_union_engine::exec(); List *get_unit_column_types(); }; typedef class st_select_lex_unit SELECT_LEX_UNIT; /* SELECT_LEX - store information of parsed SELECT statment */ class st_select_lex: public st_select_lex_node { public: Name_resolution_context context; char *db; Item *where, *having; /* WHERE & HAVING clauses */ Item *prep_where; /* saved WHERE clause for prepared statement processing */ Item *prep_having;/* saved HAVING clause for prepared statement processing */ /* Saved values of the WHERE and HAVING clauses*/ Item::cond_result cond_value, having_value; /* point on lex in which it was created, used in view subquery detection */ LEX *parent_lex; enum olap_type olap; /* FROM clause - points to the beginning of the TABLE_LIST::next_local list. */ 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; /* Usualy it is pointer to ftfunc_list_alloc, but in union used to create fake select_lex for calling mysql_select under results of union */ List *ftfunc_list; List ftfunc_list_alloc; JOIN *join; /* after JOIN::prepare it is pointer to corresponding JOIN */ List top_join_list; /* join list of the top level */ List *join_list; /* list for the currently parsed join */ TABLE_LIST *embedding; /* table embedding to the above list */ /* Beginning of the list of leaves in a FROM clause, where the leaves inlcude all base tables including view tables. The tables are connected by TABLE_LIST::next_leaf, so leaf_tables points to the left-most leaf. */ TABLE_LIST *leaf_tables; const char *type; /* type of select for EXPLAIN */ 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; /* number of items in select_list and HAVING clause used to get number bigger then can be number of entries that will be added to all item list during split_sum_func */ uint select_n_having_items; uint cond_count; /* number of arguments of and/or/xor in where/having/on */ uint between_count; /* number of between predicates in where/having/on */ uint max_equal_elems; /* maximal number of elements in multiple equalities */ /* Number of fields used in select list or where clause of current select and all inner subselects. */ uint select_n_where_fields; enum_parsing_place parsing_place; /* where we are parsing expression */ bool with_sum_func; /* sum function indicator */ ulong table_join_options; uint in_sum_expr; uint select_number; /* number of select (used for EXPLAIN) */ int nest_level; /* nesting level of select */ Item_sum *inner_sum_func_list; /* list of sum func in nested selects */ uint with_wild; /* item list contain '*' */ bool braces; /* SELECT ... UNION (SELECT ... ) <- this braces */ /* TRUE when having fix field called in processing of this SELECT */ bool having_fix_field; /* TRUE when GROUP BY fix field called in processing of this SELECT */ bool group_fix_field; /* List of references to fields referenced from inner selects */ List inner_refs_list; /* Number of Item_sum-derived objects in this SELECT */ uint n_sum_items; /* Number of Item_sum-derived objects in children and descendant SELECTs */ uint n_child_sum_items; /* explicit LIMIT clause was used */ bool explicit_limit; /* there are subquery in HAVING clause => we can't close tables before query processing end even if we use temporary table */ bool subquery_in_having; /* TRUE <=> this SELECT is correlated w.r.t. some ancestor select */ bool is_correlated; /* This variable is required to ensure proper work of subqueries and stored procedures. Generally, one should use the states of Query_arena to determine if it's a statement prepare or first execution of a stored procedure. However, in case when there was an error during the first execution of a stored procedure, the SP body is not expelled from the SP cache. Therefore, a deeply nested subquery might be left unoptimized. So we need this per-subquery variable to inidicate the optimization/execution state of every subquery. Prepared statements work OK in that regard, as in case of an error during prepare the PS is not created. */ bool first_execution; bool first_natural_join_processing; bool first_cond_optimization; /* do not wrap view fields with Item_ref */ bool no_wrap_view_item; /* exclude this select from check of unique_table() */ bool exclude_from_table_unique_test; /* List of fields that aren't under an aggregate function */ List non_agg_fields; /* index in the select list of the expression currently being fixed */ int cur_pos_in_select_list; List udf_list; /* udf function calls stack */ /* This is a copy of the original JOIN USING list that comes from the parser. The parser : 1. Sets the natural_join of the second TABLE_LIST in the join and the st_select_lex::prev_join_using. 2. Makes a parent TABLE_LIST and sets its is_natural_join/ join_using_fields members. 3. Uses the wrapper TABLE_LIST as a table in the upper level. We cannot assign directly to join_using_fields in the parser because at stage (1.) the parent TABLE_LIST is not constructed yet and the assignment will override the JOIN USING fields of the lower level joins on the right. */ List *prev_join_using; /* Bitmap used in the ONLY_FULL_GROUP_BY_MODE to prevent mixture of aggregate functions and non aggregated fields when GROUP BY list is absent. Bits: 0 - non aggregated fields are used in this select, defined as NON_AGG_FIELD_USED. 1 - aggregate functions are used in this select, defined as SUM_FUNC_USED. */ uint8 full_group_by_flag; void init_query(); void init_select(); st_select_lex_unit* master_unit(); st_select_lex_unit* first_inner_unit() { return (st_select_lex_unit*) slave; } st_select_lex* outer_select(); st_select_lex* next_select() { return (st_select_lex*) next; } st_select_lex* next_select_in_list() { return (st_select_lex*) link_next; } st_select_lex_node** next_select_in_list_addr() { return &link_next; } st_select_lex* return_after_parsing() { return master_unit()->return_after_parsing(); } void mark_as_dependent(st_select_lex *last); bool set_braces(bool value); bool inc_in_sum_expr(); uint get_in_sum_expr(); bool add_item_to_list(THD *thd, Item *item); bool add_group_to_list(THD *thd, Item *item, bool asc); bool add_ftfunc_to_list(Item_func_match *func); bool add_order_to_list(THD *thd, Item *item, bool asc); TABLE_LIST* add_table_to_list(THD *thd, Table_ident *table, LEX_STRING *alias, ulong table_options, thr_lock_type flags= TL_UNLOCK, enum_mdl_type mdl_type= MDL_SHARED_READ, List *hints= 0, LEX_STRING *option= 0); TABLE_LIST* get_table_list(); bool init_nested_join(THD *thd); TABLE_LIST *end_nested_join(THD *thd); TABLE_LIST *nest_last_join(THD *thd); void add_joined_table(TABLE_LIST *table); TABLE_LIST *convert_right_join(); List* get_item_list(); ulong get_table_join_options(); void set_lock_for_tables(thr_lock_type lock_type); inline void init_order() { order_list.elements= 0; order_list.first= 0; order_list.next= &order_list.first; } /* This method created for reiniting LEX in mysql_admin_table() and can be used only if you are going remove all SELECT_LEX & units except belonger to LEX (LEX::unit & LEX::select, for other purposes there are SELECT_LEX_UNIT::exclude_level & SELECT_LEX_UNIT::exclude_tree */ void cut_subtree() { slave= 0; } bool test_limit(); friend void lex_start(THD *thd); st_select_lex() : n_sum_items(0), n_child_sum_items(0) {} void make_empty_select() { init_query(); init_select(); } bool setup_ref_array(THD *thd, uint order_group_num); void print(THD *thd, String *str, enum_query_type query_type); static void print_order(String *str, ORDER *order, enum_query_type query_type); void print_limit(THD *thd, String *str, enum_query_type query_type); void fix_prepare_information(THD *thd, Item **conds, Item **having_conds); /* Destroy the used execution plan (JOIN) of this subtree (this SELECT_LEX and all nested SELECT_LEXes and SELECT_LEX_UNITs). */ bool cleanup(); /* Recursively cleanup the join of this select lex and of all nested select lexes. */ void cleanup_all_joins(bool full); void set_index_hint_type(enum index_hint_type type, index_clause_map clause); /* Add a index hint to the tagged list of hints. The type and clause of the hint will be the current ones (set by set_index_hint()) */ bool add_index_hint (THD *thd, char *str, uint length); /* make a list to hold index hints */ void alloc_index_hints (THD *thd); /* read and clear the index hints */ List* pop_index_hints(void) { List *hints= index_hints; index_hints= NULL; return hints; } void clear_index_hints(void) { index_hints= NULL; } private: /* current index hint kind. used in filling up index_hints */ enum index_hint_type current_index_hint_type; index_clause_map current_index_hint_clause; /* a list of USE/FORCE/IGNORE INDEX */ List *index_hints; }; typedef class st_select_lex SELECT_LEX; inline bool st_select_lex_unit::is_union () { return first_select()->next_select() && first_select()->next_select()->linkage == UNION_TYPE; } #define ALTER_ADD_COLUMN (1L << 0) #define ALTER_DROP_COLUMN (1L << 1) #define ALTER_CHANGE_COLUMN (1L << 2) #define ALTER_ADD_INDEX (1L << 3) #define ALTER_DROP_INDEX (1L << 4) #define ALTER_RENAME (1L << 5) #define ALTER_ORDER (1L << 6) #define ALTER_OPTIONS (1L << 7) #define ALTER_CHANGE_COLUMN_DEFAULT (1L << 8) #define ALTER_KEYS_ONOFF (1L << 9) #define ALTER_CONVERT (1L << 10) #define ALTER_RECREATE (1L << 11) #define ALTER_ADD_PARTITION (1L << 12) #define ALTER_DROP_PARTITION (1L << 13) #define ALTER_COALESCE_PARTITION (1L << 14) #define ALTER_REORGANIZE_PARTITION (1L << 15) #define ALTER_PARTITION (1L << 16) #define ALTER_ADMIN_PARTITION (1L << 17) #define ALTER_TABLE_REORG (1L << 18) #define ALTER_REBUILD_PARTITION (1L << 19) #define ALTER_ALL_PARTITION (1L << 20) #define ALTER_REMOVE_PARTITIONING (1L << 21) #define ALTER_FOREIGN_KEY (1L << 22) #define ALTER_TRUNCATE_PARTITION (1L << 23) enum enum_alter_table_change_level { ALTER_TABLE_METADATA_ONLY= 0, ALTER_TABLE_DATA_CHANGED= 1, ALTER_TABLE_INDEX_CHANGED= 2 }; /** Temporary hack to enable a class bound forward declaration of the enum_alter_table_change_level enumeration. To be removed once Alter_info is moved to the sql_alter.h header. */ class Alter_table_change_level { private: typedef enum enum_alter_table_change_level enum_type; enum_type value; public: void operator = (enum_type v) { value = v; } operator enum_type () { return value; } }; /** @brief Parsing data for CREATE or ALTER TABLE. This structure contains a list of columns or indexes to be created, altered or dropped. */ class Alter_info { public: List drop_list; List alter_list; List key_list; List create_list; uint flags; enum enum_enable_or_disable keys_onoff; enum tablespace_op_type tablespace_op; List partition_names; uint num_parts; enum_alter_table_change_level change_level; Create_field *datetime_field; bool error_if_not_empty; Alter_info() : flags(0), keys_onoff(LEAVE_AS_IS), tablespace_op(NO_TABLESPACE_OP), num_parts(0), change_level(ALTER_TABLE_METADATA_ONLY), datetime_field(NULL), error_if_not_empty(FALSE) {} void reset() { drop_list.empty(); alter_list.empty(); key_list.empty(); create_list.empty(); flags= 0; keys_onoff= LEAVE_AS_IS; tablespace_op= NO_TABLESPACE_OP; num_parts= 0; partition_names.empty(); change_level= ALTER_TABLE_METADATA_ONLY; datetime_field= 0; error_if_not_empty= FALSE; } Alter_info(const Alter_info &rhs, MEM_ROOT *mem_root); private: Alter_info &operator=(const Alter_info &rhs); // not implemented Alter_info(const Alter_info &rhs); // not implemented }; struct st_sp_chistics { LEX_STRING comment; enum enum_sp_suid_behaviour suid; bool detistic; enum enum_sp_data_access daccess; }; extern const LEX_STRING null_lex_str; extern const LEX_STRING empty_lex_str; struct st_trg_chistics { enum trg_action_time_type action_time; enum trg_event_type event; }; extern sys_var *trg_new_row_fake_var; enum xa_option_words {XA_NONE, XA_JOIN, XA_RESUME, XA_ONE_PHASE, XA_SUSPEND, XA_FOR_MIGRATE}; extern const LEX_STRING null_lex_str; class Sroutine_hash_entry; /* Class representing list of all tables used by statement and other information which is necessary for opening and locking its tables, like SQL command for this statement. Also contains information about stored functions used by statement since during its execution we may have to add all tables used by its stored functions/triggers to this list in order to pre-open and lock them. Also used by LEX::reset_n_backup/restore_backup_query_tables_list() methods to save and restore this information. */ class Query_tables_list { public: /** SQL command for this statement. Part of this class since the process of opening and locking tables for the statement needs this information to determine correct type of lock for some of the tables. */ enum_sql_command sql_command; /* Global list of all tables used by this statement */ TABLE_LIST *query_tables; /* Pointer to next_global member of last element in the previous list. */ TABLE_LIST **query_tables_last; /* If non-0 then indicates that query requires prelocking and points to next_global member of last own element in query table list (i.e. last table which was not added to it as part of preparation to prelocking). 0 - indicates that this query does not need prelocking. */ TABLE_LIST **query_tables_own_last; /* Set of stored routines called by statement. (Note that we use lazy-initialization for this hash). */ enum { START_SROUTINES_HASH_SIZE= 16 }; HASH sroutines; /* List linking elements of 'sroutines' set. Allows you to add new elements to this set as you iterate through the list of existing elements. 'sroutines_list_own_last' is pointer to ::next member of last element of this list which represents routine which is explicitly used by query. 'sroutines_list_own_elements' number of explicitly used routines. We use these two members for restoring of 'sroutines_list' to the state in which it was right after query parsing. */ 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 of Query_tables_list instances which are used as backup storage. */ Query_tables_list() {} ~Query_tables_list() {} /* Initializes (or resets) Query_tables_list object for "real" use. */ void reset_query_tables_list(bool init); void destroy_query_tables_list(); void set_query_tables_list(Query_tables_list *state) { *this= *state; } /* Direct addition to the list of query tables. If you are using this function, you must ensure that the table object, in particular table->db member, is initialized. */ void add_to_query_tables(TABLE_LIST *table) { *(table->prev_global= query_tables_last)= table; query_tables_last= &table->next_global; } bool requires_prelocking() { return test(query_tables_own_last); } void mark_as_requiring_prelocking(TABLE_LIST **tables_own_last) { query_tables_own_last= tables_own_last; } /* Return pointer to first not-own table in query-tables or 0 */ TABLE_LIST* first_not_own_table() { return ( query_tables_own_last ? *query_tables_own_last : 0); } void chop_off_not_own_tables() { if (query_tables_own_last) { *query_tables_own_last= 0; query_tables_last= query_tables_own_last; query_tables_own_last= 0; } } /** Return a pointer to the last element in query table list. */ TABLE_LIST *last_table() { /* Don't use offsetof() macro in order to avoid warnings. */ return query_tables ? (TABLE_LIST*) ((char*) query_tables_last - ((char*) &(query_tables->next_global) - (char*) query_tables)) : 0; } /** Enumeration listing of all types of unsafe statement. @note The order of elements of this enumeration type must correspond to the order of the elements of the @c explanations array defined in the body of @c THD::issue_unsafe_warnings. */ enum enum_binlog_stmt_unsafe { /** SELECT..LIMIT is unsafe because the set of rows returned cannot be predicted. */ BINLOG_STMT_UNSAFE_LIMIT= 0, /** INSERT DELAYED is unsafe because the time when rows are inserted cannot be predicted. */ BINLOG_STMT_UNSAFE_INSERT_DELAYED, /** Access to log tables is unsafe because slave and master probably log different things. */ BINLOG_STMT_UNSAFE_SYSTEM_TABLE, /** Inserting into an autoincrement column in a stored routine is unsafe. Even with just one autoincrement column, if the routine is invoked more than once slave is not guaranteed to execute the statement graph same way as the master. And since it's impossible to estimate how many times a routine can be invoked at the query pre-execution phase (see lock_tables), the statement is marked pessimistically unsafe. */ BINLOG_STMT_UNSAFE_AUTOINC_COLUMNS, /** Using a UDF (user-defined function) is unsafe. */ BINLOG_STMT_UNSAFE_UDF, /** Using most system variables is unsafe, because slave may run with different options than master. */ BINLOG_STMT_UNSAFE_SYSTEM_VARIABLE, /** Using some functions is unsafe (e.g., UUID). */ BINLOG_STMT_UNSAFE_SYSTEM_FUNCTION, /** Mixing transactional and non-transactional statements are unsafe if non-transactional reads or writes are occur after transactional reads or writes inside a transaction. */ BINLOG_STMT_UNSAFE_NONTRANS_AFTER_TRANS, /** Mixing self-logging and non-self-logging engines in a statement is unsafe. */ BINLOG_STMT_UNSAFE_MULTIPLE_ENGINES_AND_SELF_LOGGING_ENGINE, /** Statements that read from both transactional and non-transactional tables and write to any of them are unsafe. */ BINLOG_STMT_UNSAFE_MIXED_STATEMENT, /* The last element of this enumeration type. */ BINLOG_STMT_UNSAFE_COUNT }; /** This has all flags from 0 (inclusive) to BINLOG_STMT_FLAG_COUNT (exclusive) set. */ static const int BINLOG_STMT_UNSAFE_ALL_FLAGS= ((1 << BINLOG_STMT_UNSAFE_COUNT) - 1); /** Maps elements of enum_binlog_stmt_unsafe to error codes. */ static const int binlog_stmt_unsafe_errcode[BINLOG_STMT_UNSAFE_COUNT]; /** Determine if this statement is marked as unsafe. @retval 0 if the statement is not marked as unsafe. @retval nonzero if the statement is marked as unsafe. */ inline bool is_stmt_unsafe() const { return get_stmt_unsafe_flags() != 0; } /** Flag the current (top-level) statement as unsafe. The flag will be reset after the statement has finished. @param unsafe_type The type of unsafety: one of the @c BINLOG_STMT_FLAG_UNSAFE_* flags in @c enum_binlog_stmt_flag. */ inline void set_stmt_unsafe(enum_binlog_stmt_unsafe unsafe_type) { DBUG_ENTER("set_stmt_unsafe"); DBUG_ASSERT(unsafe_type >= 0 && unsafe_type < BINLOG_STMT_UNSAFE_COUNT); binlog_stmt_flags|= (1U << unsafe_type); DBUG_VOID_RETURN; } /** Set the bits of binlog_stmt_flags determining the type of unsafeness of the current statement. No existing bits will be cleared, but new bits may be set. @param flags A binary combination of zero or more bits, (1<= ISO_REPEATABLE_READ */ /** Sets the type of table that is about to be accessed while executing a statement. @param accessed_table Enumeration type that defines the type of table, e.g. temporary, transactional, non-transactional. */ inline void set_stmt_accessed_table(enum_stmt_accessed_table accessed_table) { DBUG_ENTER("LEX::set_stmt_accessed_table"); DBUG_ASSERT(accessed_table >= 0 && accessed_table < STMT_ACCESS_TABLE_COUNT); stmt_accessed_table_flag |= (1U << accessed_table); DBUG_VOID_RETURN; } /** Checks if a type of table is about to be accessed while executing a statement. @param accessed_table Enumeration type that defines the type of table, e.g. temporary, transactional, non-transactional. @return @retval TRUE if the type of the table is about to be accessed @retval FALSE otherwise */ inline bool stmt_accessed_table(enum_stmt_accessed_table accessed_table) { DBUG_ENTER("LEX::stmt_accessed_table"); DBUG_ASSERT(accessed_table >= 0 && accessed_table < STMT_ACCESS_TABLE_COUNT); DBUG_RETURN((stmt_accessed_table_flag & (1U << accessed_table)) != 0); } /** Checks if a temporary non-transactional table is about to be accessed while executing a statement. @return @retval TRUE if a temporary non-transactional table is about to be accessed @retval FALSE otherwise */ inline bool stmt_accessed_non_trans_temp_table() { DBUG_ENTER("THD::stmt_accessed_non_trans_temp_table"); DBUG_RETURN((stmt_accessed_table_flag & ((1U << STMT_READS_TEMP_NON_TRANS_TABLE) | (1U << STMT_WRITES_TEMP_NON_TRANS_TABLE))) != 0); } /* Checks if a mixed statement is unsafe. @param in_multi_stmt_transaction_mode defines if there is an on-going multi-transactional statement. @param binlog_direct defines if --binlog-direct-non-trans-updates is active. @param trx_cache_is_not_empty defines if the trx-cache is empty or not. @param trx_isolation defines the isolation level. @return @retval TRUE if the mixed statement is unsafe @retval FALSE otherwise */ inline bool is_mixed_stmt_unsafe(bool in_multi_stmt_transaction_mode, bool binlog_direct, bool trx_cache_is_not_empty, uint tx_isolation) { bool unsafe= FALSE; if (in_multi_stmt_transaction_mode) { uint condition= (binlog_direct ? BINLOG_DIRECT_ON : BINLOG_DIRECT_OFF) & (trx_cache_is_not_empty ? TRX_CACHE_NOT_EMPTY : TRX_CACHE_EMPTY) & (tx_isolation >= ISO_REPEATABLE_READ ? IL_GTE_REPEATABLE : IL_LT_REPEATABLE); unsafe= (binlog_unsafe_map[stmt_accessed_table_flag] & condition); #if !defined(DBUG_OFF) DBUG_PRINT("LEX::is_mixed_stmt_unsafe", ("RESULT %02X %02X %02X\n", condition, binlog_unsafe_map[stmt_accessed_table_flag], (binlog_unsafe_map[stmt_accessed_table_flag] & condition))); int type_in= 0; for (; type_in < STMT_ACCESS_TABLE_COUNT; type_in++) { if (stmt_accessed_table((enum_stmt_accessed_table) type_in)) DBUG_PRINT("LEX::is_mixed_stmt_unsafe", ("ACCESSED %s ", stmt_accessed_table_string((enum_stmt_accessed_table) type_in))); } #endif } if (stmt_accessed_table(STMT_WRITES_NON_TRANS_TABLE) && stmt_accessed_table(STMT_READS_TRANS_TABLE) && tx_isolation < ISO_REPEATABLE_READ) unsafe= TRUE; else if (stmt_accessed_table(STMT_WRITES_TEMP_NON_TRANS_TABLE) && stmt_accessed_table(STMT_READS_TRANS_TABLE) && tx_isolation < ISO_REPEATABLE_READ) unsafe= TRUE; return(unsafe); } /** true if the parsed tree contains references to stored procedures or functions, false otherwise */ bool uses_stored_routines() const { return sroutines_list.elements != 0; } private: /** Enumeration listing special types of statements. Currently, the only possible type is ROW_INJECTION. */ enum enum_binlog_stmt_type { /** The statement is a row injection (i.e., either a BINLOG statement or a row event executed by the slave SQL thread). */ BINLOG_STMT_TYPE_ROW_INJECTION = 0, /** The last element of this enumeration type. */ BINLOG_STMT_TYPE_COUNT }; /** Bit field indicating the type of statement. There are two groups of bits: - The low BINLOG_STMT_UNSAFE_COUNT bits indicate the types of unsafeness that the current statement has. - The next BINLOG_STMT_TYPE_COUNT bits indicate if the statement is of some special type. This must be a member of LEX, not of THD: each stored procedure needs to remember its unsafeness state between calls and each stored procedure has its own LEX object (but no own THD object). */ uint32 binlog_stmt_flags; /** Bit field that determines the type of tables that are about to be be accessed while executing a statement. */ uint32 stmt_accessed_table_flag; }; /* st_parsing_options contains the flags for constructions that are allowed in the current statement. */ struct st_parsing_options { bool allows_variable; bool allows_select_into; bool allows_select_procedure; bool allows_derived; st_parsing_options() { reset(); } void reset(); }; /** The state of the lexical parser, when parsing comments. */ enum enum_comment_state { /** Not parsing comments. */ NO_COMMENT, /** Parsing comments that need to be preserved. Typically, these are user comments '/' '*' ... '*' '/'. */ PRESERVE_COMMENT, /** Parsing comments that need to be discarded. Typically, these are special comments '/' '*' '!' ... '*' '/', or '/' '*' '!' 'M' 'M' 'm' 'm' 'm' ... '*' '/', where the comment markers should not be expanded. */ DISCARD_COMMENT }; /** @brief This class represents the character input stream consumed during lexical analysis. In addition to consuming the input stream, this class performs some comment pre processing, by filtering out out of bound special text from the query input stream. Two buffers, with pointers inside each buffers, are maintained in parallel. The 'raw' buffer is the original query text, which may contain out-of-bound comments. The 'cpp' (for comments pre processor) is the pre-processed buffer that contains only the query text that should be seen once out-of-bound data is removed. */ class Lex_input_stream { public: Lex_input_stream() { } ~Lex_input_stream() { } /** Object initializer. Must be called before usage. @retval FALSE OK @retval TRUE Error */ bool init(THD *thd, char *buff, unsigned int length); void reset(char *buff, unsigned int length); /** Set the echo mode. When echo is true, characters parsed from the raw input stream are preserved. When false, characters parsed are silently ignored. @param echo the echo mode. */ void set_echo(bool echo) { m_echo= echo; } void save_in_comment_state() { m_echo_saved= m_echo; in_comment_saved= in_comment; } void restore_in_comment_state() { m_echo= m_echo_saved; in_comment= in_comment_saved; } /** Skip binary from the input stream. @param n number of bytes to accept. */ void skip_binary(int n) { if (m_echo) { memcpy(m_cpp_ptr, m_ptr, n); m_cpp_ptr += n; } m_ptr += n; } /** Get a character, and advance in the stream. @return the next character to parse. */ unsigned char yyGet() { char c= *m_ptr++; if (m_echo) *m_cpp_ptr++ = c; return c; } /** Get the last character accepted. @return the last character accepted. */ unsigned char yyGetLast() { return m_ptr[-1]; } /** Look at the next character to parse, but do not accept it. */ unsigned char yyPeek() { return m_ptr[0]; } /** Look ahead at some character to parse. @param n offset of the character to look up */ unsigned char yyPeekn(int n) { return m_ptr[n]; } /** Cancel the effect of the last yyGet() or yySkip(). Note that the echo mode should not change between calls to yyGet / yySkip and yyUnget. The caller is responsible for ensuring that. */ void yyUnget() { m_ptr--; if (m_echo) m_cpp_ptr--; } /** Accept a character, by advancing the input stream. */ void yySkip() { if (m_echo) *m_cpp_ptr++ = *m_ptr++; else m_ptr++; } /** Accept multiple characters at once. @param n the number of characters to accept. */ void yySkipn(int n) { if (m_echo) { memcpy(m_cpp_ptr, m_ptr, n); m_cpp_ptr += n; } m_ptr += n; } /** Puts a character back into the stream, canceling the effect of the last yyGet() or yySkip(). Note that the echo mode should not change between calls to unput, get, or skip from the stream. */ char *yyUnput(char ch) { *--m_ptr= ch; if (m_echo) m_cpp_ptr--; return m_ptr; } /** End of file indicator for the query text to parse. @return true if there are no more characters to parse */ bool eof() { return (m_ptr >= m_end_of_query); } /** End of file indicator for the query text to parse. @param n number of characters expected @return true if there are less than n characters to parse */ bool eof(int n) { return ((m_ptr + n) >= m_end_of_query); } /** Get the raw query buffer. */ const char *get_buf() { return m_buf; } /** Get the pre-processed query buffer. */ const char *get_cpp_buf() { return m_cpp_buf; } /** Get the end of the raw query buffer. */ const char *get_end_of_query() { return m_end_of_query; } /** Mark the stream position as the start of a new token. */ void start_token() { m_tok_start_prev= m_tok_start; m_tok_start= m_ptr; m_tok_end= m_ptr; m_cpp_tok_start_prev= m_cpp_tok_start; m_cpp_tok_start= m_cpp_ptr; m_cpp_tok_end= m_cpp_ptr; } /** Adjust the starting position of the current token. This is used to compensate for starting whitespace. */ void restart_token() { m_tok_start= m_ptr; m_cpp_tok_start= m_cpp_ptr; } /** Get the token start position, in the raw buffer. */ const char *get_tok_start() { return m_tok_start; } /** Get the token start position, in the pre-processed buffer. */ const char *get_cpp_tok_start() { return m_cpp_tok_start; } /** Get the token end position, in the raw buffer. */ const char *get_tok_end() { return m_tok_end; } /** Get the token end position, in the pre-processed buffer. */ const char *get_cpp_tok_end() { return m_cpp_tok_end; } /** Get the previous token start position, in the raw buffer. */ const char *get_tok_start_prev() { return m_tok_start_prev; } /** Get the current stream pointer, in the raw buffer. */ const char *get_ptr() { return m_ptr; } /** Get the current stream pointer, in the pre-processed buffer. */ const char *get_cpp_ptr() { return m_cpp_ptr; } /** Get the length of the current token, in the raw buffer. */ uint yyLength() { /* The assumption is that the lexical analyser is always 1 character ahead, which the -1 account for. */ DBUG_ASSERT(m_ptr > m_tok_start); return (uint) ((m_ptr - m_tok_start) - 1); } /** Get the utf8-body string. */ const char *get_body_utf8_str() { return m_body_utf8; } /** Get the utf8-body length. */ uint get_body_utf8_length() { return (uint) (m_body_utf8_ptr - m_body_utf8); } void body_utf8_start(THD *thd, const char *begin_ptr); void body_utf8_append(const char *ptr); void body_utf8_append(const char *ptr, const char *end_ptr); void body_utf8_append_literal(THD *thd, const LEX_STRING *txt, CHARSET_INFO *txt_cs, const char *end_ptr); /** Current thread. */ THD *m_thd; /** Current line number. */ uint yylineno; /** Length of the last token parsed. */ uint yytoklen; /** Interface with bison, value of the last token parsed. */ LEX_YYSTYPE yylval; /** LALR(2) resolution, look ahead token. Value of the next token to return, if any, or -1, if no token was parsed in advance. Note: 0 is a legal token, and represents YYEOF. */ int lookahead_token; /** LALR(2) resolution, value of the look ahead token.*/ LEX_YYSTYPE lookahead_yylval; private: /** Pointer to the current position in the raw input stream. */ char *m_ptr; /** Starting position of the last token parsed, in the raw buffer. */ const char *m_tok_start; /** Ending position of the previous token parsed, in the raw buffer. */ const char *m_tok_end; /** End of the query text in the input stream, in the raw buffer. */ const char *m_end_of_query; /** Starting position of the previous token parsed, in the raw buffer. */ const char *m_tok_start_prev; /** Begining of the query text in the input stream, in the raw buffer. */ const char *m_buf; /** Length of the raw buffer. */ uint m_buf_length; /** Echo the parsed stream to the pre-processed buffer. */ bool m_echo; bool m_echo_saved; /** Pre-processed buffer. */ char *m_cpp_buf; /** Pointer to the current position in the pre-processed input stream. */ char *m_cpp_ptr; /** Starting position of the last token parsed, in the pre-processed buffer. */ const char *m_cpp_tok_start; /** Starting position of the previous token parsed, in the pre-procedded buffer. */ const char *m_cpp_tok_start_prev; /** Ending position of the previous token parsed, in the pre-processed buffer. */ const char *m_cpp_tok_end; /** UTF8-body buffer created during parsing. */ char *m_body_utf8; /** Pointer to the current position in the UTF8-body buffer. */ char *m_body_utf8_ptr; /** Position in the pre-processed buffer. The query from m_cpp_buf to m_cpp_utf_processed_ptr is converted to UTF8-body. */ const char *m_cpp_utf8_processed_ptr; public: /** Current state of the lexical analyser. */ enum my_lex_states next_state; /** Position of ';' in the stream, to delimit multiple queries. This delimiter is in the raw buffer. */ const char *found_semicolon; /** Token character bitmaps, to detect 7bit strings. */ uchar tok_bitmap; /** SQL_MODE = IGNORE_SPACE. */ bool ignore_space; /** TRUE if we're parsing a prepared statement: in this mode we should allow placeholders. */ bool stmt_prepare_mode; /** TRUE if we should allow multi-statements. */ bool multi_statements; /** State of the lexical analyser for comments. */ enum_comment_state in_comment; enum_comment_state in_comment_saved; /** Starting position of the TEXT_STRING or IDENT in the pre-processed buffer. NOTE: this member must be used within MYSQLlex() function only. */ const char *m_cpp_text_start; /** Ending position of the TEXT_STRING or IDENT in the pre-processed buffer. NOTE: this member must be used within MYSQLlex() function only. */ const char *m_cpp_text_end; /** Character set specified by the character-set-introducer. NOTE: this member must be used within MYSQLlex() function only. */ CHARSET_INFO *m_underscore_cs; }; /** Abstract representation of a statement. This class is an interface between the parser and the runtime. The parser builds the appropriate sub classes of Sql_statement to represent a SQL statement in the parsed tree. The execute() method in the sub classes contain the runtime implementation. Note that this interface is used for SQL statement recently implemented, the code for older statements tend to load the LEX structure with more attributes instead. The recommended way to implement new statements is to sub-class Sql_statement, as this improves code modularity (see the 'big switch' in dispatch_command()), and decrease the total size of the LEX structure (therefore saving memory in stored programs). */ class Sql_statement : public Sql_alloc { public: /** Execute this SQL statement. @param thd the current thread. @return 0 on success. */ virtual bool execute(THD *thd) = 0; protected: /** Constructor. @param lex the LEX structure that represents parts of this statement. */ Sql_statement(LEX *lex) : m_lex(lex) {} /** Destructor. */ virtual ~Sql_statement() { /* Sql_statement objects are allocated in thd->mem_root. In MySQL, the C++ destructor is never called, the underlying MEM_ROOT is simply destroyed instead. Do not rely on the destructor for any cleanup. */ DBUG_ASSERT(FALSE); } protected: /** The legacy LEX structure for this statement. The LEX structure contains the existing properties of the parsed tree. TODO: with time, attributes from LEX should move to sub classes of Sql_statement, so that the parser only builds Sql_statement objects with the minimum set of attributes, instead of a LEX structure that contains the collection of every possible attribute. */ LEX *m_lex; }; /* The state of the lex parsing. This is saved in the THD struct */ struct LEX: public Query_tables_list { SELECT_LEX_UNIT unit; /* most upper unit */ SELECT_LEX select_lex; /* first SELECT_LEX */ /* current SELECT_LEX in parsing */ SELECT_LEX *current_select; /* list of all SELECT_LEX */ SELECT_LEX *all_selects_list; char *length,*dec,*change; LEX_STRING name; char *help_arg; char *backup_dir; /* For RESTORE/BACKUP */ char* to_log; /* For PURGE MASTER LOGS TO */ char* x509_subject,*x509_issuer,*ssl_cipher; String *wild; sql_exchange *exchange; select_result *result; Item *default_value, *on_update_value; LEX_STRING comment, ident; LEX_USER *grant_user; XID *xid; THD *thd; /* maintain a list of used plugins for this LEX */ DYNAMIC_ARRAY plugins; plugin_ref plugins_static_buffer[INITIAL_LEX_PLUGIN_LIST_SIZE]; CHARSET_INFO *charset; bool text_string_is_7bit; /* store original leaf_tables for INSERT SELECT and PS/SP */ TABLE_LIST *leaf_tables_insert; /** SELECT of CREATE VIEW statement */ LEX_STRING create_view_select; /** Start of 'ON table', in trigger statements. */ const char* raw_trg_on_table_name_begin; /** End of 'ON table', in trigger statements. */ const char* raw_trg_on_table_name_end; /* Partition info structure filled in by PARTITION BY parse part */ partition_info *part_info; /* The definer of the object being created (view, trigger, stored routine). I.e. the value of DEFINER clause. */ LEX_USER *definer; List col_list; List ref_list; List interval_list; List users_list; List columns; List *insert_list,field_list,value_list,update_list; List many_values; List var_list; List set_var_list; // in-query assignment list List param_list; List view_list; // view list (list of field names in view) /* A stack of name resolution contexts for the query. This stack is used at parse time to set local name resolution contexts for various parts of a query. For example, in a JOIN ... ON (some_condition) clause the Items in 'some_condition' must be resolved only against the operands of the the join, and not against the whole clause. Similarly, Items in subqueries should be resolved against the subqueries (and outer queries). The stack is used in the following way: when the parser detects that all Items in some clause need a local context, it creates a new context and pushes it on the stack. All newly created Items always store the top-most context in the stack. Once the parser leaves the clause that required a local context, the parser pops the top-most context. */ List context_stack; 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; HA_CHECK_OPT check_opt; // check/repair options HA_CREATE_INFO create_info; KEY_CREATE_INFO key_create_info; LEX_MASTER_INFO mi; // used by CHANGE MASTER LEX_SERVER_OPTIONS server_options; USER_RESOURCES mqh; ulong type; /* This variable is used in post-parse stage to declare that sum-functions, or functions which have sense only if GROUP BY is present, are allowed. For example in a query SELECT ... FROM ...WHERE MIN(i) == 1 GROUP BY ... HAVING MIN(i) > 2 MIN(i) in the WHERE clause is not allowed in the opposite to MIN(i) in the HAVING clause. Due to possible nesting of select construct the variable can contain 0 or 1 for each nest level. */ nesting_map allow_sum_func; Sql_statement *m_stmt; /* Usually `expr` rule of yacc is quite reused but some commands better not support subqueries which comes standard with this rule, like KILL, HA_READ, CREATE/ALTER EVENT etc. Set this to `false` to get syntax error back. */ bool expr_allows_subselect; enum SSL_type ssl_type; /* defined in violite.h */ enum enum_duplicates duplicates; enum enum_tx_isolation tx_isolation; enum enum_ha_read_modes ha_read_mode; union { enum ha_rkey_function ha_rkey_mode; enum xa_option_words xa_opt; }; enum enum_var_type option_type; enum enum_view_create_mode create_view_mode; enum enum_drop_mode drop_mode; uint profile_query_id; uint profile_options; uint uint_geom_type; uint grant, grant_tot_col, which_columns; enum Foreign_key::fk_match_opt fk_match_option; enum Foreign_key::fk_option fk_update_opt; enum Foreign_key::fk_option fk_delete_opt; uint slave_thd_opt, start_transaction_opt; int nest_level; /* In LEX representing update which were transformed to multi-update stores total number of tables. For LEX representing multi-delete holds number of tables from which we will delete records. */ uint table_count; uint8 describe; /* A flag that indicates what kinds of derived tables are present in the query (0 if no derived tables, otherwise a combination of flags DERIVED_SUBQUERY and DERIVED_VIEW). */ uint8 derived_tables; uint8 create_view_algorithm; uint8 create_view_check; uint8 context_analysis_only; bool drop_if_exists, drop_temporary, local_file, one_shot_set; bool autocommit; bool verbose, no_write_to_binlog; enum enum_yes_no_unknown tx_chain, tx_release; bool safe_to_cache_query; bool subqueries, ignore; st_parsing_options parsing_options; Alter_info alter_info; /* For CREATE TABLE statement last element of table list which is not part of SELECT or LIKE part (i.e. either element for table we are creating or last of tables referenced by foreign keys). */ TABLE_LIST *create_last_non_select_table; /* Prepared statements SQL syntax:*/ LEX_STRING prepared_stmt_name; /* Statement name (in all queries) */ /* Prepared statement query text or name of variable that holds the prepared statement (in PREPARE ... queries) */ LEX_STRING prepared_stmt_code; /* If true, prepared_stmt_code is a name of variable that holds the query */ bool prepared_stmt_code_is_varref; /* Names of user variables holding parameters (in EXECUTE) */ List prepared_stmt_params; sp_head *sphead; sp_name *spname; bool sp_lex_in_use; /* Keep track on lex usage in SPs for error handling */ bool all_privileges; bool proxy_priv; sp_pcontext *spcont; st_sp_chistics sp_chistics; Event_parse_data *event_parse_data; bool only_view; /* used for SHOW CREATE TABLE/VIEW */ /* field_list was created for view and should be removed before PS/SP rexecuton */ bool empty_field_list_on_rset; /* view created to be run from definer (standard behaviour) */ uint8 create_view_suid; /* Characterstics of trigger being created */ st_trg_chistics trg_chistics; /* List of all items (Item_trigger_field objects) representing fields in old/new version of row in trigger. We use this list for checking whenever all such fields are valid at trigger creation time and for binding these fields to TABLE object at table open (altough for latter pointer to table being opened is probably enough). */ SQL_I_List trg_table_fields; /* stmt_definition_begin is intended to point to the next word after DEFINER-clause in the following statements: - CREATE TRIGGER (points to "TRIGGER"); - CREATE PROCEDURE (points to "PROCEDURE"); - CREATE FUNCTION (points to "FUNCTION" or "AGGREGATE"); - CREATE EVENT (points to "EVENT") This pointer is required to add possibly omitted DEFINER-clause to the DDL-statement before dumping it to the binlog. keyword_delayed_begin_offset is the offset to the beginning of the DELAYED keyword in INSERT DELAYED statement. keyword_delayed_end_offset is the offset to the character right after the DELAYED keyword. */ union { const char *stmt_definition_begin; uint keyword_delayed_begin_offset; }; union { const char *stmt_definition_end; uint keyword_delayed_end_offset; }; /** During name resolution search only in the table list given by Name_resolution_context::first_name_resolution_table and Name_resolution_context::last_name_resolution_table (see Item_field::fix_fields()). */ bool use_only_table_context; /* Reference to a struct that contains information in various commands to add/create/drop/change table spaces. */ st_alter_tablespace *alter_tablespace_info; bool escape_used; bool is_lex_started; /* If lex_start() did run. For debugging. */ LEX(); virtual ~LEX() { destroy_query_tables_list(); plugin_unlock_list(NULL, (plugin_ref *)plugins.buffer, plugins.elements); delete_dynamic(&plugins); } inline bool is_ps_or_view_context_analysis() { return (context_analysis_only & (CONTEXT_ANALYSIS_ONLY_PREPARE | CONTEXT_ANALYSIS_ONLY_VIEW)); } inline void uncacheable(uint8 cause) { safe_to_cache_query= 0; /* There are no sense to mark select_lex and union fields of LEX, but we should merk all subselects as uncacheable from current till most upper */ SELECT_LEX *sl; SELECT_LEX_UNIT *un; for (sl= current_select, un= sl->master_unit(); un != &unit; sl= sl->outer_select(), un= sl->master_unit()) { sl->uncacheable|= cause; un->uncacheable|= cause; } } void set_trg_event_type_for_tables(); TABLE_LIST *unlink_first_table(bool *link_to_local); void link_first_table_back(TABLE_LIST *first, bool link_to_local); void first_lists_tables_same(); bool can_be_merged(); bool can_use_merged(); bool can_not_use_merged(); bool only_view_structure(); bool need_correct_ident(); uint8 get_effective_with_check(TABLE_LIST *view); /* Is this update command where 'WHITH CHECK OPTION' clause is important SYNOPSIS LEX::which_check_option_applicable() RETURN TRUE have to take 'WHITH CHECK OPTION' clause into account FALSE 'WHITH CHECK OPTION' clause do not need */ inline bool which_check_option_applicable() { switch (sql_command) { case SQLCOM_UPDATE: case SQLCOM_UPDATE_MULTI: case SQLCOM_INSERT: case SQLCOM_INSERT_SELECT: case SQLCOM_REPLACE: case SQLCOM_REPLACE_SELECT: case SQLCOM_LOAD: return TRUE; default: return FALSE; } } void cleanup_after_one_table_open(); bool push_context(Name_resolution_context *context) { return context_stack.push_front(context); } void pop_context() { context_stack.pop(); } bool copy_db_to(char **p_db, size_t *p_db_length) const; Name_resolution_context *current_context() { return context_stack.head(); } /* Restore the LEX and THD in case of a parse error. */ static void cleanup_lex_after_parse_error(THD *thd); void reset_n_backup_query_tables_list(Query_tables_list *backup); void restore_backup_query_tables_list(Query_tables_list *backup); bool table_or_sp_used(); bool is_partition_management() const; /** @brief check if the statement is a single-level join @return result of the check @retval TRUE The statement doesn't contain subqueries, unions and stored procedure calls. @retval FALSE There are subqueries, UNIONs or stored procedure calls. */ bool is_single_level_stmt() { /* This check exploits the fact that the last added to all_select_list is on its top. So select_lex (as the first added) will be at the tail of the list. */ if (&select_lex == all_selects_list && !sroutines.records) { DBUG_ASSERT(!all_selects_list->next_select_in_list()); return TRUE; } return FALSE; } }; /** Set_signal_information is a container used in the parsed tree to represent the collection of assignments to condition items in the SIGNAL and RESIGNAL statements. */ class Set_signal_information { public: /** Empty default constructor, use clear() */ Set_signal_information() {} /** Copy constructor. */ Set_signal_information(const Set_signal_information& set); /** Destructor. */ ~Set_signal_information() {} /** Clear all items. */ void clear(); /** For each condition item assignment, m_item[] contains the parsed tree that represents the expression assigned, if any. m_item[] is an array indexed by Diag_condition_item_name. */ Item *m_item[LAST_DIAG_SET_PROPERTY+1]; }; /** The internal state of the syntax parser. This object is only available during parsing, and is private to the syntax parser implementation (sql_yacc.yy). */ class Yacc_state { public: Yacc_state() { reset(); } void reset() { yacc_yyss= NULL; yacc_yyvs= NULL; m_set_signal_info.clear(); m_lock_type= TL_READ_DEFAULT; m_mdl_type= MDL_SHARED_READ; } ~Yacc_state(); /** Reset part of the state which needs resetting before parsing substatement. */ void reset_before_substatement() { m_lock_type= TL_READ_DEFAULT; m_mdl_type= MDL_SHARED_READ; } /** Bison internal state stack, yyss, when dynamically allocated using my_yyoverflow(). */ uchar *yacc_yyss; /** Bison internal semantic value stack, yyvs, when dynamically allocated using my_yyoverflow(). */ uchar *yacc_yyvs; /** Fragments of parsed tree, used during the parsing of SIGNAL and RESIGNAL. */ Set_signal_information m_set_signal_info; /** Type of lock to be used for tables being added to the statement's table list in table_factor, table_alias_ref, single_multi and table_wild_one rules. Statements which use these rules but require lock type different from one specified by this member have to override it by using st_select_lex::set_lock_for_tables() method. The default value of this member is TL_READ_DEFAULT. The only two cases in which we change it are: - When parsing SELECT HIGH_PRIORITY. - Rule for DELETE. In which we use this member to pass information about type of lock from delete to single_multi part of rule. We should try to avoid introducing new use cases as we would like to get rid of this member eventually. */ thr_lock_type m_lock_type; /** The type of requested metadata lock for tables added to the statement table list. */ enum_mdl_type m_mdl_type; /* TODO: move more attributes from the LEX structure here. */ }; /** Internal state of the parser. The complete state consist of: - state data used during lexical parsing, - state data used during syntactic parsing. */ class Parser_state { public: Parser_state() : m_yacc() {} /** Object initializer. Must be called before usage. @retval FALSE OK @retval TRUE Error */ bool init(THD *thd, char *buff, unsigned int length) { return m_lip.init(thd, buff, length); } ~Parser_state() {} Lex_input_stream m_lip; Yacc_state m_yacc; void reset(char *found_semicolon, unsigned int length) { m_lip.reset(found_semicolon, length); m_yacc.reset(); } }; struct st_lex_local: public LEX { static void *operator new(size_t size) throw() { return sql_alloc(size); } static void *operator new(size_t size, MEM_ROOT *mem_root) throw() { return (void*) alloc_root(mem_root, (uint) size); } static void operator delete(void *ptr,size_t size) { TRASH(ptr, size); } static void operator delete(void *ptr, MEM_ROOT *mem_root) { /* Never called */ } }; extern void lex_init(void); extern void lex_free(void); extern void lex_start(THD *thd); extern void lex_end(LEX *lex); extern int MYSQLlex(void *arg, void *yythd); extern void trim_whitespace(CHARSET_INFO *cs, LEX_STRING *str); extern bool is_lex_native_function(const LEX_STRING *name); /** @} (End of group Semantic_Analysis) */ void my_missing_function_error(const LEX_STRING &token, const char *name); bool is_keyword(const char *name, uint len); #endif /* MYSQL_SERVER */ #endif /* SQL_LEX_INCLUDED */