The class represents parse-time context, which keeps track of declared variables/parameters, conditions, handlers, cursors and labels. More...

#include <sp_pcontext.h>

Public Types
enum	enum_scope { REGULAR_SCOPE , HANDLER_SCOPE }

Public Member Functions
	sp_pcontext (THD *thd)

	~sp_pcontext ()

sp_pcontext *	push_context (THD *thd, enum_scope scope)
	Create and push a new context in the tree. More...

sp_pcontext *	pop_context ()
	Pop a node from the parsing context tree. More...

sp_pcontext *	parent_context () const

int	get_level () const

size_t	diff_handlers (const sp_pcontext *ctx, bool exclusive) const
	Calculate and return the number of handlers to pop between the given context and this one. More...

size_t	diff_cursors (const sp_pcontext *ctx, bool exclusive) const
	Calculate and return the number of cursors to pop between the given context and this one. More...

uint	max_var_index () const

uint	current_var_count () const

uint	context_var_count () const

uint	var_context2runtime (uint i) const

sp_variable *	add_variable (THD *thd, LEX_STRING name, enum enum_field_types type, sp_variable::enum_mode mode)
	Add SP-variable to the parsing context. More...

void	retrieve_field_definitions (List< Create_field > *field_def_lst) const
	Retrieve full type information about SP-variables in this parsing context and its children. More...

sp_variable *	find_variable (const char *name, size_t name_len, bool current_scope_only) const
	Find SP-variable by name. More...

sp_variable *	find_variable (uint offset) const
	Find SP-variable by the offset in the root parsing context. More...

void	declare_var_boundary (uint n)
	Set the current scope boundary (for default values). More...

int	get_num_case_exprs () const

int	push_case_expr_id ()

void	pop_case_expr_id ()

int	get_current_case_expr_id () const

sp_label *	push_label (THD *thd, LEX_CSTRING name, uint ip)

sp_label *	find_label (LEX_CSTRING name)

sp_label *	last_label ()

sp_label *	pop_label ()

bool	add_condition (THD thd, LEX_STRING name, sp_condition_value value)

sp_condition_value *	find_condition (LEX_STRING name, bool current_scope_only) const
	See comment for find_variable() above. More...

sp_handler *	add_handler (THD *thd, sp_handler::enum_type type)

bool	check_duplicate_handler (const sp_condition_value *cond_value) const
	This is an auxiliary parsing-time function to check if an SQL-handler exists in the current parsing context (current scope) for the given SQL-condition. More...

sp_handler *	find_handler (const char *sql_state, uint sql_errno, Sql_condition::enum_severity_level severity) const
	Find an SQL handler for the given SQL condition according to the SQL-handler resolution rules. More...

bool	add_cursor (LEX_STRING name)

bool	find_cursor (LEX_STRING name, uint *poff, bool current_scope_only) const
	See comment for find_variable() above. More...

const LEX_STRING *	find_cursor (uint offset) const
	Find cursor by offset (for debugging only). More...

uint	max_cursor_index () const

uint	current_cursor_count () const

Private Member Functions
	sp_pcontext (THD thd, sp_pcontext prev, enum_scope scope)
	Constructor for a tree node. More...

void	init (uint var_offset, uint cursor_offset, int num_case_expressions)

	sp_pcontext (const sp_pcontext &)

void	operator= (sp_pcontext &)

Private Attributes
int	m_level
	Level of the corresponding BEGIN..END block (0 means the topmost block). More...

uint	m_max_var_index
	m_max_var_index – number of variables (including all types of arguments) in this context including all children contexts. More...

uint	m_max_cursor_index
	The maximum sub context's framesizes. More...

sp_pcontext *	m_parent
	Parent context. More...

uint	m_var_offset
	An index of the first SP-variable in this parsing context. More...

uint	m_cursor_offset
	Cursor offset for this context. More...

uint	m_pboundary
	Boundary for finding variables in this context. More...

int	m_num_case_exprs

Mem_root_array< sp_variable * >	m_vars
	SP parameters/variables. More...

Mem_root_array< int >	m_case_expr_ids
	Stack of CASE expression ids. More...

Mem_root_array< sp_condition * >	m_conditions
	Stack of SQL-conditions. More...

Mem_root_array< LEX_STRING >	m_cursors
	Stack of cursors. More...

Mem_root_array< sp_handler * >	m_handlers
	Stack of SQL-handlers. More...

List< sp_label >	m_labels
	List of labels. More...

Mem_root_array< sp_pcontext * >	m_children
	Children contexts, used for destruction. More...

enum_scope	m_scope
	Scope of this parsing context. More...

Detailed Description

The class represents parse-time context, which keeps track of declared variables/parameters, conditions, handlers, cursors and labels.

sp_context objects are organized in a tree according to the following rules:

one sp_pcontext object corresponds for for each BEGIN..END block;
one sp_pcontext object corresponds for each exception handler;
one additional sp_pcontext object is created to contain Stored Program parameters.

sp_pcontext objects are used both at parse-time and at runtime.

During the parsing stage sp_pcontext objects are used:

to look up defined names (e.g. declared variables and visible labels);
to check for duplicates;
for error checking;
to calculate offsets to be used at runtime.

During the runtime phase, a tree of sp_pcontext objects is used:

for error checking (e.g. to check correct number of parameters);
to resolve SQL-handlers.

Member Enumeration Documentation

◆ enum_scope

enum sp_pcontext::enum_scope

Enumerator
REGULAR_SCOPE	REGULAR_SCOPE designates regular BEGIN ... END blocks.
HANDLER_SCOPE	HANDLER_SCOPE designates SQL-handler blocks.

Constructor & Destructor Documentation

◆ sp_pcontext() [1/3]

sp_pcontext::sp_pcontext ( THD * thd )

◆ ~sp_pcontext()

sp_pcontext::~sp_pcontext ( )

◆ sp_pcontext() [2/3]

sp_pcontext::sp_pcontext	(	THD *	thd,
		sp_pcontext *	prev,
		sp_pcontext::enum_scope	scope
	)

private

Constructor for a tree node.

Parameters

thd	thread context
prev	the parent parsing context
scope	scope of this parsing context

◆ sp_pcontext() [3/3]

sp_pcontext::sp_pcontext ( const sp_pcontext & )

private

Member Function Documentation

◆ add_condition()

bool sp_pcontext::add_condition	(	THD *	thd,
		LEX_STRING	name,
		sp_condition_value *	value
	)

◆ add_cursor()

bool sp_pcontext::add_cursor ( LEX_STRING name )

◆ add_handler()

sp_handler * sp_pcontext::add_handler	(	THD *	thd,
		sp_handler::enum_type	type
	)

◆ add_variable()

sp_variable * sp_pcontext::add_variable	(	THD *	thd,
		LEX_STRING	name,
		enum enum_field_types	type,
		sp_variable::enum_mode	mode
	)

Add SP-variable to the parsing context.

Parameters

thd	Thread context.
name	Name of the SP-variable.
type	Type of the SP-variable.
mode	Mode of the SP-variable.

Returns: instance of newly added SP-variable.

◆ check_duplicate_handler()

bool sp_pcontext::check_duplicate_handler ( const sp_condition_value * cond_value ) const

This is an auxiliary parsing-time function to check if an SQL-handler exists in the current parsing context (current scope) for the given SQL-condition.

This function is used to check for duplicates during the parsing phase.

This function can not be used during the runtime phase to check SQL-handler existence because it searches for the SQL-handler in the current scope only (during runtime, current and parent scopes should be checked according to the SQL-handler resolution rules).

Parameters

cond_value the handler condition value (not SQL-condition!).

Return values

true	if such SQL-handler exists.
false	otherwise.

◆ context_var_count()

uint sp_pcontext::context_var_count ( ) const

inline

Returns: the number of variables in this context alone.

◆ current_cursor_count()

uint sp_pcontext::current_cursor_count ( ) const

inline

◆ current_var_count()

uint sp_pcontext::current_var_count ( ) const

inline

Returns: the current number of variables used in the parent contexts (from the root), including this context.

◆ declare_var_boundary()

void sp_pcontext::declare_var_boundary ( uint n )

inline

Set the current scope boundary (for default values).

Parameters

n	The number of variables to skip.

◆ diff_cursors()

size_t sp_pcontext::diff_cursors	(	const sp_pcontext *	ctx,
		bool	exclusive
	)		const

Calculate and return the number of cursors to pop between the given context and this one.

Parameters

ctx	the other parsing context.
exclusive	specifies if the last scope should be excluded.

Returns: the number of cursors to pop between the given context and this one. If 'exclusive' is true, don't count the last scope we are leaving; this is used for LEAVE where we will jump to the cpop instructions.

◆ diff_handlers()

size_t sp_pcontext::diff_handlers	(	const sp_pcontext *	ctx,
		bool	exclusive
	)		const

Calculate and return the number of handlers to pop between the given context and this one.

Parameters

ctx	the other parsing context.
exclusive	specifies if the last scope should be excluded.

Returns: the number of handlers to pop between the given context and this one. If 'exclusive' is true, don't count the last scope we are leaving; this is used for LEAVE where we will jump to the hpop instructions.

◆ find_condition()

sp_condition_value * sp_pcontext::find_condition	(	LEX_STRING	name,
		bool	current_scope_only
	)		const

See comment for find_variable() above.

◆ find_cursor() [1/2]

bool sp_pcontext::find_cursor	(	LEX_STRING	name,
		uint *	poff,
		bool	current_scope_only
	)		const

See comment for find_variable() above.

◆ find_cursor() [2/2]

const LEX_STRING * sp_pcontext::find_cursor ( uint offset ) const

Find cursor by offset (for debugging only).

◆ find_handler()

sp_handler * sp_pcontext::find_handler	(	const char *	sql_state,
		uint	sql_errno,
		Sql_condition::enum_severity_level	severity
	)		const

Find an SQL handler for the given SQL condition according to the SQL-handler resolution rules.

This function is used at runtime.

Parameters

sql_state	The SQL condition state
sql_errno	The error code
severity	The SQL condition severity level

Returns: a pointer to the found SQL-handler or NULL.

◆ find_label()

sp_label * sp_pcontext::find_label ( LEX_CSTRING name )

◆ find_variable() [1/2]

sp_variable * sp_pcontext::find_variable	(	const char *	name,
		size_t	name_len,
		bool	current_scope_only
	)		const

Find SP-variable by name.

The function does a linear search (from newer to older variables, in case we have shadowed names).

The function is called only at parsing time.

Parameters

name	Variable name.
name_len	Variable name length.
current_scope_only	A flag if we search only in current scope.

Returns: instance of found SP-variable, or NULL if not found.

◆ find_variable() [2/2]

sp_variable * sp_pcontext::find_variable ( uint offset ) const

Find SP-variable by the offset in the root parsing context.

The function is used for two things:

When evaluating parameters at the beginning, and setting out parameters at the end, of invocation. (Top frame only, so no recursion then.)
For printing of sp_instr_set. (Debug mode only.)

Parameters

offset Variable offset in the root parsing context.

Returns: instance of found SP-variable, or NULL if not found.

◆ get_current_case_expr_id()

int sp_pcontext::get_current_case_expr_id ( ) const

inline

◆ get_level()

int sp_pcontext::get_level ( ) const

inline

◆ get_num_case_exprs()

int sp_pcontext::get_num_case_exprs ( ) const

inline

◆ init()

void sp_pcontext::init	(	uint	var_offset,
		uint	cursor_offset,
		int	num_case_expressions
	)

private

◆ last_label()

sp_label * sp_pcontext::last_label ( )

inline

◆ max_cursor_index()

uint sp_pcontext::max_cursor_index ( ) const

inline

◆ max_var_index()

uint sp_pcontext::max_var_index ( ) const

inline

Returns: the maximum number of variables used in this and all child contexts. For the root parsing context, this gives us the number of slots needed for variables during the runtime phase.

◆ operator=()

void sp_pcontext::operator= ( sp_pcontext & )

private

◆ parent_context()

sp_pcontext * sp_pcontext::parent_context ( ) const

inline

◆ pop_case_expr_id()

void sp_pcontext::pop_case_expr_id ( )

inline

◆ pop_context()

sp_pcontext * sp_pcontext::pop_context ( )

Pop a node from the parsing context tree.

Returns: the parent node.

◆ pop_label()

sp_label * sp_pcontext::pop_label ( )

inline

◆ push_case_expr_id()

int sp_pcontext::push_case_expr_id ( )

inline

◆ push_context()

sp_pcontext * sp_pcontext::push_context	(	THD *	thd,
		sp_pcontext::enum_scope	scope
	)

Create and push a new context in the tree.

Parameters

thd	thread context.
scope	scope of the new parsing context.

Returns: the node created.

◆ push_label()

sp_label * sp_pcontext::push_label	(	THD *	thd,
		LEX_CSTRING	name,
		uint	ip
	)

◆ retrieve_field_definitions()

void sp_pcontext::retrieve_field_definitions ( List< Create_field > * field_def_lst ) const

Retrieve full type information about SP-variables in this parsing context and its children.

Parameters

[out] field_def_lst Container to store type information.

◆ var_context2runtime()

uint sp_pcontext::var_context2runtime ( uint i ) const

inline

Returns: map index in this parsing context to runtime offset.

Member Data Documentation

◆ m_case_expr_ids

Mem_root_array<int> sp_pcontext::m_case_expr_ids

private

Stack of CASE expression ids.

◆ m_children

Mem_root_array<sp_pcontext *> sp_pcontext::m_children

private

Children contexts, used for destruction.

◆ m_conditions

Mem_root_array<sp_condition *> sp_pcontext::m_conditions

private

Stack of SQL-conditions.

◆ m_cursor_offset

uint sp_pcontext::m_cursor_offset

private

Cursor offset for this context.

◆ m_cursors

Mem_root_array<LEX_STRING> sp_pcontext::m_cursors

private

Stack of cursors.

◆ m_handlers

Mem_root_array<sp_handler *> sp_pcontext::m_handlers

private

Stack of SQL-handlers.

◆ m_labels

List<sp_label> sp_pcontext::m_labels

private

List of labels.

◆ m_level

int sp_pcontext::m_level

private

Level of the corresponding BEGIN..END block (0 means the topmost block).

◆ m_max_cursor_index

uint sp_pcontext::m_max_cursor_index

private

The maximum sub context's framesizes.

◆ m_max_var_index

uint sp_pcontext::m_max_var_index

private

m_max_var_index – number of variables (including all types of arguments) in this context including all children contexts.

m_max_var_index >= m_vars.size().

m_max_var_index of the root parsing context contains number of all variables (including arguments) in all enclosed contexts.

◆ m_num_case_exprs

int sp_pcontext::m_num_case_exprs

private

◆ m_parent

sp_pcontext* sp_pcontext::m_parent

private

Parent context.

◆ m_pboundary

uint sp_pcontext::m_pboundary

private

Boundary for finding variables in this context.

This is the number of variables currently "invisible" to default clauses. This is normally 0, but will be larger during parsing of DECLARE ... DEFAULT, to get the scope right for DEFAULT values.

◆ m_scope

enum_scope sp_pcontext::m_scope

private

Scope of this parsing context.

◆ m_var_offset

uint sp_pcontext::m_var_offset

private

An index of the first SP-variable in this parsing context.

The index belongs to a runtime table of SP-variables.

Note:

m_var_offset is 0 for root parsing context;
m_var_offset is different for all nested parsing contexts.

◆ m_vars

Mem_root_array<sp_variable *> sp_pcontext::m_vars

private

SP parameters/variables.

The documentation for this class was generated from the following files:

sql/sp_pcontext.h
sql/sp_pcontext.cc

Public Types

Public Member Functions

Private Member Functions

Private Attributes

Detailed Description

Member Enumeration Documentation

◆ enum_scope

Constructor & Destructor Documentation

◆ sp_pcontext() [1/3]

◆ ~sp_pcontext()

◆ sp_pcontext() [2/3]

◆ sp_pcontext() [3/3]

Member Function Documentation

◆ add_condition()

◆ add_cursor()

◆ add_handler()

◆ add_variable()

◆ check_duplicate_handler()

◆ context_var_count()

◆ current_cursor_count()

◆ current_var_count()

◆ declare_var_boundary()

◆ diff_cursors()

◆ diff_handlers()

◆ find_condition()

◆ find_cursor() [1/2]

◆ find_cursor() [2/2]

◆ find_handler()

◆ find_label()

◆ find_variable() [1/2]

◆ find_variable() [2/2]

◆ get_current_case_expr_id()

◆ get_level()

◆ get_num_case_exprs()

◆ init()

◆ last_label()

◆ max_cursor_index()

◆ max_var_index()

◆ operator=()

◆ parent_context()

◆ pop_case_expr_id()

◆ pop_context()

◆ pop_label()

◆ push_case_expr_id()

◆ push_context()

◆ push_label()

◆ retrieve_field_definitions()

◆ var_context2runtime()

Member Data Documentation

◆ m_case_expr_ids

◆ m_children

◆ m_conditions

◆ m_cursor_offset

◆ m_cursors

◆ m_handlers

◆ m_labels

◆ m_level

◆ m_max_cursor_index

◆ m_max_var_index

◆ m_num_case_exprs

◆ m_parent

◆ m_pboundary

◆ m_scope

◆ m_var_offset

◆ m_vars