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sp_lex_branch_instr Class Reference

#include <sp_instr.h>

Inheritance diagram for sp_lex_branch_instr:
sp_lex_instr sp_branch_instr sp_instr Sql_alloc sp_printable sp_instr_jump_case_when sp_instr_jump_if_not sp_instr_set_case_expr

List of all members.

Public Member Functions

void set_cont_dest (uint cont_dest)
virtual uint opt_mark (sp_head *sp, List< sp_instr > *leads)
virtual void opt_move (uint dst, List< sp_branch_instr > *ibp)
virtual uint get_cont_dest () const
virtual bool is_invalid () const
virtual void invalidate ()
virtual LEX_STRING get_expr_query () const
virtual void set_destination (uint old_dest, uint new_dest)
virtual void backpatch (uint dest)

Protected Member Functions

 sp_lex_branch_instr (uint ip, sp_pcontext *ctx, LEX *lex, Item *expr_item, LEX_STRING expr_query)
 sp_lex_branch_instr (uint ip, sp_pcontext *ctx, LEX *lex, Item *expr_item, LEX_STRING expr_query, uint dest)

Protected Attributes

uint m_dest
 Where we will go.
uint m_cont_dest
 Where continue handlers will go.
 Expression item.
LEX_STRING m_expr_query
 SQL-query corresponding to the expression.

Detailed Description

sp_lex_branch_instr is a base class for SP-instructions, which might perform conditional jump depending on the value of an SQL-expression.

Member Function Documentation

virtual void sp_lex_branch_instr::backpatch ( uint  dest) [inline, virtual]

Update all instruction with the given label in the backpatch list to the specified instruction pointer.

destdestination instruction pointer.

Implements sp_branch_instr.

Reimplemented in sp_instr_set_case_expr.

virtual uint sp_lex_branch_instr::get_cont_dest ( ) const [inline, virtual]

Get the continuation destination (instruction pointer for the CONTINUE HANDLER) of this instruction.

the continuation destination

Reimplemented from sp_instr.

virtual LEX_STRING sp_lex_branch_instr::get_expr_query ( ) const [inline, virtual]
the expression query string. This string can not be passed directly to the parser as it is most likely not a valid SQL-statement.
as it can be seen in the get_query() implementation, get_expr_query() might return EMPTY_STR. EMPTY_STR means that no query-expression is available. That happens when class provides different implementation of get_query(). Strictly speaking, this is a drawback of the current class hierarchy.

Reimplemented from sp_lex_instr.

virtual void sp_lex_branch_instr::invalidate ( ) [inline, virtual]

Invalidate the object.

Implements sp_lex_instr.

Reimplemented in sp_instr_jump_case_when.

virtual bool sp_lex_branch_instr::is_invalid ( ) const [inline, virtual]
Return values:
falseif the object (i.e. LEX-object) is valid and exec_core() can be just called.
trueif the object is not valid any longer, exec_core() can not be called. The original query string should be re-parsed and a new LEX-object should be used.

Implements sp_lex_instr.

uint sp_lex_branch_instr::opt_mark ( sp_head sp,
List< sp_instr > *  leads 
) [virtual]

Mark this instruction as reachable during optimization and return the index to the next instruction. Jump instruction will add their destination to the leads list.

Reimplemented from sp_instr.

Reimplemented in sp_instr_set_case_expr.

void sp_lex_branch_instr::opt_move ( uint  dst,
List< sp_branch_instr > *  ibp 
) [virtual]

Inform the instruction that it has been moved during optimization. Most instructions will simply update its index, but jump instructions must also take care of their destination pointers. Forward jumps get pushed to the backpatch list 'ibp'.

Reimplemented from sp_instr.

Reimplemented in sp_instr_set_case_expr.

virtual void sp_lex_branch_instr::set_destination ( uint  old_dest,
uint  new_dest 
) [inline, virtual]

Update the destination; used by the SP-instruction-optimizer.

old_destcurrent (old) destination (instruction pointer).
new_destnew destination (instruction pointer).

Implements sp_branch_instr.

Reimplemented in sp_instr_set_case_expr.

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