summaryrefslogtreecommitdiff
path: root/sql/sp_pcontext.h
blob: 4d36ca8b47999f34b7b0240602e71ba2098cf56a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
/* -*- C++ -*- */
/* Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.

   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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335  USA */

#ifndef _SP_PCONTEXT_H_
#define _SP_PCONTEXT_H_

#ifdef USE_PRAGMA_INTERFACE
#pragma interface			/* gcc class implementation */
#endif

#include "sql_string.h"                         // LEX_STRING
#include "mysql_com.h"                          // enum_field_types
#include "field.h"                              // Create_field
#include "sql_array.h"                          // Dynamic_array


/// This class represents a stored program variable or a parameter
/// (also referenced as 'SP-variable').

class sp_variable : public Sql_alloc
{
public:
  enum enum_mode
  {
    MODE_IN,
    MODE_OUT,
    MODE_INOUT
  };

  /// Name of the SP-variable.
  LEX_CSTRING name;

  /// Mode of the SP-variable.
  enum_mode mode;

  /// The index to the variable's value in the runtime frame.
  ///
  /// It is calculated during parsing and used when creating sp_instr_set
  /// instructions and Item_splocal items. I.e. values are set/referred by
  /// array indexing in runtime.
  uint offset;

  /// Default value of the SP-variable (if any).
  Item *default_value;

  /// Full type information (field meta-data) of the SP-variable.
  Spvar_definition field_def;

  /// Field-type of the SP-variable.
  const Type_handler *type_handler() const { return field_def.type_handler(); }

public:
  sp_variable(const LEX_CSTRING *name_arg, uint offset_arg)
   :Sql_alloc(),
    name(*name_arg),
    mode(MODE_IN),
    offset(offset_arg),
    default_value(NULL)
  { }
  /*
    Find a ROW field by its qualified name.
    @param      var_name - the name of the variable
    @param      field_name - the name of the variable field
    @param[OUT] row_field_offset - the index of the field

    @retval  NULL if the variable with the given name was not found,
             or it is not a row variable, or it does not have a field
             with the given name, or a non-null pointer otherwise.
             row_field_offset[0] is set only when the method returns !NULL.
  */
  const Spvar_definition *find_row_field(const LEX_CSTRING *var_name,
                                         const LEX_CSTRING *field_name,
                                         uint *row_field_offset);
};

///////////////////////////////////////////////////////////////////////////

/// This class represents an SQL/PSM label. Can refer to the identifier
/// used with the "label_name:" construct which may precede some SQL/PSM
/// statements, or to an implicit implementation-dependent identifier which
/// the parser inserts before a high-level flow control statement such as
/// IF/WHILE/REPEAT/LOOP, when such statement is rewritten into a
/// combination of low-level jump/jump_if instructions and labels.


class sp_label : public Sql_alloc
{
public:
  enum enum_type
  {
    /// Implicit label generated by parser.
    IMPLICIT,

    /// Label at BEGIN.
    BEGIN,

    /// Label at iteration control
    ITERATION,

    /// Label for jump
    GOTO
  };

  /// Name of the label.
  LEX_CSTRING name;

  /// Instruction pointer of the label.
  uint ip;

  /// Type of the label.
  enum_type type;

  /// Scope of the label.
  class sp_pcontext *ctx;

public:
  sp_label(const LEX_CSTRING *_name,
           uint _ip, enum_type _type, sp_pcontext *_ctx)
   :Sql_alloc(),
    name(*_name),
    ip(_ip),
    type(_type),
    ctx(_ctx)
  { }
};


///////////////////////////////////////////////////////////////////////////

/// This class represents condition-value term in DECLARE CONDITION or
/// DECLARE HANDLER statements. sp_condition_value has little to do with
/// SQL-conditions.
///
/// In some sense, this class is a union -- a set of filled attributes
/// depends on the sp_condition_value::type value.

class sp_condition_value : public Sql_alloc, public Sql_state_errno
{
  bool m_is_user_defined;
public:
  enum enum_type
  {
    ERROR_CODE,
    SQLSTATE,
    WARNING,
    NOT_FOUND,
    EXCEPTION
  };

  /// Type of the condition value.
  enum_type type;

public:
  sp_condition_value(uint _mysqlerr)
   :Sql_alloc(),
    Sql_state_errno(_mysqlerr),
    m_is_user_defined(false),
    type(ERROR_CODE)
  { }

  sp_condition_value(uint _mysqlerr, const char *_sql_state)
   :Sql_alloc(),
    Sql_state_errno(_mysqlerr, _sql_state),
    m_is_user_defined(false),
    type(ERROR_CODE)
  { }

  sp_condition_value(const char *_sql_state, bool is_user_defined= false)
   :Sql_alloc(),
    Sql_state_errno(0, _sql_state),
    m_is_user_defined(is_user_defined),
    type(SQLSTATE)
  { }

  sp_condition_value(enum_type _type)
   :Sql_alloc(),
    m_is_user_defined(false),
    type(_type)
  {
    DBUG_ASSERT(type != ERROR_CODE && type != SQLSTATE);
  }

  /// Check if two instances of sp_condition_value are equal or not.
  ///
  /// @param cv another instance of sp_condition_value to check.
  ///
  /// @return true if the instances are equal, false otherwise.
  bool equals(const sp_condition_value *cv) const;


  /**
    Checks if this condition is OK for search.
    See also sp_context::find_handler().

    @param identity - The condition identity
    @param found_cv - A previously found matching condition or NULL.
    @return true    - If the current value matches identity and
                      makes a stronger match than the previously
                      found condition found_cv.
    @return false   - If the current value does not match identity,
                      of the current value makes a weaker match than found_cv.
  */
  bool matches(const Sql_condition_identity &identity,
               const sp_condition_value *found_cv) const;

  Sql_user_condition_identity get_user_condition_identity() const
  {
    return Sql_user_condition_identity(m_is_user_defined ? this : NULL);
  }
};


class sp_condition_value_user_defined: public sp_condition_value
{
public:
  sp_condition_value_user_defined()
   :sp_condition_value("45000", true)
  { }
};


///////////////////////////////////////////////////////////////////////////

/// This class represents 'DECLARE CONDITION' statement.
/// sp_condition has little to do with SQL-conditions.

class sp_condition : public Sql_alloc
{
public:
  /// Name of the condition.
  LEX_CSTRING name;

  /// Value of the condition.
  sp_condition_value *value;

public:
  sp_condition(const LEX_CSTRING *name_arg, sp_condition_value *value_arg)
   :Sql_alloc(),
    name(*name_arg),
    value(value_arg)
  { }
  sp_condition(const char *name_arg, size_t name_length_arg,
               sp_condition_value *value_arg)
   :value(value_arg)
  {
    name.str=    name_arg;
    name.length= name_length_arg;
  }
  bool eq_name(const LEX_CSTRING *str) const
  {
    return my_strnncoll(system_charset_info,
                        (const uchar *) name.str, name.length,
                        (const uchar *) str->str, str->length) == 0;
  }
};


///////////////////////////////////////////////////////////////////////////

/**
  class sp_pcursor.
  Stores information about a cursor:
  - Cursor's name in LEX_STRING.
  - Cursor's formal parameter descriptions.

    Formal parameter descriptions reside in a separate context block,
    pointed by the "m_param_context" member.

    m_param_context can be NULL. This means a cursor with no parameters.
    Otherwise, the number of variables in m_param_context means
    the number of cursor's formal parameters.

    Note, m_param_context can be not NULL, but have no variables.
    This is also means a cursor with no parameters (similar to NULL).
*/
class sp_pcursor: public LEX_CSTRING
{
  class sp_pcontext *m_param_context; // Formal parameters
  class sp_lex_cursor *m_lex;         // The cursor statement LEX
public:
  sp_pcursor(const LEX_CSTRING *name, class sp_pcontext *param_ctx,
             class sp_lex_cursor *lex)
   :LEX_CSTRING(*name), m_param_context(param_ctx), m_lex(lex)
  { }
  class sp_pcontext *param_context() const { return m_param_context; }
  class sp_lex_cursor *lex() const { return m_lex; }
  bool check_param_count_with_error(uint param_count) const;
};


///////////////////////////////////////////////////////////////////////////

/// This class represents 'DECLARE HANDLER' statement.

class sp_handler : public Sql_alloc
{
public:
  /// Enumeration of possible handler types.
  /// Note: UNDO handlers are not (and have never been) supported.
  enum enum_type
  {
    EXIT,
    CONTINUE
  };

  /// Handler type.
  enum_type type;

  /// Conditions caught by this handler.
  List<sp_condition_value> condition_values;

public:
  /// The constructor.
  ///
  /// @param _type SQL-handler type.
  sp_handler(enum_type _type)
   :Sql_alloc(),
    type(_type)
  { }
};

///////////////////////////////////////////////////////////////////////////

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

class sp_pcontext : public Sql_alloc
{
public:
  enum enum_scope
  {
    /// REGULAR_SCOPE designates regular BEGIN ... END blocks.
    REGULAR_SCOPE,

    /// HANDLER_SCOPE designates SQL-handler blocks.
    HANDLER_SCOPE
  };

  class Lex_for_loop: public Lex_for_loop_st
  {
  public:
    Lex_for_loop() { init(); }
  };

public:
  sp_pcontext();
  ~sp_pcontext();


  /// Create and push a new context in the tree.

  /// @param thd   thread context.
  /// @param scope scope of the new parsing context.
  /// @return the node created.
  sp_pcontext *push_context(THD *thd, enum_scope scope);

  /// Pop a node from the parsing context tree.
  /// @return the parent node.
  sp_pcontext *pop_context();

  sp_pcontext *parent_context() const
  { return m_parent; }

  sp_pcontext *child_context(uint i) const
  { return i < m_children.elements() ? m_children.at(i) : NULL; }

  /// Calculate and return the number of handlers to pop between the given
  /// context and this one.
  ///
  /// @param ctx       the other parsing context.
  /// @param exclusive specifies if the last scope should be excluded.
  ///
  /// @return 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.
  uint diff_handlers(const sp_pcontext *ctx, bool exclusive) const;

  /// Calculate and return the number of cursors to pop between the given
  /// context and this one.
  ///
  /// @param ctx       the other parsing context.
  /// @param exclusive specifies if the last scope should be excluded.
  ///
  /// @return 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.
  uint diff_cursors(const sp_pcontext *ctx, bool exclusive) const;

  /////////////////////////////////////////////////////////////////////////
  // SP-variables (parameters and variables).
  /////////////////////////////////////////////////////////////////////////

  /// @return 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.
  uint max_var_index() const
  { return m_max_var_index; }

  /// @return the current number of variables used in the parent contexts
  /// (from the root), including this context.
  uint current_var_count() const
  { return m_var_offset + (uint)m_vars.elements(); }

  /// @return the number of variables in this context alone.
  uint context_var_count() const
  { return (uint)m_vars.elements(); }

  /// return the i-th variable on the current context
  sp_variable *get_context_variable(uint i) const
  {
    DBUG_ASSERT(i < m_vars.elements());
    return m_vars.at(i);
  }

  /*
    Return the i-th last context variable.
    If i is 0, then return the very last variable in m_vars.
  */
  sp_variable *get_last_context_variable(uint i= 0) const
  {
    DBUG_ASSERT(i < m_vars.elements());
    return m_vars.at(m_vars.elements() - i - 1);
  }

  /// Add SP-variable to the parsing context.
  ///
  /// @param thd  Thread context.
  /// @param name Name of the SP-variable.
  ///
  /// @return instance of newly added SP-variable.
  sp_variable *add_variable(THD *thd, const LEX_CSTRING *name);

  /// Retrieve full type information about SP-variables in this parsing
  /// context and its children.
  ///
  /// @param field_def_lst[out] Container to store type information.
  void retrieve_field_definitions(List<Spvar_definition> *field_def_lst) 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.
  ///
  /// @param name               Variable name.
  /// @param current_scope_only A flag if we search only in current scope.
  ///
  /// @return instance of found SP-variable, or NULL if not found.
  sp_variable *find_variable(const LEX_CSTRING *name, bool current_scope_only) 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.)
  ///
  /// @param offset Variable offset in the root parsing context.
  ///
  /// @return instance of found SP-variable, or NULL if not found.
  sp_variable *find_variable(uint offset) const;

  /// Set the current scope boundary (for default values).
  ///
  /// @param n The number of variables to skip.
  void declare_var_boundary(uint n)
  { m_pboundary= n; }

  /////////////////////////////////////////////////////////////////////////
  // CASE expressions.
  /////////////////////////////////////////////////////////////////////////

  int register_case_expr()
  { return m_num_case_exprs++; }

  int get_num_case_exprs() const
  { return m_num_case_exprs; }

  bool push_case_expr_id(int case_expr_id)
  { return m_case_expr_ids.append(case_expr_id); }

  void pop_case_expr_id()
  { m_case_expr_ids.pop(); }

  int get_current_case_expr_id() const
  { return *m_case_expr_ids.back(); }

  /////////////////////////////////////////////////////////////////////////
  // Labels.
  /////////////////////////////////////////////////////////////////////////

  sp_label *push_label(THD *thd, const LEX_CSTRING *name, uint ip,
                       sp_label::enum_type type, List<sp_label> * list);

  sp_label *push_label(THD *thd, const LEX_CSTRING *name, uint ip,
                       sp_label::enum_type type)
  { return push_label(thd, name, ip, type, &m_labels); }

  sp_label *push_goto_label(THD *thd, const LEX_CSTRING *name, uint ip,
                            sp_label::enum_type type)
  { return push_label(thd, name, ip, type, &m_goto_labels); }

  sp_label *push_label(THD *thd, const LEX_CSTRING *name, uint ip)
  { return push_label(thd, name, ip, sp_label::IMPLICIT); }

  sp_label *push_goto_label(THD *thd, const LEX_CSTRING *name, uint ip)
  { return push_goto_label(thd, name, ip, sp_label::GOTO); }

  sp_label *find_label(const LEX_CSTRING *name);

  sp_label *find_goto_label(const LEX_CSTRING *name, bool recusive);

  sp_label *find_goto_label(const LEX_CSTRING *name)
  { return find_goto_label(name, true); }

  sp_label *find_label_current_loop_start();

  sp_label *last_label()
  {
    sp_label *label= m_labels.head();

    if (!label && m_parent)
      label= m_parent->last_label();

    return label;
  }

  sp_label *last_goto_label()
  {
    return m_goto_labels.head();
  }

  sp_label *pop_label()
  { return m_labels.pop(); }

  bool block_label_declare(LEX_CSTRING *label)
  {
    sp_label *lab= find_label(label);
    if (lab)
    {
      my_error(ER_SP_LABEL_REDEFINE, MYF(0), label->str);
      return true;
    }
    return false;
  }

  /////////////////////////////////////////////////////////////////////////
  // Conditions.
  /////////////////////////////////////////////////////////////////////////

  bool add_condition(THD *thd, const LEX_CSTRING *name,
                               sp_condition_value *value);

  /// See comment for find_variable() above.
  sp_condition_value *find_condition(const LEX_CSTRING *name,
                                     bool current_scope_only) const;

  sp_condition_value *
  find_declared_or_predefined_condition(THD *thd, const LEX_CSTRING *name) const;

  bool declare_condition(THD *thd, const LEX_CSTRING *name,
                                   sp_condition_value *val)
  {
    if (find_condition(name, true))
    {
      my_error(ER_SP_DUP_COND, MYF(0), name->str);
      return true;
    }
    return add_condition(thd, name, val);
  }

  /////////////////////////////////////////////////////////////////////////
  // Handlers.
  /////////////////////////////////////////////////////////////////////////

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

  /// This is an auxilary 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).
  ///
  /// @param condition_value the handler condition value
  ///                        (not SQL-condition!).
  ///
  /// @retval true if such SQL-handler exists.
  /// @retval false otherwise.
  bool check_duplicate_handler(const sp_condition_value *cond_value) const;

  /// Find an SQL handler for the given SQL condition according to the
  /// SQL-handler resolution rules. This function is used at runtime.
  ///
  /// @param value            The error code and the SQL state
  /// @param level            The SQL condition level
  ///
  /// @return a pointer to the found SQL-handler or NULL.
  sp_handler *find_handler(const Sql_condition_identity &identity) const;

  /////////////////////////////////////////////////////////////////////////
  // Cursors.
  /////////////////////////////////////////////////////////////////////////

  bool add_cursor(const LEX_CSTRING *name, sp_pcontext *param_ctx,
                  class sp_lex_cursor *lex);

  /// See comment for find_variable() above.
  const sp_pcursor *find_cursor(const LEX_CSTRING *name,
                                uint *poff, bool current_scope_only) const;

  const sp_pcursor *find_cursor_with_error(const LEX_CSTRING *name,
                                           uint *poff,
                                           bool current_scope_only) const
  {
    const sp_pcursor *pcursor= find_cursor(name, poff, current_scope_only);
    if (!pcursor)
    {
      my_error(ER_SP_CURSOR_MISMATCH, MYF(0), name->str);
      return NULL;
    }
    return pcursor;
  }
  /// Find cursor by offset (for SHOW {PROCEDURE|FUNCTION} CODE only).
  const sp_pcursor *find_cursor(uint offset) const;

  const sp_pcursor *get_cursor_by_local_frame_offset(uint offset) const
  { return &m_cursors.at(offset); }

  uint cursor_offset() const
  { return m_cursor_offset; }

  uint frame_cursor_count() const
  { return (uint)m_cursors.elements(); }

  uint max_cursor_index() const
  { return m_max_cursor_index + (uint)m_cursors.elements(); }

  uint current_cursor_count() const
  { return m_cursor_offset + (uint)m_cursors.elements(); }

  void set_for_loop(const Lex_for_loop_st &for_loop)
  {
    m_for_loop.init(for_loop);
  }
  const Lex_for_loop_st &for_loop()
  {
    return m_for_loop;
  }

private:
  /// Constructor for a tree node.
  /// @param prev the parent parsing context
  /// @param scope scope of this parsing context
  sp_pcontext(sp_pcontext *prev, enum_scope scope);

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

  /* Prevent use of these */
  sp_pcontext(const sp_pcontext &);
  void operator=(sp_pcontext &);

  sp_condition_value *find_predefined_condition(const LEX_CSTRING *name) const;

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

  /// The maximum sub context's framesizes.
  uint m_max_cursor_index;

  /// Parent context.
  sp_pcontext *m_parent;

  /// 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.
  uint m_var_offset;

  /// Cursor offset for this context.
  uint m_cursor_offset;

  /// 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.
  uint m_pboundary;

  int m_num_case_exprs;

  /// SP parameters/variables.
  Dynamic_array<sp_variable *> m_vars;

  /// Stack of CASE expression ids.
  Dynamic_array<int> m_case_expr_ids;

  /// Stack of SQL-conditions.
  Dynamic_array<sp_condition *> m_conditions;

  /// Stack of cursors.
  Dynamic_array<sp_pcursor> m_cursors;

  /// Stack of SQL-handlers.
  Dynamic_array<sp_handler *> m_handlers;

  /*
   In the below example the label <<lab>> has two meanings:
   - GOTO lab : must go before the beginning of the loop
   - CONTINUE lab : must go to the beginning of the loop
   We solve this by storing block labels and goto labels into separate lists.

   BEGIN
     <<lab>>
     FOR i IN a..10 LOOP
       ...
       GOTO lab;
       ...
       CONTINUE lab;
       ...
     END LOOP;
   END;
  */
  /// List of block labels
  List<sp_label> m_labels;
  /// List of goto labels
  List<sp_label> m_goto_labels;

  /// Children contexts, used for destruction.
  Dynamic_array<sp_pcontext *> m_children;

  /// Scope of this parsing context.
  enum_scope m_scope;

  /// FOR LOOP characteristics
  Lex_for_loop m_for_loop;
}; // class sp_pcontext : public Sql_alloc


#endif /* _SP_PCONTEXT_H_ */