xref: /sqlite-3.40.0/src/sqliteInt.h (revision 6b6ab133)
1 /*
2 ** 2001 September 15
3 **
4 ** The author disclaims copyright to this source code.  In place of
5 ** a legal notice, here is a blessing:
6 **
7 **    May you do good and not evil.
8 **    May you find forgiveness for yourself and forgive others.
9 **    May you share freely, never taking more than you give.
10 **
11 *************************************************************************
12 ** Internal interface definitions for SQLite.
13 **
14 ** @(#) $Id: sqliteInt.h,v 1.550 2007/04/06 11:26:00 drh Exp $
15 */
16 #ifndef _SQLITEINT_H_
17 #define _SQLITEINT_H_
18 
19 #if defined(SQLITE_TCL) || defined(TCLSH)
20 # include <tcl.h>
21 #endif
22 
23 /*
24 ** Many people are failing to set -DNDEBUG=1 when compiling SQLite.
25 ** Setting NDEBUG makes the code smaller and run faster.  So the following
26 ** lines are added to automatically set NDEBUG unless the -DSQLITE_DEBUG=1
27 ** option is set.  Thus NDEBUG becomes an opt-in rather than an opt-out
28 ** feature.
29 */
30 #if !defined(NDEBUG) && !defined(SQLITE_DEBUG)
31 # define NDEBUG 1
32 #endif
33 
34 /*
35 ** These #defines should enable >2GB file support on Posix if the
36 ** underlying operating system supports it.  If the OS lacks
37 ** large file support, or if the OS is windows, these should be no-ops.
38 **
39 ** Large file support can be disabled using the -DSQLITE_DISABLE_LFS switch
40 ** on the compiler command line.  This is necessary if you are compiling
41 ** on a recent machine (ex: RedHat 7.2) but you want your code to work
42 ** on an older machine (ex: RedHat 6.0).  If you compile on RedHat 7.2
43 ** without this option, LFS is enable.  But LFS does not exist in the kernel
44 ** in RedHat 6.0, so the code won't work.  Hence, for maximum binary
45 ** portability you should omit LFS.
46 **
47 ** Similar is true for MacOS.  LFS is only supported on MacOS 9 and later.
48 */
49 #ifndef SQLITE_DISABLE_LFS
50 # define _LARGE_FILE       1
51 # ifndef _FILE_OFFSET_BITS
52 #   define _FILE_OFFSET_BITS 64
53 # endif
54 # define _LARGEFILE_SOURCE 1
55 #endif
56 
57 #include "sqlite3.h"
58 #include "hash.h"
59 #include "parse.h"
60 #include <stdio.h>
61 #include <stdlib.h>
62 #include <string.h>
63 #include <assert.h>
64 #include <stddef.h>
65 
66 /*
67 ** If compiling for a processor that lacks floating point support,
68 ** substitute integer for floating-point
69 */
70 #ifdef SQLITE_OMIT_FLOATING_POINT
71 # define double sqlite_int64
72 # define LONGDOUBLE_TYPE sqlite_int64
73 # ifndef SQLITE_BIG_DBL
74 #   define SQLITE_BIG_DBL (0x7fffffffffffffff)
75 # endif
76 # define SQLITE_OMIT_DATETIME_FUNCS 1
77 # define SQLITE_OMIT_TRACE 1
78 #endif
79 #ifndef SQLITE_BIG_DBL
80 # define SQLITE_BIG_DBL (1e99)
81 #endif
82 
83 /*
84 ** The maximum number of in-memory pages to use for the main database
85 ** table and for temporary tables. Internally, the MAX_PAGES and
86 ** TEMP_PAGES macros are used. To override the default values at
87 ** compilation time, the SQLITE_DEFAULT_CACHE_SIZE and
88 ** SQLITE_DEFAULT_TEMP_CACHE_SIZE macros should be set.
89 */
90 #ifdef SQLITE_DEFAULT_CACHE_SIZE
91 # define MAX_PAGES SQLITE_DEFAULT_CACHE_SIZE
92 #else
93 # define MAX_PAGES   2000
94 #endif
95 #ifdef SQLITE_DEFAULT_TEMP_CACHE_SIZE
96 # define TEMP_PAGES SQLITE_DEFAULT_TEMP_CACHE_SIZE
97 #else
98 # define TEMP_PAGES   500
99 #endif
100 
101 /*
102 ** OMIT_TEMPDB is set to 1 if SQLITE_OMIT_TEMPDB is defined, or 0
103 ** afterward. Having this macro allows us to cause the C compiler
104 ** to omit code used by TEMP tables without messy #ifndef statements.
105 */
106 #ifdef SQLITE_OMIT_TEMPDB
107 #define OMIT_TEMPDB 1
108 #else
109 #define OMIT_TEMPDB 0
110 #endif
111 
112 /*
113 ** If the following macro is set to 1, then NULL values are considered
114 ** distinct when determining whether or not two entries are the same
115 ** in a UNIQUE index.  This is the way PostgreSQL, Oracle, DB2, MySQL,
116 ** OCELOT, and Firebird all work.  The SQL92 spec explicitly says this
117 ** is the way things are suppose to work.
118 **
119 ** If the following macro is set to 0, the NULLs are indistinct for
120 ** a UNIQUE index.  In this mode, you can only have a single NULL entry
121 ** for a column declared UNIQUE.  This is the way Informix and SQL Server
122 ** work.
123 */
124 #define NULL_DISTINCT_FOR_UNIQUE 1
125 
126 /*
127 ** The maximum number of attached databases.  This must be at least 2
128 ** in order to support the main database file (0) and the file used to
129 ** hold temporary tables (1).  And it must be less than 32 because
130 ** we use a bitmask of databases with a u32 in places (for example
131 ** the Parse.cookieMask field).
132 */
133 #define MAX_ATTACHED 10
134 
135 /*
136 ** The maximum value of a ?nnn wildcard that the parser will accept.
137 */
138 #define SQLITE_MAX_VARIABLE_NUMBER 999
139 
140 /*
141 ** The "file format" number is an integer that is incremented whenever
142 ** the VDBE-level file format changes.  The following macros define the
143 ** the default file format for new databases and the maximum file format
144 ** that the library can read.
145 */
146 #define SQLITE_MAX_FILE_FORMAT 4
147 #ifndef SQLITE_DEFAULT_FILE_FORMAT
148 # define SQLITE_DEFAULT_FILE_FORMAT 1
149 #endif
150 
151 /*
152 ** Provide a default value for TEMP_STORE in case it is not specified
153 ** on the command-line
154 */
155 #ifndef TEMP_STORE
156 # define TEMP_STORE 1
157 #endif
158 
159 /*
160 ** GCC does not define the offsetof() macro so we'll have to do it
161 ** ourselves.
162 */
163 #ifndef offsetof
164 #define offsetof(STRUCTURE,FIELD) ((int)((char*)&((STRUCTURE*)0)->FIELD))
165 #endif
166 
167 /*
168 ** Check to see if this machine uses EBCDIC.  (Yes, believe it or
169 ** not, there are still machines out there that use EBCDIC.)
170 */
171 #if 'A' == '\301'
172 # define SQLITE_EBCDIC 1
173 #else
174 # define SQLITE_ASCII 1
175 #endif
176 
177 /*
178 ** Integers of known sizes.  These typedefs might change for architectures
179 ** where the sizes very.  Preprocessor macros are available so that the
180 ** types can be conveniently redefined at compile-type.  Like this:
181 **
182 **         cc '-DUINTPTR_TYPE=long long int' ...
183 */
184 #ifndef UINT32_TYPE
185 # define UINT32_TYPE unsigned int
186 #endif
187 #ifndef UINT16_TYPE
188 # define UINT16_TYPE unsigned short int
189 #endif
190 #ifndef INT16_TYPE
191 # define INT16_TYPE short int
192 #endif
193 #ifndef UINT8_TYPE
194 # define UINT8_TYPE unsigned char
195 #endif
196 #ifndef INT8_TYPE
197 # define INT8_TYPE signed char
198 #endif
199 #ifndef LONGDOUBLE_TYPE
200 # define LONGDOUBLE_TYPE long double
201 #endif
202 typedef sqlite_int64 i64;          /* 8-byte signed integer */
203 typedef sqlite_uint64 u64;         /* 8-byte unsigned integer */
204 typedef UINT32_TYPE u32;           /* 4-byte unsigned integer */
205 typedef UINT16_TYPE u16;           /* 2-byte unsigned integer */
206 typedef INT16_TYPE i16;            /* 2-byte signed integer */
207 typedef UINT8_TYPE u8;             /* 1-byte unsigned integer */
208 typedef UINT8_TYPE i8;             /* 1-byte signed integer */
209 
210 /*
211 ** Macros to determine whether the machine is big or little endian,
212 ** evaluated at runtime.
213 */
214 extern const int sqlite3one;
215 #if defined(i386) || defined(__i386__) || defined(_M_IX86)
216 # define SQLITE_BIGENDIAN    0
217 # define SQLITE_LITTLEENDIAN 1
218 # define SQLITE_UTF16NATIVE  SQLITE_UTF16LE
219 #else
220 # define SQLITE_BIGENDIAN    (*(char *)(&sqlite3one)==0)
221 # define SQLITE_LITTLEENDIAN (*(char *)(&sqlite3one)==1)
222 # define SQLITE_UTF16NATIVE (SQLITE_BIGENDIAN?SQLITE_UTF16BE:SQLITE_UTF16LE)
223 #endif
224 
225 /*
226 ** An instance of the following structure is used to store the busy-handler
227 ** callback for a given sqlite handle.
228 **
229 ** The sqlite.busyHandler member of the sqlite struct contains the busy
230 ** callback for the database handle. Each pager opened via the sqlite
231 ** handle is passed a pointer to sqlite.busyHandler. The busy-handler
232 ** callback is currently invoked only from within pager.c.
233 */
234 typedef struct BusyHandler BusyHandler;
235 struct BusyHandler {
236   int (*xFunc)(void *,int);  /* The busy callback */
237   void *pArg;                /* First arg to busy callback */
238   int nBusy;                 /* Incremented with each busy call */
239 };
240 
241 /*
242 ** Defer sourcing vdbe.h and btree.h until after the "u8" and
243 ** "BusyHandler typedefs.
244 */
245 #include "vdbe.h"
246 #include "btree.h"
247 #include "pager.h"
248 
249 #ifdef SQLITE_MEMDEBUG
250 /*
251 ** The following global variables are used for testing and debugging
252 ** only.  They only work if SQLITE_MEMDEBUG is defined.
253 */
254 extern int sqlite3_nMalloc;      /* Number of sqliteMalloc() calls */
255 extern int sqlite3_nFree;        /* Number of sqliteFree() calls */
256 extern int sqlite3_iMallocFail;  /* Fail sqliteMalloc() after this many calls */
257 extern int sqlite3_iMallocReset; /* Set iMallocFail to this when it reaches 0 */
258 
259 extern void *sqlite3_pFirst;         /* Pointer to linked list of allocations */
260 extern int sqlite3_nMaxAlloc;        /* High water mark of ThreadData.nAlloc */
261 extern int sqlite3_mallocDisallowed; /* assert() in sqlite3Malloc() if set */
262 extern int sqlite3_isFail;           /* True if all malloc calls should fail */
263 extern const char *sqlite3_zFile;    /* Filename to associate debug info with */
264 extern int sqlite3_iLine;            /* Line number for debug info */
265 
266 #define ENTER_MALLOC (sqlite3_zFile = __FILE__, sqlite3_iLine = __LINE__)
267 #define sqliteMalloc(x)          (ENTER_MALLOC, sqlite3Malloc(x,1))
268 #define sqliteMallocRaw(x)       (ENTER_MALLOC, sqlite3MallocRaw(x,1))
269 #define sqliteRealloc(x,y)       (ENTER_MALLOC, sqlite3Realloc(x,y))
270 #define sqliteStrDup(x)          (ENTER_MALLOC, sqlite3StrDup(x))
271 #define sqliteStrNDup(x,y)       (ENTER_MALLOC, sqlite3StrNDup(x,y))
272 #define sqliteReallocOrFree(x,y) (ENTER_MALLOC, sqlite3ReallocOrFree(x,y))
273 
274 #else
275 
276 #define ENTER_MALLOC 0
277 #define sqliteMalloc(x)          sqlite3Malloc(x,1)
278 #define sqliteMallocRaw(x)       sqlite3MallocRaw(x,1)
279 #define sqliteRealloc(x,y)       sqlite3Realloc(x,y)
280 #define sqliteStrDup(x)          sqlite3StrDup(x)
281 #define sqliteStrNDup(x,y)       sqlite3StrNDup(x,y)
282 #define sqliteReallocOrFree(x,y) sqlite3ReallocOrFree(x,y)
283 
284 #endif
285 
286 #define sqliteFree(x)          sqlite3FreeX(x)
287 #define sqliteAllocSize(x)     sqlite3AllocSize(x)
288 
289 
290 /*
291 ** An instance of this structure might be allocated to store information
292 ** specific to a single thread.
293 */
294 struct ThreadData {
295   int dummy;               /* So that this structure is never empty */
296 
297 #ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
298   int nSoftHeapLimit;      /* Suggested max mem allocation.  No limit if <0 */
299   int nAlloc;              /* Number of bytes currently allocated */
300   Pager *pPager;           /* Linked list of all pagers in this thread */
301 #endif
302 
303 #ifndef SQLITE_OMIT_SHARED_CACHE
304   u8 useSharedData;        /* True if shared pagers and schemas are enabled */
305   BtShared *pBtree;        /* Linked list of all currently open BTrees */
306 #endif
307 };
308 
309 /*
310 ** Name of the master database table.  The master database table
311 ** is a special table that holds the names and attributes of all
312 ** user tables and indices.
313 */
314 #define MASTER_NAME       "sqlite_master"
315 #define TEMP_MASTER_NAME  "sqlite_temp_master"
316 
317 /*
318 ** The root-page of the master database table.
319 */
320 #define MASTER_ROOT       1
321 
322 /*
323 ** The name of the schema table.
324 */
325 #define SCHEMA_TABLE(x)  ((!OMIT_TEMPDB)&&(x==1)?TEMP_MASTER_NAME:MASTER_NAME)
326 
327 /*
328 ** A convenience macro that returns the number of elements in
329 ** an array.
330 */
331 #define ArraySize(X)    (sizeof(X)/sizeof(X[0]))
332 
333 /*
334 ** Forward references to structures
335 */
336 typedef struct AggInfo AggInfo;
337 typedef struct AuthContext AuthContext;
338 typedef struct CollSeq CollSeq;
339 typedef struct Column Column;
340 typedef struct Db Db;
341 typedef struct Schema Schema;
342 typedef struct Expr Expr;
343 typedef struct ExprList ExprList;
344 typedef struct FKey FKey;
345 typedef struct FuncDef FuncDef;
346 typedef struct IdList IdList;
347 typedef struct Index Index;
348 typedef struct KeyClass KeyClass;
349 typedef struct KeyInfo KeyInfo;
350 typedef struct Module Module;
351 typedef struct NameContext NameContext;
352 typedef struct Parse Parse;
353 typedef struct Select Select;
354 typedef struct SrcList SrcList;
355 typedef struct ThreadData ThreadData;
356 typedef struct Table Table;
357 typedef struct TableLock TableLock;
358 typedef struct Token Token;
359 typedef struct TriggerStack TriggerStack;
360 typedef struct TriggerStep TriggerStep;
361 typedef struct Trigger Trigger;
362 typedef struct WhereInfo WhereInfo;
363 typedef struct WhereLevel WhereLevel;
364 
365 /*
366 ** Each database file to be accessed by the system is an instance
367 ** of the following structure.  There are normally two of these structures
368 ** in the sqlite.aDb[] array.  aDb[0] is the main database file and
369 ** aDb[1] is the database file used to hold temporary tables.  Additional
370 ** databases may be attached.
371 */
372 struct Db {
373   char *zName;         /* Name of this database */
374   Btree *pBt;          /* The B*Tree structure for this database file */
375   u8 inTrans;          /* 0: not writable.  1: Transaction.  2: Checkpoint */
376   u8 safety_level;     /* How aggressive at synching data to disk */
377   void *pAux;               /* Auxiliary data.  Usually NULL */
378   void (*xFreeAux)(void*);  /* Routine to free pAux */
379   Schema *pSchema;     /* Pointer to database schema (possibly shared) */
380 };
381 
382 /*
383 ** An instance of the following structure stores a database schema.
384 */
385 struct Schema {
386   int schema_cookie;   /* Database schema version number for this file */
387   Hash tblHash;        /* All tables indexed by name */
388   Hash idxHash;        /* All (named) indices indexed by name */
389   Hash trigHash;       /* All triggers indexed by name */
390   Hash aFKey;          /* Foreign keys indexed by to-table */
391   Table *pSeqTab;      /* The sqlite_sequence table used by AUTOINCREMENT */
392   u8 file_format;      /* Schema format version for this file */
393   u8 enc;              /* Text encoding used by this database */
394   u16 flags;           /* Flags associated with this schema */
395   int cache_size;      /* Number of pages to use in the cache */
396 };
397 
398 /*
399 ** These macros can be used to test, set, or clear bits in the
400 ** Db.flags field.
401 */
402 #define DbHasProperty(D,I,P)     (((D)->aDb[I].pSchema->flags&(P))==(P))
403 #define DbHasAnyProperty(D,I,P)  (((D)->aDb[I].pSchema->flags&(P))!=0)
404 #define DbSetProperty(D,I,P)     (D)->aDb[I].pSchema->flags|=(P)
405 #define DbClearProperty(D,I,P)   (D)->aDb[I].pSchema->flags&=~(P)
406 
407 /*
408 ** Allowed values for the DB.flags field.
409 **
410 ** The DB_SchemaLoaded flag is set after the database schema has been
411 ** read into internal hash tables.
412 **
413 ** DB_UnresetViews means that one or more views have column names that
414 ** have been filled out.  If the schema changes, these column names might
415 ** changes and so the view will need to be reset.
416 */
417 #define DB_SchemaLoaded    0x0001  /* The schema has been loaded */
418 #define DB_UnresetViews    0x0002  /* Some views have defined column names */
419 #define DB_Empty           0x0004  /* The file is empty (length 0 bytes) */
420 
421 
422 /*
423 ** Each database is an instance of the following structure.
424 **
425 ** The sqlite.lastRowid records the last insert rowid generated by an
426 ** insert statement.  Inserts on views do not affect its value.  Each
427 ** trigger has its own context, so that lastRowid can be updated inside
428 ** triggers as usual.  The previous value will be restored once the trigger
429 ** exits.  Upon entering a before or instead of trigger, lastRowid is no
430 ** longer (since after version 2.8.12) reset to -1.
431 **
432 ** The sqlite.nChange does not count changes within triggers and keeps no
433 ** context.  It is reset at start of sqlite3_exec.
434 ** The sqlite.lsChange represents the number of changes made by the last
435 ** insert, update, or delete statement.  It remains constant throughout the
436 ** length of a statement and is then updated by OP_SetCounts.  It keeps a
437 ** context stack just like lastRowid so that the count of changes
438 ** within a trigger is not seen outside the trigger.  Changes to views do not
439 ** affect the value of lsChange.
440 ** The sqlite.csChange keeps track of the number of current changes (since
441 ** the last statement) and is used to update sqlite_lsChange.
442 **
443 ** The member variables sqlite.errCode, sqlite.zErrMsg and sqlite.zErrMsg16
444 ** store the most recent error code and, if applicable, string. The
445 ** internal function sqlite3Error() is used to set these variables
446 ** consistently.
447 */
448 struct sqlite3 {
449   int nDb;                      /* Number of backends currently in use */
450   Db *aDb;                      /* All backends */
451   int flags;                    /* Miscellanous flags. See below */
452   int errCode;                  /* Most recent error code (SQLITE_*) */
453   int errMask;                  /* & result codes with this before returning */
454   u8 autoCommit;                /* The auto-commit flag. */
455   u8 temp_store;                /* 1: file 2: memory 0: default */
456   int nTable;                   /* Number of tables in the database */
457   CollSeq *pDfltColl;           /* The default collating sequence (BINARY) */
458   i64 lastRowid;                /* ROWID of most recent insert (see above) */
459   i64 priorNewRowid;            /* Last randomly generated ROWID */
460   int magic;                    /* Magic number for detect library misuse */
461   int nChange;                  /* Value returned by sqlite3_changes() */
462   int nTotalChange;             /* Value returned by sqlite3_total_changes() */
463   struct sqlite3InitInfo {      /* Information used during initialization */
464     int iDb;                    /* When back is being initialized */
465     int newTnum;                /* Rootpage of table being initialized */
466     u8 busy;                    /* TRUE if currently initializing */
467   } init;
468   int nExtension;               /* Number of loaded extensions */
469   void **aExtension;            /* Array of shared libraray handles */
470   struct Vdbe *pVdbe;           /* List of active virtual machines */
471   int activeVdbeCnt;            /* Number of vdbes currently executing */
472   void (*xTrace)(void*,const char*);        /* Trace function */
473   void *pTraceArg;                          /* Argument to the trace function */
474   void (*xProfile)(void*,const char*,u64);  /* Profiling function */
475   void *pProfileArg;                        /* Argument to profile function */
476   void *pCommitArg;                 /* Argument to xCommitCallback() */
477   int (*xCommitCallback)(void*);    /* Invoked at every commit. */
478   void *pRollbackArg;               /* Argument to xRollbackCallback() */
479   void (*xRollbackCallback)(void*); /* Invoked at every commit. */
480   void *pUpdateArg;
481   void (*xUpdateCallback)(void*,int, const char*,const char*,sqlite_int64);
482   void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*);
483   void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*);
484   void *pCollNeededArg;
485   sqlite3_value *pErr;          /* Most recent error message */
486   char *zErrMsg;                /* Most recent error message (UTF-8 encoded) */
487   char *zErrMsg16;              /* Most recent error message (UTF-16 encoded) */
488   union {
489     int isInterrupted;          /* True if sqlite3_interrupt has been called */
490     double notUsed1;            /* Spacer */
491   } u1;
492 #ifndef SQLITE_OMIT_AUTHORIZATION
493   int (*xAuth)(void*,int,const char*,const char*,const char*,const char*);
494                                 /* Access authorization function */
495   void *pAuthArg;               /* 1st argument to the access auth function */
496 #endif
497 #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
498   int (*xProgress)(void *);     /* The progress callback */
499   void *pProgressArg;           /* Argument to the progress callback */
500   int nProgressOps;             /* Number of opcodes for progress callback */
501 #endif
502 #ifndef SQLITE_OMIT_VIRTUALTABLE
503   Hash aModule;                 /* populated by sqlite3_create_module() */
504   Table *pVTab;                 /* vtab with active Connect/Create method */
505   sqlite3_vtab **aVTrans;       /* Virtual tables with open transactions */
506   int nVTrans;                  /* Allocated size of aVTrans */
507 #endif
508   Hash aFunc;                   /* All functions that can be in SQL exprs */
509   Hash aCollSeq;                /* All collating sequences */
510   BusyHandler busyHandler;      /* Busy callback */
511   int busyTimeout;              /* Busy handler timeout, in msec */
512   Db aDbStatic[2];              /* Static space for the 2 default backends */
513 #ifdef SQLITE_SSE
514   sqlite3_stmt *pFetch;         /* Used by SSE to fetch stored statements */
515 #endif
516   u8 dfltLockMode;              /* Default locking-mode for attached dbs */
517 };
518 
519 /*
520 ** A macro to discover the encoding of a database.
521 */
522 #define ENC(db) ((db)->aDb[0].pSchema->enc)
523 
524 /*
525 ** Possible values for the sqlite.flags and or Db.flags fields.
526 **
527 ** On sqlite.flags, the SQLITE_InTrans value means that we have
528 ** executed a BEGIN.  On Db.flags, SQLITE_InTrans means a statement
529 ** transaction is active on that particular database file.
530 */
531 #define SQLITE_VdbeTrace      0x00000001  /* True to trace VDBE execution */
532 #define SQLITE_InTrans        0x00000008  /* True if in a transaction */
533 #define SQLITE_InternChanges  0x00000010  /* Uncommitted Hash table changes */
534 #define SQLITE_FullColNames   0x00000020  /* Show full column names on SELECT */
535 #define SQLITE_ShortColNames  0x00000040  /* Show short columns names */
536 #define SQLITE_CountRows      0x00000080  /* Count rows changed by INSERT, */
537                                           /*   DELETE, or UPDATE and return */
538                                           /*   the count using a callback. */
539 #define SQLITE_NullCallback   0x00000100  /* Invoke the callback once if the */
540                                           /*   result set is empty */
541 #define SQLITE_SqlTrace       0x00000200  /* Debug print SQL as it executes */
542 #define SQLITE_VdbeListing    0x00000400  /* Debug listings of VDBE programs */
543 #define SQLITE_WriteSchema    0x00000800  /* OK to update SQLITE_MASTER */
544 #define SQLITE_NoReadlock     0x00001000  /* Readlocks are omitted when
545                                           ** accessing read-only databases */
546 #define SQLITE_IgnoreChecks   0x00002000  /* Do not enforce check constraints */
547 #define SQLITE_ReadUncommitted 0x00004000 /* For shared-cache mode */
548 #define SQLITE_LegacyFileFmt  0x00008000  /* Create new databases in format 1 */
549 #define SQLITE_FullFSync      0x00010000  /* Use full fsync on the backend */
550 #define SQLITE_LoadExtension  0x00020000  /* Enable load_extension */
551 
552 #define SQLITE_RecoveryMode   0x00040000  /* Ignore schema errors */
553 
554 /*
555 ** Possible values for the sqlite.magic field.
556 ** The numbers are obtained at random and have no special meaning, other
557 ** than being distinct from one another.
558 */
559 #define SQLITE_MAGIC_OPEN     0xa029a697  /* Database is open */
560 #define SQLITE_MAGIC_CLOSED   0x9f3c2d33  /* Database is closed */
561 #define SQLITE_MAGIC_BUSY     0xf03b7906  /* Database currently in use */
562 #define SQLITE_MAGIC_ERROR    0xb5357930  /* An SQLITE_MISUSE error occurred */
563 
564 /*
565 ** Each SQL function is defined by an instance of the following
566 ** structure.  A pointer to this structure is stored in the sqlite.aFunc
567 ** hash table.  When multiple functions have the same name, the hash table
568 ** points to a linked list of these structures.
569 */
570 struct FuncDef {
571   i16 nArg;            /* Number of arguments.  -1 means unlimited */
572   u8 iPrefEnc;         /* Preferred text encoding (SQLITE_UTF8, 16LE, 16BE) */
573   u8 needCollSeq;      /* True if sqlite3GetFuncCollSeq() might be called */
574   u8 flags;            /* Some combination of SQLITE_FUNC_* */
575   void *pUserData;     /* User data parameter */
576   FuncDef *pNext;      /* Next function with same name */
577   void (*xFunc)(sqlite3_context*,int,sqlite3_value**); /* Regular function */
578   void (*xStep)(sqlite3_context*,int,sqlite3_value**); /* Aggregate step */
579   void (*xFinalize)(sqlite3_context*);                /* Aggregate finializer */
580   char zName[1];       /* SQL name of the function.  MUST BE LAST */
581 };
582 
583 /*
584 ** Each SQLite module (virtual table definition) is defined by an
585 ** instance of the following structure, stored in the sqlite3.aModule
586 ** hash table.
587 */
588 struct Module {
589   const sqlite3_module *pModule;       /* Callback pointers */
590   const char *zName;                   /* Name passed to create_module() */
591   void *pAux;                          /* pAux passed to create_module() */
592 };
593 
594 /*
595 ** Possible values for FuncDef.flags
596 */
597 #define SQLITE_FUNC_LIKE   0x01  /* Candidate for the LIKE optimization */
598 #define SQLITE_FUNC_CASE   0x02  /* Case-sensitive LIKE-type function */
599 #define SQLITE_FUNC_EPHEM  0x04  /* Ephermeral.  Delete with VDBE */
600 
601 /*
602 ** information about each column of an SQL table is held in an instance
603 ** of this structure.
604 */
605 struct Column {
606   char *zName;     /* Name of this column */
607   Expr *pDflt;     /* Default value of this column */
608   char *zType;     /* Data type for this column */
609   char *zColl;     /* Collating sequence.  If NULL, use the default */
610   u8 notNull;      /* True if there is a NOT NULL constraint */
611   u8 isPrimKey;    /* True if this column is part of the PRIMARY KEY */
612   char affinity;   /* One of the SQLITE_AFF_... values */
613 };
614 
615 /*
616 ** A "Collating Sequence" is defined by an instance of the following
617 ** structure. Conceptually, a collating sequence consists of a name and
618 ** a comparison routine that defines the order of that sequence.
619 **
620 ** There may two seperate implementations of the collation function, one
621 ** that processes text in UTF-8 encoding (CollSeq.xCmp) and another that
622 ** processes text encoded in UTF-16 (CollSeq.xCmp16), using the machine
623 ** native byte order. When a collation sequence is invoked, SQLite selects
624 ** the version that will require the least expensive encoding
625 ** translations, if any.
626 **
627 ** The CollSeq.pUser member variable is an extra parameter that passed in
628 ** as the first argument to the UTF-8 comparison function, xCmp.
629 ** CollSeq.pUser16 is the equivalent for the UTF-16 comparison function,
630 ** xCmp16.
631 **
632 ** If both CollSeq.xCmp and CollSeq.xCmp16 are NULL, it means that the
633 ** collating sequence is undefined.  Indices built on an undefined
634 ** collating sequence may not be read or written.
635 */
636 struct CollSeq {
637   char *zName;         /* Name of the collating sequence, UTF-8 encoded */
638   u8 enc;              /* Text encoding handled by xCmp() */
639   u8 type;             /* One of the SQLITE_COLL_... values below */
640   void *pUser;         /* First argument to xCmp() */
641   int (*xCmp)(void*,int, const void*, int, const void*);
642 };
643 
644 /*
645 ** Allowed values of CollSeq flags:
646 */
647 #define SQLITE_COLL_BINARY  1  /* The default memcmp() collating sequence */
648 #define SQLITE_COLL_NOCASE  2  /* The built-in NOCASE collating sequence */
649 #define SQLITE_COLL_REVERSE 3  /* The built-in REVERSE collating sequence */
650 #define SQLITE_COLL_USER    0  /* Any other user-defined collating sequence */
651 
652 /*
653 ** A sort order can be either ASC or DESC.
654 */
655 #define SQLITE_SO_ASC       0  /* Sort in ascending order */
656 #define SQLITE_SO_DESC      1  /* Sort in ascending order */
657 
658 /*
659 ** Column affinity types.
660 **
661 ** These used to have mnemonic name like 'i' for SQLITE_AFF_INTEGER and
662 ** 't' for SQLITE_AFF_TEXT.  But we can save a little space and improve
663 ** the speed a little by number the values consecutively.
664 **
665 ** But rather than start with 0 or 1, we begin with 'a'.  That way,
666 ** when multiple affinity types are concatenated into a string and
667 ** used as the P3 operand, they will be more readable.
668 **
669 ** Note also that the numeric types are grouped together so that testing
670 ** for a numeric type is a single comparison.
671 */
672 #define SQLITE_AFF_TEXT     'a'
673 #define SQLITE_AFF_NONE     'b'
674 #define SQLITE_AFF_NUMERIC  'c'
675 #define SQLITE_AFF_INTEGER  'd'
676 #define SQLITE_AFF_REAL     'e'
677 
678 #define sqlite3IsNumericAffinity(X)  ((X)>=SQLITE_AFF_NUMERIC)
679 
680 /*
681 ** Each SQL table is represented in memory by an instance of the
682 ** following structure.
683 **
684 ** Table.zName is the name of the table.  The case of the original
685 ** CREATE TABLE statement is stored, but case is not significant for
686 ** comparisons.
687 **
688 ** Table.nCol is the number of columns in this table.  Table.aCol is a
689 ** pointer to an array of Column structures, one for each column.
690 **
691 ** If the table has an INTEGER PRIMARY KEY, then Table.iPKey is the index of
692 ** the column that is that key.   Otherwise Table.iPKey is negative.  Note
693 ** that the datatype of the PRIMARY KEY must be INTEGER for this field to
694 ** be set.  An INTEGER PRIMARY KEY is used as the rowid for each row of
695 ** the table.  If a table has no INTEGER PRIMARY KEY, then a random rowid
696 ** is generated for each row of the table.  Table.hasPrimKey is true if
697 ** the table has any PRIMARY KEY, INTEGER or otherwise.
698 **
699 ** Table.tnum is the page number for the root BTree page of the table in the
700 ** database file.  If Table.iDb is the index of the database table backend
701 ** in sqlite.aDb[].  0 is for the main database and 1 is for the file that
702 ** holds temporary tables and indices.  If Table.isEphem
703 ** is true, then the table is stored in a file that is automatically deleted
704 ** when the VDBE cursor to the table is closed.  In this case Table.tnum
705 ** refers VDBE cursor number that holds the table open, not to the root
706 ** page number.  Transient tables are used to hold the results of a
707 ** sub-query that appears instead of a real table name in the FROM clause
708 ** of a SELECT statement.
709 */
710 struct Table {
711   char *zName;     /* Name of the table */
712   int nCol;        /* Number of columns in this table */
713   Column *aCol;    /* Information about each column */
714   int iPKey;       /* If not less then 0, use aCol[iPKey] as the primary key */
715   Index *pIndex;   /* List of SQL indexes on this table. */
716   int tnum;        /* Root BTree node for this table (see note above) */
717   Select *pSelect; /* NULL for tables.  Points to definition if a view. */
718   int nRef;          /* Number of pointers to this Table */
719   Trigger *pTrigger; /* List of SQL triggers on this table */
720   FKey *pFKey;       /* Linked list of all foreign keys in this table */
721   char *zColAff;     /* String defining the affinity of each column */
722 #ifndef SQLITE_OMIT_CHECK
723   Expr *pCheck;      /* The AND of all CHECK constraints */
724 #endif
725 #ifndef SQLITE_OMIT_ALTERTABLE
726   int addColOffset;  /* Offset in CREATE TABLE statement to add a new column */
727 #endif
728   u8 readOnly;     /* True if this table should not be written by the user */
729   u8 isEphem;      /* True if created using OP_OpenEphermeral */
730   u8 hasPrimKey;   /* True if there exists a primary key */
731   u8 keyConf;      /* What to do in case of uniqueness conflict on iPKey */
732   u8 autoInc;      /* True if the integer primary key is autoincrement */
733 #ifndef SQLITE_OMIT_VIRTUALTABLE
734   u8 isVirtual;             /* True if this is a virtual table */
735   u8 isCommit;              /* True once the CREATE TABLE has been committed */
736   Module *pMod;             /* Pointer to the implementation of the module */
737   sqlite3_vtab *pVtab;      /* Pointer to the module instance */
738   int nModuleArg;           /* Number of arguments to the module */
739   char **azModuleArg;       /* Text of all module args. [0] is module name */
740 #endif
741   Schema *pSchema;
742 };
743 
744 /*
745 ** Test to see whether or not a table is a virtual table.  This is
746 ** done as a macro so that it will be optimized out when virtual
747 ** table support is omitted from the build.
748 */
749 #ifndef SQLITE_OMIT_VIRTUALTABLE
750 #  define IsVirtual(X) ((X)->isVirtual)
751 #else
752 #  define IsVirtual(X) 0
753 #endif
754 
755 /*
756 ** Each foreign key constraint is an instance of the following structure.
757 **
758 ** A foreign key is associated with two tables.  The "from" table is
759 ** the table that contains the REFERENCES clause that creates the foreign
760 ** key.  The "to" table is the table that is named in the REFERENCES clause.
761 ** Consider this example:
762 **
763 **     CREATE TABLE ex1(
764 **       a INTEGER PRIMARY KEY,
765 **       b INTEGER CONSTRAINT fk1 REFERENCES ex2(x)
766 **     );
767 **
768 ** For foreign key "fk1", the from-table is "ex1" and the to-table is "ex2".
769 **
770 ** Each REFERENCES clause generates an instance of the following structure
771 ** which is attached to the from-table.  The to-table need not exist when
772 ** the from-table is created.  The existance of the to-table is not checked
773 ** until an attempt is made to insert data into the from-table.
774 **
775 ** The sqlite.aFKey hash table stores pointers to this structure
776 ** given the name of a to-table.  For each to-table, all foreign keys
777 ** associated with that table are on a linked list using the FKey.pNextTo
778 ** field.
779 */
780 struct FKey {
781   Table *pFrom;     /* The table that constains the REFERENCES clause */
782   FKey *pNextFrom;  /* Next foreign key in pFrom */
783   char *zTo;        /* Name of table that the key points to */
784   FKey *pNextTo;    /* Next foreign key that points to zTo */
785   int nCol;         /* Number of columns in this key */
786   struct sColMap {  /* Mapping of columns in pFrom to columns in zTo */
787     int iFrom;         /* Index of column in pFrom */
788     char *zCol;        /* Name of column in zTo.  If 0 use PRIMARY KEY */
789   } *aCol;          /* One entry for each of nCol column s */
790   u8 isDeferred;    /* True if constraint checking is deferred till COMMIT */
791   u8 updateConf;    /* How to resolve conflicts that occur on UPDATE */
792   u8 deleteConf;    /* How to resolve conflicts that occur on DELETE */
793   u8 insertConf;    /* How to resolve conflicts that occur on INSERT */
794 };
795 
796 /*
797 ** SQLite supports many different ways to resolve a contraint
798 ** error.  ROLLBACK processing means that a constraint violation
799 ** causes the operation in process to fail and for the current transaction
800 ** to be rolled back.  ABORT processing means the operation in process
801 ** fails and any prior changes from that one operation are backed out,
802 ** but the transaction is not rolled back.  FAIL processing means that
803 ** the operation in progress stops and returns an error code.  But prior
804 ** changes due to the same operation are not backed out and no rollback
805 ** occurs.  IGNORE means that the particular row that caused the constraint
806 ** error is not inserted or updated.  Processing continues and no error
807 ** is returned.  REPLACE means that preexisting database rows that caused
808 ** a UNIQUE constraint violation are removed so that the new insert or
809 ** update can proceed.  Processing continues and no error is reported.
810 **
811 ** RESTRICT, SETNULL, and CASCADE actions apply only to foreign keys.
812 ** RESTRICT is the same as ABORT for IMMEDIATE foreign keys and the
813 ** same as ROLLBACK for DEFERRED keys.  SETNULL means that the foreign
814 ** key is set to NULL.  CASCADE means that a DELETE or UPDATE of the
815 ** referenced table row is propagated into the row that holds the
816 ** foreign key.
817 **
818 ** The following symbolic values are used to record which type
819 ** of action to take.
820 */
821 #define OE_None     0   /* There is no constraint to check */
822 #define OE_Rollback 1   /* Fail the operation and rollback the transaction */
823 #define OE_Abort    2   /* Back out changes but do no rollback transaction */
824 #define OE_Fail     3   /* Stop the operation but leave all prior changes */
825 #define OE_Ignore   4   /* Ignore the error. Do not do the INSERT or UPDATE */
826 #define OE_Replace  5   /* Delete existing record, then do INSERT or UPDATE */
827 
828 #define OE_Restrict 6   /* OE_Abort for IMMEDIATE, OE_Rollback for DEFERRED */
829 #define OE_SetNull  7   /* Set the foreign key value to NULL */
830 #define OE_SetDflt  8   /* Set the foreign key value to its default */
831 #define OE_Cascade  9   /* Cascade the changes */
832 
833 #define OE_Default  99  /* Do whatever the default action is */
834 
835 
836 /*
837 ** An instance of the following structure is passed as the first
838 ** argument to sqlite3VdbeKeyCompare and is used to control the
839 ** comparison of the two index keys.
840 **
841 ** If the KeyInfo.incrKey value is true and the comparison would
842 ** otherwise be equal, then return a result as if the second key
843 ** were larger.
844 */
845 struct KeyInfo {
846   u8 enc;             /* Text encoding - one of the TEXT_Utf* values */
847   u8 incrKey;         /* Increase 2nd key by epsilon before comparison */
848   int nField;         /* Number of entries in aColl[] */
849   u8 *aSortOrder;     /* If defined an aSortOrder[i] is true, sort DESC */
850   CollSeq *aColl[1];  /* Collating sequence for each term of the key */
851 };
852 
853 /*
854 ** Each SQL index is represented in memory by an
855 ** instance of the following structure.
856 **
857 ** The columns of the table that are to be indexed are described
858 ** by the aiColumn[] field of this structure.  For example, suppose
859 ** we have the following table and index:
860 **
861 **     CREATE TABLE Ex1(c1 int, c2 int, c3 text);
862 **     CREATE INDEX Ex2 ON Ex1(c3,c1);
863 **
864 ** In the Table structure describing Ex1, nCol==3 because there are
865 ** three columns in the table.  In the Index structure describing
866 ** Ex2, nColumn==2 since 2 of the 3 columns of Ex1 are indexed.
867 ** The value of aiColumn is {2, 0}.  aiColumn[0]==2 because the
868 ** first column to be indexed (c3) has an index of 2 in Ex1.aCol[].
869 ** The second column to be indexed (c1) has an index of 0 in
870 ** Ex1.aCol[], hence Ex2.aiColumn[1]==0.
871 **
872 ** The Index.onError field determines whether or not the indexed columns
873 ** must be unique and what to do if they are not.  When Index.onError=OE_None,
874 ** it means this is not a unique index.  Otherwise it is a unique index
875 ** and the value of Index.onError indicate the which conflict resolution
876 ** algorithm to employ whenever an attempt is made to insert a non-unique
877 ** element.
878 */
879 struct Index {
880   char *zName;     /* Name of this index */
881   int nColumn;     /* Number of columns in the table used by this index */
882   int *aiColumn;   /* Which columns are used by this index.  1st is 0 */
883   unsigned *aiRowEst; /* Result of ANALYZE: Est. rows selected by each column */
884   Table *pTable;   /* The SQL table being indexed */
885   int tnum;        /* Page containing root of this index in database file */
886   u8 onError;      /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
887   u8 autoIndex;    /* True if is automatically created (ex: by UNIQUE) */
888   char *zColAff;   /* String defining the affinity of each column */
889   Index *pNext;    /* The next index associated with the same table */
890   Schema *pSchema; /* Schema containing this index */
891   u8 *aSortOrder;  /* Array of size Index.nColumn. True==DESC, False==ASC */
892   char **azColl;   /* Array of collation sequence names for index */
893 };
894 
895 /*
896 ** Each token coming out of the lexer is an instance of
897 ** this structure.  Tokens are also used as part of an expression.
898 **
899 ** Note if Token.z==0 then Token.dyn and Token.n are undefined and
900 ** may contain random values.  Do not make any assuptions about Token.dyn
901 ** and Token.n when Token.z==0.
902 */
903 struct Token {
904   const unsigned char *z; /* Text of the token.  Not NULL-terminated! */
905   unsigned dyn  : 1;      /* True for malloced memory, false for static */
906   unsigned n    : 31;     /* Number of characters in this token */
907 };
908 
909 /*
910 ** An instance of this structure contains information needed to generate
911 ** code for a SELECT that contains aggregate functions.
912 **
913 ** If Expr.op==TK_AGG_COLUMN or TK_AGG_FUNCTION then Expr.pAggInfo is a
914 ** pointer to this structure.  The Expr.iColumn field is the index in
915 ** AggInfo.aCol[] or AggInfo.aFunc[] of information needed to generate
916 ** code for that node.
917 **
918 ** AggInfo.pGroupBy and AggInfo.aFunc.pExpr point to fields within the
919 ** original Select structure that describes the SELECT statement.  These
920 ** fields do not need to be freed when deallocating the AggInfo structure.
921 */
922 struct AggInfo {
923   u8 directMode;          /* Direct rendering mode means take data directly
924                           ** from source tables rather than from accumulators */
925   u8 useSortingIdx;       /* In direct mode, reference the sorting index rather
926                           ** than the source table */
927   int sortingIdx;         /* Cursor number of the sorting index */
928   ExprList *pGroupBy;     /* The group by clause */
929   int nSortingColumn;     /* Number of columns in the sorting index */
930   struct AggInfo_col {    /* For each column used in source tables */
931     Table *pTab;             /* Source table */
932     int iTable;              /* Cursor number of the source table */
933     int iColumn;             /* Column number within the source table */
934     int iSorterColumn;       /* Column number in the sorting index */
935     int iMem;                /* Memory location that acts as accumulator */
936     Expr *pExpr;             /* The original expression */
937   } *aCol;
938   int nColumn;            /* Number of used entries in aCol[] */
939   int nColumnAlloc;       /* Number of slots allocated for aCol[] */
940   int nAccumulator;       /* Number of columns that show through to the output.
941                           ** Additional columns are used only as parameters to
942                           ** aggregate functions */
943   struct AggInfo_func {   /* For each aggregate function */
944     Expr *pExpr;             /* Expression encoding the function */
945     FuncDef *pFunc;          /* The aggregate function implementation */
946     int iMem;                /* Memory location that acts as accumulator */
947     int iDistinct;           /* Ephermeral table used to enforce DISTINCT */
948   } *aFunc;
949   int nFunc;              /* Number of entries in aFunc[] */
950   int nFuncAlloc;         /* Number of slots allocated for aFunc[] */
951 };
952 
953 /*
954 ** Each node of an expression in the parse tree is an instance
955 ** of this structure.
956 **
957 ** Expr.op is the opcode.  The integer parser token codes are reused
958 ** as opcodes here.  For example, the parser defines TK_GE to be an integer
959 ** code representing the ">=" operator.  This same integer code is reused
960 ** to represent the greater-than-or-equal-to operator in the expression
961 ** tree.
962 **
963 ** Expr.pRight and Expr.pLeft are subexpressions.  Expr.pList is a list
964 ** of argument if the expression is a function.
965 **
966 ** Expr.token is the operator token for this node.  For some expressions
967 ** that have subexpressions, Expr.token can be the complete text that gave
968 ** rise to the Expr.  In the latter case, the token is marked as being
969 ** a compound token.
970 **
971 ** An expression of the form ID or ID.ID refers to a column in a table.
972 ** For such expressions, Expr.op is set to TK_COLUMN and Expr.iTable is
973 ** the integer cursor number of a VDBE cursor pointing to that table and
974 ** Expr.iColumn is the column number for the specific column.  If the
975 ** expression is used as a result in an aggregate SELECT, then the
976 ** value is also stored in the Expr.iAgg column in the aggregate so that
977 ** it can be accessed after all aggregates are computed.
978 **
979 ** If the expression is a function, the Expr.iTable is an integer code
980 ** representing which function.  If the expression is an unbound variable
981 ** marker (a question mark character '?' in the original SQL) then the
982 ** Expr.iTable holds the index number for that variable.
983 **
984 ** If the expression is a subquery then Expr.iColumn holds an integer
985 ** register number containing the result of the subquery.  If the
986 ** subquery gives a constant result, then iTable is -1.  If the subquery
987 ** gives a different answer at different times during statement processing
988 ** then iTable is the address of a subroutine that computes the subquery.
989 **
990 ** The Expr.pSelect field points to a SELECT statement.  The SELECT might
991 ** be the right operand of an IN operator.  Or, if a scalar SELECT appears
992 ** in an expression the opcode is TK_SELECT and Expr.pSelect is the only
993 ** operand.
994 **
995 ** If the Expr is of type OP_Column, and the table it is selecting from
996 ** is a disk table or the "old.*" pseudo-table, then pTab points to the
997 ** corresponding table definition.
998 */
999 struct Expr {
1000   u8 op;                 /* Operation performed by this node */
1001   char affinity;         /* The affinity of the column or 0 if not a column */
1002   u16 flags;             /* Various flags.  See below */
1003   CollSeq *pColl;        /* The collation type of the column or 0 */
1004   Expr *pLeft, *pRight;  /* Left and right subnodes */
1005   ExprList *pList;       /* A list of expressions used as function arguments
1006                          ** or in "<expr> IN (<expr-list)" */
1007   Token token;           /* An operand token */
1008   Token span;            /* Complete text of the expression */
1009   int iTable, iColumn;   /* When op==TK_COLUMN, then this expr node means the
1010                          ** iColumn-th field of the iTable-th table. */
1011   AggInfo *pAggInfo;     /* Used by TK_AGG_COLUMN and TK_AGG_FUNCTION */
1012   int iAgg;              /* Which entry in pAggInfo->aCol[] or ->aFunc[] */
1013   int iRightJoinTable;   /* If EP_FromJoin, the right table of the join */
1014   Select *pSelect;       /* When the expression is a sub-select.  Also the
1015                          ** right side of "<expr> IN (<select>)" */
1016   Table *pTab;           /* Table for OP_Column expressions. */
1017   Schema *pSchema;
1018 };
1019 
1020 /*
1021 ** The following are the meanings of bits in the Expr.flags field.
1022 */
1023 #define EP_FromJoin     0x01  /* Originated in ON or USING clause of a join */
1024 #define EP_Agg          0x02  /* Contains one or more aggregate functions */
1025 #define EP_Resolved     0x04  /* IDs have been resolved to COLUMNs */
1026 #define EP_Error        0x08  /* Expression contains one or more errors */
1027 #define EP_Distinct     0x10  /* Aggregate function with DISTINCT keyword */
1028 #define EP_VarSelect    0x20  /* pSelect is correlated, not constant */
1029 #define EP_Dequoted     0x40  /* True if the string has been dequoted */
1030 #define EP_InfixFunc    0x80  /* True for an infix function: LIKE, GLOB, etc */
1031 #define EP_ExpCollate  0x100  /* Collating sequence specified explicitly */
1032 
1033 /*
1034 ** These macros can be used to test, set, or clear bits in the
1035 ** Expr.flags field.
1036 */
1037 #define ExprHasProperty(E,P)     (((E)->flags&(P))==(P))
1038 #define ExprHasAnyProperty(E,P)  (((E)->flags&(P))!=0)
1039 #define ExprSetProperty(E,P)     (E)->flags|=(P)
1040 #define ExprClearProperty(E,P)   (E)->flags&=~(P)
1041 
1042 /*
1043 ** A list of expressions.  Each expression may optionally have a
1044 ** name.  An expr/name combination can be used in several ways, such
1045 ** as the list of "expr AS ID" fields following a "SELECT" or in the
1046 ** list of "ID = expr" items in an UPDATE.  A list of expressions can
1047 ** also be used as the argument to a function, in which case the a.zName
1048 ** field is not used.
1049 */
1050 struct ExprList {
1051   int nExpr;             /* Number of expressions on the list */
1052   int nAlloc;            /* Number of entries allocated below */
1053   int iECursor;          /* VDBE Cursor associated with this ExprList */
1054   struct ExprList_item {
1055     Expr *pExpr;           /* The list of expressions */
1056     char *zName;           /* Token associated with this expression */
1057     u8 sortOrder;          /* 1 for DESC or 0 for ASC */
1058     u8 isAgg;              /* True if this is an aggregate like count(*) */
1059     u8 done;               /* A flag to indicate when processing is finished */
1060   } *a;                  /* One entry for each expression */
1061 };
1062 
1063 /*
1064 ** An instance of this structure can hold a simple list of identifiers,
1065 ** such as the list "a,b,c" in the following statements:
1066 **
1067 **      INSERT INTO t(a,b,c) VALUES ...;
1068 **      CREATE INDEX idx ON t(a,b,c);
1069 **      CREATE TRIGGER trig BEFORE UPDATE ON t(a,b,c) ...;
1070 **
1071 ** The IdList.a.idx field is used when the IdList represents the list of
1072 ** column names after a table name in an INSERT statement.  In the statement
1073 **
1074 **     INSERT INTO t(a,b,c) ...
1075 **
1076 ** If "a" is the k-th column of table "t", then IdList.a[0].idx==k.
1077 */
1078 struct IdList {
1079   struct IdList_item {
1080     char *zName;      /* Name of the identifier */
1081     int idx;          /* Index in some Table.aCol[] of a column named zName */
1082   } *a;
1083   int nId;         /* Number of identifiers on the list */
1084   int nAlloc;      /* Number of entries allocated for a[] below */
1085 };
1086 
1087 /*
1088 ** The bitmask datatype defined below is used for various optimizations.
1089 **
1090 ** Changing this from a 64-bit to a 32-bit type limits the number of
1091 ** tables in a join to 32 instead of 64.  But it also reduces the size
1092 ** of the library by 738 bytes on ix86.
1093 */
1094 typedef u64 Bitmask;
1095 
1096 /*
1097 ** The following structure describes the FROM clause of a SELECT statement.
1098 ** Each table or subquery in the FROM clause is a separate element of
1099 ** the SrcList.a[] array.
1100 **
1101 ** With the addition of multiple database support, the following structure
1102 ** can also be used to describe a particular table such as the table that
1103 ** is modified by an INSERT, DELETE, or UPDATE statement.  In standard SQL,
1104 ** such a table must be a simple name: ID.  But in SQLite, the table can
1105 ** now be identified by a database name, a dot, then the table name: ID.ID.
1106 **
1107 ** The jointype starts out showing the join type between the current table
1108 ** and the next table on the list.  The parser builds the list this way.
1109 ** But sqlite3SrcListShiftJoinType() later shifts the jointypes so that each
1110 ** jointype expresses the join between the table and the previous table.
1111 */
1112 struct SrcList {
1113   i16 nSrc;        /* Number of tables or subqueries in the FROM clause */
1114   i16 nAlloc;      /* Number of entries allocated in a[] below */
1115   struct SrcList_item {
1116     char *zDatabase;  /* Name of database holding this table */
1117     char *zName;      /* Name of the table */
1118     char *zAlias;     /* The "B" part of a "A AS B" phrase.  zName is the "A" */
1119     Table *pTab;      /* An SQL table corresponding to zName */
1120     Select *pSelect;  /* A SELECT statement used in place of a table name */
1121     u8 isPopulated;   /* Temporary table associated with SELECT is populated */
1122     u8 jointype;      /* Type of join between this able and the previous */
1123     int iCursor;      /* The VDBE cursor number used to access this table */
1124     Expr *pOn;        /* The ON clause of a join */
1125     IdList *pUsing;   /* The USING clause of a join */
1126     Bitmask colUsed;  /* Bit N (1<<N) set if column N or pTab is used */
1127   } a[1];             /* One entry for each identifier on the list */
1128 };
1129 
1130 /*
1131 ** Permitted values of the SrcList.a.jointype field
1132 */
1133 #define JT_INNER     0x0001    /* Any kind of inner or cross join */
1134 #define JT_CROSS     0x0002    /* Explicit use of the CROSS keyword */
1135 #define JT_NATURAL   0x0004    /* True for a "natural" join */
1136 #define JT_LEFT      0x0008    /* Left outer join */
1137 #define JT_RIGHT     0x0010    /* Right outer join */
1138 #define JT_OUTER     0x0020    /* The "OUTER" keyword is present */
1139 #define JT_ERROR     0x0040    /* unknown or unsupported join type */
1140 
1141 /*
1142 ** For each nested loop in a WHERE clause implementation, the WhereInfo
1143 ** structure contains a single instance of this structure.  This structure
1144 ** is intended to be private the the where.c module and should not be
1145 ** access or modified by other modules.
1146 **
1147 ** The pIdxInfo and pBestIdx fields are used to help pick the best
1148 ** index on a virtual table.  The pIdxInfo pointer contains indexing
1149 ** information for the i-th table in the FROM clause before reordering.
1150 ** All the pIdxInfo pointers are freed by whereInfoFree() in where.c.
1151 ** The pBestIdx pointer is a copy of pIdxInfo for the i-th table after
1152 ** FROM clause ordering.  This is a little confusing so I will repeat
1153 ** it in different words.  WhereInfo.a[i].pIdxInfo is index information
1154 ** for WhereInfo.pTabList.a[i].  WhereInfo.a[i].pBestInfo is the
1155 ** index information for the i-th loop of the join.  pBestInfo is always
1156 ** either NULL or a copy of some pIdxInfo.  So for cleanup it is
1157 ** sufficient to free all of the pIdxInfo pointers.
1158 **
1159 */
1160 struct WhereLevel {
1161   int iFrom;            /* Which entry in the FROM clause */
1162   int flags;            /* Flags associated with this level */
1163   int iMem;             /* First memory cell used by this level */
1164   int iLeftJoin;        /* Memory cell used to implement LEFT OUTER JOIN */
1165   Index *pIdx;          /* Index used.  NULL if no index */
1166   int iTabCur;          /* The VDBE cursor used to access the table */
1167   int iIdxCur;          /* The VDBE cursor used to acesss pIdx */
1168   int brk;              /* Jump here to break out of the loop */
1169   int nxt;              /* Jump here to start the next IN combination */
1170   int cont;             /* Jump here to continue with the next loop cycle */
1171   int top;              /* First instruction of interior of the loop */
1172   int op, p1, p2;       /* Opcode used to terminate the loop */
1173   int nEq;              /* Number of == or IN constraints on this loop */
1174   int nIn;              /* Number of IN operators constraining this loop */
1175   struct InLoop {
1176     int iCur;              /* The VDBE cursor used by this IN operator */
1177     int topAddr;           /* Top of the IN loop */
1178   } *aInLoop;           /* Information about each nested IN operator */
1179   sqlite3_index_info *pBestIdx;  /* Index information for this level */
1180 
1181   /* The following field is really not part of the current level.  But
1182   ** we need a place to cache index information for each table in the
1183   ** FROM clause and the WhereLevel structure is a convenient place.
1184   */
1185   sqlite3_index_info *pIdxInfo;  /* Index info for n-th source table */
1186 };
1187 
1188 /*
1189 ** The WHERE clause processing routine has two halves.  The
1190 ** first part does the start of the WHERE loop and the second
1191 ** half does the tail of the WHERE loop.  An instance of
1192 ** this structure is returned by the first half and passed
1193 ** into the second half to give some continuity.
1194 */
1195 struct WhereInfo {
1196   Parse *pParse;
1197   SrcList *pTabList;   /* List of tables in the join */
1198   int iTop;            /* The very beginning of the WHERE loop */
1199   int iContinue;       /* Jump here to continue with next record */
1200   int iBreak;          /* Jump here to break out of the loop */
1201   int nLevel;          /* Number of nested loop */
1202   sqlite3_index_info **apInfo;  /* Array of pointers to index info structures */
1203   WhereLevel a[1];     /* Information about each nest loop in the WHERE */
1204 };
1205 
1206 /*
1207 ** A NameContext defines a context in which to resolve table and column
1208 ** names.  The context consists of a list of tables (the pSrcList) field and
1209 ** a list of named expression (pEList).  The named expression list may
1210 ** be NULL.  The pSrc corresponds to the FROM clause of a SELECT or
1211 ** to the table being operated on by INSERT, UPDATE, or DELETE.  The
1212 ** pEList corresponds to the result set of a SELECT and is NULL for
1213 ** other statements.
1214 **
1215 ** NameContexts can be nested.  When resolving names, the inner-most
1216 ** context is searched first.  If no match is found, the next outer
1217 ** context is checked.  If there is still no match, the next context
1218 ** is checked.  This process continues until either a match is found
1219 ** or all contexts are check.  When a match is found, the nRef member of
1220 ** the context containing the match is incremented.
1221 **
1222 ** Each subquery gets a new NameContext.  The pNext field points to the
1223 ** NameContext in the parent query.  Thus the process of scanning the
1224 ** NameContext list corresponds to searching through successively outer
1225 ** subqueries looking for a match.
1226 */
1227 struct NameContext {
1228   Parse *pParse;       /* The parser */
1229   SrcList *pSrcList;   /* One or more tables used to resolve names */
1230   ExprList *pEList;    /* Optional list of named expressions */
1231   int nRef;            /* Number of names resolved by this context */
1232   int nErr;            /* Number of errors encountered while resolving names */
1233   u8 allowAgg;         /* Aggregate functions allowed here */
1234   u8 hasAgg;           /* True if aggregates are seen */
1235   u8 isCheck;          /* True if resolving names in a CHECK constraint */
1236   int nDepth;          /* Depth of subquery recursion. 1 for no recursion */
1237   AggInfo *pAggInfo;   /* Information about aggregates at this level */
1238   NameContext *pNext;  /* Next outer name context.  NULL for outermost */
1239 };
1240 
1241 /*
1242 ** An instance of the following structure contains all information
1243 ** needed to generate code for a single SELECT statement.
1244 **
1245 ** nLimit is set to -1 if there is no LIMIT clause.  nOffset is set to 0.
1246 ** If there is a LIMIT clause, the parser sets nLimit to the value of the
1247 ** limit and nOffset to the value of the offset (or 0 if there is not
1248 ** offset).  But later on, nLimit and nOffset become the memory locations
1249 ** in the VDBE that record the limit and offset counters.
1250 **
1251 ** addrOpenEphm[] entries contain the address of OP_OpenEphemeral opcodes.
1252 ** These addresses must be stored so that we can go back and fill in
1253 ** the P3_KEYINFO and P2 parameters later.  Neither the KeyInfo nor
1254 ** the number of columns in P2 can be computed at the same time
1255 ** as the OP_OpenEphm instruction is coded because not
1256 ** enough information about the compound query is known at that point.
1257 ** The KeyInfo for addrOpenTran[0] and [1] contains collating sequences
1258 ** for the result set.  The KeyInfo for addrOpenTran[2] contains collating
1259 ** sequences for the ORDER BY clause.
1260 */
1261 struct Select {
1262   ExprList *pEList;      /* The fields of the result */
1263   u8 op;                 /* One of: TK_UNION TK_ALL TK_INTERSECT TK_EXCEPT */
1264   u8 isDistinct;         /* True if the DISTINCT keyword is present */
1265   u8 isResolved;         /* True once sqlite3SelectResolve() has run. */
1266   u8 isAgg;              /* True if this is an aggregate query */
1267   u8 usesEphm;           /* True if uses an OpenEphemeral opcode */
1268   u8 disallowOrderBy;    /* Do not allow an ORDER BY to be attached if TRUE */
1269   SrcList *pSrc;         /* The FROM clause */
1270   Expr *pWhere;          /* The WHERE clause */
1271   ExprList *pGroupBy;    /* The GROUP BY clause */
1272   Expr *pHaving;         /* The HAVING clause */
1273   ExprList *pOrderBy;    /* The ORDER BY clause */
1274   Select *pPrior;        /* Prior select in a compound select statement */
1275   Select *pRightmost;    /* Right-most select in a compound select statement */
1276   Expr *pLimit;          /* LIMIT expression. NULL means not used. */
1277   Expr *pOffset;         /* OFFSET expression. NULL means not used. */
1278   int iLimit, iOffset;   /* Memory registers holding LIMIT & OFFSET counters */
1279   int addrOpenEphm[3];   /* OP_OpenEphem opcodes related to this select */
1280 };
1281 
1282 /*
1283 ** The results of a select can be distributed in several ways.
1284 */
1285 #define SRT_Union        1  /* Store result as keys in an index */
1286 #define SRT_Except       2  /* Remove result from a UNION index */
1287 #define SRT_Discard      3  /* Do not save the results anywhere */
1288 
1289 /* The ORDER BY clause is ignored for all of the above */
1290 #define IgnorableOrderby(X) (X<=SRT_Discard)
1291 
1292 #define SRT_Callback     4  /* Invoke a callback with each row of result */
1293 #define SRT_Mem          5  /* Store result in a memory cell */
1294 #define SRT_Set          6  /* Store non-null results as keys in an index */
1295 #define SRT_Table        7  /* Store result as data with an automatic rowid */
1296 #define SRT_EphemTab     8  /* Create transient tab and store like SRT_Table */
1297 #define SRT_Subroutine   9  /* Call a subroutine to handle results */
1298 #define SRT_Exists      10  /* Store 1 if the result is not empty */
1299 
1300 /*
1301 ** An SQL parser context.  A copy of this structure is passed through
1302 ** the parser and down into all the parser action routine in order to
1303 ** carry around information that is global to the entire parse.
1304 **
1305 ** The structure is divided into two parts.  When the parser and code
1306 ** generate call themselves recursively, the first part of the structure
1307 ** is constant but the second part is reset at the beginning and end of
1308 ** each recursion.
1309 **
1310 ** The nTableLock and aTableLock variables are only used if the shared-cache
1311 ** feature is enabled (if sqlite3Tsd()->useSharedData is true). They are
1312 ** used to store the set of table-locks required by the statement being
1313 ** compiled. Function sqlite3TableLock() is used to add entries to the
1314 ** list.
1315 */
1316 struct Parse {
1317   sqlite3 *db;         /* The main database structure */
1318   int rc;              /* Return code from execution */
1319   char *zErrMsg;       /* An error message */
1320   Vdbe *pVdbe;         /* An engine for executing database bytecode */
1321   u8 colNamesSet;      /* TRUE after OP_ColumnName has been issued to pVdbe */
1322   u8 nameClash;        /* A permanent table name clashes with temp table name */
1323   u8 checkSchema;      /* Causes schema cookie check after an error */
1324   u8 nested;           /* Number of nested calls to the parser/code generator */
1325   u8 parseError;       /* True if a parsing error has been seen */
1326   int nErr;            /* Number of errors seen */
1327   int nTab;            /* Number of previously allocated VDBE cursors */
1328   int nMem;            /* Number of memory cells used so far */
1329   int nSet;            /* Number of sets used so far */
1330   int ckOffset;        /* Stack offset to data used by CHECK constraints */
1331   u32 writeMask;       /* Start a write transaction on these databases */
1332   u32 cookieMask;      /* Bitmask of schema verified databases */
1333   int cookieGoto;      /* Address of OP_Goto to cookie verifier subroutine */
1334   int cookieValue[MAX_ATTACHED+2];  /* Values of cookies to verify */
1335 #ifndef SQLITE_OMIT_SHARED_CACHE
1336   int nTableLock;        /* Number of locks in aTableLock */
1337   TableLock *aTableLock; /* Required table locks for shared-cache mode */
1338 #endif
1339 
1340   /* Above is constant between recursions.  Below is reset before and after
1341   ** each recursion */
1342 
1343   int nVar;            /* Number of '?' variables seen in the SQL so far */
1344   int nVarExpr;        /* Number of used slots in apVarExpr[] */
1345   int nVarExprAlloc;   /* Number of allocated slots in apVarExpr[] */
1346   Expr **apVarExpr;    /* Pointers to :aaa and $aaaa wildcard expressions */
1347   u8 explain;          /* True if the EXPLAIN flag is found on the query */
1348   Token sErrToken;     /* The token at which the error occurred */
1349   Token sNameToken;    /* Token with unqualified schema object name */
1350   Token sLastToken;    /* The last token parsed */
1351   const char *zSql;    /* All SQL text */
1352   const char *zTail;   /* All SQL text past the last semicolon parsed */
1353   Table *pNewTable;    /* A table being constructed by CREATE TABLE */
1354   Trigger *pNewTrigger;     /* Trigger under construct by a CREATE TRIGGER */
1355   TriggerStack *trigStack;  /* Trigger actions being coded */
1356   const char *zAuthContext; /* The 6th parameter to db->xAuth callbacks */
1357 #ifndef SQLITE_OMIT_VIRTUALTABLE
1358   Token sArg;                /* Complete text of a module argument */
1359   u8 declareVtab;            /* True if inside sqlite3_declare_vtab() */
1360   Table *pVirtualLock;       /* Require virtual table lock on this table */
1361 #endif
1362 };
1363 
1364 #ifdef SQLITE_OMIT_VIRTUALTABLE
1365   #define IN_DECLARE_VTAB 0
1366 #else
1367   #define IN_DECLARE_VTAB (pParse->declareVtab)
1368 #endif
1369 
1370 /*
1371 ** An instance of the following structure can be declared on a stack and used
1372 ** to save the Parse.zAuthContext value so that it can be restored later.
1373 */
1374 struct AuthContext {
1375   const char *zAuthContext;   /* Put saved Parse.zAuthContext here */
1376   Parse *pParse;              /* The Parse structure */
1377 };
1378 
1379 /*
1380 ** Bitfield flags for P2 value in OP_Insert and OP_Delete
1381 */
1382 #define OPFLAG_NCHANGE   1    /* Set to update db->nChange */
1383 #define OPFLAG_LASTROWID 2    /* Set to update db->lastRowid */
1384 #define OPFLAG_ISUPDATE  4    /* This OP_Insert is an sql UPDATE */
1385 #define OPFLAG_APPEND    8    /* This is likely to be an append */
1386 
1387 /*
1388  * Each trigger present in the database schema is stored as an instance of
1389  * struct Trigger.
1390  *
1391  * Pointers to instances of struct Trigger are stored in two ways.
1392  * 1. In the "trigHash" hash table (part of the sqlite3* that represents the
1393  *    database). This allows Trigger structures to be retrieved by name.
1394  * 2. All triggers associated with a single table form a linked list, using the
1395  *    pNext member of struct Trigger. A pointer to the first element of the
1396  *    linked list is stored as the "pTrigger" member of the associated
1397  *    struct Table.
1398  *
1399  * The "step_list" member points to the first element of a linked list
1400  * containing the SQL statements specified as the trigger program.
1401  */
1402 struct Trigger {
1403   char *name;             /* The name of the trigger                        */
1404   char *table;            /* The table or view to which the trigger applies */
1405   u8 op;                  /* One of TK_DELETE, TK_UPDATE, TK_INSERT         */
1406   u8 tr_tm;               /* One of TRIGGER_BEFORE, TRIGGER_AFTER */
1407   Expr *pWhen;            /* The WHEN clause of the expresion (may be NULL) */
1408   IdList *pColumns;       /* If this is an UPDATE OF <column-list> trigger,
1409                              the <column-list> is stored here */
1410   Token nameToken;        /* Token containing zName. Use during parsing only */
1411   Schema *pSchema;        /* Schema containing the trigger */
1412   Schema *pTabSchema;     /* Schema containing the table */
1413   TriggerStep *step_list; /* Link list of trigger program steps             */
1414   Trigger *pNext;         /* Next trigger associated with the table */
1415 };
1416 
1417 /*
1418 ** A trigger is either a BEFORE or an AFTER trigger.  The following constants
1419 ** determine which.
1420 **
1421 ** If there are multiple triggers, you might of some BEFORE and some AFTER.
1422 ** In that cases, the constants below can be ORed together.
1423 */
1424 #define TRIGGER_BEFORE  1
1425 #define TRIGGER_AFTER   2
1426 
1427 /*
1428  * An instance of struct TriggerStep is used to store a single SQL statement
1429  * that is a part of a trigger-program.
1430  *
1431  * Instances of struct TriggerStep are stored in a singly linked list (linked
1432  * using the "pNext" member) referenced by the "step_list" member of the
1433  * associated struct Trigger instance. The first element of the linked list is
1434  * the first step of the trigger-program.
1435  *
1436  * The "op" member indicates whether this is a "DELETE", "INSERT", "UPDATE" or
1437  * "SELECT" statement. The meanings of the other members is determined by the
1438  * value of "op" as follows:
1439  *
1440  * (op == TK_INSERT)
1441  * orconf    -> stores the ON CONFLICT algorithm
1442  * pSelect   -> If this is an INSERT INTO ... SELECT ... statement, then
1443  *              this stores a pointer to the SELECT statement. Otherwise NULL.
1444  * target    -> A token holding the name of the table to insert into.
1445  * pExprList -> If this is an INSERT INTO ... VALUES ... statement, then
1446  *              this stores values to be inserted. Otherwise NULL.
1447  * pIdList   -> If this is an INSERT INTO ... (<column-names>) VALUES ...
1448  *              statement, then this stores the column-names to be
1449  *              inserted into.
1450  *
1451  * (op == TK_DELETE)
1452  * target    -> A token holding the name of the table to delete from.
1453  * pWhere    -> The WHERE clause of the DELETE statement if one is specified.
1454  *              Otherwise NULL.
1455  *
1456  * (op == TK_UPDATE)
1457  * target    -> A token holding the name of the table to update rows of.
1458  * pWhere    -> The WHERE clause of the UPDATE statement if one is specified.
1459  *              Otherwise NULL.
1460  * pExprList -> A list of the columns to update and the expressions to update
1461  *              them to. See sqlite3Update() documentation of "pChanges"
1462  *              argument.
1463  *
1464  */
1465 struct TriggerStep {
1466   int op;              /* One of TK_DELETE, TK_UPDATE, TK_INSERT, TK_SELECT */
1467   int orconf;          /* OE_Rollback etc. */
1468   Trigger *pTrig;      /* The trigger that this step is a part of */
1469 
1470   Select *pSelect;     /* Valid for SELECT and sometimes
1471 			  INSERT steps (when pExprList == 0) */
1472   Token target;        /* Valid for DELETE, UPDATE, INSERT steps */
1473   Expr *pWhere;        /* Valid for DELETE, UPDATE steps */
1474   ExprList *pExprList; /* Valid for UPDATE statements and sometimes
1475 			   INSERT steps (when pSelect == 0)         */
1476   IdList *pIdList;     /* Valid for INSERT statements only */
1477   TriggerStep *pNext;  /* Next in the link-list */
1478   TriggerStep *pLast;  /* Last element in link-list. Valid for 1st elem only */
1479 };
1480 
1481 /*
1482  * An instance of struct TriggerStack stores information required during code
1483  * generation of a single trigger program. While the trigger program is being
1484  * coded, its associated TriggerStack instance is pointed to by the
1485  * "pTriggerStack" member of the Parse structure.
1486  *
1487  * The pTab member points to the table that triggers are being coded on. The
1488  * newIdx member contains the index of the vdbe cursor that points at the temp
1489  * table that stores the new.* references. If new.* references are not valid
1490  * for the trigger being coded (for example an ON DELETE trigger), then newIdx
1491  * is set to -1. The oldIdx member is analogous to newIdx, for old.* references.
1492  *
1493  * The ON CONFLICT policy to be used for the trigger program steps is stored
1494  * as the orconf member. If this is OE_Default, then the ON CONFLICT clause
1495  * specified for individual triggers steps is used.
1496  *
1497  * struct TriggerStack has a "pNext" member, to allow linked lists to be
1498  * constructed. When coding nested triggers (triggers fired by other triggers)
1499  * each nested trigger stores its parent trigger's TriggerStack as the "pNext"
1500  * pointer. Once the nested trigger has been coded, the pNext value is restored
1501  * to the pTriggerStack member of the Parse stucture and coding of the parent
1502  * trigger continues.
1503  *
1504  * Before a nested trigger is coded, the linked list pointed to by the
1505  * pTriggerStack is scanned to ensure that the trigger is not about to be coded
1506  * recursively. If this condition is detected, the nested trigger is not coded.
1507  */
1508 struct TriggerStack {
1509   Table *pTab;         /* Table that triggers are currently being coded on */
1510   int newIdx;          /* Index of vdbe cursor to "new" temp table */
1511   int oldIdx;          /* Index of vdbe cursor to "old" temp table */
1512   int orconf;          /* Current orconf policy */
1513   int ignoreJump;      /* where to jump to for a RAISE(IGNORE) */
1514   Trigger *pTrigger;   /* The trigger currently being coded */
1515   TriggerStack *pNext; /* Next trigger down on the trigger stack */
1516 };
1517 
1518 /*
1519 ** The following structure contains information used by the sqliteFix...
1520 ** routines as they walk the parse tree to make database references
1521 ** explicit.
1522 */
1523 typedef struct DbFixer DbFixer;
1524 struct DbFixer {
1525   Parse *pParse;      /* The parsing context.  Error messages written here */
1526   const char *zDb;    /* Make sure all objects are contained in this database */
1527   const char *zType;  /* Type of the container - used for error messages */
1528   const Token *pName; /* Name of the container - used for error messages */
1529 };
1530 
1531 /*
1532 ** A pointer to this structure is used to communicate information
1533 ** from sqlite3Init and OP_ParseSchema into the sqlite3InitCallback.
1534 */
1535 typedef struct {
1536   sqlite3 *db;        /* The database being initialized */
1537   int iDb;            /* 0 for main database.  1 for TEMP, 2.. for ATTACHed */
1538   char **pzErrMsg;    /* Error message stored here */
1539   int rc;             /* Result code stored here */
1540 } InitData;
1541 
1542 /*
1543  * This global flag is set for performance testing of triggers. When it is set
1544  * SQLite will perform the overhead of building new and old trigger references
1545  * even when no triggers exist
1546  */
1547 extern int sqlite3_always_code_trigger_setup;
1548 
1549 /*
1550 ** The SQLITE_CORRUPT_BKPT macro can be either a constant (for production
1551 ** builds) or a function call (for debugging).  If it is a function call,
1552 ** it allows the operator to set a breakpoint at the spot where database
1553 ** corruption is first detected.
1554 */
1555 #ifdef SQLITE_DEBUG
1556   extern int sqlite3Corrupt(void);
1557 # define SQLITE_CORRUPT_BKPT sqlite3Corrupt()
1558 #else
1559 # define SQLITE_CORRUPT_BKPT SQLITE_CORRUPT
1560 #endif
1561 
1562 /*
1563 ** Internal function prototypes
1564 */
1565 int sqlite3StrICmp(const char *, const char *);
1566 int sqlite3StrNICmp(const char *, const char *, int);
1567 int sqlite3HashNoCase(const char *, int);
1568 int sqlite3IsNumber(const char*, int*, u8);
1569 int sqlite3Compare(const char *, const char *);
1570 int sqlite3SortCompare(const char *, const char *);
1571 void sqlite3RealToSortable(double r, char *);
1572 
1573 void *sqlite3Malloc(int,int);
1574 void *sqlite3MallocRaw(int,int);
1575 void sqlite3Free(void*);
1576 void *sqlite3Realloc(void*,int);
1577 char *sqlite3StrDup(const char*);
1578 char *sqlite3StrNDup(const char*, int);
1579 # define sqlite3CheckMemory(a,b)
1580 void *sqlite3ReallocOrFree(void*,int);
1581 void sqlite3FreeX(void*);
1582 void *sqlite3MallocX(int);
1583 int sqlite3AllocSize(void *);
1584 
1585 char *sqlite3MPrintf(const char*, ...);
1586 char *sqlite3VMPrintf(const char*, va_list);
1587 void sqlite3DebugPrintf(const char*, ...);
1588 void *sqlite3TextToPtr(const char*);
1589 void sqlite3SetString(char **, ...);
1590 void sqlite3ErrorMsg(Parse*, const char*, ...);
1591 void sqlite3ErrorClear(Parse*);
1592 void sqlite3Dequote(char*);
1593 void sqlite3DequoteExpr(Expr*);
1594 int sqlite3KeywordCode(const unsigned char*, int);
1595 int sqlite3RunParser(Parse*, const char*, char **);
1596 void sqlite3FinishCoding(Parse*);
1597 Expr *sqlite3Expr(int, Expr*, Expr*, const Token*);
1598 Expr *sqlite3ExprOrFree(int, Expr*, Expr*, const Token*);
1599 Expr *sqlite3RegisterExpr(Parse*,Token*);
1600 Expr *sqlite3ExprAnd(Expr*, Expr*);
1601 void sqlite3ExprSpan(Expr*,Token*,Token*);
1602 Expr *sqlite3ExprFunction(ExprList*, Token*);
1603 void sqlite3ExprAssignVarNumber(Parse*, Expr*);
1604 void sqlite3ExprDelete(Expr*);
1605 ExprList *sqlite3ExprListAppend(ExprList*,Expr*,Token*);
1606 void sqlite3ExprListDelete(ExprList*);
1607 int sqlite3Init(sqlite3*, char**);
1608 int sqlite3InitCallback(void*, int, char**, char**);
1609 void sqlite3Pragma(Parse*,Token*,Token*,Token*,int);
1610 void sqlite3ResetInternalSchema(sqlite3*, int);
1611 void sqlite3BeginParse(Parse*,int);
1612 void sqlite3CommitInternalChanges(sqlite3*);
1613 Table *sqlite3ResultSetOfSelect(Parse*,char*,Select*);
1614 void sqlite3OpenMasterTable(Parse *, int);
1615 void sqlite3StartTable(Parse*,Token*,Token*,int,int,int,int);
1616 void sqlite3AddColumn(Parse*,Token*);
1617 void sqlite3AddNotNull(Parse*, int);
1618 void sqlite3AddPrimaryKey(Parse*, ExprList*, int, int, int);
1619 void sqlite3AddCheckConstraint(Parse*, Expr*);
1620 void sqlite3AddColumnType(Parse*,Token*);
1621 void sqlite3AddDefaultValue(Parse*,Expr*);
1622 void sqlite3AddCollateType(Parse*, const char*, int);
1623 void sqlite3EndTable(Parse*,Token*,Token*,Select*);
1624 
1625 void sqlite3CreateView(Parse*,Token*,Token*,Token*,Select*,int,int);
1626 
1627 #if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE)
1628   int sqlite3ViewGetColumnNames(Parse*,Table*);
1629 #else
1630 # define sqlite3ViewGetColumnNames(A,B) 0
1631 #endif
1632 
1633 void sqlite3DropTable(Parse*, SrcList*, int, int);
1634 void sqlite3DeleteTable(sqlite3*, Table*);
1635 void sqlite3Insert(Parse*, SrcList*, ExprList*, Select*, IdList*, int);
1636 void *sqlite3ArrayAllocate(void*,int,int,int*,int*,int*);
1637 IdList *sqlite3IdListAppend(IdList*, Token*);
1638 int sqlite3IdListIndex(IdList*,const char*);
1639 SrcList *sqlite3SrcListAppend(SrcList*, Token*, Token*);
1640 SrcList *sqlite3SrcListAppendFromTerm(SrcList*, Token*, Token*, Token*,
1641                                       Select*, Expr*, IdList*);
1642 void sqlite3SrcListShiftJoinType(SrcList*);
1643 void sqlite3SrcListAssignCursors(Parse*, SrcList*);
1644 void sqlite3IdListDelete(IdList*);
1645 void sqlite3SrcListDelete(SrcList*);
1646 void sqlite3CreateIndex(Parse*,Token*,Token*,SrcList*,ExprList*,int,Token*,
1647                         Token*, int, int);
1648 void sqlite3DropIndex(Parse*, SrcList*, int);
1649 void sqlite3AddKeyType(Vdbe*, ExprList*);
1650 void sqlite3AddIdxKeyType(Vdbe*, Index*);
1651 int sqlite3Select(Parse*, Select*, int, int, Select*, int, int*, char *aff);
1652 Select *sqlite3SelectNew(ExprList*,SrcList*,Expr*,ExprList*,Expr*,ExprList*,
1653                         int,Expr*,Expr*);
1654 void sqlite3SelectDelete(Select*);
1655 void sqlite3SelectUnbind(Select*);
1656 Table *sqlite3SrcListLookup(Parse*, SrcList*);
1657 int sqlite3IsReadOnly(Parse*, Table*, int);
1658 void sqlite3OpenTable(Parse*, int iCur, int iDb, Table*, int);
1659 void sqlite3DeleteFrom(Parse*, SrcList*, Expr*);
1660 void sqlite3Update(Parse*, SrcList*, ExprList*, Expr*, int);
1661 WhereInfo *sqlite3WhereBegin(Parse*, SrcList*, Expr*, ExprList**);
1662 void sqlite3WhereEnd(WhereInfo*);
1663 void sqlite3ExprCodeGetColumn(Vdbe*, Table*, int, int);
1664 void sqlite3ExprCode(Parse*, Expr*);
1665 void sqlite3ExprCodeAndCache(Parse*, Expr*);
1666 int sqlite3ExprCodeExprList(Parse*, ExprList*);
1667 void sqlite3ExprIfTrue(Parse*, Expr*, int, int);
1668 void sqlite3ExprIfFalse(Parse*, Expr*, int, int);
1669 void sqlite3NextedParse(Parse*, const char*, ...);
1670 Table *sqlite3FindTable(sqlite3*,const char*, const char*);
1671 Table *sqlite3LocateTable(Parse*,const char*, const char*);
1672 Index *sqlite3FindIndex(sqlite3*,const char*, const char*);
1673 void sqlite3UnlinkAndDeleteTable(sqlite3*,int,const char*);
1674 void sqlite3UnlinkAndDeleteIndex(sqlite3*,int,const char*);
1675 void sqlite3Vacuum(Parse*);
1676 int sqlite3RunVacuum(char**, sqlite3*);
1677 char *sqlite3NameFromToken(Token*);
1678 int sqlite3ExprCheck(Parse*, Expr*, int, int*);
1679 int sqlite3ExprCompare(Expr*, Expr*);
1680 int sqliteFuncId(Token*);
1681 int sqlite3ExprResolveNames(NameContext *, Expr *);
1682 int sqlite3ExprAnalyzeAggregates(NameContext*, Expr*);
1683 int sqlite3ExprAnalyzeAggList(NameContext*,ExprList*);
1684 Vdbe *sqlite3GetVdbe(Parse*);
1685 Expr *sqlite3CreateIdExpr(const char*);
1686 void sqlite3Randomness(int, void*);
1687 void sqlite3RollbackAll(sqlite3*);
1688 void sqlite3CodeVerifySchema(Parse*, int);
1689 void sqlite3BeginTransaction(Parse*, int);
1690 void sqlite3CommitTransaction(Parse*);
1691 void sqlite3RollbackTransaction(Parse*);
1692 int sqlite3ExprIsConstant(Expr*);
1693 int sqlite3ExprIsConstantOrFunction(Expr*);
1694 int sqlite3ExprIsInteger(Expr*, int*);
1695 int sqlite3IsRowid(const char*);
1696 void sqlite3GenerateRowDelete(sqlite3*, Vdbe*, Table*, int, int);
1697 void sqlite3GenerateRowIndexDelete(Vdbe*, Table*, int, char*);
1698 void sqlite3GenerateIndexKey(Vdbe*, Index*, int);
1699 void sqlite3GenerateConstraintChecks(Parse*,Table*,int,char*,int,int,int,int);
1700 void sqlite3CompleteInsertion(Parse*, Table*, int, char*, int, int, int, int);
1701 void sqlite3OpenTableAndIndices(Parse*, Table*, int, int);
1702 void sqlite3BeginWriteOperation(Parse*, int, int);
1703 Expr *sqlite3ExprDup(Expr*);
1704 void sqlite3TokenCopy(Token*, Token*);
1705 ExprList *sqlite3ExprListDup(ExprList*);
1706 SrcList *sqlite3SrcListDup(SrcList*);
1707 IdList *sqlite3IdListDup(IdList*);
1708 Select *sqlite3SelectDup(Select*);
1709 FuncDef *sqlite3FindFunction(sqlite3*,const char*,int,int,u8,int);
1710 void sqlite3RegisterBuiltinFunctions(sqlite3*);
1711 void sqlite3RegisterDateTimeFunctions(sqlite3*);
1712 int sqlite3SafetyOn(sqlite3*);
1713 int sqlite3SafetyOff(sqlite3*);
1714 int sqlite3SafetyCheck(sqlite3*);
1715 void sqlite3ChangeCookie(sqlite3*, Vdbe*, int);
1716 
1717 #ifndef SQLITE_OMIT_TRIGGER
1718   void sqlite3BeginTrigger(Parse*, Token*,Token*,int,int,IdList*,SrcList*,
1719                            Expr*,int, int);
1720   void sqlite3FinishTrigger(Parse*, TriggerStep*, Token*);
1721   void sqlite3DropTrigger(Parse*, SrcList*, int);
1722   void sqlite3DropTriggerPtr(Parse*, Trigger*);
1723   int sqlite3TriggersExist(Parse*, Table*, int, ExprList*);
1724   int sqlite3CodeRowTrigger(Parse*, int, ExprList*, int, Table *, int, int,
1725                            int, int);
1726   void sqliteViewTriggers(Parse*, Table*, Expr*, int, ExprList*);
1727   void sqlite3DeleteTriggerStep(TriggerStep*);
1728   TriggerStep *sqlite3TriggerSelectStep(Select*);
1729   TriggerStep *sqlite3TriggerInsertStep(Token*, IdList*, ExprList*,Select*,int);
1730   TriggerStep *sqlite3TriggerUpdateStep(Token*, ExprList*, Expr*, int);
1731   TriggerStep *sqlite3TriggerDeleteStep(Token*, Expr*);
1732   void sqlite3DeleteTrigger(Trigger*);
1733   void sqlite3UnlinkAndDeleteTrigger(sqlite3*,int,const char*);
1734 #else
1735 # define sqlite3TriggersExist(A,B,C,D,E,F) 0
1736 # define sqlite3DeleteTrigger(A)
1737 # define sqlite3DropTriggerPtr(A,B)
1738 # define sqlite3UnlinkAndDeleteTrigger(A,B,C)
1739 # define sqlite3CodeRowTrigger(A,B,C,D,E,F,G,H,I) 0
1740 #endif
1741 
1742 int sqlite3JoinType(Parse*, Token*, Token*, Token*);
1743 void sqlite3CreateForeignKey(Parse*, ExprList*, Token*, ExprList*, int);
1744 void sqlite3DeferForeignKey(Parse*, int);
1745 #ifndef SQLITE_OMIT_AUTHORIZATION
1746   void sqlite3AuthRead(Parse*,Expr*,SrcList*);
1747   int sqlite3AuthCheck(Parse*,int, const char*, const char*, const char*);
1748   void sqlite3AuthContextPush(Parse*, AuthContext*, const char*);
1749   void sqlite3AuthContextPop(AuthContext*);
1750 #else
1751 # define sqlite3AuthRead(a,b,c)
1752 # define sqlite3AuthCheck(a,b,c,d,e)    SQLITE_OK
1753 # define sqlite3AuthContextPush(a,b,c)
1754 # define sqlite3AuthContextPop(a)  ((void)(a))
1755 #endif
1756 void sqlite3Attach(Parse*, Expr*, Expr*, Expr*);
1757 void sqlite3Detach(Parse*, Expr*);
1758 int sqlite3BtreeFactory(const sqlite3 *db, const char *zFilename,
1759                        int omitJournal, int nCache, Btree **ppBtree);
1760 int sqlite3FixInit(DbFixer*, Parse*, int, const char*, const Token*);
1761 int sqlite3FixSrcList(DbFixer*, SrcList*);
1762 int sqlite3FixSelect(DbFixer*, Select*);
1763 int sqlite3FixExpr(DbFixer*, Expr*);
1764 int sqlite3FixExprList(DbFixer*, ExprList*);
1765 int sqlite3FixTriggerStep(DbFixer*, TriggerStep*);
1766 int sqlite3AtoF(const char *z, double*);
1767 char *sqlite3_snprintf(int,char*,const char*,...);
1768 int sqlite3GetInt32(const char *, int*);
1769 int sqlite3FitsIn64Bits(const char *);
1770 int sqlite3utf16ByteLen(const void *pData, int nChar);
1771 int sqlite3utf8CharLen(const char *pData, int nByte);
1772 int sqlite3ReadUtf8(const unsigned char *);
1773 int sqlite3PutVarint(unsigned char *, u64);
1774 int sqlite3GetVarint(const unsigned char *, u64 *);
1775 int sqlite3GetVarint32(const unsigned char *, u32 *);
1776 int sqlite3VarintLen(u64 v);
1777 void sqlite3IndexAffinityStr(Vdbe *, Index *);
1778 void sqlite3TableAffinityStr(Vdbe *, Table *);
1779 char sqlite3CompareAffinity(Expr *pExpr, char aff2);
1780 int sqlite3IndexAffinityOk(Expr *pExpr, char idx_affinity);
1781 char sqlite3ExprAffinity(Expr *pExpr);
1782 int sqlite3atoi64(const char*, i64*);
1783 void sqlite3Error(sqlite3*, int, const char*,...);
1784 void *sqlite3HexToBlob(const char *z);
1785 int sqlite3TwoPartName(Parse *, Token *, Token *, Token **);
1786 const char *sqlite3ErrStr(int);
1787 int sqlite3ReadUniChar(const char *zStr, int *pOffset, u8 *pEnc, int fold);
1788 int sqlite3ReadSchema(Parse *pParse);
1789 CollSeq *sqlite3FindCollSeq(sqlite3*,u8 enc, const char *,int,int);
1790 CollSeq *sqlite3LocateCollSeq(Parse *pParse, const char *zName, int nName);
1791 CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr);
1792 Expr *sqlite3ExprSetColl(Parse *pParse, Expr *, Token *);
1793 int sqlite3CheckCollSeq(Parse *, CollSeq *);
1794 int sqlite3CheckIndexCollSeq(Parse *, Index *);
1795 int sqlite3CheckObjectName(Parse *, const char *);
1796 void sqlite3VdbeSetChanges(sqlite3 *, int);
1797 void sqlite3utf16Substr(sqlite3_context *,int,sqlite3_value **);
1798 
1799 const void *sqlite3ValueText(sqlite3_value*, u8);
1800 int sqlite3ValueBytes(sqlite3_value*, u8);
1801 void sqlite3ValueSetStr(sqlite3_value*, int, const void *,u8, void(*)(void*));
1802 void sqlite3ValueFree(sqlite3_value*);
1803 sqlite3_value *sqlite3ValueNew(void);
1804 char *sqlite3utf16to8(const void*, int);
1805 int sqlite3ValueFromExpr(Expr *, u8, u8, sqlite3_value **);
1806 void sqlite3ValueApplyAffinity(sqlite3_value *, u8, u8);
1807 extern const unsigned char sqlite3UpperToLower[];
1808 void sqlite3RootPageMoved(Db*, int, int);
1809 void sqlite3Reindex(Parse*, Token*, Token*);
1810 void sqlite3AlterFunctions(sqlite3*);
1811 void sqlite3AlterRenameTable(Parse*, SrcList*, Token*);
1812 int sqlite3GetToken(const unsigned char *, int *);
1813 void sqlite3NestedParse(Parse*, const char*, ...);
1814 void sqlite3ExpirePreparedStatements(sqlite3*);
1815 void sqlite3CodeSubselect(Parse *, Expr *);
1816 int sqlite3SelectResolve(Parse *, Select *, NameContext *);
1817 void sqlite3ColumnDefault(Vdbe *, Table *, int);
1818 void sqlite3AlterFinishAddColumn(Parse *, Token *);
1819 void sqlite3AlterBeginAddColumn(Parse *, SrcList *);
1820 const char *sqlite3TestErrorName(int);
1821 CollSeq *sqlite3GetCollSeq(sqlite3*, CollSeq *, const char *, int);
1822 char sqlite3AffinityType(const Token*);
1823 void sqlite3Analyze(Parse*, Token*, Token*);
1824 int sqlite3InvokeBusyHandler(BusyHandler*);
1825 int sqlite3FindDb(sqlite3*, Token*);
1826 void sqlite3AnalysisLoad(sqlite3*,int iDB);
1827 void sqlite3DefaultRowEst(Index*);
1828 void sqlite3RegisterLikeFunctions(sqlite3*, int);
1829 int sqlite3IsLikeFunction(sqlite3*,Expr*,int*,char*);
1830 ThreadData *sqlite3ThreadData(void);
1831 const ThreadData *sqlite3ThreadDataReadOnly(void);
1832 void sqlite3ReleaseThreadData(void);
1833 void sqlite3AttachFunctions(sqlite3 *);
1834 void sqlite3MinimumFileFormat(Parse*, int, int);
1835 void sqlite3SchemaFree(void *);
1836 Schema *sqlite3SchemaGet(Btree *);
1837 int sqlite3SchemaToIndex(sqlite3 *db, Schema *);
1838 KeyInfo *sqlite3IndexKeyinfo(Parse *, Index *);
1839 int sqlite3CreateFunc(sqlite3 *, const char *, int, int, void *,
1840   void (*)(sqlite3_context*,int,sqlite3_value **),
1841   void (*)(sqlite3_context*,int,sqlite3_value **), void (*)(sqlite3_context*));
1842 int sqlite3ApiExit(sqlite3 *db, int);
1843 int sqlite3MallocFailed(void);
1844 void sqlite3FailedMalloc(void);
1845 void sqlite3AbortOtherActiveVdbes(sqlite3 *, Vdbe *);
1846 int sqlite3OpenTempDatabase(Parse *);
1847 
1848 #ifndef SQLITE_OMIT_LOAD_EXTENSION
1849   void sqlite3CloseExtensions(sqlite3*);
1850   int sqlite3AutoLoadExtensions(sqlite3*);
1851 #else
1852 # define sqlite3CloseExtensions(X)
1853 # define sqlite3AutoLoadExtensions(X)  SQLITE_OK
1854 #endif
1855 
1856 #ifndef SQLITE_OMIT_SHARED_CACHE
1857   void sqlite3TableLock(Parse *, int, int, u8, const char *);
1858 #else
1859   #define sqlite3TableLock(v,w,x,y,z)
1860 #endif
1861 
1862 #ifdef SQLITE_MEMDEBUG
1863   void sqlite3MallocDisallow(void);
1864   void sqlite3MallocAllow(void);
1865   int sqlite3TestMallocFail(void);
1866 #else
1867   #define sqlite3TestMallocFail() 0
1868   #define sqlite3MallocDisallow()
1869   #define sqlite3MallocAllow()
1870 #endif
1871 
1872 #ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
1873   void *sqlite3ThreadSafeMalloc(int);
1874   void sqlite3ThreadSafeFree(void *);
1875 #else
1876   #define sqlite3ThreadSafeMalloc sqlite3MallocX
1877   #define sqlite3ThreadSafeFree sqlite3FreeX
1878 #endif
1879 
1880 #ifdef SQLITE_OMIT_VIRTUALTABLE
1881 #  define sqlite3VtabClear(X)
1882 #  define sqlite3VtabSync(X,Y) (Y)
1883 #  define sqlite3VtabRollback(X)
1884 #  define sqlite3VtabCommit(X)
1885 #else
1886    void sqlite3VtabClear(Table*);
1887    int sqlite3VtabSync(sqlite3 *db, int rc);
1888    int sqlite3VtabRollback(sqlite3 *db);
1889    int sqlite3VtabCommit(sqlite3 *db);
1890 #endif
1891 void sqlite3VtabLock(sqlite3_vtab*);
1892 void sqlite3VtabUnlock(sqlite3_vtab*);
1893 void sqlite3VtabBeginParse(Parse*, Token*, Token*, Token*);
1894 void sqlite3VtabFinishParse(Parse*, Token*);
1895 void sqlite3VtabArgInit(Parse*);
1896 void sqlite3VtabArgExtend(Parse*, Token*);
1897 int sqlite3VtabCallCreate(sqlite3*, int, const char *, char **);
1898 int sqlite3VtabCallConnect(Parse*, Table*);
1899 int sqlite3VtabCallDestroy(sqlite3*, int, const char *);
1900 int sqlite3VtabBegin(sqlite3 *, sqlite3_vtab *);
1901 FuncDef *sqlite3VtabOverloadFunction(FuncDef*, int nArg, Expr*);
1902 void sqlite3InvalidFunction(sqlite3_context*,int,sqlite3_value**);
1903 int sqlite3Reprepare(Vdbe*);
1904 
1905 #ifdef SQLITE_SSE
1906 #include "sseInt.h"
1907 #endif
1908 
1909 /*
1910 ** If the SQLITE_ENABLE IOTRACE exists then the global variable
1911 ** sqlite3_io_trace is a pointer to a printf-like routine used to
1912 ** print I/O tracing messages.
1913 */
1914 #ifdef SQLITE_ENABLE_IOTRACE
1915 # define IOTRACE(A)  if( sqlite3_io_trace ){ sqlite3_io_trace A; }
1916   void sqlite3VdbeIOTraceSql(Vdbe*);
1917 #else
1918 # define IOTRACE(A)
1919 # define sqlite3VdbeIOTraceSql(X)
1920 #endif
1921 extern void (*sqlite3_io_trace)(const char*,...);
1922 
1923 #endif
1924