xref: /sqlite-3.40.0/src/sqliteInt.h (revision 961303c1)
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 1.608 2007/09/03 15:19:35 drh Exp $
15 */
16 #ifndef _SQLITEINT_H_
17 #define _SQLITEINT_H_
18 #include "sqliteLimit.h"
19 
20 /*
21 ** For testing purposes, the various size limit constants are really
22 ** variables that we can modify in the testfixture.
23 */
24 #ifdef SQLITE_TEST
25   #undef SQLITE_MAX_LENGTH
26   #undef SQLITE_MAX_COLUMN
27   #undef SQLITE_MAX_SQL_LENGTH
28   #undef SQLITE_MAX_EXPR_DEPTH
29   #undef SQLITE_MAX_COMPOUND_SELECT
30   #undef SQLITE_MAX_VDBE_OP
31   #undef SQLITE_MAX_FUNCTION_ARG
32   #undef SQLITE_MAX_VARIABLE_NUMBER
33   #undef SQLITE_MAX_PAGE_SIZE
34   #undef SQLITE_MAX_PAGE_COUNT
35   #undef SQLITE_MAX_LIKE_PATTERN_LENGTH
36 
37   #define SQLITE_MAX_LENGTH              sqlite3MAX_LENGTH
38   #define SQLITE_MAX_COLUMN              sqlite3MAX_COLUMN
39   #define SQLITE_MAX_SQL_LENGTH          sqlite3MAX_SQL_LENGTH
40   #define SQLITE_MAX_EXPR_DEPTH          sqlite3MAX_EXPR_DEPTH
41   #define SQLITE_MAX_COMPOUND_SELECT     sqlite3MAX_COMPOUND_SELECT
42   #define SQLITE_MAX_VDBE_OP             sqlite3MAX_VDBE_OP
43   #define SQLITE_MAX_FUNCTION_ARG        sqlite3MAX_FUNCTION_ARG
44   #define SQLITE_MAX_VARIABLE_NUMBER     sqlite3MAX_VARIABLE_NUMBER
45   #define SQLITE_MAX_PAGE_SIZE           sqlite3MAX_PAGE_SIZE
46   #define SQLITE_MAX_PAGE_COUNT          sqlite3MAX_PAGE_COUNT
47   #define SQLITE_MAX_LIKE_PATTERN_LENGTH sqlite3MAX_LIKE_PATTERN_LENGTH
48 
49   extern int sqlite3MAX_LENGTH;
50   extern int sqlite3MAX_COLUMN;
51   extern int sqlite3MAX_SQL_LENGTH;
52   extern int sqlite3MAX_EXPR_DEPTH;
53   extern int sqlite3MAX_COMPOUND_SELECT;
54   extern int sqlite3MAX_VDBE_OP;
55   extern int sqlite3MAX_FUNCTION_ARG;
56   extern int sqlite3MAX_VARIABLE_NUMBER;
57   extern int sqlite3MAX_PAGE_SIZE;
58   extern int sqlite3MAX_PAGE_COUNT;
59   extern int sqlite3MAX_LIKE_PATTERN_LENGTH;
60 #endif
61 
62 #define _XOPEN_SOURCE 500  /* Needed to enable pthread recursive mutexes */
63 
64 #if defined(SQLITE_TCL) || defined(TCLSH)
65 # include <tcl.h>
66 #endif
67 
68 /*
69 ** Many people are failing to set -DNDEBUG=1 when compiling SQLite.
70 ** Setting NDEBUG makes the code smaller and run faster.  So the following
71 ** lines are added to automatically set NDEBUG unless the -DSQLITE_DEBUG=1
72 ** option is set.  Thus NDEBUG becomes an opt-in rather than an opt-out
73 ** feature.
74 */
75 #if !defined(NDEBUG) && !defined(SQLITE_DEBUG)
76 # define NDEBUG 1
77 #endif
78 
79 /*
80 ** The SQLITE_THREADSAFE macro must be defined as either 0 or 1.
81 ** Older versions of SQLite used an optional THREADSAFE macro.
82 ** We support that for legacy
83 */
84 #if !defined(SQLITE_THREADSAFE)
85 #if defined(THREADSAFE)
86 # define SQLITE_THREADSAFE THREADSAFE
87 #else
88 # define SQLITE_THREADSAFE 1
89 #endif
90 #endif
91 
92 /*
93 ** These #defines should enable >2GB file support on Posix if the
94 ** underlying operating system supports it.  If the OS lacks
95 ** large file support, or if the OS is windows, these should be no-ops.
96 **
97 ** Large file support can be disabled using the -DSQLITE_DISABLE_LFS switch
98 ** on the compiler command line.  This is necessary if you are compiling
99 ** on a recent machine (ex: RedHat 7.2) but you want your code to work
100 ** on an older machine (ex: RedHat 6.0).  If you compile on RedHat 7.2
101 ** without this option, LFS is enable.  But LFS does not exist in the kernel
102 ** in RedHat 6.0, so the code won't work.  Hence, for maximum binary
103 ** portability you should omit LFS.
104 **
105 ** Similar is true for MacOS.  LFS is only supported on MacOS 9 and later.
106 */
107 #ifndef SQLITE_DISABLE_LFS
108 # define _LARGE_FILE       1
109 # ifndef _FILE_OFFSET_BITS
110 #   define _FILE_OFFSET_BITS 64
111 # endif
112 # define _LARGEFILE_SOURCE 1
113 #endif
114 
115 #include "sqlite3.h"
116 #include "hash.h"
117 #include "parse.h"
118 #include <stdio.h>
119 #include <stdlib.h>
120 #include <string.h>
121 #include <assert.h>
122 #include <stddef.h>
123 
124 #define sqlite3_isnan(X)  ((X)!=(X))
125 
126 /*
127 ** If compiling for a processor that lacks floating point support,
128 ** substitute integer for floating-point
129 */
130 #ifdef SQLITE_OMIT_FLOATING_POINT
131 # define double sqlite_int64
132 # define LONGDOUBLE_TYPE sqlite_int64
133 # ifndef SQLITE_BIG_DBL
134 #   define SQLITE_BIG_DBL (0x7fffffffffffffff)
135 # endif
136 # define SQLITE_OMIT_DATETIME_FUNCS 1
137 # define SQLITE_OMIT_TRACE 1
138 # undef SQLITE_MIXED_ENDIAN_64BIT_FLOAT
139 #endif
140 #ifndef SQLITE_BIG_DBL
141 # define SQLITE_BIG_DBL (1e99)
142 #endif
143 
144 /*
145 ** OMIT_TEMPDB is set to 1 if SQLITE_OMIT_TEMPDB is defined, or 0
146 ** afterward. Having this macro allows us to cause the C compiler
147 ** to omit code used by TEMP tables without messy #ifndef statements.
148 */
149 #ifdef SQLITE_OMIT_TEMPDB
150 #define OMIT_TEMPDB 1
151 #else
152 #define OMIT_TEMPDB 0
153 #endif
154 
155 /*
156 ** If the following macro is set to 1, then NULL values are considered
157 ** distinct when determining whether or not two entries are the same
158 ** in a UNIQUE index.  This is the way PostgreSQL, Oracle, DB2, MySQL,
159 ** OCELOT, and Firebird all work.  The SQL92 spec explicitly says this
160 ** is the way things are suppose to work.
161 **
162 ** If the following macro is set to 0, the NULLs are indistinct for
163 ** a UNIQUE index.  In this mode, you can only have a single NULL entry
164 ** for a column declared UNIQUE.  This is the way Informix and SQL Server
165 ** work.
166 */
167 #define NULL_DISTINCT_FOR_UNIQUE 1
168 
169 /*
170 ** The "file format" number is an integer that is incremented whenever
171 ** the VDBE-level file format changes.  The following macros define the
172 ** the default file format for new databases and the maximum file format
173 ** that the library can read.
174 */
175 #define SQLITE_MAX_FILE_FORMAT 4
176 #ifndef SQLITE_DEFAULT_FILE_FORMAT
177 # define SQLITE_DEFAULT_FILE_FORMAT 1
178 #endif
179 
180 /*
181 ** Provide a default value for TEMP_STORE in case it is not specified
182 ** on the command-line
183 */
184 #ifndef TEMP_STORE
185 # define TEMP_STORE 1
186 #endif
187 
188 /*
189 ** GCC does not define the offsetof() macro so we'll have to do it
190 ** ourselves.
191 */
192 #ifndef offsetof
193 #define offsetof(STRUCTURE,FIELD) ((int)((char*)&((STRUCTURE*)0)->FIELD))
194 #endif
195 
196 /*
197 ** Check to see if this machine uses EBCDIC.  (Yes, believe it or
198 ** not, there are still machines out there that use EBCDIC.)
199 */
200 #if 'A' == '\301'
201 # define SQLITE_EBCDIC 1
202 #else
203 # define SQLITE_ASCII 1
204 #endif
205 
206 /*
207 ** Integers of known sizes.  These typedefs might change for architectures
208 ** where the sizes very.  Preprocessor macros are available so that the
209 ** types can be conveniently redefined at compile-type.  Like this:
210 **
211 **         cc '-DUINTPTR_TYPE=long long int' ...
212 */
213 #ifndef UINT32_TYPE
214 # define UINT32_TYPE unsigned int
215 #endif
216 #ifndef UINT16_TYPE
217 # define UINT16_TYPE unsigned short int
218 #endif
219 #ifndef INT16_TYPE
220 # define INT16_TYPE short int
221 #endif
222 #ifndef UINT8_TYPE
223 # define UINT8_TYPE unsigned char
224 #endif
225 #ifndef INT8_TYPE
226 # define INT8_TYPE signed char
227 #endif
228 #ifndef LONGDOUBLE_TYPE
229 # define LONGDOUBLE_TYPE long double
230 #endif
231 typedef sqlite_int64 i64;          /* 8-byte signed integer */
232 typedef sqlite_uint64 u64;         /* 8-byte unsigned integer */
233 typedef UINT32_TYPE u32;           /* 4-byte unsigned integer */
234 typedef UINT16_TYPE u16;           /* 2-byte unsigned integer */
235 typedef INT16_TYPE i16;            /* 2-byte signed integer */
236 typedef UINT8_TYPE u8;             /* 1-byte unsigned integer */
237 typedef UINT8_TYPE i8;             /* 1-byte signed integer */
238 
239 /*
240 ** Macros to determine whether the machine is big or little endian,
241 ** evaluated at runtime.
242 */
243 #ifdef SQLITE_AMALGAMATION
244 const int sqlite3One;
245 #else
246 extern const int sqlite3one;
247 #endif
248 #if defined(i386) || defined(__i386__) || defined(_M_IX86)
249 # define SQLITE_BIGENDIAN    0
250 # define SQLITE_LITTLEENDIAN 1
251 # define SQLITE_UTF16NATIVE  SQLITE_UTF16LE
252 #else
253 # define SQLITE_BIGENDIAN    (*(char *)(&sqlite3one)==0)
254 # define SQLITE_LITTLEENDIAN (*(char *)(&sqlite3one)==1)
255 # define SQLITE_UTF16NATIVE (SQLITE_BIGENDIAN?SQLITE_UTF16BE:SQLITE_UTF16LE)
256 #endif
257 
258 /*
259 ** An instance of the following structure is used to store the busy-handler
260 ** callback for a given sqlite handle.
261 **
262 ** The sqlite.busyHandler member of the sqlite struct contains the busy
263 ** callback for the database handle. Each pager opened via the sqlite
264 ** handle is passed a pointer to sqlite.busyHandler. The busy-handler
265 ** callback is currently invoked only from within pager.c.
266 */
267 typedef struct BusyHandler BusyHandler;
268 struct BusyHandler {
269   int (*xFunc)(void *,int);  /* The busy callback */
270   void *pArg;                /* First arg to busy callback */
271   int nBusy;                 /* Incremented with each busy call */
272 };
273 
274 /*
275 ** Defer sourcing vdbe.h and btree.h until after the "u8" and
276 ** "BusyHandler typedefs.
277 */
278 #include "btree.h"
279 #include "vdbe.h"
280 #include "pager.h"
281 
282 
283 /*
284 ** Name of the master database table.  The master database table
285 ** is a special table that holds the names and attributes of all
286 ** user tables and indices.
287 */
288 #define MASTER_NAME       "sqlite_master"
289 #define TEMP_MASTER_NAME  "sqlite_temp_master"
290 
291 /*
292 ** The root-page of the master database table.
293 */
294 #define MASTER_ROOT       1
295 
296 /*
297 ** The name of the schema table.
298 */
299 #define SCHEMA_TABLE(x)  ((!OMIT_TEMPDB)&&(x==1)?TEMP_MASTER_NAME:MASTER_NAME)
300 
301 /*
302 ** A convenience macro that returns the number of elements in
303 ** an array.
304 */
305 #define ArraySize(X)    (sizeof(X)/sizeof(X[0]))
306 
307 /*
308 ** Forward references to structures
309 */
310 typedef struct AggInfo AggInfo;
311 typedef struct AuthContext AuthContext;
312 typedef struct CollSeq CollSeq;
313 typedef struct Column Column;
314 typedef struct Db Db;
315 typedef struct Schema Schema;
316 typedef struct Expr Expr;
317 typedef struct ExprList ExprList;
318 typedef struct FKey FKey;
319 typedef struct FuncDef FuncDef;
320 typedef struct IdList IdList;
321 typedef struct Index Index;
322 typedef struct KeyClass KeyClass;
323 typedef struct KeyInfo KeyInfo;
324 typedef struct Module Module;
325 typedef struct NameContext NameContext;
326 typedef struct Parse Parse;
327 typedef struct Select Select;
328 typedef struct SrcList SrcList;
329 typedef struct Table Table;
330 typedef struct TableLock TableLock;
331 typedef struct Token Token;
332 typedef struct TriggerStack TriggerStack;
333 typedef struct TriggerStep TriggerStep;
334 typedef struct Trigger Trigger;
335 typedef struct WhereInfo WhereInfo;
336 typedef struct WhereLevel WhereLevel;
337 
338 #include "os.h"
339 #include "mutex.h"
340 
341 /*
342 ** Each database file to be accessed by the system is an instance
343 ** of the following structure.  There are normally two of these structures
344 ** in the sqlite.aDb[] array.  aDb[0] is the main database file and
345 ** aDb[1] is the database file used to hold temporary tables.  Additional
346 ** databases may be attached.
347 */
348 struct Db {
349   char *zName;         /* Name of this database */
350   Btree *pBt;          /* The B*Tree structure for this database file */
351   u8 inTrans;          /* 0: not writable.  1: Transaction.  2: Checkpoint */
352   u8 safety_level;     /* How aggressive at synching data to disk */
353   void *pAux;               /* Auxiliary data.  Usually NULL */
354   void (*xFreeAux)(void*);  /* Routine to free pAux */
355   Schema *pSchema;     /* Pointer to database schema (possibly shared) */
356 };
357 
358 /*
359 ** An instance of the following structure stores a database schema.
360 **
361 ** If there are no virtual tables configured in this schema, the
362 ** Schema.db variable is set to NULL. After the first virtual table
363 ** has been added, it is set to point to the database connection
364 ** used to create the connection. Once a virtual table has been
365 ** added to the Schema structure and the Schema.db variable populated,
366 ** only that database connection may use the Schema to prepare
367 ** statements.
368 */
369 struct Schema {
370   int schema_cookie;   /* Database schema version number for this file */
371   Hash tblHash;        /* All tables indexed by name */
372   Hash idxHash;        /* All (named) indices indexed by name */
373   Hash trigHash;       /* All triggers indexed by name */
374   Hash aFKey;          /* Foreign keys indexed by to-table */
375   Table *pSeqTab;      /* The sqlite_sequence table used by AUTOINCREMENT */
376   u8 file_format;      /* Schema format version for this file */
377   u8 enc;              /* Text encoding used by this database */
378   u16 flags;           /* Flags associated with this schema */
379   int cache_size;      /* Number of pages to use in the cache */
380 #ifndef SQLITE_OMIT_VIRTUALTABLE
381   sqlite3 *db;         /* "Owner" connection. See comment above */
382 #endif
383 };
384 
385 /*
386 ** These macros can be used to test, set, or clear bits in the
387 ** Db.flags field.
388 */
389 #define DbHasProperty(D,I,P)     (((D)->aDb[I].pSchema->flags&(P))==(P))
390 #define DbHasAnyProperty(D,I,P)  (((D)->aDb[I].pSchema->flags&(P))!=0)
391 #define DbSetProperty(D,I,P)     (D)->aDb[I].pSchema->flags|=(P)
392 #define DbClearProperty(D,I,P)   (D)->aDb[I].pSchema->flags&=~(P)
393 
394 /*
395 ** Allowed values for the DB.flags field.
396 **
397 ** The DB_SchemaLoaded flag is set after the database schema has been
398 ** read into internal hash tables.
399 **
400 ** DB_UnresetViews means that one or more views have column names that
401 ** have been filled out.  If the schema changes, these column names might
402 ** changes and so the view will need to be reset.
403 */
404 #define DB_SchemaLoaded    0x0001  /* The schema has been loaded */
405 #define DB_UnresetViews    0x0002  /* Some views have defined column names */
406 #define DB_Empty           0x0004  /* The file is empty (length 0 bytes) */
407 
408 
409 /*
410 ** Each database is an instance of the following structure.
411 **
412 ** The sqlite.lastRowid records the last insert rowid generated by an
413 ** insert statement.  Inserts on views do not affect its value.  Each
414 ** trigger has its own context, so that lastRowid can be updated inside
415 ** triggers as usual.  The previous value will be restored once the trigger
416 ** exits.  Upon entering a before or instead of trigger, lastRowid is no
417 ** longer (since after version 2.8.12) reset to -1.
418 **
419 ** The sqlite.nChange does not count changes within triggers and keeps no
420 ** context.  It is reset at start of sqlite3_exec.
421 ** The sqlite.lsChange represents the number of changes made by the last
422 ** insert, update, or delete statement.  It remains constant throughout the
423 ** length of a statement and is then updated by OP_SetCounts.  It keeps a
424 ** context stack just like lastRowid so that the count of changes
425 ** within a trigger is not seen outside the trigger.  Changes to views do not
426 ** affect the value of lsChange.
427 ** The sqlite.csChange keeps track of the number of current changes (since
428 ** the last statement) and is used to update sqlite_lsChange.
429 **
430 ** The member variables sqlite.errCode, sqlite.zErrMsg and sqlite.zErrMsg16
431 ** store the most recent error code and, if applicable, string. The
432 ** internal function sqlite3Error() is used to set these variables
433 ** consistently.
434 */
435 struct sqlite3 {
436   sqlite3_vfs *pVfs;            /* OS Interface */
437   int nDb;                      /* Number of backends currently in use */
438   Db *aDb;                      /* All backends */
439   int flags;                    /* Miscellanous flags. See below */
440   int openFlags;                /* Flags passed to sqlite3_vfs.xOpen() */
441   int errCode;                  /* Most recent error code (SQLITE_*) */
442   int errMask;                  /* & result codes with this before returning */
443   u8 autoCommit;                /* The auto-commit flag. */
444   u8 temp_store;                /* 1: file 2: memory 0: default */
445   u8 mallocFailed;              /* True if we have seen a malloc failure */
446   int nTable;                   /* Number of tables in the database */
447   CollSeq *pDfltColl;           /* The default collating sequence (BINARY) */
448   i64 lastRowid;                /* ROWID of most recent insert (see above) */
449   i64 priorNewRowid;            /* Last randomly generated ROWID */
450   int magic;                    /* Magic number for detect library misuse */
451   int nChange;                  /* Value returned by sqlite3_changes() */
452   int nTotalChange;             /* Value returned by sqlite3_total_changes() */
453   sqlite3_mutex *mutex;         /* Connection mutex */
454   struct sqlite3InitInfo {      /* Information used during initialization */
455     int iDb;                    /* When back is being initialized */
456     int newTnum;                /* Rootpage of table being initialized */
457     u8 busy;                    /* TRUE if currently initializing */
458   } init;
459   int nExtension;               /* Number of loaded extensions */
460   void **aExtension;            /* Array of shared libraray handles */
461   struct Vdbe *pVdbe;           /* List of active virtual machines */
462   int activeVdbeCnt;            /* Number of vdbes currently executing */
463   void (*xTrace)(void*,const char*);        /* Trace function */
464   void *pTraceArg;                          /* Argument to the trace function */
465   void (*xProfile)(void*,const char*,u64);  /* Profiling function */
466   void *pProfileArg;                        /* Argument to profile function */
467   void *pCommitArg;                 /* Argument to xCommitCallback() */
468   int (*xCommitCallback)(void*);    /* Invoked at every commit. */
469   void *pRollbackArg;               /* Argument to xRollbackCallback() */
470   void (*xRollbackCallback)(void*); /* Invoked at every commit. */
471   void *pUpdateArg;
472   void (*xUpdateCallback)(void*,int, const char*,const char*,sqlite_int64);
473   void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*);
474   void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*);
475   void *pCollNeededArg;
476   sqlite3_value *pErr;          /* Most recent error message */
477   char *zErrMsg;                /* Most recent error message (UTF-8 encoded) */
478   char *zErrMsg16;              /* Most recent error message (UTF-16 encoded) */
479   union {
480     int isInterrupted;          /* True if sqlite3_interrupt has been called */
481     double notUsed1;            /* Spacer */
482   } u1;
483 #ifndef SQLITE_OMIT_AUTHORIZATION
484   int (*xAuth)(void*,int,const char*,const char*,const char*,const char*);
485                                 /* Access authorization function */
486   void *pAuthArg;               /* 1st argument to the access auth function */
487 #endif
488 #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
489   int (*xProgress)(void *);     /* The progress callback */
490   void *pProgressArg;           /* Argument to the progress callback */
491   int nProgressOps;             /* Number of opcodes for progress callback */
492 #endif
493 #ifndef SQLITE_OMIT_VIRTUALTABLE
494   Hash aModule;                 /* populated by sqlite3_create_module() */
495   Table *pVTab;                 /* vtab with active Connect/Create method */
496   sqlite3_vtab **aVTrans;       /* Virtual tables with open transactions */
497   int nVTrans;                  /* Allocated size of aVTrans */
498 #endif
499   Hash aFunc;                   /* All functions that can be in SQL exprs */
500   Hash aCollSeq;                /* All collating sequences */
501   BusyHandler busyHandler;      /* Busy callback */
502   int busyTimeout;              /* Busy handler timeout, in msec */
503   Db aDbStatic[2];              /* Static space for the 2 default backends */
504 #ifdef SQLITE_SSE
505   sqlite3_stmt *pFetch;         /* Used by SSE to fetch stored statements */
506 #endif
507   u8 dfltLockMode;              /* Default locking-mode for attached dbs */
508 };
509 
510 /*
511 ** A macro to discover the encoding of a database.
512 */
513 #define ENC(db) ((db)->aDb[0].pSchema->enc)
514 
515 /*
516 ** Possible values for the sqlite.flags and or Db.flags fields.
517 **
518 ** On sqlite.flags, the SQLITE_InTrans value means that we have
519 ** executed a BEGIN.  On Db.flags, SQLITE_InTrans means a statement
520 ** transaction is active on that particular database file.
521 */
522 #define SQLITE_VdbeTrace      0x00000001  /* True to trace VDBE execution */
523 #define SQLITE_InTrans        0x00000008  /* True if in a transaction */
524 #define SQLITE_InternChanges  0x00000010  /* Uncommitted Hash table changes */
525 #define SQLITE_FullColNames   0x00000020  /* Show full column names on SELECT */
526 #define SQLITE_ShortColNames  0x00000040  /* Show short columns names */
527 #define SQLITE_CountRows      0x00000080  /* Count rows changed by INSERT, */
528                                           /*   DELETE, or UPDATE and return */
529                                           /*   the count using a callback. */
530 #define SQLITE_NullCallback   0x00000100  /* Invoke the callback once if the */
531                                           /*   result set is empty */
532 #define SQLITE_SqlTrace       0x00000200  /* Debug print SQL as it executes */
533 #define SQLITE_VdbeListing    0x00000400  /* Debug listings of VDBE programs */
534 #define SQLITE_WriteSchema    0x00000800  /* OK to update SQLITE_MASTER */
535 #define SQLITE_NoReadlock     0x00001000  /* Readlocks are omitted when
536                                           ** accessing read-only databases */
537 #define SQLITE_IgnoreChecks   0x00002000  /* Do not enforce check constraints */
538 #define SQLITE_ReadUncommitted 0x00004000 /* For shared-cache mode */
539 #define SQLITE_LegacyFileFmt  0x00008000  /* Create new databases in format 1 */
540 #define SQLITE_FullFSync      0x00010000  /* Use full fsync on the backend */
541 #define SQLITE_LoadExtension  0x00020000  /* Enable load_extension */
542 
543 #define SQLITE_RecoveryMode   0x00040000  /* Ignore schema errors */
544 #define SQLITE_SharedCache    0x00080000  /* Cache sharing is enabled */
545 #define SQLITE_Vtab           0x00100000  /* There exists a virtual table */
546 
547 /*
548 ** Possible values for the sqlite.magic field.
549 ** The numbers are obtained at random and have no special meaning, other
550 ** than being distinct from one another.
551 */
552 #define SQLITE_MAGIC_OPEN     0xa029a697  /* Database is open */
553 #define SQLITE_MAGIC_CLOSED   0x9f3c2d33  /* Database is closed */
554 #define SQLITE_MAGIC_BUSY     0xf03b7906  /* Database currently in use */
555 #define SQLITE_MAGIC_ERROR    0xb5357930  /* An SQLITE_MISUSE error occurred */
556 
557 /*
558 ** Each SQL function is defined by an instance of the following
559 ** structure.  A pointer to this structure is stored in the sqlite.aFunc
560 ** hash table.  When multiple functions have the same name, the hash table
561 ** points to a linked list of these structures.
562 */
563 struct FuncDef {
564   i16 nArg;            /* Number of arguments.  -1 means unlimited */
565   u8 iPrefEnc;         /* Preferred text encoding (SQLITE_UTF8, 16LE, 16BE) */
566   u8 needCollSeq;      /* True if sqlite3GetFuncCollSeq() might be called */
567   u8 flags;            /* Some combination of SQLITE_FUNC_* */
568   void *pUserData;     /* User data parameter */
569   FuncDef *pNext;      /* Next function with same name */
570   void (*xFunc)(sqlite3_context*,int,sqlite3_value**); /* Regular function */
571   void (*xStep)(sqlite3_context*,int,sqlite3_value**); /* Aggregate step */
572   void (*xFinalize)(sqlite3_context*);                /* Aggregate finializer */
573   char zName[1];       /* SQL name of the function.  MUST BE LAST */
574 };
575 
576 /*
577 ** Each SQLite module (virtual table definition) is defined by an
578 ** instance of the following structure, stored in the sqlite3.aModule
579 ** hash table.
580 */
581 struct Module {
582   const sqlite3_module *pModule;       /* Callback pointers */
583   const char *zName;                   /* Name passed to create_module() */
584   void *pAux;                          /* pAux passed to create_module() */
585   void (*xDestroy)(void *);            /* Module destructor function */
586 };
587 
588 /*
589 ** Possible values for FuncDef.flags
590 */
591 #define SQLITE_FUNC_LIKE   0x01  /* Candidate for the LIKE optimization */
592 #define SQLITE_FUNC_CASE   0x02  /* Case-sensitive LIKE-type function */
593 #define SQLITE_FUNC_EPHEM  0x04  /* Ephermeral.  Delete with VDBE */
594 
595 /*
596 ** information about each column of an SQL table is held in an instance
597 ** of this structure.
598 */
599 struct Column {
600   char *zName;     /* Name of this column */
601   Expr *pDflt;     /* Default value of this column */
602   char *zType;     /* Data type for this column */
603   char *zColl;     /* Collating sequence.  If NULL, use the default */
604   u8 notNull;      /* True if there is a NOT NULL constraint */
605   u8 isPrimKey;    /* True if this column is part of the PRIMARY KEY */
606   char affinity;   /* One of the SQLITE_AFF_... values */
607 #ifndef SQLITE_OMIT_VIRTUALTABLE
608   u8 isHidden;     /* True if this column is 'hidden' */
609 #endif
610 };
611 
612 /*
613 ** A "Collating Sequence" is defined by an instance of the following
614 ** structure. Conceptually, a collating sequence consists of a name and
615 ** a comparison routine that defines the order of that sequence.
616 **
617 ** There may two seperate implementations of the collation function, one
618 ** that processes text in UTF-8 encoding (CollSeq.xCmp) and another that
619 ** processes text encoded in UTF-16 (CollSeq.xCmp16), using the machine
620 ** native byte order. When a collation sequence is invoked, SQLite selects
621 ** the version that will require the least expensive encoding
622 ** translations, if any.
623 **
624 ** The CollSeq.pUser member variable is an extra parameter that passed in
625 ** as the first argument to the UTF-8 comparison function, xCmp.
626 ** CollSeq.pUser16 is the equivalent for the UTF-16 comparison function,
627 ** xCmp16.
628 **
629 ** If both CollSeq.xCmp and CollSeq.xCmp16 are NULL, it means that the
630 ** collating sequence is undefined.  Indices built on an undefined
631 ** collating sequence may not be read or written.
632 */
633 struct CollSeq {
634   char *zName;          /* Name of the collating sequence, UTF-8 encoded */
635   u8 enc;               /* Text encoding handled by xCmp() */
636   u8 type;              /* One of the SQLITE_COLL_... values below */
637   void *pUser;          /* First argument to xCmp() */
638   int (*xCmp)(void*,int, const void*, int, const void*);
639   void (*xDel)(void*);  /* Destructor for pUser */
640 };
641 
642 /*
643 ** Allowed values of CollSeq flags:
644 */
645 #define SQLITE_COLL_BINARY  1  /* The default memcmp() collating sequence */
646 #define SQLITE_COLL_NOCASE  2  /* The built-in NOCASE collating sequence */
647 #define SQLITE_COLL_REVERSE 3  /* The built-in REVERSE collating sequence */
648 #define SQLITE_COLL_USER    0  /* Any other user-defined collating sequence */
649 
650 /*
651 ** A sort order can be either ASC or DESC.
652 */
653 #define SQLITE_SO_ASC       0  /* Sort in ascending order */
654 #define SQLITE_SO_DESC      1  /* Sort in ascending order */
655 
656 /*
657 ** Column affinity types.
658 **
659 ** These used to have mnemonic name like 'i' for SQLITE_AFF_INTEGER and
660 ** 't' for SQLITE_AFF_TEXT.  But we can save a little space and improve
661 ** the speed a little by number the values consecutively.
662 **
663 ** But rather than start with 0 or 1, we begin with 'a'.  That way,
664 ** when multiple affinity types are concatenated into a string and
665 ** used as the P3 operand, they will be more readable.
666 **
667 ** Note also that the numeric types are grouped together so that testing
668 ** for a numeric type is a single comparison.
669 */
670 #define SQLITE_AFF_TEXT     'a'
671 #define SQLITE_AFF_NONE     'b'
672 #define SQLITE_AFF_NUMERIC  'c'
673 #define SQLITE_AFF_INTEGER  'd'
674 #define SQLITE_AFF_REAL     'e'
675 
676 #define sqlite3IsNumericAffinity(X)  ((X)>=SQLITE_AFF_NUMERIC)
677 
678 /*
679 ** Each SQL table is represented in memory by an instance of the
680 ** following structure.
681 **
682 ** Table.zName is the name of the table.  The case of the original
683 ** CREATE TABLE statement is stored, but case is not significant for
684 ** comparisons.
685 **
686 ** Table.nCol is the number of columns in this table.  Table.aCol is a
687 ** pointer to an array of Column structures, one for each column.
688 **
689 ** If the table has an INTEGER PRIMARY KEY, then Table.iPKey is the index of
690 ** the column that is that key.   Otherwise Table.iPKey is negative.  Note
691 ** that the datatype of the PRIMARY KEY must be INTEGER for this field to
692 ** be set.  An INTEGER PRIMARY KEY is used as the rowid for each row of
693 ** the table.  If a table has no INTEGER PRIMARY KEY, then a random rowid
694 ** is generated for each row of the table.  Table.hasPrimKey is true if
695 ** the table has any PRIMARY KEY, INTEGER or otherwise.
696 **
697 ** Table.tnum is the page number for the root BTree page of the table in the
698 ** database file.  If Table.iDb is the index of the database table backend
699 ** in sqlite.aDb[].  0 is for the main database and 1 is for the file that
700 ** holds temporary tables and indices.  If Table.isEphem
701 ** is true, then the table is stored in a file that is automatically deleted
702 ** when the VDBE cursor to the table is closed.  In this case Table.tnum
703 ** refers VDBE cursor number that holds the table open, not to the root
704 ** page number.  Transient tables are used to hold the results of a
705 ** sub-query that appears instead of a real table name in the FROM clause
706 ** of a SELECT statement.
707 */
708 struct Table {
709   char *zName;     /* Name of the table */
710   int nCol;        /* Number of columns in this table */
711   Column *aCol;    /* Information about each column */
712   int iPKey;       /* If not less then 0, use aCol[iPKey] as the primary key */
713   Index *pIndex;   /* List of SQL indexes on this table. */
714   int tnum;        /* Root BTree node for this table (see note above) */
715   Select *pSelect; /* NULL for tables.  Points to definition if a view. */
716   int nRef;          /* Number of pointers to this Table */
717   Trigger *pTrigger; /* List of SQL triggers on this table */
718   FKey *pFKey;       /* Linked list of all foreign keys in this table */
719   char *zColAff;     /* String defining the affinity of each column */
720 #ifndef SQLITE_OMIT_CHECK
721   Expr *pCheck;      /* The AND of all CHECK constraints */
722 #endif
723 #ifndef SQLITE_OMIT_ALTERTABLE
724   int addColOffset;  /* Offset in CREATE TABLE statement to add a new column */
725 #endif
726   u8 readOnly;     /* True if this table should not be written by the user */
727   u8 isEphem;      /* True if created using OP_OpenEphermeral */
728   u8 hasPrimKey;   /* True if there exists a primary key */
729   u8 keyConf;      /* What to do in case of uniqueness conflict on iPKey */
730   u8 autoInc;      /* True if the integer primary key is autoincrement */
731 #ifndef SQLITE_OMIT_VIRTUALTABLE
732   u8 isVirtual;             /* True if this is a virtual table */
733   u8 isCommit;              /* True once the CREATE TABLE has been committed */
734   Module *pMod;             /* Pointer to the implementation of the module */
735   sqlite3_vtab *pVtab;      /* Pointer to the module instance */
736   int nModuleArg;           /* Number of arguments to the module */
737   char **azModuleArg;       /* Text of all module args. [0] is module name */
738 #endif
739   Schema *pSchema;
740 };
741 
742 /*
743 ** Test to see whether or not a table is a virtual table.  This is
744 ** done as a macro so that it will be optimized out when virtual
745 ** table support is omitted from the build.
746 */
747 #ifndef SQLITE_OMIT_VIRTUALTABLE
748 #  define IsVirtual(X)      ((X)->isVirtual)
749 #  define IsHiddenColumn(X) ((X)->isHidden)
750 #else
751 #  define IsVirtual(X)      0
752 #  define IsHiddenColumn(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   sqlite3 *db;        /* The database connection */
847   u8 enc;             /* Text encoding - one of the TEXT_Utf* values */
848   u8 incrKey;         /* Increase 2nd key by epsilon before comparison */
849   int nField;         /* Number of entries in aColl[] */
850   u8 *aSortOrder;     /* If defined an aSortOrder[i] is true, sort DESC */
851   CollSeq *aColl[1];  /* Collating sequence for each term of the key */
852 };
853 
854 /*
855 ** Each SQL index is represented in memory by an
856 ** instance of the following structure.
857 **
858 ** The columns of the table that are to be indexed are described
859 ** by the aiColumn[] field of this structure.  For example, suppose
860 ** we have the following table and index:
861 **
862 **     CREATE TABLE Ex1(c1 int, c2 int, c3 text);
863 **     CREATE INDEX Ex2 ON Ex1(c3,c1);
864 **
865 ** In the Table structure describing Ex1, nCol==3 because there are
866 ** three columns in the table.  In the Index structure describing
867 ** Ex2, nColumn==2 since 2 of the 3 columns of Ex1 are indexed.
868 ** The value of aiColumn is {2, 0}.  aiColumn[0]==2 because the
869 ** first column to be indexed (c3) has an index of 2 in Ex1.aCol[].
870 ** The second column to be indexed (c1) has an index of 0 in
871 ** Ex1.aCol[], hence Ex2.aiColumn[1]==0.
872 **
873 ** The Index.onError field determines whether or not the indexed columns
874 ** must be unique and what to do if they are not.  When Index.onError=OE_None,
875 ** it means this is not a unique index.  Otherwise it is a unique index
876 ** and the value of Index.onError indicate the which conflict resolution
877 ** algorithm to employ whenever an attempt is made to insert a non-unique
878 ** element.
879 */
880 struct Index {
881   char *zName;     /* Name of this index */
882   int nColumn;     /* Number of columns in the table used by this index */
883   int *aiColumn;   /* Which columns are used by this index.  1st is 0 */
884   unsigned *aiRowEst; /* Result of ANALYZE: Est. rows selected by each column */
885   Table *pTable;   /* The SQL table being indexed */
886   int tnum;        /* Page containing root of this index in database file */
887   u8 onError;      /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
888   u8 autoIndex;    /* True if is automatically created (ex: by UNIQUE) */
889   char *zColAff;   /* String defining the affinity of each column */
890   Index *pNext;    /* The next index associated with the same table */
891   Schema *pSchema; /* Schema containing this index */
892   u8 *aSortOrder;  /* Array of size Index.nColumn. True==DESC, False==ASC */
893   char **azColl;   /* Array of collation sequence names for index */
894 };
895 
896 /*
897 ** Each token coming out of the lexer is an instance of
898 ** this structure.  Tokens are also used as part of an expression.
899 **
900 ** Note if Token.z==0 then Token.dyn and Token.n are undefined and
901 ** may contain random values.  Do not make any assuptions about Token.dyn
902 ** and Token.n when Token.z==0.
903 */
904 struct Token {
905   const unsigned char *z; /* Text of the token.  Not NULL-terminated! */
906   unsigned dyn  : 1;      /* True for malloced memory, false for static */
907   unsigned n    : 31;     /* Number of characters in this token */
908 };
909 
910 /*
911 ** An instance of this structure contains information needed to generate
912 ** code for a SELECT that contains aggregate functions.
913 **
914 ** If Expr.op==TK_AGG_COLUMN or TK_AGG_FUNCTION then Expr.pAggInfo is a
915 ** pointer to this structure.  The Expr.iColumn field is the index in
916 ** AggInfo.aCol[] or AggInfo.aFunc[] of information needed to generate
917 ** code for that node.
918 **
919 ** AggInfo.pGroupBy and AggInfo.aFunc.pExpr point to fields within the
920 ** original Select structure that describes the SELECT statement.  These
921 ** fields do not need to be freed when deallocating the AggInfo structure.
922 */
923 struct AggInfo {
924   u8 directMode;          /* Direct rendering mode means take data directly
925                           ** from source tables rather than from accumulators */
926   u8 useSortingIdx;       /* In direct mode, reference the sorting index rather
927                           ** than the source table */
928   int sortingIdx;         /* Cursor number of the sorting index */
929   ExprList *pGroupBy;     /* The group by clause */
930   int nSortingColumn;     /* Number of columns in the sorting index */
931   struct AggInfo_col {    /* For each column used in source tables */
932     Table *pTab;             /* Source table */
933     int iTable;              /* Cursor number of the source table */
934     int iColumn;             /* Column number within the source table */
935     int iSorterColumn;       /* Column number in the sorting index */
936     int iMem;                /* Memory location that acts as accumulator */
937     Expr *pExpr;             /* The original expression */
938   } *aCol;
939   int nColumn;            /* Number of used entries in aCol[] */
940   int nColumnAlloc;       /* Number of slots allocated for aCol[] */
941   int nAccumulator;       /* Number of columns that show through to the output.
942                           ** Additional columns are used only as parameters to
943                           ** aggregate functions */
944   struct AggInfo_func {   /* For each aggregate function */
945     Expr *pExpr;             /* Expression encoding the function */
946     FuncDef *pFunc;          /* The aggregate function implementation */
947     int iMem;                /* Memory location that acts as accumulator */
948     int iDistinct;           /* Ephermeral table used to enforce DISTINCT */
949   } *aFunc;
950   int nFunc;              /* Number of entries in aFunc[] */
951   int nFuncAlloc;         /* Number of slots allocated for aFunc[] */
952 };
953 
954 /*
955 ** Each node of an expression in the parse tree is an instance
956 ** of this structure.
957 **
958 ** Expr.op is the opcode.  The integer parser token codes are reused
959 ** as opcodes here.  For example, the parser defines TK_GE to be an integer
960 ** code representing the ">=" operator.  This same integer code is reused
961 ** to represent the greater-than-or-equal-to operator in the expression
962 ** tree.
963 **
964 ** Expr.pRight and Expr.pLeft are subexpressions.  Expr.pList is a list
965 ** of argument if the expression is a function.
966 **
967 ** Expr.token is the operator token for this node.  For some expressions
968 ** that have subexpressions, Expr.token can be the complete text that gave
969 ** rise to the Expr.  In the latter case, the token is marked as being
970 ** a compound token.
971 **
972 ** An expression of the form ID or ID.ID refers to a column in a table.
973 ** For such expressions, Expr.op is set to TK_COLUMN and Expr.iTable is
974 ** the integer cursor number of a VDBE cursor pointing to that table and
975 ** Expr.iColumn is the column number for the specific column.  If the
976 ** expression is used as a result in an aggregate SELECT, then the
977 ** value is also stored in the Expr.iAgg column in the aggregate so that
978 ** it can be accessed after all aggregates are computed.
979 **
980 ** If the expression is a function, the Expr.iTable is an integer code
981 ** representing which function.  If the expression is an unbound variable
982 ** marker (a question mark character '?' in the original SQL) then the
983 ** Expr.iTable holds the index number for that variable.
984 **
985 ** If the expression is a subquery then Expr.iColumn holds an integer
986 ** register number containing the result of the subquery.  If the
987 ** subquery gives a constant result, then iTable is -1.  If the subquery
988 ** gives a different answer at different times during statement processing
989 ** then iTable is the address of a subroutine that computes the subquery.
990 **
991 ** The Expr.pSelect field points to a SELECT statement.  The SELECT might
992 ** be the right operand of an IN operator.  Or, if a scalar SELECT appears
993 ** in an expression the opcode is TK_SELECT and Expr.pSelect is the only
994 ** operand.
995 **
996 ** If the Expr is of type OP_Column, and the table it is selecting from
997 ** is a disk table or the "old.*" pseudo-table, then pTab points to the
998 ** corresponding table definition.
999 */
1000 struct Expr {
1001   u8 op;                 /* Operation performed by this node */
1002   char affinity;         /* The affinity of the column or 0 if not a column */
1003   u16 flags;             /* Various flags.  See below */
1004   CollSeq *pColl;        /* The collation type of the column or 0 */
1005   Expr *pLeft, *pRight;  /* Left and right subnodes */
1006   ExprList *pList;       /* A list of expressions used as function arguments
1007                          ** or in "<expr> IN (<expr-list)" */
1008   Token token;           /* An operand token */
1009   Token span;            /* Complete text of the expression */
1010   int iTable, iColumn;   /* When op==TK_COLUMN, then this expr node means the
1011                          ** iColumn-th field of the iTable-th table. */
1012   AggInfo *pAggInfo;     /* Used by TK_AGG_COLUMN and TK_AGG_FUNCTION */
1013   int iAgg;              /* Which entry in pAggInfo->aCol[] or ->aFunc[] */
1014   int iRightJoinTable;   /* If EP_FromJoin, the right table of the join */
1015   Select *pSelect;       /* When the expression is a sub-select.  Also the
1016                          ** right side of "<expr> IN (<select>)" */
1017   Table *pTab;           /* Table for OP_Column expressions. */
1018   Schema *pSchema;
1019 #if defined(SQLITE_TEST) || SQLITE_MAX_EXPR_DEPTH>0
1020   int nHeight;           /* Height of the tree headed by this node */
1021 #endif
1022 };
1023 
1024 /*
1025 ** The following are the meanings of bits in the Expr.flags field.
1026 */
1027 #define EP_FromJoin     0x01  /* Originated in ON or USING clause of a join */
1028 #define EP_Agg          0x02  /* Contains one or more aggregate functions */
1029 #define EP_Resolved     0x04  /* IDs have been resolved to COLUMNs */
1030 #define EP_Error        0x08  /* Expression contains one or more errors */
1031 #define EP_Distinct     0x10  /* Aggregate function with DISTINCT keyword */
1032 #define EP_VarSelect    0x20  /* pSelect is correlated, not constant */
1033 #define EP_Dequoted     0x40  /* True if the string has been dequoted */
1034 #define EP_InfixFunc    0x80  /* True for an infix function: LIKE, GLOB, etc */
1035 #define EP_ExpCollate  0x100  /* Collating sequence specified explicitly */
1036 
1037 /*
1038 ** These macros can be used to test, set, or clear bits in the
1039 ** Expr.flags field.
1040 */
1041 #define ExprHasProperty(E,P)     (((E)->flags&(P))==(P))
1042 #define ExprHasAnyProperty(E,P)  (((E)->flags&(P))!=0)
1043 #define ExprSetProperty(E,P)     (E)->flags|=(P)
1044 #define ExprClearProperty(E,P)   (E)->flags&=~(P)
1045 
1046 /*
1047 ** A list of expressions.  Each expression may optionally have a
1048 ** name.  An expr/name combination can be used in several ways, such
1049 ** as the list of "expr AS ID" fields following a "SELECT" or in the
1050 ** list of "ID = expr" items in an UPDATE.  A list of expressions can
1051 ** also be used as the argument to a function, in which case the a.zName
1052 ** field is not used.
1053 */
1054 struct ExprList {
1055   int nExpr;             /* Number of expressions on the list */
1056   int nAlloc;            /* Number of entries allocated below */
1057   int iECursor;          /* VDBE Cursor associated with this ExprList */
1058   struct ExprList_item {
1059     Expr *pExpr;           /* The list of expressions */
1060     char *zName;           /* Token associated with this expression */
1061     u8 sortOrder;          /* 1 for DESC or 0 for ASC */
1062     u8 isAgg;              /* True if this is an aggregate like count(*) */
1063     u8 done;               /* A flag to indicate when processing is finished */
1064   } *a;                  /* One entry for each expression */
1065 };
1066 
1067 /*
1068 ** An instance of this structure can hold a simple list of identifiers,
1069 ** such as the list "a,b,c" in the following statements:
1070 **
1071 **      INSERT INTO t(a,b,c) VALUES ...;
1072 **      CREATE INDEX idx ON t(a,b,c);
1073 **      CREATE TRIGGER trig BEFORE UPDATE ON t(a,b,c) ...;
1074 **
1075 ** The IdList.a.idx field is used when the IdList represents the list of
1076 ** column names after a table name in an INSERT statement.  In the statement
1077 **
1078 **     INSERT INTO t(a,b,c) ...
1079 **
1080 ** If "a" is the k-th column of table "t", then IdList.a[0].idx==k.
1081 */
1082 struct IdList {
1083   struct IdList_item {
1084     char *zName;      /* Name of the identifier */
1085     int idx;          /* Index in some Table.aCol[] of a column named zName */
1086   } *a;
1087   int nId;         /* Number of identifiers on the list */
1088   int nAlloc;      /* Number of entries allocated for a[] below */
1089 };
1090 
1091 /*
1092 ** The bitmask datatype defined below is used for various optimizations.
1093 **
1094 ** Changing this from a 64-bit to a 32-bit type limits the number of
1095 ** tables in a join to 32 instead of 64.  But it also reduces the size
1096 ** of the library by 738 bytes on ix86.
1097 */
1098 typedef u64 Bitmask;
1099 
1100 /*
1101 ** The following structure describes the FROM clause of a SELECT statement.
1102 ** Each table or subquery in the FROM clause is a separate element of
1103 ** the SrcList.a[] array.
1104 **
1105 ** With the addition of multiple database support, the following structure
1106 ** can also be used to describe a particular table such as the table that
1107 ** is modified by an INSERT, DELETE, or UPDATE statement.  In standard SQL,
1108 ** such a table must be a simple name: ID.  But in SQLite, the table can
1109 ** now be identified by a database name, a dot, then the table name: ID.ID.
1110 **
1111 ** The jointype starts out showing the join type between the current table
1112 ** and the next table on the list.  The parser builds the list this way.
1113 ** But sqlite3SrcListShiftJoinType() later shifts the jointypes so that each
1114 ** jointype expresses the join between the table and the previous table.
1115 */
1116 struct SrcList {
1117   i16 nSrc;        /* Number of tables or subqueries in the FROM clause */
1118   i16 nAlloc;      /* Number of entries allocated in a[] below */
1119   struct SrcList_item {
1120     char *zDatabase;  /* Name of database holding this table */
1121     char *zName;      /* Name of the table */
1122     char *zAlias;     /* The "B" part of a "A AS B" phrase.  zName is the "A" */
1123     Table *pTab;      /* An SQL table corresponding to zName */
1124     Select *pSelect;  /* A SELECT statement used in place of a table name */
1125     u8 isPopulated;   /* Temporary table associated with SELECT is populated */
1126     u8 jointype;      /* Type of join between this able and the previous */
1127     int iCursor;      /* The VDBE cursor number used to access this table */
1128     Expr *pOn;        /* The ON clause of a join */
1129     IdList *pUsing;   /* The USING clause of a join */
1130     Bitmask colUsed;  /* Bit N (1<<N) set if column N or pTab is used */
1131   } a[1];             /* One entry for each identifier on the list */
1132 };
1133 
1134 /*
1135 ** Permitted values of the SrcList.a.jointype field
1136 */
1137 #define JT_INNER     0x0001    /* Any kind of inner or cross join */
1138 #define JT_CROSS     0x0002    /* Explicit use of the CROSS keyword */
1139 #define JT_NATURAL   0x0004    /* True for a "natural" join */
1140 #define JT_LEFT      0x0008    /* Left outer join */
1141 #define JT_RIGHT     0x0010    /* Right outer join */
1142 #define JT_OUTER     0x0020    /* The "OUTER" keyword is present */
1143 #define JT_ERROR     0x0040    /* unknown or unsupported join type */
1144 
1145 /*
1146 ** For each nested loop in a WHERE clause implementation, the WhereInfo
1147 ** structure contains a single instance of this structure.  This structure
1148 ** is intended to be private the the where.c module and should not be
1149 ** access or modified by other modules.
1150 **
1151 ** The pIdxInfo and pBestIdx fields are used to help pick the best
1152 ** index on a virtual table.  The pIdxInfo pointer contains indexing
1153 ** information for the i-th table in the FROM clause before reordering.
1154 ** All the pIdxInfo pointers are freed by whereInfoFree() in where.c.
1155 ** The pBestIdx pointer is a copy of pIdxInfo for the i-th table after
1156 ** FROM clause ordering.  This is a little confusing so I will repeat
1157 ** it in different words.  WhereInfo.a[i].pIdxInfo is index information
1158 ** for WhereInfo.pTabList.a[i].  WhereInfo.a[i].pBestInfo is the
1159 ** index information for the i-th loop of the join.  pBestInfo is always
1160 ** either NULL or a copy of some pIdxInfo.  So for cleanup it is
1161 ** sufficient to free all of the pIdxInfo pointers.
1162 **
1163 */
1164 struct WhereLevel {
1165   int iFrom;            /* Which entry in the FROM clause */
1166   int flags;            /* Flags associated with this level */
1167   int iMem;             /* First memory cell used by this level */
1168   int iLeftJoin;        /* Memory cell used to implement LEFT OUTER JOIN */
1169   Index *pIdx;          /* Index used.  NULL if no index */
1170   int iTabCur;          /* The VDBE cursor used to access the table */
1171   int iIdxCur;          /* The VDBE cursor used to acesss pIdx */
1172   int brk;              /* Jump here to break out of the loop */
1173   int nxt;              /* Jump here to start the next IN combination */
1174   int cont;             /* Jump here to continue with the next loop cycle */
1175   int top;              /* First instruction of interior of the loop */
1176   int op, p1, p2;       /* Opcode used to terminate the loop */
1177   int nEq;              /* Number of == or IN constraints on this loop */
1178   int nIn;              /* Number of IN operators constraining this loop */
1179   struct InLoop {
1180     int iCur;              /* The VDBE cursor used by this IN operator */
1181     int topAddr;           /* Top of the IN loop */
1182   } *aInLoop;           /* Information about each nested IN operator */
1183   sqlite3_index_info *pBestIdx;  /* Index information for this level */
1184 
1185   /* The following field is really not part of the current level.  But
1186   ** we need a place to cache index information for each table in the
1187   ** FROM clause and the WhereLevel structure is a convenient place.
1188   */
1189   sqlite3_index_info *pIdxInfo;  /* Index info for n-th source table */
1190 };
1191 
1192 /*
1193 ** The WHERE clause processing routine has two halves.  The
1194 ** first part does the start of the WHERE loop and the second
1195 ** half does the tail of the WHERE loop.  An instance of
1196 ** this structure is returned by the first half and passed
1197 ** into the second half to give some continuity.
1198 */
1199 struct WhereInfo {
1200   Parse *pParse;
1201   SrcList *pTabList;   /* List of tables in the join */
1202   int iTop;            /* The very beginning of the WHERE loop */
1203   int iContinue;       /* Jump here to continue with next record */
1204   int iBreak;          /* Jump here to break out of the loop */
1205   int nLevel;          /* Number of nested loop */
1206   sqlite3_index_info **apInfo;  /* Array of pointers to index info structures */
1207   WhereLevel a[1];     /* Information about each nest loop in the WHERE */
1208 };
1209 
1210 /*
1211 ** A NameContext defines a context in which to resolve table and column
1212 ** names.  The context consists of a list of tables (the pSrcList) field and
1213 ** a list of named expression (pEList).  The named expression list may
1214 ** be NULL.  The pSrc corresponds to the FROM clause of a SELECT or
1215 ** to the table being operated on by INSERT, UPDATE, or DELETE.  The
1216 ** pEList corresponds to the result set of a SELECT and is NULL for
1217 ** other statements.
1218 **
1219 ** NameContexts can be nested.  When resolving names, the inner-most
1220 ** context is searched first.  If no match is found, the next outer
1221 ** context is checked.  If there is still no match, the next context
1222 ** is checked.  This process continues until either a match is found
1223 ** or all contexts are check.  When a match is found, the nRef member of
1224 ** the context containing the match is incremented.
1225 **
1226 ** Each subquery gets a new NameContext.  The pNext field points to the
1227 ** NameContext in the parent query.  Thus the process of scanning the
1228 ** NameContext list corresponds to searching through successively outer
1229 ** subqueries looking for a match.
1230 */
1231 struct NameContext {
1232   Parse *pParse;       /* The parser */
1233   SrcList *pSrcList;   /* One or more tables used to resolve names */
1234   ExprList *pEList;    /* Optional list of named expressions */
1235   int nRef;            /* Number of names resolved by this context */
1236   int nErr;            /* Number of errors encountered while resolving names */
1237   u8 allowAgg;         /* Aggregate functions allowed here */
1238   u8 hasAgg;           /* True if aggregates are seen */
1239   u8 isCheck;          /* True if resolving names in a CHECK constraint */
1240   int nDepth;          /* Depth of subquery recursion. 1 for no recursion */
1241   AggInfo *pAggInfo;   /* Information about aggregates at this level */
1242   NameContext *pNext;  /* Next outer name context.  NULL for outermost */
1243 };
1244 
1245 /*
1246 ** An instance of the following structure contains all information
1247 ** needed to generate code for a single SELECT statement.
1248 **
1249 ** nLimit is set to -1 if there is no LIMIT clause.  nOffset is set to 0.
1250 ** If there is a LIMIT clause, the parser sets nLimit to the value of the
1251 ** limit and nOffset to the value of the offset (or 0 if there is not
1252 ** offset).  But later on, nLimit and nOffset become the memory locations
1253 ** in the VDBE that record the limit and offset counters.
1254 **
1255 ** addrOpenEphm[] entries contain the address of OP_OpenEphemeral opcodes.
1256 ** These addresses must be stored so that we can go back and fill in
1257 ** the P3_KEYINFO and P2 parameters later.  Neither the KeyInfo nor
1258 ** the number of columns in P2 can be computed at the same time
1259 ** as the OP_OpenEphm instruction is coded because not
1260 ** enough information about the compound query is known at that point.
1261 ** The KeyInfo for addrOpenTran[0] and [1] contains collating sequences
1262 ** for the result set.  The KeyInfo for addrOpenTran[2] contains collating
1263 ** sequences for the ORDER BY clause.
1264 */
1265 struct Select {
1266   ExprList *pEList;      /* The fields of the result */
1267   u8 op;                 /* One of: TK_UNION TK_ALL TK_INTERSECT TK_EXCEPT */
1268   u8 isDistinct;         /* True if the DISTINCT keyword is present */
1269   u8 isResolved;         /* True once sqlite3SelectResolve() has run. */
1270   u8 isAgg;              /* True if this is an aggregate query */
1271   u8 usesEphm;           /* True if uses an OpenEphemeral opcode */
1272   u8 disallowOrderBy;    /* Do not allow an ORDER BY to be attached if TRUE */
1273   char affinity;         /* MakeRecord with this affinity for SRT_Set */
1274   SrcList *pSrc;         /* The FROM clause */
1275   Expr *pWhere;          /* The WHERE clause */
1276   ExprList *pGroupBy;    /* The GROUP BY clause */
1277   Expr *pHaving;         /* The HAVING clause */
1278   ExprList *pOrderBy;    /* The ORDER BY clause */
1279   Select *pPrior;        /* Prior select in a compound select statement */
1280   Select *pRightmost;    /* Right-most select in a compound select statement */
1281   Expr *pLimit;          /* LIMIT expression. NULL means not used. */
1282   Expr *pOffset;         /* OFFSET expression. NULL means not used. */
1283   int iLimit, iOffset;   /* Memory registers holding LIMIT & OFFSET counters */
1284   int addrOpenEphm[3];   /* OP_OpenEphem opcodes related to this select */
1285 };
1286 
1287 /*
1288 ** The results of a select can be distributed in several ways.
1289 */
1290 #define SRT_Union        1  /* Store result as keys in an index */
1291 #define SRT_Except       2  /* Remove result from a UNION index */
1292 #define SRT_Discard      3  /* Do not save the results anywhere */
1293 
1294 /* The ORDER BY clause is ignored for all of the above */
1295 #define IgnorableOrderby(X) (X<=SRT_Discard)
1296 
1297 #define SRT_Callback     4  /* Invoke a callback with each row of result */
1298 #define SRT_Mem          5  /* Store result in a memory cell */
1299 #define SRT_Set          6  /* Store non-null results as keys in an index */
1300 #define SRT_Table        7  /* Store result as data with an automatic rowid */
1301 #define SRT_EphemTab     8  /* Create transient tab and store like SRT_Table */
1302 #define SRT_Subroutine   9  /* Call a subroutine to handle results */
1303 #define SRT_Exists      10  /* Store 1 if the result is not empty */
1304 
1305 /*
1306 ** An SQL parser context.  A copy of this structure is passed through
1307 ** the parser and down into all the parser action routine in order to
1308 ** carry around information that is global to the entire parse.
1309 **
1310 ** The structure is divided into two parts.  When the parser and code
1311 ** generate call themselves recursively, the first part of the structure
1312 ** is constant but the second part is reset at the beginning and end of
1313 ** each recursion.
1314 **
1315 ** The nTableLock and aTableLock variables are only used if the shared-cache
1316 ** feature is enabled (if sqlite3Tsd()->useSharedData is true). They are
1317 ** used to store the set of table-locks required by the statement being
1318 ** compiled. Function sqlite3TableLock() is used to add entries to the
1319 ** list.
1320 */
1321 struct Parse {
1322   sqlite3 *db;         /* The main database structure */
1323   int rc;              /* Return code from execution */
1324   char *zErrMsg;       /* An error message */
1325   Vdbe *pVdbe;         /* An engine for executing database bytecode */
1326   u8 colNamesSet;      /* TRUE after OP_ColumnName has been issued to pVdbe */
1327   u8 nameClash;        /* A permanent table name clashes with temp table name */
1328   u8 checkSchema;      /* Causes schema cookie check after an error */
1329   u8 nested;           /* Number of nested calls to the parser/code generator */
1330   u8 parseError;       /* True after a parsing error.  Ticket #1794 */
1331   int nErr;            /* Number of errors seen */
1332   int nTab;            /* Number of previously allocated VDBE cursors */
1333   int nMem;            /* Number of memory cells used so far */
1334   int nSet;            /* Number of sets used so far */
1335   int ckOffset;        /* Stack offset to data used by CHECK constraints */
1336   u32 writeMask;       /* Start a write transaction on these databases */
1337   u32 cookieMask;      /* Bitmask of schema verified databases */
1338   int cookieGoto;      /* Address of OP_Goto to cookie verifier subroutine */
1339   int cookieValue[SQLITE_MAX_ATTACHED+2];  /* Values of cookies to verify */
1340 #ifndef SQLITE_OMIT_SHARED_CACHE
1341   int nTableLock;        /* Number of locks in aTableLock */
1342   TableLock *aTableLock; /* Required table locks for shared-cache mode */
1343 #endif
1344 
1345   /* Above is constant between recursions.  Below is reset before and after
1346   ** each recursion */
1347 
1348   int nVar;            /* Number of '?' variables seen in the SQL so far */
1349   int nVarExpr;        /* Number of used slots in apVarExpr[] */
1350   int nVarExprAlloc;   /* Number of allocated slots in apVarExpr[] */
1351   Expr **apVarExpr;    /* Pointers to :aaa and $aaaa wildcard expressions */
1352   u8 explain;          /* True if the EXPLAIN flag is found on the query */
1353   Token sErrToken;     /* The token at which the error occurred */
1354   Token sNameToken;    /* Token with unqualified schema object name */
1355   Token sLastToken;    /* The last token parsed */
1356   const char *zSql;    /* All SQL text */
1357   const char *zTail;   /* All SQL text past the last semicolon parsed */
1358   Table *pNewTable;    /* A table being constructed by CREATE TABLE */
1359   Trigger *pNewTrigger;     /* Trigger under construct by a CREATE TRIGGER */
1360   TriggerStack *trigStack;  /* Trigger actions being coded */
1361   const char *zAuthContext; /* The 6th parameter to db->xAuth callbacks */
1362 #ifndef SQLITE_OMIT_VIRTUALTABLE
1363   Token sArg;                /* Complete text of a module argument */
1364   u8 declareVtab;            /* True if inside sqlite3_declare_vtab() */
1365   Table *pVirtualLock;       /* Require virtual table lock on this table */
1366 #endif
1367 #if defined(SQLITE_TEST) || SQLITE_MAX_EXPR_DEPTH>0
1368   int nHeight;            /* Expression tree height of current sub-select */
1369 #endif
1370 };
1371 
1372 #ifdef SQLITE_OMIT_VIRTUALTABLE
1373   #define IN_DECLARE_VTAB 0
1374 #else
1375   #define IN_DECLARE_VTAB (pParse->declareVtab)
1376 #endif
1377 
1378 /*
1379 ** An instance of the following structure can be declared on a stack and used
1380 ** to save the Parse.zAuthContext value so that it can be restored later.
1381 */
1382 struct AuthContext {
1383   const char *zAuthContext;   /* Put saved Parse.zAuthContext here */
1384   Parse *pParse;              /* The Parse structure */
1385 };
1386 
1387 /*
1388 ** Bitfield flags for P2 value in OP_Insert and OP_Delete
1389 */
1390 #define OPFLAG_NCHANGE   1    /* Set to update db->nChange */
1391 #define OPFLAG_LASTROWID 2    /* Set to update db->lastRowid */
1392 #define OPFLAG_ISUPDATE  4    /* This OP_Insert is an sql UPDATE */
1393 #define OPFLAG_APPEND    8    /* This is likely to be an append */
1394 
1395 /*
1396  * Each trigger present in the database schema is stored as an instance of
1397  * struct Trigger.
1398  *
1399  * Pointers to instances of struct Trigger are stored in two ways.
1400  * 1. In the "trigHash" hash table (part of the sqlite3* that represents the
1401  *    database). This allows Trigger structures to be retrieved by name.
1402  * 2. All triggers associated with a single table form a linked list, using the
1403  *    pNext member of struct Trigger. A pointer to the first element of the
1404  *    linked list is stored as the "pTrigger" member of the associated
1405  *    struct Table.
1406  *
1407  * The "step_list" member points to the first element of a linked list
1408  * containing the SQL statements specified as the trigger program.
1409  */
1410 struct Trigger {
1411   char *name;             /* The name of the trigger                        */
1412   char *table;            /* The table or view to which the trigger applies */
1413   u8 op;                  /* One of TK_DELETE, TK_UPDATE, TK_INSERT         */
1414   u8 tr_tm;               /* One of TRIGGER_BEFORE, TRIGGER_AFTER */
1415   Expr *pWhen;            /* The WHEN clause of the expresion (may be NULL) */
1416   IdList *pColumns;       /* If this is an UPDATE OF <column-list> trigger,
1417                              the <column-list> is stored here */
1418   Token nameToken;        /* Token containing zName. Use during parsing only */
1419   Schema *pSchema;        /* Schema containing the trigger */
1420   Schema *pTabSchema;     /* Schema containing the table */
1421   TriggerStep *step_list; /* Link list of trigger program steps             */
1422   Trigger *pNext;         /* Next trigger associated with the table */
1423 };
1424 
1425 /*
1426 ** A trigger is either a BEFORE or an AFTER trigger.  The following constants
1427 ** determine which.
1428 **
1429 ** If there are multiple triggers, you might of some BEFORE and some AFTER.
1430 ** In that cases, the constants below can be ORed together.
1431 */
1432 #define TRIGGER_BEFORE  1
1433 #define TRIGGER_AFTER   2
1434 
1435 /*
1436  * An instance of struct TriggerStep is used to store a single SQL statement
1437  * that is a part of a trigger-program.
1438  *
1439  * Instances of struct TriggerStep are stored in a singly linked list (linked
1440  * using the "pNext" member) referenced by the "step_list" member of the
1441  * associated struct Trigger instance. The first element of the linked list is
1442  * the first step of the trigger-program.
1443  *
1444  * The "op" member indicates whether this is a "DELETE", "INSERT", "UPDATE" or
1445  * "SELECT" statement. The meanings of the other members is determined by the
1446  * value of "op" as follows:
1447  *
1448  * (op == TK_INSERT)
1449  * orconf    -> stores the ON CONFLICT algorithm
1450  * pSelect   -> If this is an INSERT INTO ... SELECT ... statement, then
1451  *              this stores a pointer to the SELECT statement. Otherwise NULL.
1452  * target    -> A token holding the name of the table to insert into.
1453  * pExprList -> If this is an INSERT INTO ... VALUES ... statement, then
1454  *              this stores values to be inserted. Otherwise NULL.
1455  * pIdList   -> If this is an INSERT INTO ... (<column-names>) VALUES ...
1456  *              statement, then this stores the column-names to be
1457  *              inserted into.
1458  *
1459  * (op == TK_DELETE)
1460  * target    -> A token holding the name of the table to delete from.
1461  * pWhere    -> The WHERE clause of the DELETE statement if one is specified.
1462  *              Otherwise NULL.
1463  *
1464  * (op == TK_UPDATE)
1465  * target    -> A token holding the name of the table to update rows of.
1466  * pWhere    -> The WHERE clause of the UPDATE statement if one is specified.
1467  *              Otherwise NULL.
1468  * pExprList -> A list of the columns to update and the expressions to update
1469  *              them to. See sqlite3Update() documentation of "pChanges"
1470  *              argument.
1471  *
1472  */
1473 struct TriggerStep {
1474   int op;              /* One of TK_DELETE, TK_UPDATE, TK_INSERT, TK_SELECT */
1475   int orconf;          /* OE_Rollback etc. */
1476   Trigger *pTrig;      /* The trigger that this step is a part of */
1477 
1478   Select *pSelect;     /* Valid for SELECT and sometimes
1479                           INSERT steps (when pExprList == 0) */
1480   Token target;        /* Valid for DELETE, UPDATE, INSERT steps */
1481   Expr *pWhere;        /* Valid for DELETE, UPDATE steps */
1482   ExprList *pExprList; /* Valid for UPDATE statements and sometimes
1483                            INSERT steps (when pSelect == 0)         */
1484   IdList *pIdList;     /* Valid for INSERT statements only */
1485   TriggerStep *pNext;  /* Next in the link-list */
1486   TriggerStep *pLast;  /* Last element in link-list. Valid for 1st elem only */
1487 };
1488 
1489 /*
1490  * An instance of struct TriggerStack stores information required during code
1491  * generation of a single trigger program. While the trigger program is being
1492  * coded, its associated TriggerStack instance is pointed to by the
1493  * "pTriggerStack" member of the Parse structure.
1494  *
1495  * The pTab member points to the table that triggers are being coded on. The
1496  * newIdx member contains the index of the vdbe cursor that points at the temp
1497  * table that stores the new.* references. If new.* references are not valid
1498  * for the trigger being coded (for example an ON DELETE trigger), then newIdx
1499  * is set to -1. The oldIdx member is analogous to newIdx, for old.* references.
1500  *
1501  * The ON CONFLICT policy to be used for the trigger program steps is stored
1502  * as the orconf member. If this is OE_Default, then the ON CONFLICT clause
1503  * specified for individual triggers steps is used.
1504  *
1505  * struct TriggerStack has a "pNext" member, to allow linked lists to be
1506  * constructed. When coding nested triggers (triggers fired by other triggers)
1507  * each nested trigger stores its parent trigger's TriggerStack as the "pNext"
1508  * pointer. Once the nested trigger has been coded, the pNext value is restored
1509  * to the pTriggerStack member of the Parse stucture and coding of the parent
1510  * trigger continues.
1511  *
1512  * Before a nested trigger is coded, the linked list pointed to by the
1513  * pTriggerStack is scanned to ensure that the trigger is not about to be coded
1514  * recursively. If this condition is detected, the nested trigger is not coded.
1515  */
1516 struct TriggerStack {
1517   Table *pTab;         /* Table that triggers are currently being coded on */
1518   int newIdx;          /* Index of vdbe cursor to "new" temp table */
1519   int oldIdx;          /* Index of vdbe cursor to "old" temp table */
1520   int orconf;          /* Current orconf policy */
1521   int ignoreJump;      /* where to jump to for a RAISE(IGNORE) */
1522   Trigger *pTrigger;   /* The trigger currently being coded */
1523   TriggerStack *pNext; /* Next trigger down on the trigger stack */
1524 };
1525 
1526 /*
1527 ** The following structure contains information used by the sqliteFix...
1528 ** routines as they walk the parse tree to make database references
1529 ** explicit.
1530 */
1531 typedef struct DbFixer DbFixer;
1532 struct DbFixer {
1533   Parse *pParse;      /* The parsing context.  Error messages written here */
1534   const char *zDb;    /* Make sure all objects are contained in this database */
1535   const char *zType;  /* Type of the container - used for error messages */
1536   const Token *pName; /* Name of the container - used for error messages */
1537 };
1538 
1539 /*
1540 ** A pointer to this structure is used to communicate information
1541 ** from sqlite3Init and OP_ParseSchema into the sqlite3InitCallback.
1542 */
1543 typedef struct {
1544   sqlite3 *db;        /* The database being initialized */
1545   int iDb;            /* 0 for main database.  1 for TEMP, 2.. for ATTACHed */
1546   char **pzErrMsg;    /* Error message stored here */
1547   int rc;             /* Result code stored here */
1548 } InitData;
1549 
1550 /*
1551 ** Assuming zIn points to the first byte of a UTF-8 character,
1552 ** advance zIn to point to the first byte of the next UTF-8 character.
1553 */
1554 #define SQLITE_SKIP_UTF8(zIn) {                        \
1555   if( (*(zIn++))>=0xc0 ){                              \
1556     while( (*zIn & 0xc0)==0x80 ){ zIn++; }             \
1557   }                                                    \
1558 }
1559 
1560 /*
1561 ** The SQLITE_CORRUPT_BKPT macro can be either a constant (for production
1562 ** builds) or a function call (for debugging).  If it is a function call,
1563 ** it allows the operator to set a breakpoint at the spot where database
1564 ** corruption is first detected.
1565 */
1566 #ifdef SQLITE_DEBUG
1567   int sqlite3Corrupt(void);
1568 # define SQLITE_CORRUPT_BKPT sqlite3Corrupt()
1569 #else
1570 # define SQLITE_CORRUPT_BKPT SQLITE_CORRUPT
1571 #endif
1572 
1573 /*
1574 ** Internal function prototypes
1575 */
1576 int sqlite3StrICmp(const char *, const char *);
1577 int sqlite3StrNICmp(const char *, const char *, int);
1578 int sqlite3IsNumber(const char*, int*, u8);
1579 
1580 void *sqlite3MallocZero(unsigned);
1581 void *sqlite3DbMallocZero(sqlite3*, unsigned);
1582 void *sqlite3DbMallocRaw(sqlite3*, unsigned);
1583 char *sqlite3StrDup(const char*);
1584 char *sqlite3StrNDup(const char*, int);
1585 char *sqlite3DbStrDup(sqlite3*,const char*);
1586 char *sqlite3DbStrNDup(sqlite3*,const char*, int);
1587 void *sqlite3DbReallocOrFree(sqlite3 *, void *, int);
1588 void *sqlite3DbRealloc(sqlite3 *, void *, int);
1589 
1590 char *sqlite3MPrintf(sqlite3*,const char*, ...);
1591 char *sqlite3VMPrintf(sqlite3*,const char*, va_list);
1592 #if defined(SQLITE_TEST) || defined(SQLITE_DEBUG)
1593   void sqlite3DebugPrintf(const char*, ...);
1594   void *sqlite3TextToPtr(const char*);
1595 #endif
1596 void sqlite3SetString(char **, ...);
1597 void sqlite3ErrorMsg(Parse*, const char*, ...);
1598 void sqlite3ErrorClear(Parse*);
1599 void sqlite3Dequote(char*);
1600 void sqlite3DequoteExpr(sqlite3*, Expr*);
1601 int sqlite3KeywordCode(const unsigned char*, int);
1602 int sqlite3RunParser(Parse*, const char*, char **);
1603 void sqlite3FinishCoding(Parse*);
1604 Expr *sqlite3Expr(sqlite3*, int, Expr*, Expr*, const Token*);
1605 Expr *sqlite3PExpr(Parse*, int, Expr*, Expr*, const Token*);
1606 Expr *sqlite3RegisterExpr(Parse*,Token*);
1607 Expr *sqlite3ExprAnd(sqlite3*,Expr*, Expr*);
1608 void sqlite3ExprSpan(Expr*,Token*,Token*);
1609 Expr *sqlite3ExprFunction(Parse*,ExprList*, Token*);
1610 void sqlite3ExprAssignVarNumber(Parse*, Expr*);
1611 void sqlite3ExprDelete(Expr*);
1612 ExprList *sqlite3ExprListAppend(Parse*,ExprList*,Expr*,Token*);
1613 void sqlite3ExprListDelete(ExprList*);
1614 int sqlite3Init(sqlite3*, char**);
1615 int sqlite3InitCallback(void*, int, char**, char**);
1616 void sqlite3Pragma(Parse*,Token*,Token*,Token*,int);
1617 void sqlite3ResetInternalSchema(sqlite3*, int);
1618 void sqlite3BeginParse(Parse*,int);
1619 void sqlite3CommitInternalChanges(sqlite3*);
1620 Table *sqlite3ResultSetOfSelect(Parse*,char*,Select*);
1621 void sqlite3OpenMasterTable(Parse *, int);
1622 void sqlite3StartTable(Parse*,Token*,Token*,int,int,int,int);
1623 void sqlite3AddColumn(Parse*,Token*);
1624 void sqlite3AddNotNull(Parse*, int);
1625 void sqlite3AddPrimaryKey(Parse*, ExprList*, int, int, int);
1626 void sqlite3AddCheckConstraint(Parse*, Expr*);
1627 void sqlite3AddColumnType(Parse*,Token*);
1628 void sqlite3AddDefaultValue(Parse*,Expr*);
1629 void sqlite3AddCollateType(Parse*, const char*, int);
1630 void sqlite3EndTable(Parse*,Token*,Token*,Select*);
1631 
1632 void sqlite3CreateView(Parse*,Token*,Token*,Token*,Select*,int,int);
1633 
1634 #if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE)
1635   int sqlite3ViewGetColumnNames(Parse*,Table*);
1636 #else
1637 # define sqlite3ViewGetColumnNames(A,B) 0
1638 #endif
1639 
1640 void sqlite3DropTable(Parse*, SrcList*, int, int);
1641 void sqlite3DeleteTable(Table*);
1642 void sqlite3Insert(Parse*, SrcList*, ExprList*, Select*, IdList*, int);
1643 void *sqlite3ArrayAllocate(sqlite3*,void*,int,int,int*,int*,int*);
1644 IdList *sqlite3IdListAppend(sqlite3*, IdList*, Token*);
1645 int sqlite3IdListIndex(IdList*,const char*);
1646 SrcList *sqlite3SrcListAppend(sqlite3*, SrcList*, Token*, Token*);
1647 SrcList *sqlite3SrcListAppendFromTerm(Parse*, SrcList*, Token*, Token*, Token*,
1648                                       Select*, Expr*, IdList*);
1649 void sqlite3SrcListShiftJoinType(SrcList*);
1650 void sqlite3SrcListAssignCursors(Parse*, SrcList*);
1651 void sqlite3IdListDelete(IdList*);
1652 void sqlite3SrcListDelete(SrcList*);
1653 void sqlite3CreateIndex(Parse*,Token*,Token*,SrcList*,ExprList*,int,Token*,
1654                         Token*, int, int);
1655 void sqlite3DropIndex(Parse*, SrcList*, int);
1656 int sqlite3Select(Parse*, Select*, int, int, Select*, int, int*, char *aff);
1657 Select *sqlite3SelectNew(Parse*,ExprList*,SrcList*,Expr*,ExprList*,
1658                          Expr*,ExprList*,int,Expr*,Expr*);
1659 void sqlite3SelectDelete(Select*);
1660 Table *sqlite3SrcListLookup(Parse*, SrcList*);
1661 int sqlite3IsReadOnly(Parse*, Table*, int);
1662 void sqlite3OpenTable(Parse*, int iCur, int iDb, Table*, int);
1663 void sqlite3DeleteFrom(Parse*, SrcList*, Expr*);
1664 void sqlite3Update(Parse*, SrcList*, ExprList*, Expr*, int);
1665 WhereInfo *sqlite3WhereBegin(Parse*, SrcList*, Expr*, ExprList**);
1666 void sqlite3WhereEnd(WhereInfo*);
1667 void sqlite3ExprCodeGetColumn(Vdbe*, Table*, int, int);
1668 void sqlite3ExprCode(Parse*, Expr*);
1669 void sqlite3ExprCodeAndCache(Parse*, Expr*);
1670 int sqlite3ExprCodeExprList(Parse*, ExprList*);
1671 void sqlite3ExprIfTrue(Parse*, Expr*, int, int);
1672 void sqlite3ExprIfFalse(Parse*, Expr*, int, int);
1673 Table *sqlite3FindTable(sqlite3*,const char*, const char*);
1674 Table *sqlite3LocateTable(Parse*,const char*, const char*);
1675 Index *sqlite3FindIndex(sqlite3*,const char*, const char*);
1676 void sqlite3UnlinkAndDeleteTable(sqlite3*,int,const char*);
1677 void sqlite3UnlinkAndDeleteIndex(sqlite3*,int,const char*);
1678 void sqlite3Vacuum(Parse*);
1679 int sqlite3RunVacuum(char**, sqlite3*);
1680 char *sqlite3NameFromToken(sqlite3*, Token*);
1681 int sqlite3ExprCompare(Expr*, Expr*);
1682 int sqlite3ExprResolveNames(NameContext *, Expr *);
1683 int sqlite3ExprAnalyzeAggregates(NameContext*, Expr*);
1684 int sqlite3ExprAnalyzeAggList(NameContext*,ExprList*);
1685 Vdbe *sqlite3GetVdbe(Parse*);
1686 Expr *sqlite3CreateIdExpr(Parse *, const char*);
1687 void sqlite3Randomness(int, void*);
1688 void sqlite3RollbackAll(sqlite3*);
1689 void sqlite3CodeVerifySchema(Parse*, int);
1690 void sqlite3BeginTransaction(Parse*, int);
1691 void sqlite3CommitTransaction(Parse*);
1692 void sqlite3RollbackTransaction(Parse*);
1693 int sqlite3ExprIsConstant(Expr*);
1694 int sqlite3ExprIsConstantNotJoin(Expr*);
1695 int sqlite3ExprIsConstantOrFunction(Expr*);
1696 int sqlite3ExprIsInteger(Expr*, int*);
1697 int sqlite3IsRowid(const char*);
1698 void sqlite3GenerateRowDelete(sqlite3*, Vdbe*, Table*, int, int);
1699 void sqlite3GenerateRowIndexDelete(Vdbe*, Table*, int, char*);
1700 void sqlite3GenerateIndexKey(Vdbe*, Index*, int);
1701 void sqlite3GenerateConstraintChecks(Parse*,Table*,int,char*,int,int,int,int);
1702 void sqlite3CompleteInsertion(Parse*, Table*, int, char*, int, int, int, int);
1703 void sqlite3OpenTableAndIndices(Parse*, Table*, int, int);
1704 void sqlite3BeginWriteOperation(Parse*, int, int);
1705 Expr *sqlite3ExprDup(sqlite3*,Expr*);
1706 void sqlite3TokenCopy(sqlite3*,Token*, Token*);
1707 ExprList *sqlite3ExprListDup(sqlite3*,ExprList*);
1708 SrcList *sqlite3SrcListDup(sqlite3*,SrcList*);
1709 IdList *sqlite3IdListDup(sqlite3*,IdList*);
1710 Select *sqlite3SelectDup(sqlite3*,Select*);
1711 FuncDef *sqlite3FindFunction(sqlite3*,const char*,int,int,u8,int);
1712 void sqlite3RegisterBuiltinFunctions(sqlite3*);
1713 void sqlite3RegisterDateTimeFunctions(sqlite3*);
1714 int sqlite3SafetyOn(sqlite3*);
1715 int sqlite3SafetyOff(sqlite3*);
1716 int sqlite3SafetyCheck(sqlite3*);
1717 void sqlite3ChangeCookie(sqlite3*, Vdbe*, int);
1718 
1719 #ifndef SQLITE_OMIT_TRIGGER
1720   void sqlite3BeginTrigger(Parse*, Token*,Token*,int,int,IdList*,SrcList*,
1721                            Expr*,int, int);
1722   void sqlite3FinishTrigger(Parse*, TriggerStep*, Token*);
1723   void sqlite3DropTrigger(Parse*, SrcList*, int);
1724   void sqlite3DropTriggerPtr(Parse*, Trigger*);
1725   int sqlite3TriggersExist(Parse*, Table*, int, ExprList*);
1726   int sqlite3CodeRowTrigger(Parse*, int, ExprList*, int, Table *, int, int,
1727                            int, int);
1728   void sqliteViewTriggers(Parse*, Table*, Expr*, int, ExprList*);
1729   void sqlite3DeleteTriggerStep(TriggerStep*);
1730   TriggerStep *sqlite3TriggerSelectStep(sqlite3*,Select*);
1731   TriggerStep *sqlite3TriggerInsertStep(sqlite3*,Token*, IdList*,
1732                                         ExprList*,Select*,int);
1733   TriggerStep *sqlite3TriggerUpdateStep(sqlite3*,Token*,ExprList*, Expr*, int);
1734   TriggerStep *sqlite3TriggerDeleteStep(sqlite3*,Token*, Expr*);
1735   void sqlite3DeleteTrigger(Trigger*);
1736   void sqlite3UnlinkAndDeleteTrigger(sqlite3*,int,const char*);
1737 #else
1738 # define sqlite3TriggersExist(A,B,C,D,E,F) 0
1739 # define sqlite3DeleteTrigger(A)
1740 # define sqlite3DropTriggerPtr(A,B)
1741 # define sqlite3UnlinkAndDeleteTrigger(A,B,C)
1742 # define sqlite3CodeRowTrigger(A,B,C,D,E,F,G,H,I) 0
1743 #endif
1744 
1745 int sqlite3JoinType(Parse*, Token*, Token*, Token*);
1746 void sqlite3CreateForeignKey(Parse*, ExprList*, Token*, ExprList*, int);
1747 void sqlite3DeferForeignKey(Parse*, int);
1748 #ifndef SQLITE_OMIT_AUTHORIZATION
1749   void sqlite3AuthRead(Parse*,Expr*,SrcList*);
1750   int sqlite3AuthCheck(Parse*,int, const char*, const char*, const char*);
1751   void sqlite3AuthContextPush(Parse*, AuthContext*, const char*);
1752   void sqlite3AuthContextPop(AuthContext*);
1753 #else
1754 # define sqlite3AuthRead(a,b,c)
1755 # define sqlite3AuthCheck(a,b,c,d,e)    SQLITE_OK
1756 # define sqlite3AuthContextPush(a,b,c)
1757 # define sqlite3AuthContextPop(a)  ((void)(a))
1758 #endif
1759 void sqlite3Attach(Parse*, Expr*, Expr*, Expr*);
1760 void sqlite3Detach(Parse*, Expr*);
1761 int sqlite3BtreeFactory(const sqlite3 *db, const char *zFilename,
1762                        int omitJournal, int nCache, int flags, Btree **ppBtree);
1763 int sqlite3FixInit(DbFixer*, Parse*, int, const char*, const Token*);
1764 int sqlite3FixSrcList(DbFixer*, SrcList*);
1765 int sqlite3FixSelect(DbFixer*, Select*);
1766 int sqlite3FixExpr(DbFixer*, Expr*);
1767 int sqlite3FixExprList(DbFixer*, ExprList*);
1768 int sqlite3FixTriggerStep(DbFixer*, TriggerStep*);
1769 int sqlite3AtoF(const char *z, double*);
1770 char *sqlite3_snprintf(int,char*,const char*,...);
1771 int sqlite3GetInt32(const char *, int*);
1772 int sqlite3FitsIn64Bits(const char *);
1773 int sqlite3Utf16ByteLen(const void *pData, int nChar);
1774 int sqlite3Utf8CharLen(const char *pData, int nByte);
1775 int sqlite3Utf8Read(const u8*, const u8*, const u8**);
1776 int sqlite3PutVarint(unsigned char *, u64);
1777 int sqlite3GetVarint(const unsigned char *, u64 *);
1778 int sqlite3GetVarint32(const unsigned char *, u32 *);
1779 int sqlite3VarintLen(u64 v);
1780 void sqlite3IndexAffinityStr(Vdbe *, Index *);
1781 void sqlite3TableAffinityStr(Vdbe *, Table *);
1782 char sqlite3CompareAffinity(Expr *pExpr, char aff2);
1783 int sqlite3IndexAffinityOk(Expr *pExpr, char idx_affinity);
1784 char sqlite3ExprAffinity(Expr *pExpr);
1785 int sqlite3Atoi64(const char*, i64*);
1786 void sqlite3Error(sqlite3*, int, const char*,...);
1787 void *sqlite3HexToBlob(sqlite3*, const char *z);
1788 int sqlite3TwoPartName(Parse *, Token *, Token *, Token **);
1789 const char *sqlite3ErrStr(int);
1790 int sqlite3ReadSchema(Parse *pParse);
1791 CollSeq *sqlite3FindCollSeq(sqlite3*,u8 enc, const char *,int,int);
1792 CollSeq *sqlite3LocateCollSeq(Parse *pParse, const char *zName, int nName);
1793 CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr);
1794 Expr *sqlite3ExprSetColl(Parse *pParse, Expr *, Token *);
1795 int sqlite3CheckCollSeq(Parse *, CollSeq *);
1796 int sqlite3CheckObjectName(Parse *, const char *);
1797 void sqlite3VdbeSetChanges(sqlite3 *, int);
1798 
1799 const void *sqlite3ValueText(sqlite3_value*, u8);
1800 int sqlite3ValueBytes(sqlite3_value*, u8);
1801 void sqlite3ValueSetStr(sqlite3_value*, int, const void *,u8,
1802                         void(*)(void*));
1803 void sqlite3ValueFree(sqlite3_value*);
1804 sqlite3_value *sqlite3ValueNew(sqlite3 *);
1805 char *sqlite3Utf16to8(sqlite3 *, const void*, int);
1806 int sqlite3ValueFromExpr(sqlite3 *, Expr *, u8, u8, sqlite3_value **);
1807 void sqlite3ValueApplyAffinity(sqlite3_value *, u8, u8);
1808 #ifndef SQLITE_AMALGAMATION
1809 extern const unsigned char sqlite3UpperToLower[];
1810 #endif
1811 void sqlite3RootPageMoved(Db*, int, int);
1812 void sqlite3Reindex(Parse*, Token*, Token*);
1813 void sqlite3AlterFunctions(sqlite3*);
1814 void sqlite3AlterRenameTable(Parse*, SrcList*, Token*);
1815 int sqlite3GetToken(const unsigned char *, int *);
1816 void sqlite3NestedParse(Parse*, const char*, ...);
1817 void sqlite3ExpirePreparedStatements(sqlite3*);
1818 void sqlite3CodeSubselect(Parse *, Expr *);
1819 int sqlite3SelectResolve(Parse *, Select *, NameContext *);
1820 void sqlite3ColumnDefault(Vdbe *, Table *, int);
1821 void sqlite3AlterFinishAddColumn(Parse *, Token *);
1822 void sqlite3AlterBeginAddColumn(Parse *, SrcList *);
1823 CollSeq *sqlite3GetCollSeq(sqlite3*, CollSeq *, const char *, int);
1824 char sqlite3AffinityType(const Token*);
1825 void sqlite3Analyze(Parse*, Token*, Token*);
1826 int sqlite3InvokeBusyHandler(BusyHandler*);
1827 int sqlite3FindDb(sqlite3*, Token*);
1828 int sqlite3AnalysisLoad(sqlite3*,int iDB);
1829 void sqlite3DefaultRowEst(Index*);
1830 void sqlite3RegisterLikeFunctions(sqlite3*, int);
1831 int sqlite3IsLikeFunction(sqlite3*,Expr*,int*,char*);
1832 void sqlite3AttachFunctions(sqlite3 *);
1833 void sqlite3MinimumFileFormat(Parse*, int, int);
1834 void sqlite3SchemaFree(void *);
1835 Schema *sqlite3SchemaGet(sqlite3 *, Btree *);
1836 int sqlite3SchemaToIndex(sqlite3 *db, Schema *);
1837 KeyInfo *sqlite3IndexKeyinfo(Parse *, Index *);
1838 int sqlite3CreateFunc(sqlite3 *, const char *, int, int, void *,
1839   void (*)(sqlite3_context*,int,sqlite3_value **),
1840   void (*)(sqlite3_context*,int,sqlite3_value **), void (*)(sqlite3_context*));
1841 int sqlite3ApiExit(sqlite3 *db, int);
1842 void sqlite3AbortOtherActiveVdbes(sqlite3 *, Vdbe *);
1843 int sqlite3OpenTempDatabase(Parse *);
1844 
1845 
1846 /*
1847 ** The interface to the LEMON-generated parser
1848 */
1849 void *sqlite3ParserAlloc(void*(*)(size_t));
1850 void sqlite3ParserFree(void*, void(*)(void*));
1851 void sqlite3Parser(void*, int, Token, Parse*);
1852 
1853 #ifndef SQLITE_OMIT_LOAD_EXTENSION
1854   void sqlite3CloseExtensions(sqlite3*);
1855   int sqlite3AutoLoadExtensions(sqlite3*);
1856 #else
1857 # define sqlite3CloseExtensions(X)
1858 # define sqlite3AutoLoadExtensions(X)  SQLITE_OK
1859 #endif
1860 
1861 #ifndef SQLITE_OMIT_SHARED_CACHE
1862   void sqlite3TableLock(Parse *, int, int, u8, const char *);
1863 #else
1864   #define sqlite3TableLock(v,w,x,y,z)
1865 #endif
1866 
1867 #ifdef SQLITE_TEST
1868   int sqlite3Utf8To8(unsigned char*);
1869 #endif
1870 
1871 /*
1872 ** The MallocDisallow() and MallocAllow() routines are like asserts.
1873 ** Call them around a section of code that you do not expect to do
1874 ** any memory allocation.
1875 */
1876 #ifdef SQLITE_MEMDEBUG
1877   void sqlite3MallocDisallow(void);
1878   void sqlite3MallocAllow(void);
1879   void sqlite3MallocBenignFailure(int);
1880 #else
1881 # define sqlite3MallocDisallow()
1882 # define sqlite3MallocAllow()
1883 # define sqlite3MallocBenignFailure(x)
1884 #endif
1885 
1886 
1887 #ifdef SQLITE_OMIT_VIRTUALTABLE
1888 #  define sqlite3VtabClear(X)
1889 #  define sqlite3VtabSync(X,Y) (Y)
1890 #  define sqlite3VtabRollback(X)
1891 #  define sqlite3VtabCommit(X)
1892 #else
1893    void sqlite3VtabClear(Table*);
1894    int sqlite3VtabSync(sqlite3 *db, int rc);
1895    int sqlite3VtabRollback(sqlite3 *db);
1896    int sqlite3VtabCommit(sqlite3 *db);
1897 #endif
1898 void sqlite3VtabLock(sqlite3_vtab*);
1899 void sqlite3VtabUnlock(sqlite3*, sqlite3_vtab*);
1900 void sqlite3VtabBeginParse(Parse*, Token*, Token*, Token*);
1901 void sqlite3VtabFinishParse(Parse*, Token*);
1902 void sqlite3VtabArgInit(Parse*);
1903 void sqlite3VtabArgExtend(Parse*, Token*);
1904 int sqlite3VtabCallCreate(sqlite3*, int, const char *, char **);
1905 int sqlite3VtabCallConnect(Parse*, Table*);
1906 int sqlite3VtabCallDestroy(sqlite3*, int, const char *);
1907 int sqlite3VtabBegin(sqlite3 *, sqlite3_vtab *);
1908 FuncDef *sqlite3VtabOverloadFunction(sqlite3 *,FuncDef*, int nArg, Expr*);
1909 void sqlite3InvalidFunction(sqlite3_context*,int,sqlite3_value**);
1910 int sqlite3Reprepare(Vdbe*);
1911 void sqlite3ExprListCheckLength(Parse*, ExprList*, int, const char*);
1912 CollSeq *sqlite3BinaryCompareCollSeq(Parse *, Expr *, Expr *);
1913 
1914 #ifdef SQLITE_ENABLE_ATOMIC_WRITE
1915   int sqlite3JournalOpen(sqlite3_vfs *, const char *, sqlite3_file *, int, int);
1916   int sqlite3JournalSize(sqlite3_vfs *);
1917   int sqlite3JournalCreate(sqlite3_file *);
1918 #else
1919   #define sqlite3JournalSize(pVfs) ((pVfs)->szOsFile)
1920 #endif
1921 
1922 #if defined(SQLITE_TEST) || SQLITE_MAX_EXPR_DEPTH>0
1923   void sqlite3ExprSetHeight(Expr *);
1924   int sqlite3SelectExprHeight(Select *);
1925 #else
1926   #define sqlite3ExprSetHeight(x)
1927 #endif
1928 
1929 u32 sqlite3Get4byte(const u8*);
1930 void sqlite3Put4byte(u8*, u32);
1931 
1932 #ifdef SQLITE_SSE
1933 #include "sseInt.h"
1934 #endif
1935 
1936 #ifdef SQLITE_DEBUG
1937   void sqlite3ParserTrace(FILE*, char *);
1938 #endif
1939 
1940 /*
1941 ** If the SQLITE_ENABLE IOTRACE exists then the global variable
1942 ** sqlite3_io_trace is a pointer to a printf-like routine used to
1943 ** print I/O tracing messages.
1944 */
1945 #ifdef SQLITE_ENABLE_IOTRACE
1946 # define IOTRACE(A)  if( sqlite3_io_trace ){ sqlite3_io_trace A; }
1947   void sqlite3VdbeIOTraceSql(Vdbe*);
1948 #else
1949 # define IOTRACE(A)
1950 # define sqlite3VdbeIOTraceSql(X)
1951 #endif
1952 SQLITE_EXTERN void (*sqlite3_io_trace)(const char*,...);
1953 
1954 #endif
1955