xref: /sqlite-3.40.0/src/sqliteInt.h (revision 7fdb522c)
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 1.747 2008/07/28 19:34:54 drh Exp $
15 */
16 #ifndef _SQLITEINT_H_
17 #define _SQLITEINT_H_
18 
19 /*
20 ** Include the configuration header output by 'configure' if we're using the
21 ** autoconf-based build
22 */
23 #ifdef _HAVE_SQLITE_CONFIG_H
24 #include "config.h"
25 #endif
26 
27 #include "sqliteLimit.h"
28 
29 /* Disable nuisance warnings on Borland compilers */
30 #if defined(__BORLANDC__)
31 #pragma warn -rch /* unreachable code */
32 #pragma warn -ccc /* Condition is always true or false */
33 #pragma warn -aus /* Assigned value is never used */
34 #pragma warn -csu /* Comparing signed and unsigned */
35 #pragma warn -spa /* Suspicous pointer arithmetic */
36 #endif
37 
38 /* Needed for various definitions... */
39 #define _GNU_SOURCE
40 
41 /*
42 ** Include standard header files as necessary
43 */
44 #ifdef HAVE_STDINT_H
45 #include <stdint.h>
46 #endif
47 #ifdef HAVE_INTTYPES_H
48 #include <inttypes.h>
49 #endif
50 
51 /*
52 ** A macro used to aid in coverage testing.  When doing coverage
53 ** testing, the condition inside the argument must be evaluated
54 ** both true and false in order to get full branch coverage.
55 ** This macro can be inserted to ensure adequate test coverage
56 ** in places where simple condition/decision coverage is inadequate.
57 */
58 #ifdef SQLITE_COVERAGE_TEST
59   void sqlite3Coverage(int);
60 # define testcase(X)  if( X ){ sqlite3Coverage(__LINE__); }
61 #else
62 # define testcase(X)
63 #endif
64 
65 /*
66 ** The ALWAYS and NEVER macros surround boolean expressions which
67 ** are intended to always be true or false, respectively.  Such
68 ** expressions could be omitted from the code completely.  But they
69 ** are included in a few cases in order to enhance the resilience
70 ** of SQLite to unexpected behavior - to make the code "self-healing"
71 ** or "ductile" rather than being "brittle" and crashing at the first
72 ** hint of unplanned behavior.
73 **
74 ** When doing coverage testing ALWAYS and NEVER are hard-coded to
75 ** be true and false so that the unreachable code then specify will
76 ** not be counted as untested code.
77 */
78 #ifdef SQLITE_COVERAGE_TEST
79 # define ALWAYS(X)      (1)
80 # define NEVER(X)       (0)
81 #else
82 # define ALWAYS(X)      (X)
83 # define NEVER(X)       (X)
84 #endif
85 
86 /*
87 ** The macro unlikely() is a hint that surrounds a boolean
88 ** expression that is usually false.  Macro likely() surrounds
89 ** a boolean expression that is usually true.  GCC is able to
90 ** use these hints to generate better code, sometimes.
91 */
92 #if defined(__GNUC__) && 0
93 # define likely(X)    __builtin_expect((X),1)
94 # define unlikely(X)  __builtin_expect((X),0)
95 #else
96 # define likely(X)    !!(X)
97 # define unlikely(X)  !!(X)
98 #endif
99 
100 /*
101  * This macro is used to "hide" some ugliness in casting an int
102  * value to a ptr value under the MSVC 64-bit compiler.   Casting
103  * non 64-bit values to ptr types results in a "hard" error with
104  * the MSVC 64-bit compiler which this attempts to avoid.
105  *
106  * A simple compiler pragma or casting sequence could not be found
107  * to correct this in all situations, so this macro was introduced.
108  *
109  * It could be argued that the intptr_t type could be used in this
110  * case, but that type is not available on all compilers, or
111  * requires the #include of specific headers which differs between
112  * platforms.
113  */
114 #define SQLITE_INT_TO_PTR(X)   ((void*)&((char*)0)[X])
115 #define SQLITE_PTR_TO_INT(X)   ((int)(((char*)X)-(char*)0))
116 
117 /*
118 ** These #defines should enable >2GB file support on Posix if the
119 ** underlying operating system supports it.  If the OS lacks
120 ** large file support, or if the OS is windows, these should be no-ops.
121 **
122 ** Ticket #2739:  The _LARGEFILE_SOURCE macro must appear before any
123 ** system #includes.  Hence, this block of code must be the very first
124 ** code in all source files.
125 **
126 ** Large file support can be disabled using the -DSQLITE_DISABLE_LFS switch
127 ** on the compiler command line.  This is necessary if you are compiling
128 ** on a recent machine (ex: RedHat 7.2) but you want your code to work
129 ** on an older machine (ex: RedHat 6.0).  If you compile on RedHat 7.2
130 ** without this option, LFS is enable.  But LFS does not exist in the kernel
131 ** in RedHat 6.0, so the code won't work.  Hence, for maximum binary
132 ** portability you should omit LFS.
133 **
134 ** Similar is true for MacOS.  LFS is only supported on MacOS 9 and later.
135 */
136 #ifndef SQLITE_DISABLE_LFS
137 # define _LARGE_FILE       1
138 # ifndef _FILE_OFFSET_BITS
139 #   define _FILE_OFFSET_BITS 64
140 # endif
141 # define _LARGEFILE_SOURCE 1
142 #endif
143 
144 
145 /*
146 ** The SQLITE_THREADSAFE macro must be defined as either 0 or 1.
147 ** Older versions of SQLite used an optional THREADSAFE macro.
148 ** We support that for legacy
149 */
150 #if !defined(SQLITE_THREADSAFE)
151 #if defined(THREADSAFE)
152 # define SQLITE_THREADSAFE THREADSAFE
153 #else
154 # define SQLITE_THREADSAFE 1
155 #endif
156 #endif
157 
158 /*
159 ** Exactly one of the following macros must be defined in order to
160 ** specify which memory allocation subsystem to use.
161 **
162 **     SQLITE_SYSTEM_MALLOC          // Use normal system malloc()
163 **     SQLITE_MEMDEBUG               // Debugging version of system malloc()
164 **     SQLITE_MEMORY_SIZE            // internal allocator #1
165 **     SQLITE_MMAP_HEAP_SIZE         // internal mmap() allocator
166 **     SQLITE_POW2_MEMORY_SIZE       // internal power-of-two allocator
167 **
168 ** If none of the above are defined, then set SQLITE_SYSTEM_MALLOC as
169 ** the default.
170 */
171 #if defined(SQLITE_SYSTEM_MALLOC)+defined(SQLITE_MEMDEBUG)+\
172     defined(SQLITE_MEMORY_SIZE)+defined(SQLITE_MMAP_HEAP_SIZE)+\
173     defined(SQLITE_POW2_MEMORY_SIZE)>1
174 # error "At most one of the following compile-time configuration options\
175  is allows: SQLITE_SYSTEM_MALLOC, SQLITE_MEMDEBUG, SQLITE_MEMORY_SIZE,\
176  SQLITE_MMAP_HEAP_SIZE, SQLITE_POW2_MEMORY_SIZE"
177 #endif
178 #if defined(SQLITE_SYSTEM_MALLOC)+defined(SQLITE_MEMDEBUG)+\
179     defined(SQLITE_MEMORY_SIZE)+defined(SQLITE_MMAP_HEAP_SIZE)+\
180     defined(SQLITE_POW2_MEMORY_SIZE)==0
181 # define SQLITE_SYSTEM_MALLOC 1
182 #endif
183 
184 /*
185 ** If SQLITE_MALLOC_SOFT_LIMIT is defined, then try to keep the
186 ** sizes of memory allocations below this value where possible.
187 */
188 #if defined(SQLITE_POW2_MEMORY_SIZE) && !defined(SQLITE_MALLOC_SOFT_LIMIT)
189 # define SQLITE_MALLOC_SOFT_LIMIT 1024
190 #endif
191 
192 /*
193 ** We need to define _XOPEN_SOURCE as follows in order to enable
194 ** recursive mutexes on most unix systems.  But Mac OS X is different.
195 ** The _XOPEN_SOURCE define causes problems for Mac OS X we are told,
196 ** so it is omitted there.  See ticket #2673.
197 **
198 ** Later we learn that _XOPEN_SOURCE is poorly or incorrectly
199 ** implemented on some systems.  So we avoid defining it at all
200 ** if it is already defined or if it is unneeded because we are
201 ** not doing a threadsafe build.  Ticket #2681.
202 **
203 ** See also ticket #2741.
204 */
205 #if !defined(_XOPEN_SOURCE) && !defined(__DARWIN__) && !defined(__APPLE__) && SQLITE_THREADSAFE
206 #  define _XOPEN_SOURCE 500  /* Needed to enable pthread recursive mutexes */
207 #endif
208 
209 #if defined(SQLITE_TCL) || defined(TCLSH)
210 # include <tcl.h>
211 #endif
212 
213 /*
214 ** Many people are failing to set -DNDEBUG=1 when compiling SQLite.
215 ** Setting NDEBUG makes the code smaller and run faster.  So the following
216 ** lines are added to automatically set NDEBUG unless the -DSQLITE_DEBUG=1
217 ** option is set.  Thus NDEBUG becomes an opt-in rather than an opt-out
218 ** feature.
219 */
220 #if !defined(NDEBUG) && !defined(SQLITE_DEBUG)
221 # define NDEBUG 1
222 #endif
223 
224 #include "sqlite3.h"
225 #include "hash.h"
226 #include "parse.h"
227 #include <stdio.h>
228 #include <stdlib.h>
229 #include <string.h>
230 #include <assert.h>
231 #include <stddef.h>
232 
233 /*
234 ** If compiling for a processor that lacks floating point support,
235 ** substitute integer for floating-point
236 */
237 #ifdef SQLITE_OMIT_FLOATING_POINT
238 # define double sqlite_int64
239 # define LONGDOUBLE_TYPE sqlite_int64
240 # ifndef SQLITE_BIG_DBL
241 #   define SQLITE_BIG_DBL (0x7fffffffffffffff)
242 # endif
243 # define SQLITE_OMIT_DATETIME_FUNCS 1
244 # define SQLITE_OMIT_TRACE 1
245 # undef SQLITE_MIXED_ENDIAN_64BIT_FLOAT
246 #endif
247 #ifndef SQLITE_BIG_DBL
248 # define SQLITE_BIG_DBL (1e99)
249 #endif
250 
251 /*
252 ** OMIT_TEMPDB is set to 1 if SQLITE_OMIT_TEMPDB is defined, or 0
253 ** afterward. Having this macro allows us to cause the C compiler
254 ** to omit code used by TEMP tables without messy #ifndef statements.
255 */
256 #ifdef SQLITE_OMIT_TEMPDB
257 #define OMIT_TEMPDB 1
258 #else
259 #define OMIT_TEMPDB 0
260 #endif
261 
262 /*
263 ** If the following macro is set to 1, then NULL values are considered
264 ** distinct when determining whether or not two entries are the same
265 ** in a UNIQUE index.  This is the way PostgreSQL, Oracle, DB2, MySQL,
266 ** OCELOT, and Firebird all work.  The SQL92 spec explicitly says this
267 ** is the way things are suppose to work.
268 **
269 ** If the following macro is set to 0, the NULLs are indistinct for
270 ** a UNIQUE index.  In this mode, you can only have a single NULL entry
271 ** for a column declared UNIQUE.  This is the way Informix and SQL Server
272 ** work.
273 */
274 #define NULL_DISTINCT_FOR_UNIQUE 1
275 
276 /*
277 ** The "file format" number is an integer that is incremented whenever
278 ** the VDBE-level file format changes.  The following macros define the
279 ** the default file format for new databases and the maximum file format
280 ** that the library can read.
281 */
282 #define SQLITE_MAX_FILE_FORMAT 4
283 #ifndef SQLITE_DEFAULT_FILE_FORMAT
284 # define SQLITE_DEFAULT_FILE_FORMAT 1
285 #endif
286 
287 /*
288 ** Provide a default value for SQLITE_TEMP_STORE in case it is not specified
289 ** on the command-line
290 */
291 #ifndef SQLITE_TEMP_STORE
292 # define SQLITE_TEMP_STORE 1
293 #endif
294 
295 /*
296 ** GCC does not define the offsetof() macro so we'll have to do it
297 ** ourselves.
298 */
299 #ifndef offsetof
300 #define offsetof(STRUCTURE,FIELD) ((int)((char*)&((STRUCTURE*)0)->FIELD))
301 #endif
302 
303 /*
304 ** Check to see if this machine uses EBCDIC.  (Yes, believe it or
305 ** not, there are still machines out there that use EBCDIC.)
306 */
307 #if 'A' == '\301'
308 # define SQLITE_EBCDIC 1
309 #else
310 # define SQLITE_ASCII 1
311 #endif
312 
313 /*
314 ** Integers of known sizes.  These typedefs might change for architectures
315 ** where the sizes very.  Preprocessor macros are available so that the
316 ** types can be conveniently redefined at compile-type.  Like this:
317 **
318 **         cc '-DUINTPTR_TYPE=long long int' ...
319 */
320 #ifndef UINT32_TYPE
321 # ifdef HAVE_UINT32_T
322 #  define UINT32_TYPE uint32_t
323 # else
324 #  define UINT32_TYPE unsigned int
325 # endif
326 #endif
327 #ifndef UINT16_TYPE
328 # ifdef HAVE_UINT16_T
329 #  define UINT16_TYPE uint16_t
330 # else
331 #  define UINT16_TYPE unsigned short int
332 # endif
333 #endif
334 #ifndef INT16_TYPE
335 # ifdef HAVE_INT16_T
336 #  define INT16_TYPE int16_t
337 # else
338 #  define INT16_TYPE short int
339 # endif
340 #endif
341 #ifndef UINT8_TYPE
342 # ifdef HAVE_UINT8_T
343 #  define UINT8_TYPE uint8_t
344 # else
345 #  define UINT8_TYPE unsigned char
346 # endif
347 #endif
348 #ifndef INT8_TYPE
349 # ifdef HAVE_INT8_T
350 #  define INT8_TYPE int8_t
351 # else
352 #  define INT8_TYPE signed char
353 # endif
354 #endif
355 #ifndef LONGDOUBLE_TYPE
356 # define LONGDOUBLE_TYPE long double
357 #endif
358 typedef sqlite_int64 i64;          /* 8-byte signed integer */
359 typedef sqlite_uint64 u64;         /* 8-byte unsigned integer */
360 typedef UINT32_TYPE u32;           /* 4-byte unsigned integer */
361 typedef UINT16_TYPE u16;           /* 2-byte unsigned integer */
362 typedef INT16_TYPE i16;            /* 2-byte signed integer */
363 typedef UINT8_TYPE u8;             /* 1-byte unsigned integer */
364 typedef UINT8_TYPE i8;             /* 1-byte signed integer */
365 
366 /*
367 ** Macros to determine whether the machine is big or little endian,
368 ** evaluated at runtime.
369 */
370 #ifdef SQLITE_AMALGAMATION
371 const int sqlite3one;
372 #else
373 extern const int sqlite3one;
374 #endif
375 #if defined(i386) || defined(__i386__) || defined(_M_IX86)
376 # define SQLITE_BIGENDIAN    0
377 # define SQLITE_LITTLEENDIAN 1
378 # define SQLITE_UTF16NATIVE  SQLITE_UTF16LE
379 #else
380 # define SQLITE_BIGENDIAN    (*(char *)(&sqlite3one)==0)
381 # define SQLITE_LITTLEENDIAN (*(char *)(&sqlite3one)==1)
382 # define SQLITE_UTF16NATIVE (SQLITE_BIGENDIAN?SQLITE_UTF16BE:SQLITE_UTF16LE)
383 #endif
384 
385 /*
386 ** Constants for the largest and smallest possible 64-bit signed integers.
387 ** These macros are designed to work correctly on both 32-bit and 64-bit
388 ** compilers.
389 */
390 #define LARGEST_INT64  (0xffffffff|(((i64)0x7fffffff)<<32))
391 #define SMALLEST_INT64 (((i64)-1) - LARGEST_INT64)
392 
393 /*
394 ** An instance of the following structure is used to store the busy-handler
395 ** callback for a given sqlite handle.
396 **
397 ** The sqlite.busyHandler member of the sqlite struct contains the busy
398 ** callback for the database handle. Each pager opened via the sqlite
399 ** handle is passed a pointer to sqlite.busyHandler. The busy-handler
400 ** callback is currently invoked only from within pager.c.
401 */
402 typedef struct BusyHandler BusyHandler;
403 struct BusyHandler {
404   int (*xFunc)(void *,int);  /* The busy callback */
405   void *pArg;                /* First arg to busy callback */
406   int nBusy;                 /* Incremented with each busy call */
407 };
408 
409 /*
410 ** Name of the master database table.  The master database table
411 ** is a special table that holds the names and attributes of all
412 ** user tables and indices.
413 */
414 #define MASTER_NAME       "sqlite_master"
415 #define TEMP_MASTER_NAME  "sqlite_temp_master"
416 
417 /*
418 ** The root-page of the master database table.
419 */
420 #define MASTER_ROOT       1
421 
422 /*
423 ** The name of the schema table.
424 */
425 #define SCHEMA_TABLE(x)  ((!OMIT_TEMPDB)&&(x==1)?TEMP_MASTER_NAME:MASTER_NAME)
426 
427 /*
428 ** A convenience macro that returns the number of elements in
429 ** an array.
430 */
431 #define ArraySize(X)    (sizeof(X)/sizeof(X[0]))
432 
433 /*
434 ** The following value as a destructor means to use sqlite3DbFree().
435 ** This is an internal extension to SQLITE_STATIC and SQLITE_TRANSIENT.
436 */
437 #define SQLITE_DYNAMIC   ((sqlite3_destructor_type)sqlite3DbFree)
438 
439 /*
440 ** Forward references to structures
441 */
442 typedef struct AggInfo AggInfo;
443 typedef struct AuthContext AuthContext;
444 typedef struct Bitvec Bitvec;
445 typedef struct CollSeq CollSeq;
446 typedef struct Column Column;
447 typedef struct Db Db;
448 typedef struct Schema Schema;
449 typedef struct Expr Expr;
450 typedef struct ExprList ExprList;
451 typedef struct FKey FKey;
452 typedef struct FuncDef FuncDef;
453 typedef struct IdList IdList;
454 typedef struct Index Index;
455 typedef struct KeyClass KeyClass;
456 typedef struct KeyInfo KeyInfo;
457 typedef struct Lookaside Lookaside;
458 typedef struct LookasideSlot LookasideSlot;
459 typedef struct Module Module;
460 typedef struct NameContext NameContext;
461 typedef struct Parse Parse;
462 typedef struct Select Select;
463 typedef struct SrcList SrcList;
464 typedef struct StrAccum StrAccum;
465 typedef struct Table Table;
466 typedef struct TableLock TableLock;
467 typedef struct Token Token;
468 typedef struct TriggerStack TriggerStack;
469 typedef struct TriggerStep TriggerStep;
470 typedef struct Trigger Trigger;
471 typedef struct WhereInfo WhereInfo;
472 typedef struct WhereLevel WhereLevel;
473 
474 /*
475 ** Defer sourcing vdbe.h and btree.h until after the "u8" and
476 ** "BusyHandler" typedefs. vdbe.h also requires a few of the opaque
477 ** pointer types (i.e. FuncDef) defined above.
478 */
479 #include "btree.h"
480 #include "vdbe.h"
481 #include "pager.h"
482 
483 #include "os.h"
484 #include "mutex.h"
485 
486 
487 /*
488 ** Each database file to be accessed by the system is an instance
489 ** of the following structure.  There are normally two of these structures
490 ** in the sqlite.aDb[] array.  aDb[0] is the main database file and
491 ** aDb[1] is the database file used to hold temporary tables.  Additional
492 ** databases may be attached.
493 */
494 struct Db {
495   char *zName;         /* Name of this database */
496   Btree *pBt;          /* The B*Tree structure for this database file */
497   u8 inTrans;          /* 0: not writable.  1: Transaction.  2: Checkpoint */
498   u8 safety_level;     /* How aggressive at synching data to disk */
499   void *pAux;               /* Auxiliary data.  Usually NULL */
500   void (*xFreeAux)(void*);  /* Routine to free pAux */
501   Schema *pSchema;     /* Pointer to database schema (possibly shared) */
502 };
503 
504 /*
505 ** An instance of the following structure stores a database schema.
506 **
507 ** If there are no virtual tables configured in this schema, the
508 ** Schema.db variable is set to NULL. After the first virtual table
509 ** has been added, it is set to point to the database connection
510 ** used to create the connection. Once a virtual table has been
511 ** added to the Schema structure and the Schema.db variable populated,
512 ** only that database connection may use the Schema to prepare
513 ** statements.
514 */
515 struct Schema {
516   int schema_cookie;   /* Database schema version number for this file */
517   Hash tblHash;        /* All tables indexed by name */
518   Hash idxHash;        /* All (named) indices indexed by name */
519   Hash trigHash;       /* All triggers indexed by name */
520   Hash aFKey;          /* Foreign keys indexed by to-table */
521   Table *pSeqTab;      /* The sqlite_sequence table used by AUTOINCREMENT */
522   u8 file_format;      /* Schema format version for this file */
523   u8 enc;              /* Text encoding used by this database */
524   u16 flags;           /* Flags associated with this schema */
525   int cache_size;      /* Number of pages to use in the cache */
526 #ifndef SQLITE_OMIT_VIRTUALTABLE
527   sqlite3 *db;         /* "Owner" connection. See comment above */
528 #endif
529 };
530 
531 /*
532 ** These macros can be used to test, set, or clear bits in the
533 ** Db.flags field.
534 */
535 #define DbHasProperty(D,I,P)     (((D)->aDb[I].pSchema->flags&(P))==(P))
536 #define DbHasAnyProperty(D,I,P)  (((D)->aDb[I].pSchema->flags&(P))!=0)
537 #define DbSetProperty(D,I,P)     (D)->aDb[I].pSchema->flags|=(P)
538 #define DbClearProperty(D,I,P)   (D)->aDb[I].pSchema->flags&=~(P)
539 
540 /*
541 ** Allowed values for the DB.flags field.
542 **
543 ** The DB_SchemaLoaded flag is set after the database schema has been
544 ** read into internal hash tables.
545 **
546 ** DB_UnresetViews means that one or more views have column names that
547 ** have been filled out.  If the schema changes, these column names might
548 ** changes and so the view will need to be reset.
549 */
550 #define DB_SchemaLoaded    0x0001  /* The schema has been loaded */
551 #define DB_UnresetViews    0x0002  /* Some views have defined column names */
552 #define DB_Empty           0x0004  /* The file is empty (length 0 bytes) */
553 
554 /*
555 ** The number of different kinds of things that can be limited
556 ** using the sqlite3_limit() interface.
557 */
558 #define SQLITE_N_LIMIT (SQLITE_LIMIT_VARIABLE_NUMBER+1)
559 
560 /*
561 ** Lookaside malloc is a set of fixed-size buffers that can be used
562 ** to satisify small transient memory allocation requests for objects
563 ** associated with a particular database connection.  The use of
564 ** lookaside malloc provides a significant performance enhancement
565 ** (approx 10%) by avoiding numerous malloc/free requests while parsing
566 ** SQL statements.
567 **
568 ** The Lookaside structure holds configuration information about the
569 ** lookaside malloc subsystem.  Each available memory allocation in
570 ** the lookaside subsystem is stored on a linked list of LookasideSlot
571 ** objects.
572 */
573 struct Lookaside {
574   u16 sz;                 /* Size of each buffer in bytes */
575   u8 bEnabled;            /* True if use lookaside.  False to ignore it */
576   int nOut;               /* Number of buffers currently checked out */
577   int mxOut;              /* Highwater mark for nOut */
578   LookasideSlot *pFree;   /* List if available buffers */
579   void *pStart;           /* First byte of available memory space */
580   void *pEnd;             /* First byte past end of available space */
581 };
582 struct LookasideSlot {
583   LookasideSlot *pNext;    /* Next buffer in the list of free buffers */
584 };
585 
586 /*
587 ** Each database is an instance of the following structure.
588 **
589 ** The sqlite.lastRowid records the last insert rowid generated by an
590 ** insert statement.  Inserts on views do not affect its value.  Each
591 ** trigger has its own context, so that lastRowid can be updated inside
592 ** triggers as usual.  The previous value will be restored once the trigger
593 ** exits.  Upon entering a before or instead of trigger, lastRowid is no
594 ** longer (since after version 2.8.12) reset to -1.
595 **
596 ** The sqlite.nChange does not count changes within triggers and keeps no
597 ** context.  It is reset at start of sqlite3_exec.
598 ** The sqlite.lsChange represents the number of changes made by the last
599 ** insert, update, or delete statement.  It remains constant throughout the
600 ** length of a statement and is then updated by OP_SetCounts.  It keeps a
601 ** context stack just like lastRowid so that the count of changes
602 ** within a trigger is not seen outside the trigger.  Changes to views do not
603 ** affect the value of lsChange.
604 ** The sqlite.csChange keeps track of the number of current changes (since
605 ** the last statement) and is used to update sqlite_lsChange.
606 **
607 ** The member variables sqlite.errCode, sqlite.zErrMsg and sqlite.zErrMsg16
608 ** store the most recent error code and, if applicable, string. The
609 ** internal function sqlite3Error() is used to set these variables
610 ** consistently.
611 */
612 struct sqlite3 {
613   sqlite3_vfs *pVfs;            /* OS Interface */
614   int nDb;                      /* Number of backends currently in use */
615   Db *aDb;                      /* All backends */
616   int flags;                    /* Miscellanous flags. See below */
617   int openFlags;                /* Flags passed to sqlite3_vfs.xOpen() */
618   int errCode;                  /* Most recent error code (SQLITE_*) */
619   int errMask;                  /* & result codes with this before returning */
620   u8 autoCommit;                /* The auto-commit flag. */
621   u8 temp_store;                /* 1: file 2: memory 0: default */
622   u8 mallocFailed;              /* True if we have seen a malloc failure */
623   u8 dfltLockMode;              /* Default locking-mode for attached dbs */
624   u8 dfltJournalMode;           /* Default journal mode for attached dbs */
625   signed char nextAutovac;      /* Autovac setting after VACUUM if >=0 */
626   int nextPagesize;             /* Pagesize after VACUUM if >0 */
627   int nTable;                   /* Number of tables in the database */
628   CollSeq *pDfltColl;           /* The default collating sequence (BINARY) */
629   i64 lastRowid;                /* ROWID of most recent insert (see above) */
630   i64 priorNewRowid;            /* Last randomly generated ROWID */
631   int magic;                    /* Magic number for detect library misuse */
632   int nChange;                  /* Value returned by sqlite3_changes() */
633   int nTotalChange;             /* Value returned by sqlite3_total_changes() */
634   sqlite3_mutex *mutex;         /* Connection mutex */
635   int aLimit[SQLITE_N_LIMIT];   /* Limits */
636   struct sqlite3InitInfo {      /* Information used during initialization */
637     int iDb;                    /* When back is being initialized */
638     int newTnum;                /* Rootpage of table being initialized */
639     u8 busy;                    /* TRUE if currently initializing */
640   } init;
641   int nExtension;               /* Number of loaded extensions */
642   void **aExtension;            /* Array of shared libraray handles */
643   struct Vdbe *pVdbe;           /* List of active virtual machines */
644   int activeVdbeCnt;            /* Number of vdbes currently executing */
645   void (*xTrace)(void*,const char*);        /* Trace function */
646   void *pTraceArg;                          /* Argument to the trace function */
647   void (*xProfile)(void*,const char*,u64);  /* Profiling function */
648   void *pProfileArg;                        /* Argument to profile function */
649   void *pCommitArg;                 /* Argument to xCommitCallback() */
650   int (*xCommitCallback)(void*);    /* Invoked at every commit. */
651   void *pRollbackArg;               /* Argument to xRollbackCallback() */
652   void (*xRollbackCallback)(void*); /* Invoked at every commit. */
653   void *pUpdateArg;
654   void (*xUpdateCallback)(void*,int, const char*,const char*,sqlite_int64);
655   void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*);
656   void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*);
657   void *pCollNeededArg;
658   sqlite3_value *pErr;          /* Most recent error message */
659   char *zErrMsg;                /* Most recent error message (UTF-8 encoded) */
660   char *zErrMsg16;              /* Most recent error message (UTF-16 encoded) */
661   union {
662     int isInterrupted;          /* True if sqlite3_interrupt has been called */
663     double notUsed1;            /* Spacer */
664   } u1;
665   Lookaside lookaside;          /* Lookaside malloc configuration */
666 #ifndef SQLITE_OMIT_AUTHORIZATION
667   int (*xAuth)(void*,int,const char*,const char*,const char*,const char*);
668                                 /* Access authorization function */
669   void *pAuthArg;               /* 1st argument to the access auth function */
670 #endif
671 #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
672   int (*xProgress)(void *);     /* The progress callback */
673   void *pProgressArg;           /* Argument to the progress callback */
674   int nProgressOps;             /* Number of opcodes for progress callback */
675 #endif
676 #ifndef SQLITE_OMIT_VIRTUALTABLE
677   Hash aModule;                 /* populated by sqlite3_create_module() */
678   Table *pVTab;                 /* vtab with active Connect/Create method */
679   sqlite3_vtab **aVTrans;       /* Virtual tables with open transactions */
680   int nVTrans;                  /* Allocated size of aVTrans */
681 #endif
682   Hash aFunc;                   /* All functions that can be in SQL exprs */
683   Hash aCollSeq;                /* All collating sequences */
684   BusyHandler busyHandler;      /* Busy callback */
685   int busyTimeout;              /* Busy handler timeout, in msec */
686   Db aDbStatic[2];              /* Static space for the 2 default backends */
687 #ifdef SQLITE_SSE
688   sqlite3_stmt *pFetch;         /* Used by SSE to fetch stored statements */
689 #endif
690 };
691 
692 /*
693 ** A macro to discover the encoding of a database.
694 */
695 #define ENC(db) ((db)->aDb[0].pSchema->enc)
696 
697 /*
698 ** Possible values for the sqlite.flags and or Db.flags fields.
699 **
700 ** On sqlite.flags, the SQLITE_InTrans value means that we have
701 ** executed a BEGIN.  On Db.flags, SQLITE_InTrans means a statement
702 ** transaction is active on that particular database file.
703 */
704 #define SQLITE_VdbeTrace      0x00000001  /* True to trace VDBE execution */
705 #define SQLITE_InTrans        0x00000008  /* True if in a transaction */
706 #define SQLITE_InternChanges  0x00000010  /* Uncommitted Hash table changes */
707 #define SQLITE_FullColNames   0x00000020  /* Show full column names on SELECT */
708 #define SQLITE_ShortColNames  0x00000040  /* Show short columns names */
709 #define SQLITE_CountRows      0x00000080  /* Count rows changed by INSERT, */
710                                           /*   DELETE, or UPDATE and return */
711                                           /*   the count using a callback. */
712 #define SQLITE_NullCallback   0x00000100  /* Invoke the callback once if the */
713                                           /*   result set is empty */
714 #define SQLITE_SqlTrace       0x00000200  /* Debug print SQL as it executes */
715 #define SQLITE_VdbeListing    0x00000400  /* Debug listings of VDBE programs */
716 #define SQLITE_WriteSchema    0x00000800  /* OK to update SQLITE_MASTER */
717 #define SQLITE_NoReadlock     0x00001000  /* Readlocks are omitted when
718                                           ** accessing read-only databases */
719 #define SQLITE_IgnoreChecks   0x00002000  /* Do not enforce check constraints */
720 #define SQLITE_ReadUncommitted 0x00004000 /* For shared-cache mode */
721 #define SQLITE_LegacyFileFmt  0x00008000  /* Create new databases in format 1 */
722 #define SQLITE_FullFSync      0x00010000  /* Use full fsync on the backend */
723 #define SQLITE_LoadExtension  0x00020000  /* Enable load_extension */
724 
725 #define SQLITE_RecoveryMode   0x00040000  /* Ignore schema errors */
726 #define SQLITE_SharedCache    0x00080000  /* Cache sharing is enabled */
727 #define SQLITE_Vtab           0x00100000  /* There exists a virtual table */
728 
729 /*
730 ** Possible values for the sqlite.magic field.
731 ** The numbers are obtained at random and have no special meaning, other
732 ** than being distinct from one another.
733 */
734 #define SQLITE_MAGIC_OPEN     0xa029a697  /* Database is open */
735 #define SQLITE_MAGIC_CLOSED   0x9f3c2d33  /* Database is closed */
736 #define SQLITE_MAGIC_SICK     0x4b771290  /* Error and awaiting close */
737 #define SQLITE_MAGIC_BUSY     0xf03b7906  /* Database currently in use */
738 #define SQLITE_MAGIC_ERROR    0xb5357930  /* An SQLITE_MISUSE error occurred */
739 
740 /*
741 ** Each SQL function is defined by an instance of the following
742 ** structure.  A pointer to this structure is stored in the sqlite.aFunc
743 ** hash table.  When multiple functions have the same name, the hash table
744 ** points to a linked list of these structures.
745 */
746 struct FuncDef {
747   i16 nArg;            /* Number of arguments.  -1 means unlimited */
748   u8 iPrefEnc;         /* Preferred text encoding (SQLITE_UTF8, 16LE, 16BE) */
749   u8 needCollSeq;      /* True if sqlite3GetFuncCollSeq() might be called */
750   u8 flags;            /* Some combination of SQLITE_FUNC_* */
751   void *pUserData;     /* User data parameter */
752   FuncDef *pNext;      /* Next function with same name */
753   void (*xFunc)(sqlite3_context*,int,sqlite3_value**); /* Regular function */
754   void (*xStep)(sqlite3_context*,int,sqlite3_value**); /* Aggregate step */
755   void (*xFinalize)(sqlite3_context*);                /* Aggregate finializer */
756   char zName[1];       /* SQL name of the function.  MUST BE LAST */
757 };
758 
759 /*
760 ** Each SQLite module (virtual table definition) is defined by an
761 ** instance of the following structure, stored in the sqlite3.aModule
762 ** hash table.
763 */
764 struct Module {
765   const sqlite3_module *pModule;       /* Callback pointers */
766   const char *zName;                   /* Name passed to create_module() */
767   void *pAux;                          /* pAux passed to create_module() */
768   void (*xDestroy)(void *);            /* Module destructor function */
769 };
770 
771 /*
772 ** Possible values for FuncDef.flags
773 */
774 #define SQLITE_FUNC_LIKE   0x01  /* Candidate for the LIKE optimization */
775 #define SQLITE_FUNC_CASE   0x02  /* Case-sensitive LIKE-type function */
776 #define SQLITE_FUNC_EPHEM  0x04  /* Ephermeral.  Delete with VDBE */
777 
778 /*
779 ** information about each column of an SQL table is held in an instance
780 ** of this structure.
781 */
782 struct Column {
783   char *zName;     /* Name of this column */
784   Expr *pDflt;     /* Default value of this column */
785   char *zType;     /* Data type for this column */
786   char *zColl;     /* Collating sequence.  If NULL, use the default */
787   u8 notNull;      /* True if there is a NOT NULL constraint */
788   u8 isPrimKey;    /* True if this column is part of the PRIMARY KEY */
789   char affinity;   /* One of the SQLITE_AFF_... values */
790 #ifndef SQLITE_OMIT_VIRTUALTABLE
791   u8 isHidden;     /* True if this column is 'hidden' */
792 #endif
793 };
794 
795 /*
796 ** A "Collating Sequence" is defined by an instance of the following
797 ** structure. Conceptually, a collating sequence consists of a name and
798 ** a comparison routine that defines the order of that sequence.
799 **
800 ** There may two seperate implementations of the collation function, one
801 ** that processes text in UTF-8 encoding (CollSeq.xCmp) and another that
802 ** processes text encoded in UTF-16 (CollSeq.xCmp16), using the machine
803 ** native byte order. When a collation sequence is invoked, SQLite selects
804 ** the version that will require the least expensive encoding
805 ** translations, if any.
806 **
807 ** The CollSeq.pUser member variable is an extra parameter that passed in
808 ** as the first argument to the UTF-8 comparison function, xCmp.
809 ** CollSeq.pUser16 is the equivalent for the UTF-16 comparison function,
810 ** xCmp16.
811 **
812 ** If both CollSeq.xCmp and CollSeq.xCmp16 are NULL, it means that the
813 ** collating sequence is undefined.  Indices built on an undefined
814 ** collating sequence may not be read or written.
815 */
816 struct CollSeq {
817   char *zName;          /* Name of the collating sequence, UTF-8 encoded */
818   u8 enc;               /* Text encoding handled by xCmp() */
819   u8 type;              /* One of the SQLITE_COLL_... values below */
820   void *pUser;          /* First argument to xCmp() */
821   int (*xCmp)(void*,int, const void*, int, const void*);
822   void (*xDel)(void*);  /* Destructor for pUser */
823 };
824 
825 /*
826 ** Allowed values of CollSeq flags:
827 */
828 #define SQLITE_COLL_BINARY  1  /* The default memcmp() collating sequence */
829 #define SQLITE_COLL_NOCASE  2  /* The built-in NOCASE collating sequence */
830 #define SQLITE_COLL_REVERSE 3  /* The built-in REVERSE collating sequence */
831 #define SQLITE_COLL_USER    0  /* Any other user-defined collating sequence */
832 
833 /*
834 ** A sort order can be either ASC or DESC.
835 */
836 #define SQLITE_SO_ASC       0  /* Sort in ascending order */
837 #define SQLITE_SO_DESC      1  /* Sort in ascending order */
838 
839 /*
840 ** Column affinity types.
841 **
842 ** These used to have mnemonic name like 'i' for SQLITE_AFF_INTEGER and
843 ** 't' for SQLITE_AFF_TEXT.  But we can save a little space and improve
844 ** the speed a little by number the values consecutively.
845 **
846 ** But rather than start with 0 or 1, we begin with 'a'.  That way,
847 ** when multiple affinity types are concatenated into a string and
848 ** used as the P4 operand, they will be more readable.
849 **
850 ** Note also that the numeric types are grouped together so that testing
851 ** for a numeric type is a single comparison.
852 */
853 #define SQLITE_AFF_TEXT     'a'
854 #define SQLITE_AFF_NONE     'b'
855 #define SQLITE_AFF_NUMERIC  'c'
856 #define SQLITE_AFF_INTEGER  'd'
857 #define SQLITE_AFF_REAL     'e'
858 
859 #define sqlite3IsNumericAffinity(X)  ((X)>=SQLITE_AFF_NUMERIC)
860 
861 /*
862 ** The SQLITE_AFF_MASK values masks off the significant bits of an
863 ** affinity value.
864 */
865 #define SQLITE_AFF_MASK     0x67
866 
867 /*
868 ** Additional bit values that can be ORed with an affinity without
869 ** changing the affinity.
870 */
871 #define SQLITE_JUMPIFNULL   0x08  /* jumps if either operand is NULL */
872 #define SQLITE_STOREP2      0x10  /* Store result in reg[P2] rather than jump */
873 
874 /*
875 ** Each SQL table is represented in memory by an instance of the
876 ** following structure.
877 **
878 ** Table.zName is the name of the table.  The case of the original
879 ** CREATE TABLE statement is stored, but case is not significant for
880 ** comparisons.
881 **
882 ** Table.nCol is the number of columns in this table.  Table.aCol is a
883 ** pointer to an array of Column structures, one for each column.
884 **
885 ** If the table has an INTEGER PRIMARY KEY, then Table.iPKey is the index of
886 ** the column that is that key.   Otherwise Table.iPKey is negative.  Note
887 ** that the datatype of the PRIMARY KEY must be INTEGER for this field to
888 ** be set.  An INTEGER PRIMARY KEY is used as the rowid for each row of
889 ** the table.  If a table has no INTEGER PRIMARY KEY, then a random rowid
890 ** is generated for each row of the table.  Table.hasPrimKey is true if
891 ** the table has any PRIMARY KEY, INTEGER or otherwise.
892 **
893 ** Table.tnum is the page number for the root BTree page of the table in the
894 ** database file.  If Table.iDb is the index of the database table backend
895 ** in sqlite.aDb[].  0 is for the main database and 1 is for the file that
896 ** holds temporary tables and indices.  If Table.isEphem
897 ** is true, then the table is stored in a file that is automatically deleted
898 ** when the VDBE cursor to the table is closed.  In this case Table.tnum
899 ** refers VDBE cursor number that holds the table open, not to the root
900 ** page number.  Transient tables are used to hold the results of a
901 ** sub-query that appears instead of a real table name in the FROM clause
902 ** of a SELECT statement.
903 */
904 struct Table {
905   sqlite3 *db;     /* Associated database connection.  Might be NULL. */
906   char *zName;     /* Name of the table */
907   int nCol;        /* Number of columns in this table */
908   Column *aCol;    /* Information about each column */
909   int iPKey;       /* If not less then 0, use aCol[iPKey] as the primary key */
910   Index *pIndex;   /* List of SQL indexes on this table. */
911   int tnum;        /* Root BTree node for this table (see note above) */
912   Select *pSelect; /* NULL for tables.  Points to definition if a view. */
913   int nRef;          /* Number of pointers to this Table */
914   Trigger *pTrigger; /* List of SQL triggers on this table */
915   FKey *pFKey;       /* Linked list of all foreign keys in this table */
916   char *zColAff;     /* String defining the affinity of each column */
917 #ifndef SQLITE_OMIT_CHECK
918   Expr *pCheck;      /* The AND of all CHECK constraints */
919 #endif
920 #ifndef SQLITE_OMIT_ALTERTABLE
921   int addColOffset;  /* Offset in CREATE TABLE statement to add a new column */
922 #endif
923   u8 readOnly;     /* True if this table should not be written by the user */
924   u8 isEphem;      /* True if created using OP_OpenEphermeral */
925   u8 hasPrimKey;   /* True if there exists a primary key */
926   u8 keyConf;      /* What to do in case of uniqueness conflict on iPKey */
927   u8 autoInc;      /* True if the integer primary key is autoincrement */
928 #ifndef SQLITE_OMIT_VIRTUALTABLE
929   u8 isVirtual;             /* True if this is a virtual table */
930   u8 isCommit;              /* True once the CREATE TABLE has been committed */
931   Module *pMod;             /* Pointer to the implementation of the module */
932   sqlite3_vtab *pVtab;      /* Pointer to the module instance */
933   int nModuleArg;           /* Number of arguments to the module */
934   char **azModuleArg;       /* Text of all module args. [0] is module name */
935 #endif
936   Schema *pSchema;          /* Schema that contains this table */
937 };
938 
939 /*
940 ** Test to see whether or not a table is a virtual table.  This is
941 ** done as a macro so that it will be optimized out when virtual
942 ** table support is omitted from the build.
943 */
944 #ifndef SQLITE_OMIT_VIRTUALTABLE
945 #  define IsVirtual(X)      ((X)->isVirtual)
946 #  define IsHiddenColumn(X) ((X)->isHidden)
947 #else
948 #  define IsVirtual(X)      0
949 #  define IsHiddenColumn(X) 0
950 #endif
951 
952 /*
953 ** Each foreign key constraint is an instance of the following structure.
954 **
955 ** A foreign key is associated with two tables.  The "from" table is
956 ** the table that contains the REFERENCES clause that creates the foreign
957 ** key.  The "to" table is the table that is named in the REFERENCES clause.
958 ** Consider this example:
959 **
960 **     CREATE TABLE ex1(
961 **       a INTEGER PRIMARY KEY,
962 **       b INTEGER CONSTRAINT fk1 REFERENCES ex2(x)
963 **     );
964 **
965 ** For foreign key "fk1", the from-table is "ex1" and the to-table is "ex2".
966 **
967 ** Each REFERENCES clause generates an instance of the following structure
968 ** which is attached to the from-table.  The to-table need not exist when
969 ** the from-table is created.  The existance of the to-table is not checked
970 ** until an attempt is made to insert data into the from-table.
971 **
972 ** The sqlite.aFKey hash table stores pointers to this structure
973 ** given the name of a to-table.  For each to-table, all foreign keys
974 ** associated with that table are on a linked list using the FKey.pNextTo
975 ** field.
976 */
977 struct FKey {
978   Table *pFrom;     /* The table that constains the REFERENCES clause */
979   FKey *pNextFrom;  /* Next foreign key in pFrom */
980   char *zTo;        /* Name of table that the key points to */
981   FKey *pNextTo;    /* Next foreign key that points to zTo */
982   int nCol;         /* Number of columns in this key */
983   struct sColMap {  /* Mapping of columns in pFrom to columns in zTo */
984     int iFrom;         /* Index of column in pFrom */
985     char *zCol;        /* Name of column in zTo.  If 0 use PRIMARY KEY */
986   } *aCol;          /* One entry for each of nCol column s */
987   u8 isDeferred;    /* True if constraint checking is deferred till COMMIT */
988   u8 updateConf;    /* How to resolve conflicts that occur on UPDATE */
989   u8 deleteConf;    /* How to resolve conflicts that occur on DELETE */
990   u8 insertConf;    /* How to resolve conflicts that occur on INSERT */
991 };
992 
993 /*
994 ** SQLite supports many different ways to resolve a constraint
995 ** error.  ROLLBACK processing means that a constraint violation
996 ** causes the operation in process to fail and for the current transaction
997 ** to be rolled back.  ABORT processing means the operation in process
998 ** fails and any prior changes from that one operation are backed out,
999 ** but the transaction is not rolled back.  FAIL processing means that
1000 ** the operation in progress stops and returns an error code.  But prior
1001 ** changes due to the same operation are not backed out and no rollback
1002 ** occurs.  IGNORE means that the particular row that caused the constraint
1003 ** error is not inserted or updated.  Processing continues and no error
1004 ** is returned.  REPLACE means that preexisting database rows that caused
1005 ** a UNIQUE constraint violation are removed so that the new insert or
1006 ** update can proceed.  Processing continues and no error is reported.
1007 **
1008 ** RESTRICT, SETNULL, and CASCADE actions apply only to foreign keys.
1009 ** RESTRICT is the same as ABORT for IMMEDIATE foreign keys and the
1010 ** same as ROLLBACK for DEFERRED keys.  SETNULL means that the foreign
1011 ** key is set to NULL.  CASCADE means that a DELETE or UPDATE of the
1012 ** referenced table row is propagated into the row that holds the
1013 ** foreign key.
1014 **
1015 ** The following symbolic values are used to record which type
1016 ** of action to take.
1017 */
1018 #define OE_None     0   /* There is no constraint to check */
1019 #define OE_Rollback 1   /* Fail the operation and rollback the transaction */
1020 #define OE_Abort    2   /* Back out changes but do no rollback transaction */
1021 #define OE_Fail     3   /* Stop the operation but leave all prior changes */
1022 #define OE_Ignore   4   /* Ignore the error. Do not do the INSERT or UPDATE */
1023 #define OE_Replace  5   /* Delete existing record, then do INSERT or UPDATE */
1024 
1025 #define OE_Restrict 6   /* OE_Abort for IMMEDIATE, OE_Rollback for DEFERRED */
1026 #define OE_SetNull  7   /* Set the foreign key value to NULL */
1027 #define OE_SetDflt  8   /* Set the foreign key value to its default */
1028 #define OE_Cascade  9   /* Cascade the changes */
1029 
1030 #define OE_Default  99  /* Do whatever the default action is */
1031 
1032 
1033 /*
1034 ** An instance of the following structure is passed as the first
1035 ** argument to sqlite3VdbeKeyCompare and is used to control the
1036 ** comparison of the two index keys.
1037 **
1038 ** If the KeyInfo.incrKey value is true and the comparison would
1039 ** otherwise be equal, then return a result as if the second key
1040 ** were larger.
1041 */
1042 struct KeyInfo {
1043   sqlite3 *db;        /* The database connection */
1044   u8 enc;             /* Text encoding - one of the TEXT_Utf* values */
1045   u8 incrKey;         /* Increase 2nd key by epsilon before comparison */
1046   u8 prefixIsEqual;   /* Treat a prefix as equal */
1047   int nField;         /* Number of entries in aColl[] */
1048   u8 *aSortOrder;     /* If defined an aSortOrder[i] is true, sort DESC */
1049   CollSeq *aColl[1];  /* Collating sequence for each term of the key */
1050 };
1051 
1052 /*
1053 ** Each SQL index is represented in memory by an
1054 ** instance of the following structure.
1055 **
1056 ** The columns of the table that are to be indexed are described
1057 ** by the aiColumn[] field of this structure.  For example, suppose
1058 ** we have the following table and index:
1059 **
1060 **     CREATE TABLE Ex1(c1 int, c2 int, c3 text);
1061 **     CREATE INDEX Ex2 ON Ex1(c3,c1);
1062 **
1063 ** In the Table structure describing Ex1, nCol==3 because there are
1064 ** three columns in the table.  In the Index structure describing
1065 ** Ex2, nColumn==2 since 2 of the 3 columns of Ex1 are indexed.
1066 ** The value of aiColumn is {2, 0}.  aiColumn[0]==2 because the
1067 ** first column to be indexed (c3) has an index of 2 in Ex1.aCol[].
1068 ** The second column to be indexed (c1) has an index of 0 in
1069 ** Ex1.aCol[], hence Ex2.aiColumn[1]==0.
1070 **
1071 ** The Index.onError field determines whether or not the indexed columns
1072 ** must be unique and what to do if they are not.  When Index.onError=OE_None,
1073 ** it means this is not a unique index.  Otherwise it is a unique index
1074 ** and the value of Index.onError indicate the which conflict resolution
1075 ** algorithm to employ whenever an attempt is made to insert a non-unique
1076 ** element.
1077 */
1078 struct Index {
1079   char *zName;     /* Name of this index */
1080   int nColumn;     /* Number of columns in the table used by this index */
1081   int *aiColumn;   /* Which columns are used by this index.  1st is 0 */
1082   unsigned *aiRowEst; /* Result of ANALYZE: Est. rows selected by each column */
1083   Table *pTable;   /* The SQL table being indexed */
1084   int tnum;        /* Page containing root of this index in database file */
1085   u8 onError;      /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
1086   u8 autoIndex;    /* True if is automatically created (ex: by UNIQUE) */
1087   char *zColAff;   /* String defining the affinity of each column */
1088   Index *pNext;    /* The next index associated with the same table */
1089   Schema *pSchema; /* Schema containing this index */
1090   u8 *aSortOrder;  /* Array of size Index.nColumn. True==DESC, False==ASC */
1091   char **azColl;   /* Array of collation sequence names for index */
1092 };
1093 
1094 /*
1095 ** Each token coming out of the lexer is an instance of
1096 ** this structure.  Tokens are also used as part of an expression.
1097 **
1098 ** Note if Token.z==0 then Token.dyn and Token.n are undefined and
1099 ** may contain random values.  Do not make any assuptions about Token.dyn
1100 ** and Token.n when Token.z==0.
1101 */
1102 struct Token {
1103   const unsigned char *z; /* Text of the token.  Not NULL-terminated! */
1104   unsigned dyn  : 1;      /* True for malloced memory, false for static */
1105   unsigned n    : 31;     /* Number of characters in this token */
1106 };
1107 
1108 /*
1109 ** An instance of this structure contains information needed to generate
1110 ** code for a SELECT that contains aggregate functions.
1111 **
1112 ** If Expr.op==TK_AGG_COLUMN or TK_AGG_FUNCTION then Expr.pAggInfo is a
1113 ** pointer to this structure.  The Expr.iColumn field is the index in
1114 ** AggInfo.aCol[] or AggInfo.aFunc[] of information needed to generate
1115 ** code for that node.
1116 **
1117 ** AggInfo.pGroupBy and AggInfo.aFunc.pExpr point to fields within the
1118 ** original Select structure that describes the SELECT statement.  These
1119 ** fields do not need to be freed when deallocating the AggInfo structure.
1120 */
1121 struct AggInfo {
1122   u8 directMode;          /* Direct rendering mode means take data directly
1123                           ** from source tables rather than from accumulators */
1124   u8 useSortingIdx;       /* In direct mode, reference the sorting index rather
1125                           ** than the source table */
1126   int sortingIdx;         /* Cursor number of the sorting index */
1127   ExprList *pGroupBy;     /* The group by clause */
1128   int nSortingColumn;     /* Number of columns in the sorting index */
1129   struct AggInfo_col {    /* For each column used in source tables */
1130     Table *pTab;             /* Source table */
1131     int iTable;              /* Cursor number of the source table */
1132     int iColumn;             /* Column number within the source table */
1133     int iSorterColumn;       /* Column number in the sorting index */
1134     int iMem;                /* Memory location that acts as accumulator */
1135     Expr *pExpr;             /* The original expression */
1136   } *aCol;
1137   int nColumn;            /* Number of used entries in aCol[] */
1138   int nColumnAlloc;       /* Number of slots allocated for aCol[] */
1139   int nAccumulator;       /* Number of columns that show through to the output.
1140                           ** Additional columns are used only as parameters to
1141                           ** aggregate functions */
1142   struct AggInfo_func {   /* For each aggregate function */
1143     Expr *pExpr;             /* Expression encoding the function */
1144     FuncDef *pFunc;          /* The aggregate function implementation */
1145     int iMem;                /* Memory location that acts as accumulator */
1146     int iDistinct;           /* Ephermeral table used to enforce DISTINCT */
1147   } *aFunc;
1148   int nFunc;              /* Number of entries in aFunc[] */
1149   int nFuncAlloc;         /* Number of slots allocated for aFunc[] */
1150 };
1151 
1152 /*
1153 ** Each node of an expression in the parse tree is an instance
1154 ** of this structure.
1155 **
1156 ** Expr.op is the opcode.  The integer parser token codes are reused
1157 ** as opcodes here.  For example, the parser defines TK_GE to be an integer
1158 ** code representing the ">=" operator.  This same integer code is reused
1159 ** to represent the greater-than-or-equal-to operator in the expression
1160 ** tree.
1161 **
1162 ** Expr.pRight and Expr.pLeft are subexpressions.  Expr.pList is a list
1163 ** of argument if the expression is a function.
1164 **
1165 ** Expr.token is the operator token for this node.  For some expressions
1166 ** that have subexpressions, Expr.token can be the complete text that gave
1167 ** rise to the Expr.  In the latter case, the token is marked as being
1168 ** a compound token.
1169 **
1170 ** An expression of the form ID or ID.ID refers to a column in a table.
1171 ** For such expressions, Expr.op is set to TK_COLUMN and Expr.iTable is
1172 ** the integer cursor number of a VDBE cursor pointing to that table and
1173 ** Expr.iColumn is the column number for the specific column.  If the
1174 ** expression is used as a result in an aggregate SELECT, then the
1175 ** value is also stored in the Expr.iAgg column in the aggregate so that
1176 ** it can be accessed after all aggregates are computed.
1177 **
1178 ** If the expression is a function, the Expr.iTable is an integer code
1179 ** representing which function.  If the expression is an unbound variable
1180 ** marker (a question mark character '?' in the original SQL) then the
1181 ** Expr.iTable holds the index number for that variable.
1182 **
1183 ** If the expression is a subquery then Expr.iColumn holds an integer
1184 ** register number containing the result of the subquery.  If the
1185 ** subquery gives a constant result, then iTable is -1.  If the subquery
1186 ** gives a different answer at different times during statement processing
1187 ** then iTable is the address of a subroutine that computes the subquery.
1188 **
1189 ** The Expr.pSelect field points to a SELECT statement.  The SELECT might
1190 ** be the right operand of an IN operator.  Or, if a scalar SELECT appears
1191 ** in an expression the opcode is TK_SELECT and Expr.pSelect is the only
1192 ** operand.
1193 **
1194 ** If the Expr is of type OP_Column, and the table it is selecting from
1195 ** is a disk table or the "old.*" pseudo-table, then pTab points to the
1196 ** corresponding table definition.
1197 */
1198 struct Expr {
1199   u8 op;                 /* Operation performed by this node */
1200   char affinity;         /* The affinity of the column or 0 if not a column */
1201   u16 flags;             /* Various flags.  See below */
1202   CollSeq *pColl;        /* The collation type of the column or 0 */
1203   Expr *pLeft, *pRight;  /* Left and right subnodes */
1204   ExprList *pList;       /* A list of expressions used as function arguments
1205                          ** or in "<expr> IN (<expr-list)" */
1206   Token token;           /* An operand token */
1207   Token span;            /* Complete text of the expression */
1208   int iTable, iColumn;   /* When op==TK_COLUMN, then this expr node means the
1209                          ** iColumn-th field of the iTable-th table. */
1210   AggInfo *pAggInfo;     /* Used by TK_AGG_COLUMN and TK_AGG_FUNCTION */
1211   int iAgg;              /* Which entry in pAggInfo->aCol[] or ->aFunc[] */
1212   int iRightJoinTable;   /* If EP_FromJoin, the right table of the join */
1213   Select *pSelect;       /* When the expression is a sub-select.  Also the
1214                          ** right side of "<expr> IN (<select>)" */
1215   Table *pTab;           /* Table for OP_Column expressions. */
1216 #if SQLITE_MAX_EXPR_DEPTH>0
1217   int nHeight;           /* Height of the tree headed by this node */
1218 #endif
1219 };
1220 
1221 /*
1222 ** The following are the meanings of bits in the Expr.flags field.
1223 */
1224 #define EP_FromJoin   0x0001  /* Originated in ON or USING clause of a join */
1225 #define EP_Agg        0x0002  /* Contains one or more aggregate functions */
1226 #define EP_Resolved   0x0004  /* IDs have been resolved to COLUMNs */
1227 #define EP_Error      0x0008  /* Expression contains one or more errors */
1228 #define EP_Distinct   0x0010  /* Aggregate function with DISTINCT keyword */
1229 #define EP_VarSelect  0x0020  /* pSelect is correlated, not constant */
1230 #define EP_Dequoted   0x0040  /* True if the string has been dequoted */
1231 #define EP_InfixFunc  0x0080  /* True for an infix function: LIKE, GLOB, etc */
1232 #define EP_ExpCollate 0x0100  /* Collating sequence specified explicitly */
1233 #define EP_AnyAff     0x0200  /* Can take a cached column of any affinity */
1234 #define EP_FixedDest  0x0400  /* Result needed in a specific register */
1235 #define EP_IntValue   0x0800  /* Integer value contained in iTable */
1236 /*
1237 ** These macros can be used to test, set, or clear bits in the
1238 ** Expr.flags field.
1239 */
1240 #define ExprHasProperty(E,P)     (((E)->flags&(P))==(P))
1241 #define ExprHasAnyProperty(E,P)  (((E)->flags&(P))!=0)
1242 #define ExprSetProperty(E,P)     (E)->flags|=(P)
1243 #define ExprClearProperty(E,P)   (E)->flags&=~(P)
1244 
1245 /*
1246 ** A list of expressions.  Each expression may optionally have a
1247 ** name.  An expr/name combination can be used in several ways, such
1248 ** as the list of "expr AS ID" fields following a "SELECT" or in the
1249 ** list of "ID = expr" items in an UPDATE.  A list of expressions can
1250 ** also be used as the argument to a function, in which case the a.zName
1251 ** field is not used.
1252 */
1253 struct ExprList {
1254   int nExpr;             /* Number of expressions on the list */
1255   int nAlloc;            /* Number of entries allocated below */
1256   int iECursor;          /* VDBE Cursor associated with this ExprList */
1257   struct ExprList_item {
1258     Expr *pExpr;           /* The list of expressions */
1259     char *zName;           /* Token associated with this expression */
1260     u8 sortOrder;          /* 1 for DESC or 0 for ASC */
1261     u8 isAgg;              /* True if this is an aggregate like count(*) */
1262     u8 done;               /* A flag to indicate when processing is finished */
1263   } *a;                  /* One entry for each expression */
1264 };
1265 
1266 /*
1267 ** An instance of this structure can hold a simple list of identifiers,
1268 ** such as the list "a,b,c" in the following statements:
1269 **
1270 **      INSERT INTO t(a,b,c) VALUES ...;
1271 **      CREATE INDEX idx ON t(a,b,c);
1272 **      CREATE TRIGGER trig BEFORE UPDATE ON t(a,b,c) ...;
1273 **
1274 ** The IdList.a.idx field is used when the IdList represents the list of
1275 ** column names after a table name in an INSERT statement.  In the statement
1276 **
1277 **     INSERT INTO t(a,b,c) ...
1278 **
1279 ** If "a" is the k-th column of table "t", then IdList.a[0].idx==k.
1280 */
1281 struct IdList {
1282   struct IdList_item {
1283     char *zName;      /* Name of the identifier */
1284     int idx;          /* Index in some Table.aCol[] of a column named zName */
1285   } *a;
1286   int nId;         /* Number of identifiers on the list */
1287   int nAlloc;      /* Number of entries allocated for a[] below */
1288 };
1289 
1290 /*
1291 ** The bitmask datatype defined below is used for various optimizations.
1292 **
1293 ** Changing this from a 64-bit to a 32-bit type limits the number of
1294 ** tables in a join to 32 instead of 64.  But it also reduces the size
1295 ** of the library by 738 bytes on ix86.
1296 */
1297 typedef u64 Bitmask;
1298 
1299 /*
1300 ** The following structure describes the FROM clause of a SELECT statement.
1301 ** Each table or subquery in the FROM clause is a separate element of
1302 ** the SrcList.a[] array.
1303 **
1304 ** With the addition of multiple database support, the following structure
1305 ** can also be used to describe a particular table such as the table that
1306 ** is modified by an INSERT, DELETE, or UPDATE statement.  In standard SQL,
1307 ** such a table must be a simple name: ID.  But in SQLite, the table can
1308 ** now be identified by a database name, a dot, then the table name: ID.ID.
1309 **
1310 ** The jointype starts out showing the join type between the current table
1311 ** and the next table on the list.  The parser builds the list this way.
1312 ** But sqlite3SrcListShiftJoinType() later shifts the jointypes so that each
1313 ** jointype expresses the join between the table and the previous table.
1314 */
1315 struct SrcList {
1316   i16 nSrc;        /* Number of tables or subqueries in the FROM clause */
1317   i16 nAlloc;      /* Number of entries allocated in a[] below */
1318   struct SrcList_item {
1319     char *zDatabase;  /* Name of database holding this table */
1320     char *zName;      /* Name of the table */
1321     char *zAlias;     /* The "B" part of a "A AS B" phrase.  zName is the "A" */
1322     Table *pTab;      /* An SQL table corresponding to zName */
1323     Select *pSelect;  /* A SELECT statement used in place of a table name */
1324     u8 isPopulated;   /* Temporary table associated with SELECT is populated */
1325     u8 jointype;      /* Type of join between this able and the previous */
1326     int iCursor;      /* The VDBE cursor number used to access this table */
1327     Expr *pOn;        /* The ON clause of a join */
1328     IdList *pUsing;   /* The USING clause of a join */
1329     Bitmask colUsed;  /* Bit N (1<<N) set if column N or pTab is used */
1330   } a[1];             /* One entry for each identifier on the list */
1331 };
1332 
1333 /*
1334 ** Permitted values of the SrcList.a.jointype field
1335 */
1336 #define JT_INNER     0x0001    /* Any kind of inner or cross join */
1337 #define JT_CROSS     0x0002    /* Explicit use of the CROSS keyword */
1338 #define JT_NATURAL   0x0004    /* True for a "natural" join */
1339 #define JT_LEFT      0x0008    /* Left outer join */
1340 #define JT_RIGHT     0x0010    /* Right outer join */
1341 #define JT_OUTER     0x0020    /* The "OUTER" keyword is present */
1342 #define JT_ERROR     0x0040    /* unknown or unsupported join type */
1343 
1344 /*
1345 ** For each nested loop in a WHERE clause implementation, the WhereInfo
1346 ** structure contains a single instance of this structure.  This structure
1347 ** is intended to be private the the where.c module and should not be
1348 ** access or modified by other modules.
1349 **
1350 ** The pIdxInfo and pBestIdx fields are used to help pick the best
1351 ** index on a virtual table.  The pIdxInfo pointer contains indexing
1352 ** information for the i-th table in the FROM clause before reordering.
1353 ** All the pIdxInfo pointers are freed by whereInfoFree() in where.c.
1354 ** The pBestIdx pointer is a copy of pIdxInfo for the i-th table after
1355 ** FROM clause ordering.  This is a little confusing so I will repeat
1356 ** it in different words.  WhereInfo.a[i].pIdxInfo is index information
1357 ** for WhereInfo.pTabList.a[i].  WhereInfo.a[i].pBestInfo is the
1358 ** index information for the i-th loop of the join.  pBestInfo is always
1359 ** either NULL or a copy of some pIdxInfo.  So for cleanup it is
1360 ** sufficient to free all of the pIdxInfo pointers.
1361 **
1362 */
1363 struct WhereLevel {
1364   int iFrom;            /* Which entry in the FROM clause */
1365   int flags;            /* Flags associated with this level */
1366   int iMem;             /* First memory cell used by this level */
1367   int iLeftJoin;        /* Memory cell used to implement LEFT OUTER JOIN */
1368   Index *pIdx;          /* Index used.  NULL if no index */
1369   int iTabCur;          /* The VDBE cursor used to access the table */
1370   int iIdxCur;          /* The VDBE cursor used to acesss pIdx */
1371   int brk;              /* Jump here to break out of the loop */
1372   int nxt;              /* Jump here to start the next IN combination */
1373   int cont;             /* Jump here to continue with the next loop cycle */
1374   int top;              /* First instruction of interior of the loop */
1375   int op, p1, p2;       /* Opcode used to terminate the loop */
1376   int nEq;              /* Number of == or IN constraints on this loop */
1377   int nIn;              /* Number of IN operators constraining this loop */
1378   struct InLoop {
1379     int iCur;              /* The VDBE cursor used by this IN operator */
1380     int topAddr;           /* Top of the IN loop */
1381   } *aInLoop;           /* Information about each nested IN operator */
1382   sqlite3_index_info *pBestIdx;  /* Index information for this level */
1383 
1384   /* The following field is really not part of the current level.  But
1385   ** we need a place to cache index information for each table in the
1386   ** FROM clause and the WhereLevel structure is a convenient place.
1387   */
1388   sqlite3_index_info *pIdxInfo;  /* Index info for n-th source table */
1389 };
1390 
1391 /*
1392 ** Flags appropriate for the wflags parameter of sqlite3WhereBegin().
1393 */
1394 #define WHERE_ORDERBY_NORMAL     0   /* No-op */
1395 #define WHERE_ORDERBY_MIN        1   /* ORDER BY processing for min() func */
1396 #define WHERE_ORDERBY_MAX        2   /* ORDER BY processing for max() func */
1397 #define WHERE_ONEPASS_DESIRED    4   /* Want to do one-pass UPDATE/DELETE */
1398 
1399 /*
1400 ** The WHERE clause processing routine has two halves.  The
1401 ** first part does the start of the WHERE loop and the second
1402 ** half does the tail of the WHERE loop.  An instance of
1403 ** this structure is returned by the first half and passed
1404 ** into the second half to give some continuity.
1405 */
1406 struct WhereInfo {
1407   Parse *pParse;       /* Parsing and code generating context */
1408   u8 okOnePass;        /* Ok to use one-pass algorithm for UPDATE or DELETE */
1409   SrcList *pTabList;   /* List of tables in the join */
1410   int iTop;            /* The very beginning of the WHERE loop */
1411   int iContinue;       /* Jump here to continue with next record */
1412   int iBreak;          /* Jump here to break out of the loop */
1413   int nLevel;          /* Number of nested loop */
1414   sqlite3_index_info **apInfo;  /* Array of pointers to index info structures */
1415   WhereLevel a[1];     /* Information about each nest loop in the WHERE */
1416 };
1417 
1418 /*
1419 ** A NameContext defines a context in which to resolve table and column
1420 ** names.  The context consists of a list of tables (the pSrcList) field and
1421 ** a list of named expression (pEList).  The named expression list may
1422 ** be NULL.  The pSrc corresponds to the FROM clause of a SELECT or
1423 ** to the table being operated on by INSERT, UPDATE, or DELETE.  The
1424 ** pEList corresponds to the result set of a SELECT and is NULL for
1425 ** other statements.
1426 **
1427 ** NameContexts can be nested.  When resolving names, the inner-most
1428 ** context is searched first.  If no match is found, the next outer
1429 ** context is checked.  If there is still no match, the next context
1430 ** is checked.  This process continues until either a match is found
1431 ** or all contexts are check.  When a match is found, the nRef member of
1432 ** the context containing the match is incremented.
1433 **
1434 ** Each subquery gets a new NameContext.  The pNext field points to the
1435 ** NameContext in the parent query.  Thus the process of scanning the
1436 ** NameContext list corresponds to searching through successively outer
1437 ** subqueries looking for a match.
1438 */
1439 struct NameContext {
1440   Parse *pParse;       /* The parser */
1441   SrcList *pSrcList;   /* One or more tables used to resolve names */
1442   ExprList *pEList;    /* Optional list of named expressions */
1443   int nRef;            /* Number of names resolved by this context */
1444   int nErr;            /* Number of errors encountered while resolving names */
1445   u8 allowAgg;         /* Aggregate functions allowed here */
1446   u8 hasAgg;           /* True if aggregates are seen */
1447   u8 isCheck;          /* True if resolving names in a CHECK constraint */
1448   int nDepth;          /* Depth of subquery recursion. 1 for no recursion */
1449   AggInfo *pAggInfo;   /* Information about aggregates at this level */
1450   NameContext *pNext;  /* Next outer name context.  NULL for outermost */
1451 };
1452 
1453 /*
1454 ** An instance of the following structure contains all information
1455 ** needed to generate code for a single SELECT statement.
1456 **
1457 ** nLimit is set to -1 if there is no LIMIT clause.  nOffset is set to 0.
1458 ** If there is a LIMIT clause, the parser sets nLimit to the value of the
1459 ** limit and nOffset to the value of the offset (or 0 if there is not
1460 ** offset).  But later on, nLimit and nOffset become the memory locations
1461 ** in the VDBE that record the limit and offset counters.
1462 **
1463 ** addrOpenEphm[] entries contain the address of OP_OpenEphemeral opcodes.
1464 ** These addresses must be stored so that we can go back and fill in
1465 ** the P4_KEYINFO and P2 parameters later.  Neither the KeyInfo nor
1466 ** the number of columns in P2 can be computed at the same time
1467 ** as the OP_OpenEphm instruction is coded because not
1468 ** enough information about the compound query is known at that point.
1469 ** The KeyInfo for addrOpenTran[0] and [1] contains collating sequences
1470 ** for the result set.  The KeyInfo for addrOpenTran[2] contains collating
1471 ** sequences for the ORDER BY clause.
1472 */
1473 struct Select {
1474   ExprList *pEList;      /* The fields of the result */
1475   u8 op;                 /* One of: TK_UNION TK_ALL TK_INTERSECT TK_EXCEPT */
1476   u8 isDistinct;         /* True if the DISTINCT keyword is present */
1477   u8 isResolved;         /* True once sqlite3SelectResolve() has run. */
1478   u8 isAgg;              /* True if this is an aggregate query */
1479   u8 usesEphm;           /* True if uses an OpenEphemeral opcode */
1480   u8 disallowOrderBy;    /* Do not allow an ORDER BY to be attached if TRUE */
1481   char affinity;         /* MakeRecord with this affinity for SRT_Set */
1482   SrcList *pSrc;         /* The FROM clause */
1483   Expr *pWhere;          /* The WHERE clause */
1484   ExprList *pGroupBy;    /* The GROUP BY clause */
1485   Expr *pHaving;         /* The HAVING clause */
1486   ExprList *pOrderBy;    /* The ORDER BY clause */
1487   Select *pPrior;        /* Prior select in a compound select statement */
1488   Select *pNext;         /* Next select to the left in a compound */
1489   Select *pRightmost;    /* Right-most select in a compound select statement */
1490   Expr *pLimit;          /* LIMIT expression. NULL means not used. */
1491   Expr *pOffset;         /* OFFSET expression. NULL means not used. */
1492   int iLimit, iOffset;   /* Memory registers holding LIMIT & OFFSET counters */
1493   int addrOpenEphm[3];   /* OP_OpenEphem opcodes related to this select */
1494 };
1495 
1496 /*
1497 ** The results of a select can be distributed in several ways.
1498 */
1499 #define SRT_Union        1  /* Store result as keys in an index */
1500 #define SRT_Except       2  /* Remove result from a UNION index */
1501 #define SRT_Exists       3  /* Store 1 if the result is not empty */
1502 #define SRT_Discard      4  /* Do not save the results anywhere */
1503 
1504 /* The ORDER BY clause is ignored for all of the above */
1505 #define IgnorableOrderby(X) ((X->eDest)<=SRT_Discard)
1506 
1507 #define SRT_Callback     5  /* Invoke a callback with each row of result */
1508 #define SRT_Mem          6  /* Store result in a memory cell */
1509 #define SRT_Set          7  /* Store results as keys in an index */
1510 #define SRT_Table        8  /* Store result as data with an automatic rowid */
1511 #define SRT_EphemTab     9  /* Create transient tab and store like SRT_Table */
1512 #define SRT_Coroutine   10  /* Generate a single row of result */
1513 
1514 /*
1515 ** A structure used to customize the behaviour of sqlite3Select(). See
1516 ** comments above sqlite3Select() for details.
1517 */
1518 typedef struct SelectDest SelectDest;
1519 struct SelectDest {
1520   u8 eDest;         /* How to dispose of the results */
1521   u8 affinity;      /* Affinity used when eDest==SRT_Set */
1522   int iParm;        /* A parameter used by the eDest disposal method */
1523   int iMem;         /* Base register where results are written */
1524   int nMem;         /* Number of registers allocated */
1525 };
1526 
1527 /*
1528 ** An SQL parser context.  A copy of this structure is passed through
1529 ** the parser and down into all the parser action routine in order to
1530 ** carry around information that is global to the entire parse.
1531 **
1532 ** The structure is divided into two parts.  When the parser and code
1533 ** generate call themselves recursively, the first part of the structure
1534 ** is constant but the second part is reset at the beginning and end of
1535 ** each recursion.
1536 **
1537 ** The nTableLock and aTableLock variables are only used if the shared-cache
1538 ** feature is enabled (if sqlite3Tsd()->useSharedData is true). They are
1539 ** used to store the set of table-locks required by the statement being
1540 ** compiled. Function sqlite3TableLock() is used to add entries to the
1541 ** list.
1542 */
1543 struct Parse {
1544   sqlite3 *db;         /* The main database structure */
1545   int rc;              /* Return code from execution */
1546   char *zErrMsg;       /* An error message */
1547   Vdbe *pVdbe;         /* An engine for executing database bytecode */
1548   u8 colNamesSet;      /* TRUE after OP_ColumnName has been issued to pVdbe */
1549   u8 nameClash;        /* A permanent table name clashes with temp table name */
1550   u8 checkSchema;      /* Causes schema cookie check after an error */
1551   u8 nested;           /* Number of nested calls to the parser/code generator */
1552   u8 parseError;       /* True after a parsing error.  Ticket #1794 */
1553   u8 nTempReg;         /* Number of temporary registers in aTempReg[] */
1554   u8 nTempInUse;       /* Number of aTempReg[] currently checked out */
1555   int aTempReg[8];     /* Holding area for temporary registers */
1556   int nRangeReg;       /* Size of the temporary register block */
1557   int iRangeReg;       /* First register in temporary register block */
1558   int nErr;            /* Number of errors seen */
1559   int nTab;            /* Number of previously allocated VDBE cursors */
1560   int nMem;            /* Number of memory cells used so far */
1561   int nSet;            /* Number of sets used so far */
1562   int ckBase;          /* Base register of data during check constraints */
1563   int disableColCache; /* True to disable adding to column cache */
1564   int nColCache;       /* Number of entries in the column cache */
1565   int iColCache;       /* Next entry of the cache to replace */
1566   struct yColCache {
1567     int iTable;           /* Table cursor number */
1568     int iColumn;          /* Table column number */
1569     char affChange;       /* True if this register has had an affinity change */
1570     int iReg;             /* Register holding value of this column */
1571   } aColCache[10];     /* One for each valid column cache entry */
1572   u32 writeMask;       /* Start a write transaction on these databases */
1573   u32 cookieMask;      /* Bitmask of schema verified databases */
1574   int cookieGoto;      /* Address of OP_Goto to cookie verifier subroutine */
1575   int cookieValue[SQLITE_MAX_ATTACHED+2];  /* Values of cookies to verify */
1576 #ifndef SQLITE_OMIT_SHARED_CACHE
1577   int nTableLock;        /* Number of locks in aTableLock */
1578   TableLock *aTableLock; /* Required table locks for shared-cache mode */
1579 #endif
1580   int regRowid;        /* Register holding rowid of CREATE TABLE entry */
1581   int regRoot;         /* Register holding root page number for new objects */
1582 
1583   /* Above is constant between recursions.  Below is reset before and after
1584   ** each recursion */
1585 
1586   int nVar;            /* Number of '?' variables seen in the SQL so far */
1587   int nVarExpr;        /* Number of used slots in apVarExpr[] */
1588   int nVarExprAlloc;   /* Number of allocated slots in apVarExpr[] */
1589   Expr **apVarExpr;    /* Pointers to :aaa and $aaaa wildcard expressions */
1590   u8 explain;          /* True if the EXPLAIN flag is found on the query */
1591   Token sErrToken;     /* The token at which the error occurred */
1592   Token sNameToken;    /* Token with unqualified schema object name */
1593   Token sLastToken;    /* The last token parsed */
1594   const char *zSql;    /* All SQL text */
1595   const char *zTail;   /* All SQL text past the last semicolon parsed */
1596   Table *pNewTable;    /* A table being constructed by CREATE TABLE */
1597   Trigger *pNewTrigger;     /* Trigger under construct by a CREATE TRIGGER */
1598   TriggerStack *trigStack;  /* Trigger actions being coded */
1599   const char *zAuthContext; /* The 6th parameter to db->xAuth callbacks */
1600 #ifndef SQLITE_OMIT_VIRTUALTABLE
1601   Token sArg;                /* Complete text of a module argument */
1602   u8 declareVtab;            /* True if inside sqlite3_declare_vtab() */
1603   int nVtabLock;             /* Number of virtual tables to lock */
1604   Table **apVtabLock;        /* Pointer to virtual tables needing locking */
1605 #endif
1606   int nHeight;            /* Expression tree height of current sub-select */
1607 };
1608 
1609 #ifdef SQLITE_OMIT_VIRTUALTABLE
1610   #define IN_DECLARE_VTAB 0
1611 #else
1612   #define IN_DECLARE_VTAB (pParse->declareVtab)
1613 #endif
1614 
1615 /*
1616 ** An instance of the following structure can be declared on a stack and used
1617 ** to save the Parse.zAuthContext value so that it can be restored later.
1618 */
1619 struct AuthContext {
1620   const char *zAuthContext;   /* Put saved Parse.zAuthContext here */
1621   Parse *pParse;              /* The Parse structure */
1622 };
1623 
1624 /*
1625 ** Bitfield flags for P2 value in OP_Insert and OP_Delete
1626 */
1627 #define OPFLAG_NCHANGE   1    /* Set to update db->nChange */
1628 #define OPFLAG_LASTROWID 2    /* Set to update db->lastRowid */
1629 #define OPFLAG_ISUPDATE  4    /* This OP_Insert is an sql UPDATE */
1630 #define OPFLAG_APPEND    8    /* This is likely to be an append */
1631 
1632 /*
1633  * Each trigger present in the database schema is stored as an instance of
1634  * struct Trigger.
1635  *
1636  * Pointers to instances of struct Trigger are stored in two ways.
1637  * 1. In the "trigHash" hash table (part of the sqlite3* that represents the
1638  *    database). This allows Trigger structures to be retrieved by name.
1639  * 2. All triggers associated with a single table form a linked list, using the
1640  *    pNext member of struct Trigger. A pointer to the first element of the
1641  *    linked list is stored as the "pTrigger" member of the associated
1642  *    struct Table.
1643  *
1644  * The "step_list" member points to the first element of a linked list
1645  * containing the SQL statements specified as the trigger program.
1646  */
1647 struct Trigger {
1648   char *name;             /* The name of the trigger                        */
1649   char *table;            /* The table or view to which the trigger applies */
1650   u8 op;                  /* One of TK_DELETE, TK_UPDATE, TK_INSERT         */
1651   u8 tr_tm;               /* One of TRIGGER_BEFORE, TRIGGER_AFTER */
1652   Expr *pWhen;            /* The WHEN clause of the expresion (may be NULL) */
1653   IdList *pColumns;       /* If this is an UPDATE OF <column-list> trigger,
1654                              the <column-list> is stored here */
1655   Token nameToken;        /* Token containing zName. Use during parsing only */
1656   Schema *pSchema;        /* Schema containing the trigger */
1657   Schema *pTabSchema;     /* Schema containing the table */
1658   TriggerStep *step_list; /* Link list of trigger program steps             */
1659   Trigger *pNext;         /* Next trigger associated with the table */
1660 };
1661 
1662 /*
1663 ** A trigger is either a BEFORE or an AFTER trigger.  The following constants
1664 ** determine which.
1665 **
1666 ** If there are multiple triggers, you might of some BEFORE and some AFTER.
1667 ** In that cases, the constants below can be ORed together.
1668 */
1669 #define TRIGGER_BEFORE  1
1670 #define TRIGGER_AFTER   2
1671 
1672 /*
1673  * An instance of struct TriggerStep is used to store a single SQL statement
1674  * that is a part of a trigger-program.
1675  *
1676  * Instances of struct TriggerStep are stored in a singly linked list (linked
1677  * using the "pNext" member) referenced by the "step_list" member of the
1678  * associated struct Trigger instance. The first element of the linked list is
1679  * the first step of the trigger-program.
1680  *
1681  * The "op" member indicates whether this is a "DELETE", "INSERT", "UPDATE" or
1682  * "SELECT" statement. The meanings of the other members is determined by the
1683  * value of "op" as follows:
1684  *
1685  * (op == TK_INSERT)
1686  * orconf    -> stores the ON CONFLICT algorithm
1687  * pSelect   -> If this is an INSERT INTO ... SELECT ... statement, then
1688  *              this stores a pointer to the SELECT statement. Otherwise NULL.
1689  * target    -> A token holding the name of the table to insert into.
1690  * pExprList -> If this is an INSERT INTO ... VALUES ... statement, then
1691  *              this stores values to be inserted. Otherwise NULL.
1692  * pIdList   -> If this is an INSERT INTO ... (<column-names>) VALUES ...
1693  *              statement, then this stores the column-names to be
1694  *              inserted into.
1695  *
1696  * (op == TK_DELETE)
1697  * target    -> A token holding the name of the table to delete from.
1698  * pWhere    -> The WHERE clause of the DELETE statement if one is specified.
1699  *              Otherwise NULL.
1700  *
1701  * (op == TK_UPDATE)
1702  * target    -> A token holding the name of the table to update rows of.
1703  * pWhere    -> The WHERE clause of the UPDATE statement if one is specified.
1704  *              Otherwise NULL.
1705  * pExprList -> A list of the columns to update and the expressions to update
1706  *              them to. See sqlite3Update() documentation of "pChanges"
1707  *              argument.
1708  *
1709  */
1710 struct TriggerStep {
1711   int op;              /* One of TK_DELETE, TK_UPDATE, TK_INSERT, TK_SELECT */
1712   int orconf;          /* OE_Rollback etc. */
1713   Trigger *pTrig;      /* The trigger that this step is a part of */
1714 
1715   Select *pSelect;     /* Valid for SELECT and sometimes
1716                           INSERT steps (when pExprList == 0) */
1717   Token target;        /* Valid for DELETE, UPDATE, INSERT steps */
1718   Expr *pWhere;        /* Valid for DELETE, UPDATE steps */
1719   ExprList *pExprList; /* Valid for UPDATE statements and sometimes
1720                            INSERT steps (when pSelect == 0)         */
1721   IdList *pIdList;     /* Valid for INSERT statements only */
1722   TriggerStep *pNext;  /* Next in the link-list */
1723   TriggerStep *pLast;  /* Last element in link-list. Valid for 1st elem only */
1724 };
1725 
1726 /*
1727  * An instance of struct TriggerStack stores information required during code
1728  * generation of a single trigger program. While the trigger program is being
1729  * coded, its associated TriggerStack instance is pointed to by the
1730  * "pTriggerStack" member of the Parse structure.
1731  *
1732  * The pTab member points to the table that triggers are being coded on. The
1733  * newIdx member contains the index of the vdbe cursor that points at the temp
1734  * table that stores the new.* references. If new.* references are not valid
1735  * for the trigger being coded (for example an ON DELETE trigger), then newIdx
1736  * is set to -1. The oldIdx member is analogous to newIdx, for old.* references.
1737  *
1738  * The ON CONFLICT policy to be used for the trigger program steps is stored
1739  * as the orconf member. If this is OE_Default, then the ON CONFLICT clause
1740  * specified for individual triggers steps is used.
1741  *
1742  * struct TriggerStack has a "pNext" member, to allow linked lists to be
1743  * constructed. When coding nested triggers (triggers fired by other triggers)
1744  * each nested trigger stores its parent trigger's TriggerStack as the "pNext"
1745  * pointer. Once the nested trigger has been coded, the pNext value is restored
1746  * to the pTriggerStack member of the Parse stucture and coding of the parent
1747  * trigger continues.
1748  *
1749  * Before a nested trigger is coded, the linked list pointed to by the
1750  * pTriggerStack is scanned to ensure that the trigger is not about to be coded
1751  * recursively. If this condition is detected, the nested trigger is not coded.
1752  */
1753 struct TriggerStack {
1754   Table *pTab;         /* Table that triggers are currently being coded on */
1755   int newIdx;          /* Index of vdbe cursor to "new" temp table */
1756   int oldIdx;          /* Index of vdbe cursor to "old" temp table */
1757   u32 newColMask;
1758   u32 oldColMask;
1759   int orconf;          /* Current orconf policy */
1760   int ignoreJump;      /* where to jump to for a RAISE(IGNORE) */
1761   Trigger *pTrigger;   /* The trigger currently being coded */
1762   TriggerStack *pNext; /* Next trigger down on the trigger stack */
1763 };
1764 
1765 /*
1766 ** The following structure contains information used by the sqliteFix...
1767 ** routines as they walk the parse tree to make database references
1768 ** explicit.
1769 */
1770 typedef struct DbFixer DbFixer;
1771 struct DbFixer {
1772   Parse *pParse;      /* The parsing context.  Error messages written here */
1773   const char *zDb;    /* Make sure all objects are contained in this database */
1774   const char *zType;  /* Type of the container - used for error messages */
1775   const Token *pName; /* Name of the container - used for error messages */
1776 };
1777 
1778 /*
1779 ** An objected used to accumulate the text of a string where we
1780 ** do not necessarily know how big the string will be in the end.
1781 */
1782 struct StrAccum {
1783   sqlite3 *db;         /* Optional database for lookaside.  Can be NULL */
1784   char *zBase;         /* A base allocation.  Not from malloc. */
1785   char *zText;         /* The string collected so far */
1786   int  nChar;          /* Length of the string so far */
1787   int  nAlloc;         /* Amount of space allocated in zText */
1788   int  mxAlloc;        /* Maximum allowed string length */
1789   u8   mallocFailed;   /* Becomes true if any memory allocation fails */
1790   u8   useMalloc;      /* True if zText is enlargable using realloc */
1791   u8   tooBig;         /* Becomes true if string size exceeds limits */
1792 };
1793 
1794 /*
1795 ** A pointer to this structure is used to communicate information
1796 ** from sqlite3Init and OP_ParseSchema into the sqlite3InitCallback.
1797 */
1798 typedef struct {
1799   sqlite3 *db;        /* The database being initialized */
1800   int iDb;            /* 0 for main database.  1 for TEMP, 2.. for ATTACHed */
1801   char **pzErrMsg;    /* Error message stored here */
1802   int rc;             /* Result code stored here */
1803 } InitData;
1804 
1805 /*
1806 ** Structure containing global configuration data for the SQLite library.
1807 **
1808 ** This structure also contains some state information.
1809 */
1810 struct Sqlite3Config {
1811   int bMemstat;                     /* True to enable memory status */
1812   int bCoreMutex;                   /* True to enable core mutexing */
1813   int bFullMutex;                   /* True to enable full mutexing */
1814   int mxStrlen;                     /* Maximum string length */
1815   int szLookaside;                  /* Default lookaside buffer size */
1816   int nLookaside;                   /* Default lookaside buffer count */
1817   sqlite3_mem_methods m;            /* Low-level memory allocation interface */
1818   sqlite3_mutex_methods mutex;      /* Low-level mutex interface */
1819   void *pHeap;                      /* Heap storage space */
1820   int nHeap;                        /* Size of pHeap[] */
1821   int mnReq, mxReq;                 /* Min and max heap requests sizes */
1822   void *pScratch;                   /* Scratch memory */
1823   int szScratch;                    /* Size of each scratch buffer */
1824   int nScratch;                     /* Number of scratch buffers */
1825   void *pPage;                      /* Page cache memory */
1826   int szPage;                       /* Size of each page in pPage[] */
1827   int nPage;                        /* Number of pages in pPage[] */
1828   int isInit;                       /* True after initialization has finished */
1829   int isMallocInit;                 /* True after malloc is initialized */
1830   sqlite3_mutex *pInitMutex;        /* Mutex used by sqlite3_initialize() */
1831   int nSmall;                       /* alloc size threshold used by mem6.c */
1832   int mxParserStack;                /* maximum depth of the parser stack */
1833 };
1834 
1835 /*
1836 ** Assuming zIn points to the first byte of a UTF-8 character,
1837 ** advance zIn to point to the first byte of the next UTF-8 character.
1838 */
1839 #define SQLITE_SKIP_UTF8(zIn) {                        \
1840   if( (*(zIn++))>=0xc0 ){                              \
1841     while( (*zIn & 0xc0)==0x80 ){ zIn++; }             \
1842   }                                                    \
1843 }
1844 
1845 /*
1846 ** The SQLITE_CORRUPT_BKPT macro can be either a constant (for production
1847 ** builds) or a function call (for debugging).  If it is a function call,
1848 ** it allows the operator to set a breakpoint at the spot where database
1849 ** corruption is first detected.
1850 */
1851 #ifdef SQLITE_DEBUG
1852   int sqlite3Corrupt(void);
1853 # define SQLITE_CORRUPT_BKPT sqlite3Corrupt()
1854 #else
1855 # define SQLITE_CORRUPT_BKPT SQLITE_CORRUPT
1856 #endif
1857 
1858 /*
1859 ** Internal function prototypes
1860 */
1861 int sqlite3StrICmp(const char *, const char *);
1862 int sqlite3StrNICmp(const char *, const char *, int);
1863 int sqlite3IsNumber(const char*, int*, u8);
1864 int sqlite3Strlen(sqlite3*, const char*);
1865 
1866 int sqlite3MallocInit(void);
1867 void sqlite3MallocEnd(void);
1868 void *sqlite3Malloc(int);
1869 void *sqlite3MallocZero(int);
1870 void *sqlite3DbMallocZero(sqlite3*, int);
1871 void *sqlite3DbMallocRaw(sqlite3*, int);
1872 char *sqlite3DbStrDup(sqlite3*,const char*);
1873 char *sqlite3DbStrNDup(sqlite3*,const char*, int);
1874 void *sqlite3Realloc(void*, int);
1875 void *sqlite3DbReallocOrFree(sqlite3 *, void *, int);
1876 void *sqlite3DbRealloc(sqlite3 *, void *, int);
1877 void sqlite3DbFree(sqlite3*, void*);
1878 int sqlite3MallocSize(void*);
1879 int sqlite3DbMallocSize(sqlite3*, void*);
1880 void *sqlite3ScratchMalloc(int);
1881 void sqlite3ScratchFree(void*);
1882 void *sqlite3PageMalloc(int);
1883 void sqlite3PageFree(void*);
1884 void sqlite3MemSetDefault(void);
1885 const sqlite3_mem_methods *sqlite3MemGetDefault(void);
1886 const sqlite3_mem_methods *sqlite3MemGetMemsys5(void);
1887 const sqlite3_mem_methods *sqlite3MemGetMemsys3(void);
1888 const sqlite3_mem_methods *sqlite3MemGetMemsys6(void);
1889 void sqlite3BenignMallocHooks(void (*)(void), void (*)(void));
1890 
1891 #ifndef SQLITE_MUTEX_NOOP
1892   sqlite3_mutex_methods *sqlite3DefaultMutex(void);
1893   sqlite3_mutex *sqlite3MutexAlloc(int);
1894   int sqlite3MutexInit(void);
1895   int sqlite3MutexEnd(void);
1896 #endif
1897 
1898 void sqlite3StatusReset(void);
1899 int sqlite3StatusValue(int);
1900 void sqlite3StatusAdd(int, int);
1901 void sqlite3StatusSet(int, int);
1902 
1903 int sqlite3IsNaN(double);
1904 
1905 void sqlite3VXPrintf(StrAccum*, int, const char*, va_list);
1906 char *sqlite3MPrintf(sqlite3*,const char*, ...);
1907 char *sqlite3VMPrintf(sqlite3*,const char*, va_list);
1908 char *sqlite3MAppendf(sqlite3*,char*,const char*,...);
1909 #if defined(SQLITE_TEST) || defined(SQLITE_DEBUG)
1910   void sqlite3DebugPrintf(const char*, ...);
1911 #endif
1912 #if defined(SQLITE_TEST)
1913   void *sqlite3TestTextToPtr(const char*);
1914 #endif
1915 void sqlite3SetString(char **, sqlite3*, const char*, ...);
1916 void sqlite3ErrorMsg(Parse*, const char*, ...);
1917 void sqlite3ErrorClear(Parse*);
1918 void sqlite3Dequote(char*);
1919 void sqlite3DequoteExpr(sqlite3*, Expr*);
1920 int sqlite3KeywordCode(const unsigned char*, int);
1921 int sqlite3RunParser(Parse*, const char*, char **);
1922 void sqlite3FinishCoding(Parse*);
1923 int sqlite3GetTempReg(Parse*);
1924 void sqlite3ReleaseTempReg(Parse*,int);
1925 int sqlite3GetTempRange(Parse*,int);
1926 void sqlite3ReleaseTempRange(Parse*,int,int);
1927 Expr *sqlite3Expr(sqlite3*, int, Expr*, Expr*, const Token*);
1928 Expr *sqlite3PExpr(Parse*, int, Expr*, Expr*, const Token*);
1929 Expr *sqlite3RegisterExpr(Parse*,Token*);
1930 Expr *sqlite3ExprAnd(sqlite3*,Expr*, Expr*);
1931 void sqlite3ExprSpan(Expr*,Token*,Token*);
1932 Expr *sqlite3ExprFunction(Parse*,ExprList*, Token*);
1933 void sqlite3ExprAssignVarNumber(Parse*, Expr*);
1934 void sqlite3ExprDelete(sqlite3*, Expr*);
1935 ExprList *sqlite3ExprListAppend(Parse*,ExprList*,Expr*,Token*);
1936 void sqlite3ExprListDelete(sqlite3*, ExprList*);
1937 int sqlite3Init(sqlite3*, char**);
1938 int sqlite3InitCallback(void*, int, char**, char**);
1939 void sqlite3Pragma(Parse*,Token*,Token*,Token*,int);
1940 void sqlite3ResetInternalSchema(sqlite3*, int);
1941 void sqlite3BeginParse(Parse*,int);
1942 void sqlite3CommitInternalChanges(sqlite3*);
1943 Table *sqlite3ResultSetOfSelect(Parse*,char*,Select*);
1944 void sqlite3OpenMasterTable(Parse *, int);
1945 void sqlite3StartTable(Parse*,Token*,Token*,int,int,int,int);
1946 void sqlite3AddColumn(Parse*,Token*);
1947 void sqlite3AddNotNull(Parse*, int);
1948 void sqlite3AddPrimaryKey(Parse*, ExprList*, int, int, int);
1949 void sqlite3AddCheckConstraint(Parse*, Expr*);
1950 void sqlite3AddColumnType(Parse*,Token*);
1951 void sqlite3AddDefaultValue(Parse*,Expr*);
1952 void sqlite3AddCollateType(Parse*, Token*);
1953 void sqlite3EndTable(Parse*,Token*,Token*,Select*);
1954 
1955 Bitvec *sqlite3BitvecCreate(u32);
1956 int sqlite3BitvecTest(Bitvec*, u32);
1957 int sqlite3BitvecSet(Bitvec*, u32);
1958 void sqlite3BitvecClear(Bitvec*, u32);
1959 void sqlite3BitvecDestroy(Bitvec*);
1960 int sqlite3BitvecBuiltinTest(int,int*);
1961 
1962 void sqlite3CreateView(Parse*,Token*,Token*,Token*,Select*,int,int);
1963 
1964 #if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE)
1965   int sqlite3ViewGetColumnNames(Parse*,Table*);
1966 #else
1967 # define sqlite3ViewGetColumnNames(A,B) 0
1968 #endif
1969 
1970 void sqlite3DropTable(Parse*, SrcList*, int, int);
1971 void sqlite3DeleteTable(Table*);
1972 void sqlite3Insert(Parse*, SrcList*, ExprList*, Select*, IdList*, int);
1973 void *sqlite3ArrayAllocate(sqlite3*,void*,int,int,int*,int*,int*);
1974 IdList *sqlite3IdListAppend(sqlite3*, IdList*, Token*);
1975 int sqlite3IdListIndex(IdList*,const char*);
1976 SrcList *sqlite3SrcListAppend(sqlite3*, SrcList*, Token*, Token*);
1977 SrcList *sqlite3SrcListAppendFromTerm(Parse*, SrcList*, Token*, Token*, Token*,
1978                                       Select*, Expr*, IdList*);
1979 void sqlite3SrcListShiftJoinType(SrcList*);
1980 void sqlite3SrcListAssignCursors(Parse*, SrcList*);
1981 void sqlite3IdListDelete(sqlite3*, IdList*);
1982 void sqlite3SrcListDelete(sqlite3*, SrcList*);
1983 void sqlite3CreateIndex(Parse*,Token*,Token*,SrcList*,ExprList*,int,Token*,
1984                         Token*, int, int);
1985 void sqlite3DropIndex(Parse*, SrcList*, int);
1986 int sqlite3Select(Parse*, Select*, SelectDest*, Select*, int, int*);
1987 Select *sqlite3SelectNew(Parse*,ExprList*,SrcList*,Expr*,ExprList*,
1988                          Expr*,ExprList*,int,Expr*,Expr*);
1989 void sqlite3SelectDelete(sqlite3*, Select*);
1990 Table *sqlite3SrcListLookup(Parse*, SrcList*);
1991 int sqlite3IsReadOnly(Parse*, Table*, int);
1992 void sqlite3OpenTable(Parse*, int iCur, int iDb, Table*, int);
1993 void sqlite3DeleteFrom(Parse*, SrcList*, Expr*);
1994 void sqlite3Update(Parse*, SrcList*, ExprList*, Expr*, int);
1995 WhereInfo *sqlite3WhereBegin(Parse*, SrcList*, Expr*, ExprList**, u8);
1996 void sqlite3WhereEnd(WhereInfo*);
1997 int sqlite3ExprCodeGetColumn(Parse*, Table*, int, int, int, int);
1998 void sqlite3ExprCodeMove(Parse*, int, int, int);
1999 void sqlite3ExprCodeCopy(Parse*, int, int, int);
2000 void sqlite3ExprClearColumnCache(Parse*, int);
2001 void sqlite3ExprCacheAffinityChange(Parse*, int, int);
2002 int sqlite3ExprWritableRegister(Parse*,int,int);
2003 void sqlite3ExprHardCopy(Parse*,int,int);
2004 int sqlite3ExprCode(Parse*, Expr*, int);
2005 int sqlite3ExprCodeTemp(Parse*, Expr*, int*);
2006 int sqlite3ExprCodeTarget(Parse*, Expr*, int);
2007 int sqlite3ExprCodeAndCache(Parse*, Expr*, int);
2008 void sqlite3ExprCodeConstants(Parse*, Expr*);
2009 int sqlite3ExprCodeExprList(Parse*, ExprList*, int, int);
2010 void sqlite3ExprIfTrue(Parse*, Expr*, int, int);
2011 void sqlite3ExprIfFalse(Parse*, Expr*, int, int);
2012 Table *sqlite3FindTable(sqlite3*,const char*, const char*);
2013 Table *sqlite3LocateTable(Parse*,int isView,const char*, const char*);
2014 Index *sqlite3FindIndex(sqlite3*,const char*, const char*);
2015 void sqlite3UnlinkAndDeleteTable(sqlite3*,int,const char*);
2016 void sqlite3UnlinkAndDeleteIndex(sqlite3*,int,const char*);
2017 void sqlite3Vacuum(Parse*);
2018 int sqlite3RunVacuum(char**, sqlite3*);
2019 char *sqlite3NameFromToken(sqlite3*, Token*);
2020 int sqlite3ExprCompare(Expr*, Expr*);
2021 int sqlite3ExprResolveNames(NameContext *, Expr *);
2022 void sqlite3ExprAnalyzeAggregates(NameContext*, Expr*);
2023 void sqlite3ExprAnalyzeAggList(NameContext*,ExprList*);
2024 Vdbe *sqlite3GetVdbe(Parse*);
2025 Expr *sqlite3CreateIdExpr(Parse *, const char*);
2026 void sqlite3PrngSaveState(void);
2027 void sqlite3PrngRestoreState(void);
2028 void sqlite3PrngResetState(void);
2029 void sqlite3RollbackAll(sqlite3*);
2030 void sqlite3CodeVerifySchema(Parse*, int);
2031 void sqlite3BeginTransaction(Parse*, int);
2032 void sqlite3CommitTransaction(Parse*);
2033 void sqlite3RollbackTransaction(Parse*);
2034 int sqlite3ExprIsConstant(Expr*);
2035 int sqlite3ExprIsConstantNotJoin(Expr*);
2036 int sqlite3ExprIsConstantOrFunction(Expr*);
2037 int sqlite3ExprIsInteger(Expr*, int*);
2038 int sqlite3IsRowid(const char*);
2039 void sqlite3GenerateRowDelete(Parse*, Table*, int, int, int);
2040 void sqlite3GenerateRowIndexDelete(Parse*, Table*, int, int*);
2041 int sqlite3GenerateIndexKey(Parse*, Index*, int, int, int);
2042 void sqlite3GenerateConstraintChecks(Parse*,Table*,int,int,
2043                                      int*,int,int,int,int);
2044 void sqlite3CompleteInsertion(Parse*, Table*, int, int, int*,int,int,int,int);
2045 int sqlite3OpenTableAndIndices(Parse*, Table*, int, int);
2046 void sqlite3BeginWriteOperation(Parse*, int, int);
2047 Expr *sqlite3ExprDup(sqlite3*,Expr*);
2048 void sqlite3TokenCopy(sqlite3*,Token*, Token*);
2049 ExprList *sqlite3ExprListDup(sqlite3*,ExprList*);
2050 SrcList *sqlite3SrcListDup(sqlite3*,SrcList*);
2051 IdList *sqlite3IdListDup(sqlite3*,IdList*);
2052 Select *sqlite3SelectDup(sqlite3*,Select*);
2053 FuncDef *sqlite3FindFunction(sqlite3*,const char*,int,int,u8,int);
2054 void sqlite3RegisterBuiltinFunctions(sqlite3*);
2055 void sqlite3RegisterDateTimeFunctions(sqlite3*);
2056 #ifdef SQLITE_DEBUG
2057   int sqlite3SafetyOn(sqlite3*);
2058   int sqlite3SafetyOff(sqlite3*);
2059 #else
2060 # define sqlite3SafetyOn(A) 0
2061 # define sqlite3SafetyOff(A) 0
2062 #endif
2063 int sqlite3SafetyCheckOk(sqlite3*);
2064 int sqlite3SafetyCheckSickOrOk(sqlite3*);
2065 void sqlite3ChangeCookie(Parse*, int);
2066 void sqlite3MaterializeView(Parse*, Select*, Expr*, int);
2067 
2068 #ifndef SQLITE_OMIT_TRIGGER
2069   void sqlite3BeginTrigger(Parse*, Token*,Token*,int,int,IdList*,SrcList*,
2070                            Expr*,int, int);
2071   void sqlite3FinishTrigger(Parse*, TriggerStep*, Token*);
2072   void sqlite3DropTrigger(Parse*, SrcList*, int);
2073   void sqlite3DropTriggerPtr(Parse*, Trigger*);
2074   int sqlite3TriggersExist(Parse*, Table*, int, ExprList*);
2075   int sqlite3CodeRowTrigger(Parse*, int, ExprList*, int, Table *, int, int,
2076                            int, int, u32*, u32*);
2077   void sqliteViewTriggers(Parse*, Table*, Expr*, int, ExprList*);
2078   void sqlite3DeleteTriggerStep(sqlite3*, TriggerStep*);
2079   TriggerStep *sqlite3TriggerSelectStep(sqlite3*,Select*);
2080   TriggerStep *sqlite3TriggerInsertStep(sqlite3*,Token*, IdList*,
2081                                         ExprList*,Select*,int);
2082   TriggerStep *sqlite3TriggerUpdateStep(sqlite3*,Token*,ExprList*, Expr*, int);
2083   TriggerStep *sqlite3TriggerDeleteStep(sqlite3*,Token*, Expr*);
2084   void sqlite3DeleteTrigger(sqlite3*, Trigger*);
2085   void sqlite3UnlinkAndDeleteTrigger(sqlite3*,int,const char*);
2086 #else
2087 # define sqlite3TriggersExist(A,B,C,D,E,F) 0
2088 # define sqlite3DeleteTrigger(A,B)
2089 # define sqlite3DropTriggerPtr(A,B)
2090 # define sqlite3UnlinkAndDeleteTrigger(A,B,C)
2091 # define sqlite3CodeRowTrigger(A,B,C,D,E,F,G,H,I,J,K) 0
2092 #endif
2093 
2094 int sqlite3JoinType(Parse*, Token*, Token*, Token*);
2095 void sqlite3CreateForeignKey(Parse*, ExprList*, Token*, ExprList*, int);
2096 void sqlite3DeferForeignKey(Parse*, int);
2097 #ifndef SQLITE_OMIT_AUTHORIZATION
2098   void sqlite3AuthRead(Parse*,Expr*,Schema*,SrcList*);
2099   int sqlite3AuthCheck(Parse*,int, const char*, const char*, const char*);
2100   void sqlite3AuthContextPush(Parse*, AuthContext*, const char*);
2101   void sqlite3AuthContextPop(AuthContext*);
2102 #else
2103 # define sqlite3AuthRead(a,b,c,d)
2104 # define sqlite3AuthCheck(a,b,c,d,e)    SQLITE_OK
2105 # define sqlite3AuthContextPush(a,b,c)
2106 # define sqlite3AuthContextPop(a)  ((void)(a))
2107 #endif
2108 void sqlite3Attach(Parse*, Expr*, Expr*, Expr*);
2109 void sqlite3Detach(Parse*, Expr*);
2110 int sqlite3BtreeFactory(const sqlite3 *db, const char *zFilename,
2111                        int omitJournal, int nCache, int flags, Btree **ppBtree);
2112 int sqlite3FixInit(DbFixer*, Parse*, int, const char*, const Token*);
2113 int sqlite3FixSrcList(DbFixer*, SrcList*);
2114 int sqlite3FixSelect(DbFixer*, Select*);
2115 int sqlite3FixExpr(DbFixer*, Expr*);
2116 int sqlite3FixExprList(DbFixer*, ExprList*);
2117 int sqlite3FixTriggerStep(DbFixer*, TriggerStep*);
2118 int sqlite3AtoF(const char *z, double*);
2119 char *sqlite3_snprintf(int,char*,const char*,...);
2120 int sqlite3GetInt32(const char *, int*);
2121 int sqlite3FitsIn64Bits(const char *, int);
2122 int sqlite3Utf16ByteLen(const void *pData, int nChar);
2123 int sqlite3Utf8CharLen(const char *pData, int nByte);
2124 int sqlite3Utf8Read(const u8*, const u8*, const u8**);
2125 
2126 /*
2127 ** Routines to read and write variable-length integers.  These used to
2128 ** be defined locally, but now we use the varint routines in the util.c
2129 ** file.  Code should use the MACRO forms below, as the Varint32 versions
2130 ** are coded to assume the single byte case is already handled (which
2131 ** the MACRO form does).
2132 */
2133 int sqlite3PutVarint(unsigned char*, u64);
2134 int sqlite3PutVarint32(unsigned char*, u32);
2135 int sqlite3GetVarint(const unsigned char *, u64 *);
2136 int sqlite3GetVarint32(const unsigned char *, u32 *);
2137 int sqlite3VarintLen(u64 v);
2138 
2139 /*
2140 ** The header of a record consists of a sequence variable-length integers.
2141 ** These integers are almost always small and are encoded as a single byte.
2142 ** The following macros take advantage this fact to provide a fast encode
2143 ** and decode of the integers in a record header.  It is faster for the common
2144 ** case where the integer is a single byte.  It is a little slower when the
2145 ** integer is two or more bytes.  But overall it is faster.
2146 **
2147 ** The following expressions are equivalent:
2148 **
2149 **     x = sqlite3GetVarint32( A, &B );
2150 **     x = sqlite3PutVarint32( A, B );
2151 **
2152 **     x = getVarint32( A, B );
2153 **     x = putVarint32( A, B );
2154 **
2155 */
2156 #define getVarint32(A,B)  ((*(A)<(unsigned char)0x80) ? ((B) = (u32)*(A)),1 : sqlite3GetVarint32((A), &(B)))
2157 #define putVarint32(A,B)  (((B)<(u32)0x80) ? (*(A) = (unsigned char)(B)),1 : sqlite3PutVarint32((A), (B)))
2158 #define getVarint    sqlite3GetVarint
2159 #define putVarint    sqlite3PutVarint
2160 
2161 
2162 void sqlite3IndexAffinityStr(Vdbe *, Index *);
2163 void sqlite3TableAffinityStr(Vdbe *, Table *);
2164 char sqlite3CompareAffinity(Expr *pExpr, char aff2);
2165 int sqlite3IndexAffinityOk(Expr *pExpr, char idx_affinity);
2166 char sqlite3ExprAffinity(Expr *pExpr);
2167 int sqlite3Atoi64(const char*, i64*);
2168 void sqlite3Error(sqlite3*, int, const char*,...);
2169 void *sqlite3HexToBlob(sqlite3*, const char *z, int n);
2170 int sqlite3TwoPartName(Parse *, Token *, Token *, Token **);
2171 const char *sqlite3ErrStr(int);
2172 int sqlite3ReadSchema(Parse *pParse);
2173 CollSeq *sqlite3FindCollSeq(sqlite3*,u8 enc, const char *,int,int);
2174 CollSeq *sqlite3LocateCollSeq(Parse *pParse, const char *zName, int nName);
2175 CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr);
2176 Expr *sqlite3ExprSetColl(Parse *pParse, Expr *, Token *);
2177 int sqlite3CheckCollSeq(Parse *, CollSeq *);
2178 int sqlite3CheckObjectName(Parse *, const char *);
2179 void sqlite3VdbeSetChanges(sqlite3 *, int);
2180 
2181 const void *sqlite3ValueText(sqlite3_value*, u8);
2182 int sqlite3ValueBytes(sqlite3_value*, u8);
2183 void sqlite3ValueSetStr(sqlite3_value*, int, const void *,u8,
2184                         void(*)(void*));
2185 void sqlite3ValueFree(sqlite3_value*);
2186 sqlite3_value *sqlite3ValueNew(sqlite3 *);
2187 char *sqlite3Utf16to8(sqlite3 *, const void*, int);
2188 int sqlite3ValueFromExpr(sqlite3 *, Expr *, u8, u8, sqlite3_value **);
2189 void sqlite3ValueApplyAffinity(sqlite3_value *, u8, u8);
2190 #ifndef SQLITE_AMALGAMATION
2191 extern const unsigned char sqlite3UpperToLower[];
2192 extern struct Sqlite3Config sqlite3Config;
2193 #endif
2194 void sqlite3RootPageMoved(Db*, int, int);
2195 void sqlite3Reindex(Parse*, Token*, Token*);
2196 void sqlite3AlterFunctions(sqlite3*);
2197 void sqlite3AlterRenameTable(Parse*, SrcList*, Token*);
2198 int sqlite3GetToken(const unsigned char *, int *);
2199 void sqlite3NestedParse(Parse*, const char*, ...);
2200 void sqlite3ExpirePreparedStatements(sqlite3*);
2201 void sqlite3CodeSubselect(Parse *, Expr *, int);
2202 int sqlite3SelectResolve(Parse *, Select *, NameContext *);
2203 void sqlite3ColumnDefault(Vdbe *, Table *, int);
2204 void sqlite3AlterFinishAddColumn(Parse *, Token *);
2205 void sqlite3AlterBeginAddColumn(Parse *, SrcList *);
2206 CollSeq *sqlite3GetCollSeq(sqlite3*, CollSeq *, const char *, int);
2207 char sqlite3AffinityType(const Token*);
2208 void sqlite3Analyze(Parse*, Token*, Token*);
2209 int sqlite3InvokeBusyHandler(BusyHandler*);
2210 int sqlite3FindDb(sqlite3*, Token*);
2211 int sqlite3AnalysisLoad(sqlite3*,int iDB);
2212 void sqlite3DefaultRowEst(Index*);
2213 void sqlite3RegisterLikeFunctions(sqlite3*, int);
2214 int sqlite3IsLikeFunction(sqlite3*,Expr*,int*,char*);
2215 void sqlite3AttachFunctions(sqlite3 *);
2216 void sqlite3MinimumFileFormat(Parse*, int, int);
2217 void sqlite3SchemaFree(void *);
2218 Schema *sqlite3SchemaGet(sqlite3 *, Btree *);
2219 int sqlite3SchemaToIndex(sqlite3 *db, Schema *);
2220 KeyInfo *sqlite3IndexKeyinfo(Parse *, Index *);
2221 int sqlite3CreateFunc(sqlite3 *, const char *, int, int, void *,
2222   void (*)(sqlite3_context*,int,sqlite3_value **),
2223   void (*)(sqlite3_context*,int,sqlite3_value **), void (*)(sqlite3_context*));
2224 int sqlite3ApiExit(sqlite3 *db, int);
2225 int sqlite3OpenTempDatabase(Parse *);
2226 
2227 void sqlite3StrAccumInit(StrAccum*, char*, int, int);
2228 void sqlite3StrAccumAppend(StrAccum*,const char*,int);
2229 char *sqlite3StrAccumFinish(StrAccum*);
2230 void sqlite3StrAccumReset(StrAccum*);
2231 void sqlite3SelectDestInit(SelectDest*,int,int);
2232 
2233 /*
2234 ** The interface to the LEMON-generated parser
2235 */
2236 void *sqlite3ParserAlloc(void*(*)(size_t));
2237 void sqlite3ParserFree(void*, void(*)(void*));
2238 void sqlite3Parser(void*, int, Token, Parse*);
2239 #ifdef YYTRACKMAXSTACKDEPTH
2240   int sqlite3ParserStackPeak(void*);
2241 #endif
2242 
2243 int sqlite3AutoLoadExtensions(sqlite3*);
2244 #ifndef SQLITE_OMIT_LOAD_EXTENSION
2245   void sqlite3CloseExtensions(sqlite3*);
2246 #else
2247 # define sqlite3CloseExtensions(X)
2248 #endif
2249 
2250 #ifndef SQLITE_OMIT_SHARED_CACHE
2251   void sqlite3TableLock(Parse *, int, int, u8, const char *);
2252 #else
2253   #define sqlite3TableLock(v,w,x,y,z)
2254 #endif
2255 
2256 #ifdef SQLITE_TEST
2257   int sqlite3Utf8To8(unsigned char*);
2258 #endif
2259 
2260 #ifdef SQLITE_OMIT_VIRTUALTABLE
2261 #  define sqlite3VtabClear(X)
2262 #  define sqlite3VtabSync(X,Y) (Y)
2263 #  define sqlite3VtabRollback(X)
2264 #  define sqlite3VtabCommit(X)
2265 #  define sqlite3VtabTransferError(A,B,C)
2266 #else
2267    void sqlite3VtabClear(Table*);
2268    int sqlite3VtabSync(sqlite3 *db, int rc);
2269    int sqlite3VtabRollback(sqlite3 *db);
2270    int sqlite3VtabCommit(sqlite3 *db);
2271    void sqlite3VtabTransferError(sqlite3 *db, int, sqlite3_vtab*);
2272 #endif
2273 void sqlite3VtabMakeWritable(Parse*,Table*);
2274 void sqlite3VtabLock(sqlite3_vtab*);
2275 void sqlite3VtabUnlock(sqlite3*, sqlite3_vtab*);
2276 void sqlite3VtabBeginParse(Parse*, Token*, Token*, Token*);
2277 void sqlite3VtabFinishParse(Parse*, Token*);
2278 void sqlite3VtabArgInit(Parse*);
2279 void sqlite3VtabArgExtend(Parse*, Token*);
2280 int sqlite3VtabCallCreate(sqlite3*, int, const char *, char **);
2281 int sqlite3VtabCallConnect(Parse*, Table*);
2282 int sqlite3VtabCallDestroy(sqlite3*, int, const char *);
2283 int sqlite3VtabBegin(sqlite3 *, sqlite3_vtab *);
2284 FuncDef *sqlite3VtabOverloadFunction(sqlite3 *,FuncDef*, int nArg, Expr*);
2285 void sqlite3InvalidFunction(sqlite3_context*,int,sqlite3_value**);
2286 int sqlite3Reprepare(Vdbe*);
2287 void sqlite3ExprListCheckLength(Parse*, ExprList*, const char*);
2288 CollSeq *sqlite3BinaryCompareCollSeq(Parse *, Expr *, Expr *);
2289 
2290 
2291 /*
2292 ** Available fault injectors.  Should be numbered beginning with 0.
2293 */
2294 #define SQLITE_FAULTINJECTOR_MALLOC     0
2295 #define SQLITE_FAULTINJECTOR_COUNT      1
2296 
2297 /*
2298 ** The interface to the code in fault.c used for identifying "benign"
2299 ** malloc failures. This is only present if SQLITE_OMIT_BUILTIN_TEST
2300 ** is not defined.
2301 */
2302 #ifndef SQLITE_OMIT_BUILTIN_TEST
2303   void sqlite3BeginBenignMalloc(void);
2304   void sqlite3EndBenignMalloc(void);
2305 #else
2306   #define sqlite3BeginBenignMalloc()
2307   #define sqlite3EndBenignMalloc()
2308 #endif
2309 
2310 #define IN_INDEX_ROWID           1
2311 #define IN_INDEX_EPH             2
2312 #define IN_INDEX_INDEX           3
2313 int sqlite3FindInIndex(Parse *, Expr *, int*);
2314 
2315 #ifdef SQLITE_ENABLE_ATOMIC_WRITE
2316   int sqlite3JournalOpen(sqlite3_vfs *, const char *, sqlite3_file *, int, int);
2317   int sqlite3JournalSize(sqlite3_vfs *);
2318   int sqlite3JournalCreate(sqlite3_file *);
2319 #else
2320   #define sqlite3JournalSize(pVfs) ((pVfs)->szOsFile)
2321 #endif
2322 
2323 #if SQLITE_MAX_EXPR_DEPTH>0
2324   void sqlite3ExprSetHeight(Parse *pParse, Expr *p);
2325   int sqlite3SelectExprHeight(Select *);
2326 #else
2327   #define sqlite3ExprSetHeight(x,y)
2328   #define sqlite3SelectExprHeight(x) 0
2329 #endif
2330 
2331 u32 sqlite3Get4byte(const u8*);
2332 void sqlite3Put4byte(u8*, u32);
2333 
2334 #ifdef SQLITE_SSE
2335 #include "sseInt.h"
2336 #endif
2337 
2338 #ifdef SQLITE_DEBUG
2339   void sqlite3ParserTrace(FILE*, char *);
2340 #endif
2341 
2342 /*
2343 ** If the SQLITE_ENABLE IOTRACE exists then the global variable
2344 ** sqlite3IoTrace is a pointer to a printf-like routine used to
2345 ** print I/O tracing messages.
2346 */
2347 #ifdef SQLITE_ENABLE_IOTRACE
2348 # define IOTRACE(A)  if( sqlite3IoTrace ){ sqlite3IoTrace A; }
2349   void sqlite3VdbeIOTraceSql(Vdbe*);
2350 SQLITE_EXTERN void (*sqlite3IoTrace)(const char*,...);
2351 #else
2352 # define IOTRACE(A)
2353 # define sqlite3VdbeIOTraceSql(X)
2354 #endif
2355 
2356 #endif
2357