xref: /sqlite-3.40.0/src/sqliteInt.h (revision b39187ae)
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 1.816 2008/12/28 16:55:25 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 /* Suspicious pointer arithmetic */
36 #endif
37 
38 /* Needed for various definitions... */
39 #ifndef _GNU_SOURCE
40 # define _GNU_SOURCE
41 #endif
42 
43 /*
44 ** Include standard header files as necessary
45 */
46 #ifdef HAVE_STDINT_H
47 #include <stdint.h>
48 #endif
49 #ifdef HAVE_INTTYPES_H
50 #include <inttypes.h>
51 #endif
52 
53 /*
54 ** A macro used to aid in coverage testing.  When doing coverage
55 ** testing, the condition inside the argument must be evaluated
56 ** both true and false in order to get full branch coverage.
57 ** This macro can be inserted to ensure adequate test coverage
58 ** in places where simple condition/decision coverage is inadequate.
59 */
60 #ifdef SQLITE_COVERAGE_TEST
61   void sqlite3Coverage(int);
62 # define testcase(X)  if( X ){ sqlite3Coverage(__LINE__); }
63 #else
64 # define testcase(X)
65 #endif
66 
67 /*
68 ** The ALWAYS and NEVER macros surround boolean expressions which
69 ** are intended to always be true or false, respectively.  Such
70 ** expressions could be omitted from the code completely.  But they
71 ** are included in a few cases in order to enhance the resilience
72 ** of SQLite to unexpected behavior - to make the code "self-healing"
73 ** or "ductile" rather than being "brittle" and crashing at the first
74 ** hint of unplanned behavior.
75 **
76 ** When doing coverage testing ALWAYS and NEVER are hard-coded to
77 ** be true and false so that the unreachable code then specify will
78 ** not be counted as untested code.
79 */
80 #ifdef SQLITE_COVERAGE_TEST
81 # define ALWAYS(X)      (1)
82 # define NEVER(X)       (0)
83 #else
84 # define ALWAYS(X)      (X)
85 # define NEVER(X)       (X)
86 #endif
87 
88 /*
89 ** The macro unlikely() is a hint that surrounds a boolean
90 ** expression that is usually false.  Macro likely() surrounds
91 ** a boolean expression that is usually true.  GCC is able to
92 ** use these hints to generate better code, sometimes.
93 */
94 #if defined(__GNUC__) && 0
95 # define likely(X)    __builtin_expect((X),1)
96 # define unlikely(X)  __builtin_expect((X),0)
97 #else
98 # define likely(X)    !!(X)
99 # define unlikely(X)  !!(X)
100 #endif
101 
102 /*
103  * This macro is used to "hide" some ugliness in casting an int
104  * value to a ptr value under the MSVC 64-bit compiler.   Casting
105  * non 64-bit values to ptr types results in a "hard" error with
106  * the MSVC 64-bit compiler which this attempts to avoid.
107  *
108  * A simple compiler pragma or casting sequence could not be found
109  * to correct this in all situations, so this macro was introduced.
110  *
111  * It could be argued that the intptr_t type could be used in this
112  * case, but that type is not available on all compilers, or
113  * requires the #include of specific headers which differs between
114  * platforms.
115  */
116 #define SQLITE_INT_TO_PTR(X)   ((void*)&((char*)0)[X])
117 #define SQLITE_PTR_TO_INT(X)   ((int)(((char*)X)-(char*)0))
118 
119 /*
120 ** These #defines should enable >2GB file support on POSIX if the
121 ** underlying operating system supports it.  If the OS lacks
122 ** large file support, or if the OS is windows, these should be no-ops.
123 **
124 ** Ticket #2739:  The _LARGEFILE_SOURCE macro must appear before any
125 ** system #includes.  Hence, this block of code must be the very first
126 ** code in all source files.
127 **
128 ** Large file support can be disabled using the -DSQLITE_DISABLE_LFS switch
129 ** on the compiler command line.  This is necessary if you are compiling
130 ** on a recent machine (ex: Red Hat 7.2) but you want your code to work
131 ** on an older machine (ex: Red Hat 6.0).  If you compile on Red Hat 7.2
132 ** without this option, LFS is enable.  But LFS does not exist in the kernel
133 ** in Red Hat 6.0, so the code won't work.  Hence, for maximum binary
134 ** portability you should omit LFS.
135 **
136 ** Similar is true for Mac OS X.  LFS is only supported on Mac OS X 9 and later.
137 */
138 #ifndef SQLITE_DISABLE_LFS
139 # define _LARGE_FILE       1
140 # ifndef _FILE_OFFSET_BITS
141 #   define _FILE_OFFSET_BITS 64
142 # endif
143 # define _LARGEFILE_SOURCE 1
144 #endif
145 
146 
147 /*
148 ** The SQLITE_THREADSAFE macro must be defined as either 0 or 1.
149 ** Older versions of SQLite used an optional THREADSAFE macro.
150 ** We support that for legacy
151 */
152 #if !defined(SQLITE_THREADSAFE)
153 #if defined(THREADSAFE)
154 # define SQLITE_THREADSAFE THREADSAFE
155 #else
156 # define SQLITE_THREADSAFE 1
157 #endif
158 #endif
159 
160 /*
161 ** The SQLITE_DEFAULT_MEMSTATUS macro must be defined as either 0 or 1.
162 ** It determines whether or not the features related to
163 ** SQLITE_CONFIG_MEMSTATUS are available by default or not. This value can
164 ** be overridden at runtime using the sqlite3_config() API.
165 */
166 #if !defined(SQLITE_DEFAULT_MEMSTATUS)
167 # define SQLITE_DEFAULT_MEMSTATUS 1
168 #endif
169 
170 /*
171 ** Exactly one of the following macros must be defined in order to
172 ** specify which memory allocation subsystem to use.
173 **
174 **     SQLITE_SYSTEM_MALLOC          // Use normal system malloc()
175 **     SQLITE_MEMDEBUG               // Debugging version of system malloc()
176 **     SQLITE_MEMORY_SIZE            // internal allocator #1
177 **     SQLITE_MMAP_HEAP_SIZE         // internal mmap() allocator
178 **     SQLITE_POW2_MEMORY_SIZE       // internal power-of-two allocator
179 **
180 ** If none of the above are defined, then set SQLITE_SYSTEM_MALLOC as
181 ** the default.
182 */
183 #if defined(SQLITE_SYSTEM_MALLOC)+defined(SQLITE_MEMDEBUG)+\
184     defined(SQLITE_MEMORY_SIZE)+defined(SQLITE_MMAP_HEAP_SIZE)+\
185     defined(SQLITE_POW2_MEMORY_SIZE)>1
186 # error "At most one of the following compile-time configuration options\
187  is allows: SQLITE_SYSTEM_MALLOC, SQLITE_MEMDEBUG, SQLITE_MEMORY_SIZE,\
188  SQLITE_MMAP_HEAP_SIZE, SQLITE_POW2_MEMORY_SIZE"
189 #endif
190 #if defined(SQLITE_SYSTEM_MALLOC)+defined(SQLITE_MEMDEBUG)+\
191     defined(SQLITE_MEMORY_SIZE)+defined(SQLITE_MMAP_HEAP_SIZE)+\
192     defined(SQLITE_POW2_MEMORY_SIZE)==0
193 # define SQLITE_SYSTEM_MALLOC 1
194 #endif
195 
196 /*
197 ** If SQLITE_MALLOC_SOFT_LIMIT is defined, then try to keep the
198 ** sizes of memory allocations below this value where possible.
199 */
200 #if defined(SQLITE_POW2_MEMORY_SIZE) && !defined(SQLITE_MALLOC_SOFT_LIMIT)
201 # define SQLITE_MALLOC_SOFT_LIMIT 1024
202 #endif
203 
204 /*
205 ** We need to define _XOPEN_SOURCE as follows in order to enable
206 ** recursive mutexes on most Unix systems.  But Mac OS X is different.
207 ** The _XOPEN_SOURCE define causes problems for Mac OS X we are told,
208 ** so it is omitted there.  See ticket #2673.
209 **
210 ** Later we learn that _XOPEN_SOURCE is poorly or incorrectly
211 ** implemented on some systems.  So we avoid defining it at all
212 ** if it is already defined or if it is unneeded because we are
213 ** not doing a threadsafe build.  Ticket #2681.
214 **
215 ** See also ticket #2741.
216 */
217 #if !defined(_XOPEN_SOURCE) && !defined(__DARWIN__) && !defined(__APPLE__) && SQLITE_THREADSAFE
218 #  define _XOPEN_SOURCE 500  /* Needed to enable pthread recursive mutexes */
219 #endif
220 
221 /*
222 ** The TCL headers are only needed when compiling the TCL bindings.
223 */
224 #if defined(SQLITE_TCL) || defined(TCLSH)
225 # include <tcl.h>
226 #endif
227 
228 /*
229 ** Many people are failing to set -DNDEBUG=1 when compiling SQLite.
230 ** Setting NDEBUG makes the code smaller and run faster.  So the following
231 ** lines are added to automatically set NDEBUG unless the -DSQLITE_DEBUG=1
232 ** option is set.  Thus NDEBUG becomes an opt-in rather than an opt-out
233 ** feature.
234 */
235 #if !defined(NDEBUG) && !defined(SQLITE_DEBUG)
236 # define NDEBUG 1
237 #endif
238 
239 #include "sqlite3.h"
240 #include "hash.h"
241 #include "parse.h"
242 #include <stdio.h>
243 #include <stdlib.h>
244 #include <string.h>
245 #include <assert.h>
246 #include <stddef.h>
247 
248 /*
249 ** If compiling for a processor that lacks floating point support,
250 ** substitute integer for floating-point
251 */
252 #ifdef SQLITE_OMIT_FLOATING_POINT
253 # define double sqlite_int64
254 # define LONGDOUBLE_TYPE sqlite_int64
255 # ifndef SQLITE_BIG_DBL
256 #   define SQLITE_BIG_DBL (0x7fffffffffffffff)
257 # endif
258 # define SQLITE_OMIT_DATETIME_FUNCS 1
259 # define SQLITE_OMIT_TRACE 1
260 # undef SQLITE_MIXED_ENDIAN_64BIT_FLOAT
261 #endif
262 #ifndef SQLITE_BIG_DBL
263 # define SQLITE_BIG_DBL (1e99)
264 #endif
265 
266 /*
267 ** OMIT_TEMPDB is set to 1 if SQLITE_OMIT_TEMPDB is defined, or 0
268 ** afterward. Having this macro allows us to cause the C compiler
269 ** to omit code used by TEMP tables without messy #ifndef statements.
270 */
271 #ifdef SQLITE_OMIT_TEMPDB
272 #define OMIT_TEMPDB 1
273 #else
274 #define OMIT_TEMPDB 0
275 #endif
276 
277 /*
278 ** If the following macro is set to 1, then NULL values are considered
279 ** distinct when determining whether or not two entries are the same
280 ** in a UNIQUE index.  This is the way PostgreSQL, Oracle, DB2, MySQL,
281 ** OCELOT, and Firebird all work.  The SQL92 spec explicitly says this
282 ** is the way things are suppose to work.
283 **
284 ** If the following macro is set to 0, the NULLs are indistinct for
285 ** a UNIQUE index.  In this mode, you can only have a single NULL entry
286 ** for a column declared UNIQUE.  This is the way Informix and SQL Server
287 ** work.
288 */
289 #define NULL_DISTINCT_FOR_UNIQUE 1
290 
291 /*
292 ** The "file format" number is an integer that is incremented whenever
293 ** the VDBE-level file format changes.  The following macros define the
294 ** the default file format for new databases and the maximum file format
295 ** that the library can read.
296 */
297 #define SQLITE_MAX_FILE_FORMAT 4
298 #ifndef SQLITE_DEFAULT_FILE_FORMAT
299 # define SQLITE_DEFAULT_FILE_FORMAT 1
300 #endif
301 
302 /*
303 ** Provide a default value for SQLITE_TEMP_STORE in case it is not specified
304 ** on the command-line
305 */
306 #ifndef SQLITE_TEMP_STORE
307 # define SQLITE_TEMP_STORE 1
308 #endif
309 
310 /*
311 ** GCC does not define the offsetof() macro so we'll have to do it
312 ** ourselves.
313 */
314 #ifndef offsetof
315 #define offsetof(STRUCTURE,FIELD) ((int)((char*)&((STRUCTURE*)0)->FIELD))
316 #endif
317 
318 /*
319 ** Check to see if this machine uses EBCDIC.  (Yes, believe it or
320 ** not, there are still machines out there that use EBCDIC.)
321 */
322 #if 'A' == '\301'
323 # define SQLITE_EBCDIC 1
324 #else
325 # define SQLITE_ASCII 1
326 #endif
327 
328 /*
329 ** Integers of known sizes.  These typedefs might change for architectures
330 ** where the sizes very.  Preprocessor macros are available so that the
331 ** types can be conveniently redefined at compile-type.  Like this:
332 **
333 **         cc '-DUINTPTR_TYPE=long long int' ...
334 */
335 #ifndef UINT32_TYPE
336 # ifdef HAVE_UINT32_T
337 #  define UINT32_TYPE uint32_t
338 # else
339 #  define UINT32_TYPE unsigned int
340 # endif
341 #endif
342 #ifndef UINT16_TYPE
343 # ifdef HAVE_UINT16_T
344 #  define UINT16_TYPE uint16_t
345 # else
346 #  define UINT16_TYPE unsigned short int
347 # endif
348 #endif
349 #ifndef INT16_TYPE
350 # ifdef HAVE_INT16_T
351 #  define INT16_TYPE int16_t
352 # else
353 #  define INT16_TYPE short int
354 # endif
355 #endif
356 #ifndef UINT8_TYPE
357 # ifdef HAVE_UINT8_T
358 #  define UINT8_TYPE uint8_t
359 # else
360 #  define UINT8_TYPE unsigned char
361 # endif
362 #endif
363 #ifndef INT8_TYPE
364 # ifdef HAVE_INT8_T
365 #  define INT8_TYPE int8_t
366 # else
367 #  define INT8_TYPE signed char
368 # endif
369 #endif
370 #ifndef LONGDOUBLE_TYPE
371 # define LONGDOUBLE_TYPE long double
372 #endif
373 typedef sqlite_int64 i64;          /* 8-byte signed integer */
374 typedef sqlite_uint64 u64;         /* 8-byte unsigned integer */
375 typedef UINT32_TYPE u32;           /* 4-byte unsigned integer */
376 typedef UINT16_TYPE u16;           /* 2-byte unsigned integer */
377 typedef INT16_TYPE i16;            /* 2-byte signed integer */
378 typedef UINT8_TYPE u8;             /* 1-byte unsigned integer */
379 typedef INT8_TYPE i8;              /* 1-byte signed integer */
380 
381 /*
382 ** Macros to determine whether the machine is big or little endian,
383 ** evaluated at runtime.
384 */
385 #ifdef SQLITE_AMALGAMATION
386 const int sqlite3one = 1;
387 #else
388 extern const int sqlite3one;
389 #endif
390 #if defined(i386) || defined(__i386__) || defined(_M_IX86)\
391                              || defined(__x86_64) || defined(__x86_64__)
392 # define SQLITE_BIGENDIAN    0
393 # define SQLITE_LITTLEENDIAN 1
394 # define SQLITE_UTF16NATIVE  SQLITE_UTF16LE
395 #else
396 # define SQLITE_BIGENDIAN    (*(char *)(&sqlite3one)==0)
397 # define SQLITE_LITTLEENDIAN (*(char *)(&sqlite3one)==1)
398 # define SQLITE_UTF16NATIVE (SQLITE_BIGENDIAN?SQLITE_UTF16BE:SQLITE_UTF16LE)
399 #endif
400 
401 /*
402 ** Constants for the largest and smallest possible 64-bit signed integers.
403 ** These macros are designed to work correctly on both 32-bit and 64-bit
404 ** compilers.
405 */
406 #define LARGEST_INT64  (0xffffffff|(((i64)0x7fffffff)<<32))
407 #define SMALLEST_INT64 (((i64)-1) - LARGEST_INT64)
408 
409 /*
410 ** An instance of the following structure is used to store the busy-handler
411 ** callback for a given sqlite handle.
412 **
413 ** The sqlite.busyHandler member of the sqlite struct contains the busy
414 ** callback for the database handle. Each pager opened via the sqlite
415 ** handle is passed a pointer to sqlite.busyHandler. The busy-handler
416 ** callback is currently invoked only from within pager.c.
417 */
418 typedef struct BusyHandler BusyHandler;
419 struct BusyHandler {
420   int (*xFunc)(void *,int);  /* The busy callback */
421   void *pArg;                /* First arg to busy callback */
422   int nBusy;                 /* Incremented with each busy call */
423 };
424 
425 /*
426 ** Name of the master database table.  The master database table
427 ** is a special table that holds the names and attributes of all
428 ** user tables and indices.
429 */
430 #define MASTER_NAME       "sqlite_master"
431 #define TEMP_MASTER_NAME  "sqlite_temp_master"
432 
433 /*
434 ** The root-page of the master database table.
435 */
436 #define MASTER_ROOT       1
437 
438 /*
439 ** The name of the schema table.
440 */
441 #define SCHEMA_TABLE(x)  ((!OMIT_TEMPDB)&&(x==1)?TEMP_MASTER_NAME:MASTER_NAME)
442 
443 /*
444 ** A convenience macro that returns the number of elements in
445 ** an array.
446 */
447 #define ArraySize(X)    ((int)(sizeof(X)/sizeof(X[0])))
448 
449 /*
450 ** The following value as a destructor means to use sqlite3DbFree().
451 ** This is an internal extension to SQLITE_STATIC and SQLITE_TRANSIENT.
452 */
453 #define SQLITE_DYNAMIC   ((sqlite3_destructor_type)sqlite3DbFree)
454 
455 /*
456 ** When SQLITE_OMIT_WSD is defined, it means that the target platform does
457 ** not support Writable Static Data (WSD) such as global and static variables.
458 ** All variables must either be on the stack or dynamically allocated from
459 ** the heap.  When WSD is unsupported, the variable declarations scattered
460 ** throughout the SQLite code must become constants instead.  The SQLITE_WSD
461 ** macro is used for this purpose.  And instead of referencing the variable
462 ** directly, we use its constant as a key to lookup the run-time allocated
463 ** buffer that holds real variable.  The constant is also the initializer
464 ** for the run-time allocated buffer.
465 **
466 ** In the usual case where WSD is supported, the SQLITE_WSD and GLOBAL
467 ** macros become no-ops and have zero performance impact.
468 */
469 #ifdef SQLITE_OMIT_WSD
470   #define SQLITE_WSD const
471   #define GLOBAL(t,v) (*(t*)sqlite3_wsd_find((void*)&(v), sizeof(v)))
472   #define sqlite3GlobalConfig GLOBAL(struct Sqlite3Config, sqlite3Config)
473   int sqlite3_wsd_init(int N, int J);
474   void *sqlite3_wsd_find(void *K, int L);
475 #else
476   #define SQLITE_WSD
477   #define GLOBAL(t,v) v
478   #define sqlite3GlobalConfig sqlite3Config
479 #endif
480 
481 /*
482 ** The following macros are used to suppress compiler warnings and to
483 ** make it clear to human readers when a function parameter is deliberately
484 ** left unused within the body of a function. This usually happens when
485 ** a function is called via a function pointer. For example the
486 ** implementation of an SQL aggregate step callback may not use the
487 ** parameter indicating the number of arguments passed to the aggregate,
488 ** if it knows that this is enforced elsewhere.
489 **
490 ** When a function parameter is not used at all within the body of a function,
491 ** it is generally named "NotUsed" or "NotUsed2" to make things even clearer.
492 ** However, these macros may also be used to suppress warnings related to
493 ** parameters that may or may not be used depending on compilation options.
494 ** For example those parameters only used in assert() statements. In these
495 ** cases the parameters are named as per the usual conventions.
496 */
497 #define UNUSED_PARAMETER(x) (void)(x)
498 #define UNUSED_PARAMETER2(x,y) UNUSED_PARAMETER(x),UNUSED_PARAMETER(y)
499 
500 /*
501 ** Forward references to structures
502 */
503 typedef struct AggInfo AggInfo;
504 typedef struct AuthContext AuthContext;
505 typedef struct Bitvec Bitvec;
506 typedef struct RowSet RowSet;
507 typedef struct CollSeq CollSeq;
508 typedef struct Column Column;
509 typedef struct Db Db;
510 typedef struct Schema Schema;
511 typedef struct Expr Expr;
512 typedef struct ExprList ExprList;
513 typedef struct FKey FKey;
514 typedef struct FuncDef FuncDef;
515 typedef struct FuncDefHash FuncDefHash;
516 typedef struct IdList IdList;
517 typedef struct Index Index;
518 typedef struct KeyClass KeyClass;
519 typedef struct KeyInfo KeyInfo;
520 typedef struct Lookaside Lookaside;
521 typedef struct LookasideSlot LookasideSlot;
522 typedef struct Module Module;
523 typedef struct NameContext NameContext;
524 typedef struct Parse Parse;
525 typedef struct Savepoint Savepoint;
526 typedef struct Select Select;
527 typedef struct SrcList SrcList;
528 typedef struct StrAccum StrAccum;
529 typedef struct Table Table;
530 typedef struct TableLock TableLock;
531 typedef struct Token Token;
532 typedef struct TriggerStack TriggerStack;
533 typedef struct TriggerStep TriggerStep;
534 typedef struct Trigger Trigger;
535 typedef struct UnpackedRecord UnpackedRecord;
536 typedef struct Walker Walker;
537 typedef struct WherePlan WherePlan;
538 typedef struct WhereInfo WhereInfo;
539 typedef struct WhereLevel WhereLevel;
540 
541 /*
542 ** Defer sourcing vdbe.h and btree.h until after the "u8" and
543 ** "BusyHandler" typedefs. vdbe.h also requires a few of the opaque
544 ** pointer types (i.e. FuncDef) defined above.
545 */
546 #include "btree.h"
547 #include "vdbe.h"
548 #include "pager.h"
549 #include "pcache.h"
550 
551 #include "os.h"
552 #include "mutex.h"
553 
554 
555 /*
556 ** Each database file to be accessed by the system is an instance
557 ** of the following structure.  There are normally two of these structures
558 ** in the sqlite.aDb[] array.  aDb[0] is the main database file and
559 ** aDb[1] is the database file used to hold temporary tables.  Additional
560 ** databases may be attached.
561 */
562 struct Db {
563   char *zName;         /* Name of this database */
564   Btree *pBt;          /* The B*Tree structure for this database file */
565   u8 inTrans;          /* 0: not writable.  1: Transaction.  2: Checkpoint */
566   u8 safety_level;     /* How aggressive at syncing data to disk */
567   void *pAux;               /* Auxiliary data.  Usually NULL */
568   void (*xFreeAux)(void*);  /* Routine to free pAux */
569   Schema *pSchema;     /* Pointer to database schema (possibly shared) */
570 };
571 
572 /*
573 ** An instance of the following structure stores a database schema.
574 **
575 ** If there are no virtual tables configured in this schema, the
576 ** Schema.db variable is set to NULL. After the first virtual table
577 ** has been added, it is set to point to the database connection
578 ** used to create the connection. Once a virtual table has been
579 ** added to the Schema structure and the Schema.db variable populated,
580 ** only that database connection may use the Schema to prepare
581 ** statements.
582 */
583 struct Schema {
584   int schema_cookie;   /* Database schema version number for this file */
585   Hash tblHash;        /* All tables indexed by name */
586   Hash idxHash;        /* All (named) indices indexed by name */
587   Hash trigHash;       /* All triggers indexed by name */
588   Hash aFKey;          /* Foreign keys indexed by to-table */
589   Table *pSeqTab;      /* The sqlite_sequence table used by AUTOINCREMENT */
590   u8 file_format;      /* Schema format version for this file */
591   u8 enc;              /* Text encoding used by this database */
592   u16 flags;           /* Flags associated with this schema */
593   int cache_size;      /* Number of pages to use in the cache */
594 #ifndef SQLITE_OMIT_VIRTUALTABLE
595   sqlite3 *db;         /* "Owner" connection. See comment above */
596 #endif
597 };
598 
599 /*
600 ** These macros can be used to test, set, or clear bits in the
601 ** Db.flags field.
602 */
603 #define DbHasProperty(D,I,P)     (((D)->aDb[I].pSchema->flags&(P))==(P))
604 #define DbHasAnyProperty(D,I,P)  (((D)->aDb[I].pSchema->flags&(P))!=0)
605 #define DbSetProperty(D,I,P)     (D)->aDb[I].pSchema->flags|=(P)
606 #define DbClearProperty(D,I,P)   (D)->aDb[I].pSchema->flags&=~(P)
607 
608 /*
609 ** Allowed values for the DB.flags field.
610 **
611 ** The DB_SchemaLoaded flag is set after the database schema has been
612 ** read into internal hash tables.
613 **
614 ** DB_UnresetViews means that one or more views have column names that
615 ** have been filled out.  If the schema changes, these column names might
616 ** changes and so the view will need to be reset.
617 */
618 #define DB_SchemaLoaded    0x0001  /* The schema has been loaded */
619 #define DB_UnresetViews    0x0002  /* Some views have defined column names */
620 #define DB_Empty           0x0004  /* The file is empty (length 0 bytes) */
621 
622 /*
623 ** The number of different kinds of things that can be limited
624 ** using the sqlite3_limit() interface.
625 */
626 #define SQLITE_N_LIMIT (SQLITE_LIMIT_VARIABLE_NUMBER+1)
627 
628 /*
629 ** Lookaside malloc is a set of fixed-size buffers that can be used
630 ** to satisfy small transient memory allocation requests for objects
631 ** associated with a particular database connection.  The use of
632 ** lookaside malloc provides a significant performance enhancement
633 ** (approx 10%) by avoiding numerous malloc/free requests while parsing
634 ** SQL statements.
635 **
636 ** The Lookaside structure holds configuration information about the
637 ** lookaside malloc subsystem.  Each available memory allocation in
638 ** the lookaside subsystem is stored on a linked list of LookasideSlot
639 ** objects.
640 */
641 struct Lookaside {
642   u16 sz;                 /* Size of each buffer in bytes */
643   u8 bEnabled;            /* True if use lookaside.  False to ignore it */
644   u8 bMalloced;           /* True if pStart obtained from sqlite3_malloc() */
645   int nOut;               /* Number of buffers currently checked out */
646   int mxOut;              /* Highwater mark for nOut */
647   LookasideSlot *pFree;   /* List of available buffers */
648   void *pStart;           /* First byte of available memory space */
649   void *pEnd;             /* First byte past end of available space */
650 };
651 struct LookasideSlot {
652   LookasideSlot *pNext;    /* Next buffer in the list of free buffers */
653 };
654 
655 /*
656 ** A hash table for function definitions.
657 **
658 ** Hash each FuncDef structure into one of the FuncDefHash.a[] slots.
659 ** Collisions are on the FuncDef.pHash chain.
660 */
661 struct FuncDefHash {
662   FuncDef *a[23];       /* Hash table for functions */
663 };
664 
665 /*
666 ** Each database is an instance of the following structure.
667 **
668 ** The sqlite.lastRowid records the last insert rowid generated by an
669 ** insert statement.  Inserts on views do not affect its value.  Each
670 ** trigger has its own context, so that lastRowid can be updated inside
671 ** triggers as usual.  The previous value will be restored once the trigger
672 ** exits.  Upon entering a before or instead of trigger, lastRowid is no
673 ** longer (since after version 2.8.12) reset to -1.
674 **
675 ** The sqlite.nChange does not count changes within triggers and keeps no
676 ** context.  It is reset at start of sqlite3_exec.
677 ** The sqlite.lsChange represents the number of changes made by the last
678 ** insert, update, or delete statement.  It remains constant throughout the
679 ** length of a statement and is then updated by OP_SetCounts.  It keeps a
680 ** context stack just like lastRowid so that the count of changes
681 ** within a trigger is not seen outside the trigger.  Changes to views do not
682 ** affect the value of lsChange.
683 ** The sqlite.csChange keeps track of the number of current changes (since
684 ** the last statement) and is used to update sqlite_lsChange.
685 **
686 ** The member variables sqlite.errCode, sqlite.zErrMsg and sqlite.zErrMsg16
687 ** store the most recent error code and, if applicable, string. The
688 ** internal function sqlite3Error() is used to set these variables
689 ** consistently.
690 */
691 struct sqlite3 {
692   sqlite3_vfs *pVfs;            /* OS Interface */
693   int nDb;                      /* Number of backends currently in use */
694   Db *aDb;                      /* All backends */
695   int flags;                    /* Miscellaneous flags. See below */
696   int openFlags;                /* Flags passed to sqlite3_vfs.xOpen() */
697   int errCode;                  /* Most recent error code (SQLITE_*) */
698   int errMask;                  /* & result codes with this before returning */
699   u8 autoCommit;                /* The auto-commit flag. */
700   u8 temp_store;                /* 1: file 2: memory 0: default */
701   u8 mallocFailed;              /* True if we have seen a malloc failure */
702   u8 dfltLockMode;              /* Default locking-mode for attached dbs */
703   u8 dfltJournalMode;           /* Default journal mode for attached dbs */
704   signed char nextAutovac;      /* Autovac setting after VACUUM if >=0 */
705   int nextPagesize;             /* Pagesize after VACUUM if >0 */
706   int nTable;                   /* Number of tables in the database */
707   CollSeq *pDfltColl;           /* The default collating sequence (BINARY) */
708   i64 lastRowid;                /* ROWID of most recent insert (see above) */
709   i64 priorNewRowid;            /* Last randomly generated ROWID */
710   u32 magic;                    /* Magic number for detect library misuse */
711   int nChange;                  /* Value returned by sqlite3_changes() */
712   int nTotalChange;             /* Value returned by sqlite3_total_changes() */
713   sqlite3_mutex *mutex;         /* Connection mutex */
714   int aLimit[SQLITE_N_LIMIT];   /* Limits */
715   struct sqlite3InitInfo {      /* Information used during initialization */
716     int iDb;                    /* When back is being initialized */
717     int newTnum;                /* Rootpage of table being initialized */
718     u8 busy;                    /* TRUE if currently initializing */
719   } init;
720   int nExtension;               /* Number of loaded extensions */
721   void **aExtension;            /* Array of shared library handles */
722   struct Vdbe *pVdbe;           /* List of active virtual machines */
723   int activeVdbeCnt;            /* Number of VDBEs currently executing */
724   int writeVdbeCnt;             /* Number of active VDBEs that are writing */
725   void (*xTrace)(void*,const char*);        /* Trace function */
726   void *pTraceArg;                          /* Argument to the trace function */
727   void (*xProfile)(void*,const char*,u64);  /* Profiling function */
728   void *pProfileArg;                        /* Argument to profile function */
729   void *pCommitArg;                 /* Argument to xCommitCallback() */
730   int (*xCommitCallback)(void*);    /* Invoked at every commit. */
731   void *pRollbackArg;               /* Argument to xRollbackCallback() */
732   void (*xRollbackCallback)(void*); /* Invoked at every commit. */
733   void *pUpdateArg;
734   void (*xUpdateCallback)(void*,int, const char*,const char*,sqlite_int64);
735   void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*);
736   void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*);
737   void *pCollNeededArg;
738   sqlite3_value *pErr;          /* Most recent error message */
739   char *zErrMsg;                /* Most recent error message (UTF-8 encoded) */
740   char *zErrMsg16;              /* Most recent error message (UTF-16 encoded) */
741   union {
742     volatile int isInterrupted; /* True if sqlite3_interrupt has been called */
743     double notUsed1;            /* Spacer */
744   } u1;
745   Lookaside lookaside;          /* Lookaside malloc configuration */
746 #ifndef SQLITE_OMIT_AUTHORIZATION
747   int (*xAuth)(void*,int,const char*,const char*,const char*,const char*);
748                                 /* Access authorization function */
749   void *pAuthArg;               /* 1st argument to the access auth function */
750 #endif
751 #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
752   int (*xProgress)(void *);     /* The progress callback */
753   void *pProgressArg;           /* Argument to the progress callback */
754   int nProgressOps;             /* Number of opcodes for progress callback */
755 #endif
756 #ifndef SQLITE_OMIT_VIRTUALTABLE
757   Hash aModule;                 /* populated by sqlite3_create_module() */
758   Table *pVTab;                 /* vtab with active Connect/Create method */
759   sqlite3_vtab **aVTrans;       /* Virtual tables with open transactions */
760   int nVTrans;                  /* Allocated size of aVTrans */
761 #endif
762   FuncDefHash aFunc;            /* Hash table of connection functions */
763   Hash aCollSeq;                /* All collating sequences */
764   BusyHandler busyHandler;      /* Busy callback */
765   int busyTimeout;              /* Busy handler timeout, in msec */
766   Db aDbStatic[2];              /* Static space for the 2 default backends */
767 #ifdef SQLITE_SSE
768   sqlite3_stmt *pFetch;         /* Used by SSE to fetch stored statements */
769 #endif
770   Savepoint *pSavepoint;        /* List of active savepoints */
771   int nSavepoint;               /* Number of non-transaction savepoints */
772   u8 isTransactionSavepoint;    /* True if the outermost savepoint is a TS */
773 };
774 
775 /*
776 ** A macro to discover the encoding of a database.
777 */
778 #define ENC(db) ((db)->aDb[0].pSchema->enc)
779 
780 /*
781 ** Possible values for the sqlite.flags and or Db.flags fields.
782 **
783 ** On sqlite.flags, the SQLITE_InTrans value means that we have
784 ** executed a BEGIN.  On Db.flags, SQLITE_InTrans means a statement
785 ** transaction is active on that particular database file.
786 */
787 #define SQLITE_VdbeTrace      0x00000001  /* True to trace VDBE execution */
788 #define SQLITE_InTrans        0x00000008  /* True if in a transaction */
789 #define SQLITE_InternChanges  0x00000010  /* Uncommitted Hash table changes */
790 #define SQLITE_FullColNames   0x00000020  /* Show full column names on SELECT */
791 #define SQLITE_ShortColNames  0x00000040  /* Show short columns names */
792 #define SQLITE_CountRows      0x00000080  /* Count rows changed by INSERT, */
793                                           /*   DELETE, or UPDATE and return */
794                                           /*   the count using a callback. */
795 #define SQLITE_NullCallback   0x00000100  /* Invoke the callback once if the */
796                                           /*   result set is empty */
797 #define SQLITE_SqlTrace       0x00000200  /* Debug print SQL as it executes */
798 #define SQLITE_VdbeListing    0x00000400  /* Debug listings of VDBE programs */
799 #define SQLITE_WriteSchema    0x00000800  /* OK to update SQLITE_MASTER */
800 #define SQLITE_NoReadlock     0x00001000  /* Readlocks are omitted when
801                                           ** accessing read-only databases */
802 #define SQLITE_IgnoreChecks   0x00002000  /* Do not enforce check constraints */
803 #define SQLITE_ReadUncommitted 0x00004000 /* For shared-cache mode */
804 #define SQLITE_LegacyFileFmt  0x00008000  /* Create new databases in format 1 */
805 #define SQLITE_FullFSync      0x00010000  /* Use full fsync on the backend */
806 #define SQLITE_LoadExtension  0x00020000  /* Enable load_extension */
807 
808 #define SQLITE_RecoveryMode   0x00040000  /* Ignore schema errors */
809 #define SQLITE_SharedCache    0x00080000  /* Cache sharing is enabled */
810 #define SQLITE_Vtab           0x00100000  /* There exists a virtual table */
811 
812 /*
813 ** Possible values for the sqlite.magic field.
814 ** The numbers are obtained at random and have no special meaning, other
815 ** than being distinct from one another.
816 */
817 #define SQLITE_MAGIC_OPEN     0xa029a697  /* Database is open */
818 #define SQLITE_MAGIC_CLOSED   0x9f3c2d33  /* Database is closed */
819 #define SQLITE_MAGIC_SICK     0x4b771290  /* Error and awaiting close */
820 #define SQLITE_MAGIC_BUSY     0xf03b7906  /* Database currently in use */
821 #define SQLITE_MAGIC_ERROR    0xb5357930  /* An SQLITE_MISUSE error occurred */
822 
823 /*
824 ** Each SQL function is defined by an instance of the following
825 ** structure.  A pointer to this structure is stored in the sqlite.aFunc
826 ** hash table.  When multiple functions have the same name, the hash table
827 ** points to a linked list of these structures.
828 */
829 struct FuncDef {
830   i16 nArg;            /* Number of arguments.  -1 means unlimited */
831   u8 iPrefEnc;         /* Preferred text encoding (SQLITE_UTF8, 16LE, 16BE) */
832   u8 flags;            /* Some combination of SQLITE_FUNC_* */
833   void *pUserData;     /* User data parameter */
834   FuncDef *pNext;      /* Next function with same name */
835   void (*xFunc)(sqlite3_context*,int,sqlite3_value**); /* Regular function */
836   void (*xStep)(sqlite3_context*,int,sqlite3_value**); /* Aggregate step */
837   void (*xFinalize)(sqlite3_context*);                /* Aggregate finalizer */
838   char *zName;         /* SQL name of the function. */
839   FuncDef *pHash;      /* Next with a different name but the same hash */
840 };
841 
842 /*
843 ** Possible values for FuncDef.flags
844 */
845 #define SQLITE_FUNC_LIKE     0x01 /* Candidate for the LIKE optimization */
846 #define SQLITE_FUNC_CASE     0x02 /* Case-sensitive LIKE-type function */
847 #define SQLITE_FUNC_EPHEM    0x04 /* Ephemeral.  Delete with VDBE */
848 #define SQLITE_FUNC_NEEDCOLL 0x08 /* sqlite3GetFuncCollSeq() might be called */
849 
850 /*
851 ** The following three macros, FUNCTION(), LIKEFUNC() and AGGREGATE() are
852 ** used to create the initializers for the FuncDef structures.
853 **
854 **   FUNCTION(zName, nArg, iArg, bNC, xFunc)
855 **     Used to create a scalar function definition of a function zName
856 **     implemented by C function xFunc that accepts nArg arguments. The
857 **     value passed as iArg is cast to a (void*) and made available
858 **     as the user-data (sqlite3_user_data()) for the function. If
859 **     argument bNC is true, then the FuncDef.needCollate flag is set.
860 **
861 **   AGGREGATE(zName, nArg, iArg, bNC, xStep, xFinal)
862 **     Used to create an aggregate function definition implemented by
863 **     the C functions xStep and xFinal. The first four parameters
864 **     are interpreted in the same way as the first 4 parameters to
865 **     FUNCTION().
866 **
867 **   LIKEFUNC(zName, nArg, pArg, flags)
868 **     Used to create a scalar function definition of a function zName
869 **     that accepts nArg arguments and is implemented by a call to C
870 **     function likeFunc. Argument pArg is cast to a (void *) and made
871 **     available as the function user-data (sqlite3_user_data()). The
872 **     FuncDef.flags variable is set to the value passed as the flags
873 **     parameter.
874 */
875 #define FUNCTION(zName, nArg, iArg, bNC, xFunc) \
876   {nArg, SQLITE_UTF8, bNC*8, SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, 0, #zName, 0}
877 #define STR_FUNCTION(zName, nArg, pArg, bNC, xFunc) \
878   {nArg, SQLITE_UTF8, bNC*8, pArg, 0, xFunc, 0, 0, #zName, 0}
879 #define LIKEFUNC(zName, nArg, arg, flags) \
880   {nArg, SQLITE_UTF8, flags, (void *)arg, 0, likeFunc, 0, 0, #zName, 0}
881 #define AGGREGATE(zName, nArg, arg, nc, xStep, xFinal) \
882   {nArg, SQLITE_UTF8, nc*8, SQLITE_INT_TO_PTR(arg), 0, 0, xStep,xFinal,#zName,0}
883 
884 /*
885 ** All current savepoints are stored in a linked list starting at
886 ** sqlite3.pSavepoint. The first element in the list is the most recently
887 ** opened savepoint. Savepoints are added to the list by the vdbe
888 ** OP_Savepoint instruction.
889 */
890 struct Savepoint {
891   char *zName;                        /* Savepoint name (nul-terminated) */
892   Savepoint *pNext;                   /* Parent savepoint (if any) */
893 };
894 
895 /*
896 ** The following are used as the second parameter to sqlite3Savepoint(),
897 ** and as the P1 argument to the OP_Savepoint instruction.
898 */
899 #define SAVEPOINT_BEGIN      0
900 #define SAVEPOINT_RELEASE    1
901 #define SAVEPOINT_ROLLBACK   2
902 
903 
904 /*
905 ** Each SQLite module (virtual table definition) is defined by an
906 ** instance of the following structure, stored in the sqlite3.aModule
907 ** hash table.
908 */
909 struct Module {
910   const sqlite3_module *pModule;       /* Callback pointers */
911   const char *zName;                   /* Name passed to create_module() */
912   void *pAux;                          /* pAux passed to create_module() */
913   void (*xDestroy)(void *);            /* Module destructor function */
914 };
915 
916 /*
917 ** information about each column of an SQL table is held in an instance
918 ** of this structure.
919 */
920 struct Column {
921   char *zName;     /* Name of this column */
922   Expr *pDflt;     /* Default value of this column */
923   char *zType;     /* Data type for this column */
924   char *zColl;     /* Collating sequence.  If NULL, use the default */
925   u8 notNull;      /* True if there is a NOT NULL constraint */
926   u8 isPrimKey;    /* True if this column is part of the PRIMARY KEY */
927   char affinity;   /* One of the SQLITE_AFF_... values */
928 #ifndef SQLITE_OMIT_VIRTUALTABLE
929   u8 isHidden;     /* True if this column is 'hidden' */
930 #endif
931 };
932 
933 /*
934 ** A "Collating Sequence" is defined by an instance of the following
935 ** structure. Conceptually, a collating sequence consists of a name and
936 ** a comparison routine that defines the order of that sequence.
937 **
938 ** There may two separate implementations of the collation function, one
939 ** that processes text in UTF-8 encoding (CollSeq.xCmp) and another that
940 ** processes text encoded in UTF-16 (CollSeq.xCmp16), using the machine
941 ** native byte order. When a collation sequence is invoked, SQLite selects
942 ** the version that will require the least expensive encoding
943 ** translations, if any.
944 **
945 ** The CollSeq.pUser member variable is an extra parameter that passed in
946 ** as the first argument to the UTF-8 comparison function, xCmp.
947 ** CollSeq.pUser16 is the equivalent for the UTF-16 comparison function,
948 ** xCmp16.
949 **
950 ** If both CollSeq.xCmp and CollSeq.xCmp16 are NULL, it means that the
951 ** collating sequence is undefined.  Indices built on an undefined
952 ** collating sequence may not be read or written.
953 */
954 struct CollSeq {
955   char *zName;          /* Name of the collating sequence, UTF-8 encoded */
956   u8 enc;               /* Text encoding handled by xCmp() */
957   u8 type;              /* One of the SQLITE_COLL_... values below */
958   void *pUser;          /* First argument to xCmp() */
959   int (*xCmp)(void*,int, const void*, int, const void*);
960   void (*xDel)(void*);  /* Destructor for pUser */
961 };
962 
963 /*
964 ** Allowed values of CollSeq.type:
965 */
966 #define SQLITE_COLL_BINARY  1  /* The default memcmp() collating sequence */
967 #define SQLITE_COLL_NOCASE  2  /* The built-in NOCASE collating sequence */
968 #define SQLITE_COLL_REVERSE 3  /* The built-in REVERSE collating sequence */
969 #define SQLITE_COLL_USER    0  /* Any other user-defined collating sequence */
970 
971 /*
972 ** A sort order can be either ASC or DESC.
973 */
974 #define SQLITE_SO_ASC       0  /* Sort in ascending order */
975 #define SQLITE_SO_DESC      1  /* Sort in ascending order */
976 
977 /*
978 ** Column affinity types.
979 **
980 ** These used to have mnemonic name like 'i' for SQLITE_AFF_INTEGER and
981 ** 't' for SQLITE_AFF_TEXT.  But we can save a little space and improve
982 ** the speed a little by numbering the values consecutively.
983 **
984 ** But rather than start with 0 or 1, we begin with 'a'.  That way,
985 ** when multiple affinity types are concatenated into a string and
986 ** used as the P4 operand, they will be more readable.
987 **
988 ** Note also that the numeric types are grouped together so that testing
989 ** for a numeric type is a single comparison.
990 */
991 #define SQLITE_AFF_TEXT     'a'
992 #define SQLITE_AFF_NONE     'b'
993 #define SQLITE_AFF_NUMERIC  'c'
994 #define SQLITE_AFF_INTEGER  'd'
995 #define SQLITE_AFF_REAL     'e'
996 
997 #define sqlite3IsNumericAffinity(X)  ((X)>=SQLITE_AFF_NUMERIC)
998 
999 /*
1000 ** The SQLITE_AFF_MASK values masks off the significant bits of an
1001 ** affinity value.
1002 */
1003 #define SQLITE_AFF_MASK     0x67
1004 
1005 /*
1006 ** Additional bit values that can be ORed with an affinity without
1007 ** changing the affinity.
1008 */
1009 #define SQLITE_JUMPIFNULL   0x08  /* jumps if either operand is NULL */
1010 #define SQLITE_STOREP2      0x10  /* Store result in reg[P2] rather than jump */
1011 
1012 /*
1013 ** Each SQL table is represented in memory by an instance of the
1014 ** following structure.
1015 **
1016 ** Table.zName is the name of the table.  The case of the original
1017 ** CREATE TABLE statement is stored, but case is not significant for
1018 ** comparisons.
1019 **
1020 ** Table.nCol is the number of columns in this table.  Table.aCol is a
1021 ** pointer to an array of Column structures, one for each column.
1022 **
1023 ** If the table has an INTEGER PRIMARY KEY, then Table.iPKey is the index of
1024 ** the column that is that key.   Otherwise Table.iPKey is negative.  Note
1025 ** that the datatype of the PRIMARY KEY must be INTEGER for this field to
1026 ** be set.  An INTEGER PRIMARY KEY is used as the rowid for each row of
1027 ** the table.  If a table has no INTEGER PRIMARY KEY, then a random rowid
1028 ** is generated for each row of the table.  TF_HasPrimaryKey is set if
1029 ** the table has any PRIMARY KEY, INTEGER or otherwise.
1030 **
1031 ** Table.tnum is the page number for the root BTree page of the table in the
1032 ** database file.  If Table.iDb is the index of the database table backend
1033 ** in sqlite.aDb[].  0 is for the main database and 1 is for the file that
1034 ** holds temporary tables and indices.  If TF_Ephemeral is set
1035 ** then the table is stored in a file that is automatically deleted
1036 ** when the VDBE cursor to the table is closed.  In this case Table.tnum
1037 ** refers VDBE cursor number that holds the table open, not to the root
1038 ** page number.  Transient tables are used to hold the results of a
1039 ** sub-query that appears instead of a real table name in the FROM clause
1040 ** of a SELECT statement.
1041 */
1042 struct Table {
1043   sqlite3 *db;         /* Associated database connection.  Might be NULL. */
1044   char *zName;         /* Name of the table or view */
1045   int iPKey;           /* If not negative, use aCol[iPKey] as the primary key */
1046   int nCol;            /* Number of columns in this table */
1047   Column *aCol;        /* Information about each column */
1048   Index *pIndex;       /* List of SQL indexes on this table. */
1049   int tnum;            /* Root BTree node for this table (see note above) */
1050   Select *pSelect;     /* NULL for tables.  Points to definition if a view. */
1051   u16 nRef;            /* Number of pointers to this Table */
1052   u8 tabFlags;         /* Mask of TF_* values */
1053   u8 keyConf;          /* What to do in case of uniqueness conflict on iPKey */
1054   Trigger *pTrigger;   /* List of SQL triggers on this table */
1055   FKey *pFKey;         /* Linked list of all foreign keys in this table */
1056   char *zColAff;       /* String defining the affinity of each column */
1057 #ifndef SQLITE_OMIT_CHECK
1058   Expr *pCheck;        /* The AND of all CHECK constraints */
1059 #endif
1060 #ifndef SQLITE_OMIT_ALTERTABLE
1061   int addColOffset;    /* Offset in CREATE TABLE stmt to add a new column */
1062 #endif
1063 #ifndef SQLITE_OMIT_VIRTUALTABLE
1064   Module *pMod;        /* Pointer to the implementation of the module */
1065   sqlite3_vtab *pVtab; /* Pointer to the module instance */
1066   int nModuleArg;      /* Number of arguments to the module */
1067   char **azModuleArg;  /* Text of all module args. [0] is module name */
1068 #endif
1069   Schema *pSchema;     /* Schema that contains this table */
1070   Table *pNextZombie;  /* Next on the Parse.pZombieTab list */
1071 };
1072 
1073 /*
1074 ** Allowed values for Tabe.tabFlags.
1075 */
1076 #define TF_Readonly        0x01    /* Read-only system table */
1077 #define TF_Ephemeral       0x02    /* An ephemeral table */
1078 #define TF_HasPrimaryKey   0x04    /* Table has a primary key */
1079 #define TF_Autoincrement   0x08    /* Integer primary key is autoincrement */
1080 #define TF_Virtual         0x10    /* Is a virtual table */
1081 #define TF_NeedMetadata    0x20    /* aCol[].zType and aCol[].pColl missing */
1082 
1083 
1084 
1085 /*
1086 ** Test to see whether or not a table is a virtual table.  This is
1087 ** done as a macro so that it will be optimized out when virtual
1088 ** table support is omitted from the build.
1089 */
1090 #ifndef SQLITE_OMIT_VIRTUALTABLE
1091 #  define IsVirtual(X)      (((X)->tabFlags & TF_Virtual)!=0)
1092 #  define IsHiddenColumn(X) ((X)->isHidden)
1093 #else
1094 #  define IsVirtual(X)      0
1095 #  define IsHiddenColumn(X) 0
1096 #endif
1097 
1098 /*
1099 ** Each foreign key constraint is an instance of the following structure.
1100 **
1101 ** A foreign key is associated with two tables.  The "from" table is
1102 ** the table that contains the REFERENCES clause that creates the foreign
1103 ** key.  The "to" table is the table that is named in the REFERENCES clause.
1104 ** Consider this example:
1105 **
1106 **     CREATE TABLE ex1(
1107 **       a INTEGER PRIMARY KEY,
1108 **       b INTEGER CONSTRAINT fk1 REFERENCES ex2(x)
1109 **     );
1110 **
1111 ** For foreign key "fk1", the from-table is "ex1" and the to-table is "ex2".
1112 **
1113 ** Each REFERENCES clause generates an instance of the following structure
1114 ** which is attached to the from-table.  The to-table need not exist when
1115 ** the from-table is created.  The existence of the to-table is not checked
1116 ** until an attempt is made to insert data into the from-table.
1117 **
1118 ** The sqlite.aFKey hash table stores pointers to this structure
1119 ** given the name of a to-table.  For each to-table, all foreign keys
1120 ** associated with that table are on a linked list using the FKey.pNextTo
1121 ** field.
1122 */
1123 struct FKey {
1124   Table *pFrom;     /* The table that contains the REFERENCES clause */
1125   FKey *pNextFrom;  /* Next foreign key in pFrom */
1126   char *zTo;        /* Name of table that the key points to */
1127   FKey *pNextTo;    /* Next foreign key that points to zTo */
1128   int nCol;         /* Number of columns in this key */
1129   struct sColMap {  /* Mapping of columns in pFrom to columns in zTo */
1130     int iFrom;         /* Index of column in pFrom */
1131     char *zCol;        /* Name of column in zTo.  If 0 use PRIMARY KEY */
1132   } *aCol;          /* One entry for each of nCol column s */
1133   u8 isDeferred;    /* True if constraint checking is deferred till COMMIT */
1134   u8 updateConf;    /* How to resolve conflicts that occur on UPDATE */
1135   u8 deleteConf;    /* How to resolve conflicts that occur on DELETE */
1136   u8 insertConf;    /* How to resolve conflicts that occur on INSERT */
1137 };
1138 
1139 /*
1140 ** SQLite supports many different ways to resolve a constraint
1141 ** error.  ROLLBACK processing means that a constraint violation
1142 ** causes the operation in process to fail and for the current transaction
1143 ** to be rolled back.  ABORT processing means the operation in process
1144 ** fails and any prior changes from that one operation are backed out,
1145 ** but the transaction is not rolled back.  FAIL processing means that
1146 ** the operation in progress stops and returns an error code.  But prior
1147 ** changes due to the same operation are not backed out and no rollback
1148 ** occurs.  IGNORE means that the particular row that caused the constraint
1149 ** error is not inserted or updated.  Processing continues and no error
1150 ** is returned.  REPLACE means that preexisting database rows that caused
1151 ** a UNIQUE constraint violation are removed so that the new insert or
1152 ** update can proceed.  Processing continues and no error is reported.
1153 **
1154 ** RESTRICT, SETNULL, and CASCADE actions apply only to foreign keys.
1155 ** RESTRICT is the same as ABORT for IMMEDIATE foreign keys and the
1156 ** same as ROLLBACK for DEFERRED keys.  SETNULL means that the foreign
1157 ** key is set to NULL.  CASCADE means that a DELETE or UPDATE of the
1158 ** referenced table row is propagated into the row that holds the
1159 ** foreign key.
1160 **
1161 ** The following symbolic values are used to record which type
1162 ** of action to take.
1163 */
1164 #define OE_None     0   /* There is no constraint to check */
1165 #define OE_Rollback 1   /* Fail the operation and rollback the transaction */
1166 #define OE_Abort    2   /* Back out changes but do no rollback transaction */
1167 #define OE_Fail     3   /* Stop the operation but leave all prior changes */
1168 #define OE_Ignore   4   /* Ignore the error. Do not do the INSERT or UPDATE */
1169 #define OE_Replace  5   /* Delete existing record, then do INSERT or UPDATE */
1170 
1171 #define OE_Restrict 6   /* OE_Abort for IMMEDIATE, OE_Rollback for DEFERRED */
1172 #define OE_SetNull  7   /* Set the foreign key value to NULL */
1173 #define OE_SetDflt  8   /* Set the foreign key value to its default */
1174 #define OE_Cascade  9   /* Cascade the changes */
1175 
1176 #define OE_Default  99  /* Do whatever the default action is */
1177 
1178 
1179 /*
1180 ** An instance of the following structure is passed as the first
1181 ** argument to sqlite3VdbeKeyCompare and is used to control the
1182 ** comparison of the two index keys.
1183 */
1184 struct KeyInfo {
1185   sqlite3 *db;        /* The database connection */
1186   u8 enc;             /* Text encoding - one of the TEXT_Utf* values */
1187   u16 nField;         /* Number of entries in aColl[] */
1188   u8 *aSortOrder;     /* If defined an aSortOrder[i] is true, sort DESC */
1189   CollSeq *aColl[1];  /* Collating sequence for each term of the key */
1190 };
1191 
1192 /*
1193 ** An instance of the following structure holds information about a
1194 ** single index record that has already been parsed out into individual
1195 ** values.
1196 **
1197 ** A record is an object that contains one or more fields of data.
1198 ** Records are used to store the content of a table row and to store
1199 ** the key of an index.  A blob encoding of a record is created by
1200 ** the OP_MakeRecord opcode of the VDBE and is disassembled by the
1201 ** OP_Column opcode.
1202 **
1203 ** This structure holds a record that has already been disassembled
1204 ** into its constituent fields.
1205 */
1206 struct UnpackedRecord {
1207   KeyInfo *pKeyInfo;  /* Collation and sort-order information */
1208   u16 nField;         /* Number of entries in apMem[] */
1209   u16 flags;          /* Boolean settings.  UNPACKED_... below */
1210   Mem *aMem;          /* Values */
1211 };
1212 
1213 /*
1214 ** Allowed values of UnpackedRecord.flags
1215 */
1216 #define UNPACKED_NEED_FREE     0x0001  /* Memory is from sqlite3Malloc() */
1217 #define UNPACKED_NEED_DESTROY  0x0002  /* apMem[]s should all be destroyed */
1218 #define UNPACKED_IGNORE_ROWID  0x0004  /* Ignore trailing rowid on key1 */
1219 #define UNPACKED_INCRKEY       0x0008  /* Make this key an epsilon larger */
1220 #define UNPACKED_PREFIX_MATCH  0x0010  /* A prefix match is considered OK */
1221 
1222 /*
1223 ** Each SQL index is represented in memory by an
1224 ** instance of the following structure.
1225 **
1226 ** The columns of the table that are to be indexed are described
1227 ** by the aiColumn[] field of this structure.  For example, suppose
1228 ** we have the following table and index:
1229 **
1230 **     CREATE TABLE Ex1(c1 int, c2 int, c3 text);
1231 **     CREATE INDEX Ex2 ON Ex1(c3,c1);
1232 **
1233 ** In the Table structure describing Ex1, nCol==3 because there are
1234 ** three columns in the table.  In the Index structure describing
1235 ** Ex2, nColumn==2 since 2 of the 3 columns of Ex1 are indexed.
1236 ** The value of aiColumn is {2, 0}.  aiColumn[0]==2 because the
1237 ** first column to be indexed (c3) has an index of 2 in Ex1.aCol[].
1238 ** The second column to be indexed (c1) has an index of 0 in
1239 ** Ex1.aCol[], hence Ex2.aiColumn[1]==0.
1240 **
1241 ** The Index.onError field determines whether or not the indexed columns
1242 ** must be unique and what to do if they are not.  When Index.onError=OE_None,
1243 ** it means this is not a unique index.  Otherwise it is a unique index
1244 ** and the value of Index.onError indicate the which conflict resolution
1245 ** algorithm to employ whenever an attempt is made to insert a non-unique
1246 ** element.
1247 */
1248 struct Index {
1249   char *zName;     /* Name of this index */
1250   int nColumn;     /* Number of columns in the table used by this index */
1251   int *aiColumn;   /* Which columns are used by this index.  1st is 0 */
1252   unsigned *aiRowEst; /* Result of ANALYZE: Est. rows selected by each column */
1253   Table *pTable;   /* The SQL table being indexed */
1254   int tnum;        /* Page containing root of this index in database file */
1255   u8 onError;      /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
1256   u8 autoIndex;    /* True if is automatically created (ex: by UNIQUE) */
1257   char *zColAff;   /* String defining the affinity of each column */
1258   Index *pNext;    /* The next index associated with the same table */
1259   Schema *pSchema; /* Schema containing this index */
1260   u8 *aSortOrder;  /* Array of size Index.nColumn. True==DESC, False==ASC */
1261   char **azColl;   /* Array of collation sequence names for index */
1262 };
1263 
1264 /*
1265 ** Each token coming out of the lexer is an instance of
1266 ** this structure.  Tokens are also used as part of an expression.
1267 **
1268 ** Note if Token.z==0 then Token.dyn and Token.n are undefined and
1269 ** may contain random values.  Do not make any assumptions about Token.dyn
1270 ** and Token.n when Token.z==0.
1271 */
1272 struct Token {
1273   const unsigned char *z; /* Text of the token.  Not NULL-terminated! */
1274   unsigned dyn  : 1;      /* True for malloced memory, false for static */
1275   unsigned n    : 31;     /* Number of characters in this token */
1276 };
1277 
1278 /*
1279 ** An instance of this structure contains information needed to generate
1280 ** code for a SELECT that contains aggregate functions.
1281 **
1282 ** If Expr.op==TK_AGG_COLUMN or TK_AGG_FUNCTION then Expr.pAggInfo is a
1283 ** pointer to this structure.  The Expr.iColumn field is the index in
1284 ** AggInfo.aCol[] or AggInfo.aFunc[] of information needed to generate
1285 ** code for that node.
1286 **
1287 ** AggInfo.pGroupBy and AggInfo.aFunc.pExpr point to fields within the
1288 ** original Select structure that describes the SELECT statement.  These
1289 ** fields do not need to be freed when deallocating the AggInfo structure.
1290 */
1291 struct AggInfo {
1292   u8 directMode;          /* Direct rendering mode means take data directly
1293                           ** from source tables rather than from accumulators */
1294   u8 useSortingIdx;       /* In direct mode, reference the sorting index rather
1295                           ** than the source table */
1296   int sortingIdx;         /* Cursor number of the sorting index */
1297   ExprList *pGroupBy;     /* The group by clause */
1298   int nSortingColumn;     /* Number of columns in the sorting index */
1299   struct AggInfo_col {    /* For each column used in source tables */
1300     Table *pTab;             /* Source table */
1301     int iTable;              /* Cursor number of the source table */
1302     int iColumn;             /* Column number within the source table */
1303     int iSorterColumn;       /* Column number in the sorting index */
1304     int iMem;                /* Memory location that acts as accumulator */
1305     Expr *pExpr;             /* The original expression */
1306   } *aCol;
1307   int nColumn;            /* Number of used entries in aCol[] */
1308   int nColumnAlloc;       /* Number of slots allocated for aCol[] */
1309   int nAccumulator;       /* Number of columns that show through to the output.
1310                           ** Additional columns are used only as parameters to
1311                           ** aggregate functions */
1312   struct AggInfo_func {   /* For each aggregate function */
1313     Expr *pExpr;             /* Expression encoding the function */
1314     FuncDef *pFunc;          /* The aggregate function implementation */
1315     int iMem;                /* Memory location that acts as accumulator */
1316     int iDistinct;           /* Ephemeral table used to enforce DISTINCT */
1317   } *aFunc;
1318   int nFunc;              /* Number of entries in aFunc[] */
1319   int nFuncAlloc;         /* Number of slots allocated for aFunc[] */
1320 };
1321 
1322 /*
1323 ** Each node of an expression in the parse tree is an instance
1324 ** of this structure.
1325 **
1326 ** Expr.op is the opcode.  The integer parser token codes are reused
1327 ** as opcodes here.  For example, the parser defines TK_GE to be an integer
1328 ** code representing the ">=" operator.  This same integer code is reused
1329 ** to represent the greater-than-or-equal-to operator in the expression
1330 ** tree.
1331 **
1332 ** Expr.pRight and Expr.pLeft are subexpressions.  Expr.pList is a list
1333 ** of argument if the expression is a function.
1334 **
1335 ** Expr.token is the operator token for this node.  For some expressions
1336 ** that have subexpressions, Expr.token can be the complete text that gave
1337 ** rise to the Expr.  In the latter case, the token is marked as being
1338 ** a compound token.
1339 **
1340 ** An expression of the form ID or ID.ID refers to a column in a table.
1341 ** For such expressions, Expr.op is set to TK_COLUMN and Expr.iTable is
1342 ** the integer cursor number of a VDBE cursor pointing to that table and
1343 ** Expr.iColumn is the column number for the specific column.  If the
1344 ** expression is used as a result in an aggregate SELECT, then the
1345 ** value is also stored in the Expr.iAgg column in the aggregate so that
1346 ** it can be accessed after all aggregates are computed.
1347 **
1348 ** If the expression is a function, the Expr.iTable is an integer code
1349 ** representing which function.  If the expression is an unbound variable
1350 ** marker (a question mark character '?' in the original SQL) then the
1351 ** Expr.iTable holds the index number for that variable.
1352 **
1353 ** If the expression is a subquery then Expr.iColumn holds an integer
1354 ** register number containing the result of the subquery.  If the
1355 ** subquery gives a constant result, then iTable is -1.  If the subquery
1356 ** gives a different answer at different times during statement processing
1357 ** then iTable is the address of a subroutine that computes the subquery.
1358 **
1359 ** The Expr.pSelect field points to a SELECT statement.  The SELECT might
1360 ** be the right operand of an IN operator.  Or, if a scalar SELECT appears
1361 ** in an expression the opcode is TK_SELECT and Expr.pSelect is the only
1362 ** operand.
1363 **
1364 ** If the Expr is of type OP_Column, and the table it is selecting from
1365 ** is a disk table or the "old.*" pseudo-table, then pTab points to the
1366 ** corresponding table definition.
1367 */
1368 struct Expr {
1369   u8 op;                 /* Operation performed by this node */
1370   char affinity;         /* The affinity of the column or 0 if not a column */
1371   u16 flags;             /* Various flags.  See below */
1372   CollSeq *pColl;        /* The collation type of the column or 0 */
1373   Expr *pLeft, *pRight;  /* Left and right subnodes */
1374   ExprList *pList;       /* A list of expressions used as function arguments
1375                          ** or in "<expr> IN (<expr-list)" */
1376   Token token;           /* An operand token */
1377   Token span;            /* Complete text of the expression */
1378   int iTable, iColumn;   /* When op==TK_COLUMN, then this expr node means the
1379                          ** iColumn-th field of the iTable-th table. */
1380   AggInfo *pAggInfo;     /* Used by TK_AGG_COLUMN and TK_AGG_FUNCTION */
1381   int iAgg;              /* Which entry in pAggInfo->aCol[] or ->aFunc[] */
1382   int iRightJoinTable;   /* If EP_FromJoin, the right table of the join */
1383   Select *pSelect;       /* When the expression is a sub-select.  Also the
1384                          ** right side of "<expr> IN (<select>)" */
1385   Table *pTab;           /* Table for TK_COLUMN expressions. */
1386 #if SQLITE_MAX_EXPR_DEPTH>0
1387   int nHeight;           /* Height of the tree headed by this node */
1388 #endif
1389 };
1390 
1391 /*
1392 ** The following are the meanings of bits in the Expr.flags field.
1393 */
1394 #define EP_FromJoin   0x0001  /* Originated in ON or USING clause of a join */
1395 #define EP_Agg        0x0002  /* Contains one or more aggregate functions */
1396 #define EP_Resolved   0x0004  /* IDs have been resolved to COLUMNs */
1397 #define EP_Error      0x0008  /* Expression contains one or more errors */
1398 #define EP_Distinct   0x0010  /* Aggregate function with DISTINCT keyword */
1399 #define EP_VarSelect  0x0020  /* pSelect is correlated, not constant */
1400 #define EP_Dequoted   0x0040  /* True if the string has been dequoted */
1401 #define EP_InfixFunc  0x0080  /* True for an infix function: LIKE, GLOB, etc */
1402 #define EP_ExpCollate 0x0100  /* Collating sequence specified explicitly */
1403 #define EP_AnyAff     0x0200  /* Can take a cached column of any affinity */
1404 #define EP_FixedDest  0x0400  /* Result needed in a specific register */
1405 #define EP_IntValue   0x0800  /* Integer value contained in iTable */
1406 /*
1407 ** These macros can be used to test, set, or clear bits in the
1408 ** Expr.flags field.
1409 */
1410 #define ExprHasProperty(E,P)     (((E)->flags&(P))==(P))
1411 #define ExprHasAnyProperty(E,P)  (((E)->flags&(P))!=0)
1412 #define ExprSetProperty(E,P)     (E)->flags|=(P)
1413 #define ExprClearProperty(E,P)   (E)->flags&=~(P)
1414 
1415 /*
1416 ** A list of expressions.  Each expression may optionally have a
1417 ** name.  An expr/name combination can be used in several ways, such
1418 ** as the list of "expr AS ID" fields following a "SELECT" or in the
1419 ** list of "ID = expr" items in an UPDATE.  A list of expressions can
1420 ** also be used as the argument to a function, in which case the a.zName
1421 ** field is not used.
1422 */
1423 struct ExprList {
1424   int nExpr;             /* Number of expressions on the list */
1425   int nAlloc;            /* Number of entries allocated below */
1426   int iECursor;          /* VDBE Cursor associated with this ExprList */
1427   struct ExprList_item {
1428     Expr *pExpr;           /* The list of expressions */
1429     char *zName;           /* Token associated with this expression */
1430     u8 sortOrder;          /* 1 for DESC or 0 for ASC */
1431     u8 done;               /* A flag to indicate when processing is finished */
1432     u16 iCol;              /* For ORDER BY, column number in result set */
1433     u16 iAlias;            /* Index into Parse.aAlias[] for zName */
1434   } *a;                  /* One entry for each expression */
1435 };
1436 
1437 /*
1438 ** An instance of this structure can hold a simple list of identifiers,
1439 ** such as the list "a,b,c" in the following statements:
1440 **
1441 **      INSERT INTO t(a,b,c) VALUES ...;
1442 **      CREATE INDEX idx ON t(a,b,c);
1443 **      CREATE TRIGGER trig BEFORE UPDATE ON t(a,b,c) ...;
1444 **
1445 ** The IdList.a.idx field is used when the IdList represents the list of
1446 ** column names after a table name in an INSERT statement.  In the statement
1447 **
1448 **     INSERT INTO t(a,b,c) ...
1449 **
1450 ** If "a" is the k-th column of table "t", then IdList.a[0].idx==k.
1451 */
1452 struct IdList {
1453   struct IdList_item {
1454     char *zName;      /* Name of the identifier */
1455     int idx;          /* Index in some Table.aCol[] of a column named zName */
1456   } *a;
1457   int nId;         /* Number of identifiers on the list */
1458   int nAlloc;      /* Number of entries allocated for a[] below */
1459 };
1460 
1461 /*
1462 ** The bitmask datatype defined below is used for various optimizations.
1463 **
1464 ** Changing this from a 64-bit to a 32-bit type limits the number of
1465 ** tables in a join to 32 instead of 64.  But it also reduces the size
1466 ** of the library by 738 bytes on ix86.
1467 */
1468 typedef u64 Bitmask;
1469 
1470 /*
1471 ** The number of bits in a Bitmask.  "BMS" means "BitMask Size".
1472 */
1473 #define BMS  ((int)(sizeof(Bitmask)*8))
1474 
1475 /*
1476 ** The following structure describes the FROM clause of a SELECT statement.
1477 ** Each table or subquery in the FROM clause is a separate element of
1478 ** the SrcList.a[] array.
1479 **
1480 ** With the addition of multiple database support, the following structure
1481 ** can also be used to describe a particular table such as the table that
1482 ** is modified by an INSERT, DELETE, or UPDATE statement.  In standard SQL,
1483 ** such a table must be a simple name: ID.  But in SQLite, the table can
1484 ** now be identified by a database name, a dot, then the table name: ID.ID.
1485 **
1486 ** The jointype starts out showing the join type between the current table
1487 ** and the next table on the list.  The parser builds the list this way.
1488 ** But sqlite3SrcListShiftJoinType() later shifts the jointypes so that each
1489 ** jointype expresses the join between the table and the previous table.
1490 */
1491 struct SrcList {
1492   i16 nSrc;        /* Number of tables or subqueries in the FROM clause */
1493   i16 nAlloc;      /* Number of entries allocated in a[] below */
1494   struct SrcList_item {
1495     char *zDatabase;  /* Name of database holding this table */
1496     char *zName;      /* Name of the table */
1497     char *zAlias;     /* The "B" part of a "A AS B" phrase.  zName is the "A" */
1498     Table *pTab;      /* An SQL table corresponding to zName */
1499     Select *pSelect;  /* A SELECT statement used in place of a table name */
1500     u8 isPopulated;   /* Temporary table associated with SELECT is populated */
1501     u8 jointype;      /* Type of join between this able and the previous */
1502     u8 notIndexed;    /* True if there is a NOT INDEXED clause */
1503     int iCursor;      /* The VDBE cursor number used to access this table */
1504     Expr *pOn;        /* The ON clause of a join */
1505     IdList *pUsing;   /* The USING clause of a join */
1506     Bitmask colUsed;  /* Bit N (1<<N) set if column N or pTab is used */
1507     char *zIndex;     /* Identifier from "INDEXED BY <zIndex>" clause */
1508     Index *pIndex;    /* Index structure corresponding to zIndex, if any */
1509   } a[1];             /* One entry for each identifier on the list */
1510 };
1511 
1512 /*
1513 ** Permitted values of the SrcList.a.jointype field
1514 */
1515 #define JT_INNER     0x0001    /* Any kind of inner or cross join */
1516 #define JT_CROSS     0x0002    /* Explicit use of the CROSS keyword */
1517 #define JT_NATURAL   0x0004    /* True for a "natural" join */
1518 #define JT_LEFT      0x0008    /* Left outer join */
1519 #define JT_RIGHT     0x0010    /* Right outer join */
1520 #define JT_OUTER     0x0020    /* The "OUTER" keyword is present */
1521 #define JT_ERROR     0x0040    /* unknown or unsupported join type */
1522 
1523 
1524 /*
1525 ** A WherePlan object holds information that describes a lookup
1526 ** strategy.
1527 **
1528 ** This object is intended to be opaque outside of the where.c module.
1529 ** It is included here only so that that compiler will know how big it
1530 ** is.  None of the fields in this object should be used outside of
1531 ** the where.c module.
1532 **
1533 ** Within the union, pIdx is only used when wsFlags&WHERE_INDEXED is true.
1534 ** pTerm is only used when wsFlags&WHERE_MULTI_OR is true.  And pVtabIdx
1535 ** is only used when wsFlags&WHERE_VIRTUALTABLE is true.  It is never the
1536 ** case that more than one of these conditions is true.
1537 */
1538 struct WherePlan {
1539   u32 wsFlags;                   /* WHERE_* flags that describe the strategy */
1540   u32 nEq;                       /* Number of == constraints */
1541   union {
1542     Index *pIdx;                   /* Index when WHERE_INDEXED is true */
1543     struct WhereTerm *pTerm;       /* WHERE clause term for OR-search */
1544     sqlite3_index_info *pVtabIdx;  /* Virtual table index to use */
1545   } u;
1546 };
1547 
1548 /*
1549 ** For each nested loop in a WHERE clause implementation, the WhereInfo
1550 ** structure contains a single instance of this structure.  This structure
1551 ** is intended to be private the the where.c module and should not be
1552 ** access or modified by other modules.
1553 **
1554 ** The pIdxInfo field is used to help pick the best index on a
1555 ** virtual table.  The pIdxInfo pointer contains indexing
1556 ** information for the i-th table in the FROM clause before reordering.
1557 ** All the pIdxInfo pointers are freed by whereInfoFree() in where.c.
1558 ** All other information in the i-th WhereLevel object for the i-th table
1559 ** after FROM clause ordering.
1560 */
1561 struct WhereLevel {
1562   WherePlan plan;       /* query plan for this element of the FROM clause */
1563   int iLeftJoin;        /* Memory cell used to implement LEFT OUTER JOIN */
1564   int iTabCur;          /* The VDBE cursor used to access the table */
1565   int iIdxCur;          /* The VDBE cursor used to access pIdx */
1566   int addrBrk;          /* Jump here to break out of the loop */
1567   int addrNxt;          /* Jump here to start the next IN combination */
1568   int addrCont;         /* Jump here to continue with the next loop cycle */
1569   int addrFirst;        /* First instruction of interior of the loop */
1570   u8 iFrom;             /* Which entry in the FROM clause */
1571   u8 op, p5;            /* Opcode and P5 of the opcode that ends the loop */
1572   int p1, p2;           /* Operands of the opcode used to ends the loop */
1573   union {               /* Information that depends on plan.wsFlags */
1574     struct {
1575       int nIn;              /* Number of entries in aInLoop[] */
1576       struct InLoop {
1577         int iCur;              /* The VDBE cursor used by this IN operator */
1578         int addrInTop;         /* Top of the IN loop */
1579       } *aInLoop;           /* Information about each nested IN operator */
1580     } in;                 /* Used when plan.wsFlags&WHERE_IN_ABLE */
1581     struct {
1582       WherePlan *aPlan;     /* Plans for each term of the WHERE clause */
1583     } or;                 /* Used when plan.wsFlags&WHERE_MULTI_OR */
1584   } u;
1585 
1586   /* The following field is really not part of the current level.  But
1587   ** we need a place to cache virtual table index information for each
1588   ** virtual table in the FROM clause and the WhereLevel structure is
1589   ** a convenient place since there is one WhereLevel for each FROM clause
1590   ** element.
1591   */
1592   sqlite3_index_info *pIdxInfo;  /* Index info for n-th source table */
1593 };
1594 
1595 /*
1596 ** Flags appropriate for the wctrlFlags parameter of sqlite3WhereBegin().
1597 */
1598 #define WHERE_ORDERBY_NORMAL   0x0000 /* No-op */
1599 #define WHERE_ORDERBY_MIN      0x0001 /* ORDER BY processing for min() func */
1600 #define WHERE_ORDERBY_MAX      0x0002 /* ORDER BY processing for max() func */
1601 #define WHERE_ONEPASS_DESIRED  0x0004 /* Want to do one-pass UPDATE/DELETE */
1602 #define WHERE_FILL_ROWSET      0x0008  /* Save results in a RowSet object */
1603 #define WHERE_OMIT_OPEN        0x0010  /* Table cursor are already open */
1604 #define WHERE_OMIT_CLOSE       0x0020  /* Omit close of table & index cursors */
1605 
1606 /*
1607 ** The WHERE clause processing routine has two halves.  The
1608 ** first part does the start of the WHERE loop and the second
1609 ** half does the tail of the WHERE loop.  An instance of
1610 ** this structure is returned by the first half and passed
1611 ** into the second half to give some continuity.
1612 */
1613 struct WhereInfo {
1614   Parse *pParse;       /* Parsing and code generating context */
1615   u16 wctrlFlags;      /* Flags originally passed to sqlite3WhereBegin() */
1616   u8 okOnePass;        /* Ok to use one-pass algorithm for UPDATE or DELETE */
1617   int regRowSet;                 /* Store rowids in this rowset if >=0 */
1618   SrcList *pTabList;             /* List of tables in the join */
1619   int iTop;                      /* The very beginning of the WHERE loop */
1620   int iContinue;                 /* Jump here to continue with next record */
1621   int iBreak;                    /* Jump here to break out of the loop */
1622   int nLevel;                    /* Number of nested loop */
1623   struct WhereClause *pWC;       /* Decomposition of the WHERE clause */
1624   WhereLevel a[1];               /* Information about each nest loop in WHERE */
1625 };
1626 
1627 /*
1628 ** A NameContext defines a context in which to resolve table and column
1629 ** names.  The context consists of a list of tables (the pSrcList) field and
1630 ** a list of named expression (pEList).  The named expression list may
1631 ** be NULL.  The pSrc corresponds to the FROM clause of a SELECT or
1632 ** to the table being operated on by INSERT, UPDATE, or DELETE.  The
1633 ** pEList corresponds to the result set of a SELECT and is NULL for
1634 ** other statements.
1635 **
1636 ** NameContexts can be nested.  When resolving names, the inner-most
1637 ** context is searched first.  If no match is found, the next outer
1638 ** context is checked.  If there is still no match, the next context
1639 ** is checked.  This process continues until either a match is found
1640 ** or all contexts are check.  When a match is found, the nRef member of
1641 ** the context containing the match is incremented.
1642 **
1643 ** Each subquery gets a new NameContext.  The pNext field points to the
1644 ** NameContext in the parent query.  Thus the process of scanning the
1645 ** NameContext list corresponds to searching through successively outer
1646 ** subqueries looking for a match.
1647 */
1648 struct NameContext {
1649   Parse *pParse;       /* The parser */
1650   SrcList *pSrcList;   /* One or more tables used to resolve names */
1651   ExprList *pEList;    /* Optional list of named expressions */
1652   int nRef;            /* Number of names resolved by this context */
1653   int nErr;            /* Number of errors encountered while resolving names */
1654   u8 allowAgg;         /* Aggregate functions allowed here */
1655   u8 hasAgg;           /* True if aggregates are seen */
1656   u8 isCheck;          /* True if resolving names in a CHECK constraint */
1657   int nDepth;          /* Depth of subquery recursion. 1 for no recursion */
1658   AggInfo *pAggInfo;   /* Information about aggregates at this level */
1659   NameContext *pNext;  /* Next outer name context.  NULL for outermost */
1660 };
1661 
1662 /*
1663 ** An instance of the following structure contains all information
1664 ** needed to generate code for a single SELECT statement.
1665 **
1666 ** nLimit is set to -1 if there is no LIMIT clause.  nOffset is set to 0.
1667 ** If there is a LIMIT clause, the parser sets nLimit to the value of the
1668 ** limit and nOffset to the value of the offset (or 0 if there is not
1669 ** offset).  But later on, nLimit and nOffset become the memory locations
1670 ** in the VDBE that record the limit and offset counters.
1671 **
1672 ** addrOpenEphm[] entries contain the address of OP_OpenEphemeral opcodes.
1673 ** These addresses must be stored so that we can go back and fill in
1674 ** the P4_KEYINFO and P2 parameters later.  Neither the KeyInfo nor
1675 ** the number of columns in P2 can be computed at the same time
1676 ** as the OP_OpenEphm instruction is coded because not
1677 ** enough information about the compound query is known at that point.
1678 ** The KeyInfo for addrOpenTran[0] and [1] contains collating sequences
1679 ** for the result set.  The KeyInfo for addrOpenTran[2] contains collating
1680 ** sequences for the ORDER BY clause.
1681 */
1682 struct Select {
1683   ExprList *pEList;      /* The fields of the result */
1684   u8 op;                 /* One of: TK_UNION TK_ALL TK_INTERSECT TK_EXCEPT */
1685   char affinity;         /* MakeRecord with this affinity for SRT_Set */
1686   u16 selFlags;          /* Various SF_* values */
1687   SrcList *pSrc;         /* The FROM clause */
1688   Expr *pWhere;          /* The WHERE clause */
1689   ExprList *pGroupBy;    /* The GROUP BY clause */
1690   Expr *pHaving;         /* The HAVING clause */
1691   ExprList *pOrderBy;    /* The ORDER BY clause */
1692   Select *pPrior;        /* Prior select in a compound select statement */
1693   Select *pNext;         /* Next select to the left in a compound */
1694   Select *pRightmost;    /* Right-most select in a compound select statement */
1695   Expr *pLimit;          /* LIMIT expression. NULL means not used. */
1696   Expr *pOffset;         /* OFFSET expression. NULL means not used. */
1697   int iLimit, iOffset;   /* Memory registers holding LIMIT & OFFSET counters */
1698   int addrOpenEphm[3];   /* OP_OpenEphem opcodes related to this select */
1699 };
1700 
1701 /*
1702 ** Allowed values for Select.selFlags.  The "SF" prefix stands for
1703 ** "Select Flag".
1704 */
1705 #define SF_Distinct        0x0001  /* Output should be DISTINCT */
1706 #define SF_Resolved        0x0002  /* Identifiers have been resolved */
1707 #define SF_Aggregate       0x0004  /* Contains aggregate functions */
1708 #define SF_UsesEphemeral   0x0008  /* Uses the OpenEphemeral opcode */
1709 #define SF_Expanded        0x0010  /* sqlite3SelectExpand() called on this */
1710 #define SF_HasTypeInfo     0x0020  /* FROM subqueries have Table metadata */
1711 
1712 
1713 /*
1714 ** The results of a select can be distributed in several ways.  The
1715 ** "SRT" prefix means "SELECT Result Type".
1716 */
1717 #define SRT_Union        1  /* Store result as keys in an index */
1718 #define SRT_Except       2  /* Remove result from a UNION index */
1719 #define SRT_Exists       3  /* Store 1 if the result is not empty */
1720 #define SRT_Discard      4  /* Do not save the results anywhere */
1721 
1722 /* The ORDER BY clause is ignored for all of the above */
1723 #define IgnorableOrderby(X) ((X->eDest)<=SRT_Discard)
1724 
1725 #define SRT_Output       5  /* Output each row of result */
1726 #define SRT_Mem          6  /* Store result in a memory cell */
1727 #define SRT_Set          7  /* Store results as keys in an index */
1728 #define SRT_Table        8  /* Store result as data with an automatic rowid */
1729 #define SRT_EphemTab     9  /* Create transient tab and store like SRT_Table */
1730 #define SRT_Coroutine   10  /* Generate a single row of result */
1731 
1732 /*
1733 ** A structure used to customize the behavior of sqlite3Select(). See
1734 ** comments above sqlite3Select() for details.
1735 */
1736 typedef struct SelectDest SelectDest;
1737 struct SelectDest {
1738   u8 eDest;         /* How to dispose of the results */
1739   u8 affinity;      /* Affinity used when eDest==SRT_Set */
1740   int iParm;        /* A parameter used by the eDest disposal method */
1741   int iMem;         /* Base register where results are written */
1742   int nMem;         /* Number of registers allocated */
1743 };
1744 
1745 /*
1746 ** An SQL parser context.  A copy of this structure is passed through
1747 ** the parser and down into all the parser action routine in order to
1748 ** carry around information that is global to the entire parse.
1749 **
1750 ** The structure is divided into two parts.  When the parser and code
1751 ** generate call themselves recursively, the first part of the structure
1752 ** is constant but the second part is reset at the beginning and end of
1753 ** each recursion.
1754 **
1755 ** The nTableLock and aTableLock variables are only used if the shared-cache
1756 ** feature is enabled (if sqlite3Tsd()->useSharedData is true). They are
1757 ** used to store the set of table-locks required by the statement being
1758 ** compiled. Function sqlite3TableLock() is used to add entries to the
1759 ** list.
1760 */
1761 struct Parse {
1762   sqlite3 *db;         /* The main database structure */
1763   int rc;              /* Return code from execution */
1764   char *zErrMsg;       /* An error message */
1765   Vdbe *pVdbe;         /* An engine for executing database bytecode */
1766   u8 colNamesSet;      /* TRUE after OP_ColumnName has been issued to pVdbe */
1767   u8 nameClash;        /* A permanent table name clashes with temp table name */
1768   u8 checkSchema;      /* Causes schema cookie check after an error */
1769   u8 nested;           /* Number of nested calls to the parser/code generator */
1770   u8 parseError;       /* True after a parsing error.  Ticket #1794 */
1771   u8 nTempReg;         /* Number of temporary registers in aTempReg[] */
1772   u8 nTempInUse;       /* Number of aTempReg[] currently checked out */
1773   int aTempReg[8];     /* Holding area for temporary registers */
1774   int nRangeReg;       /* Size of the temporary register block */
1775   int iRangeReg;       /* First register in temporary register block */
1776   int nErr;            /* Number of errors seen */
1777   int nTab;            /* Number of previously allocated VDBE cursors */
1778   int nMem;            /* Number of memory cells used so far */
1779   int nSet;            /* Number of sets used so far */
1780   int ckBase;          /* Base register of data during check constraints */
1781   int disableColCache; /* True to disable adding to column cache */
1782   int nColCache;       /* Number of entries in the column cache */
1783   int iColCache;       /* Next entry of the cache to replace */
1784   struct yColCache {
1785     int iTable;           /* Table cursor number */
1786     int iColumn;          /* Table column number */
1787     char affChange;       /* True if this register has had an affinity change */
1788     int iReg;             /* Register holding value of this column */
1789   } aColCache[10];     /* One for each valid column cache entry */
1790   u32 writeMask;       /* Start a write transaction on these databases */
1791   u32 cookieMask;      /* Bitmask of schema verified databases */
1792   int cookieGoto;      /* Address of OP_Goto to cookie verifier subroutine */
1793   int cookieValue[SQLITE_MAX_ATTACHED+2];  /* Values of cookies to verify */
1794 #ifndef SQLITE_OMIT_SHARED_CACHE
1795   int nTableLock;        /* Number of locks in aTableLock */
1796   TableLock *aTableLock; /* Required table locks for shared-cache mode */
1797 #endif
1798   int regRowid;        /* Register holding rowid of CREATE TABLE entry */
1799   int regRoot;         /* Register holding root page number for new objects */
1800 
1801   /* Above is constant between recursions.  Below is reset before and after
1802   ** each recursion */
1803 
1804   int nVar;            /* Number of '?' variables seen in the SQL so far */
1805   int nVarExpr;        /* Number of used slots in apVarExpr[] */
1806   int nVarExprAlloc;   /* Number of allocated slots in apVarExpr[] */
1807   Expr **apVarExpr;    /* Pointers to :aaa and $aaaa wildcard expressions */
1808   int nAlias;          /* Number of aliased result set columns */
1809   int nAliasAlloc;     /* Number of allocated slots for aAlias[] */
1810   int *aAlias;         /* Register used to hold aliased result */
1811   u8 explain;          /* True if the EXPLAIN flag is found on the query */
1812   Token sErrToken;     /* The token at which the error occurred */
1813   Token sNameToken;    /* Token with unqualified schema object name */
1814   Token sLastToken;    /* The last token parsed */
1815   const char *zSql;    /* All SQL text */
1816   const char *zTail;   /* All SQL text past the last semicolon parsed */
1817   Table *pNewTable;    /* A table being constructed by CREATE TABLE */
1818   Trigger *pNewTrigger;     /* Trigger under construct by a CREATE TRIGGER */
1819   TriggerStack *trigStack;  /* Trigger actions being coded */
1820   const char *zAuthContext; /* The 6th parameter to db->xAuth callbacks */
1821 #ifndef SQLITE_OMIT_VIRTUALTABLE
1822   Token sArg;                /* Complete text of a module argument */
1823   u8 declareVtab;            /* True if inside sqlite3_declare_vtab() */
1824   int nVtabLock;             /* Number of virtual tables to lock */
1825   Table **apVtabLock;        /* Pointer to virtual tables needing locking */
1826 #endif
1827   int nHeight;            /* Expression tree height of current sub-select */
1828   Table *pZombieTab;      /* List of Table objects to delete after code gen */
1829 };
1830 
1831 #ifdef SQLITE_OMIT_VIRTUALTABLE
1832   #define IN_DECLARE_VTAB 0
1833 #else
1834   #define IN_DECLARE_VTAB (pParse->declareVtab)
1835 #endif
1836 
1837 /*
1838 ** An instance of the following structure can be declared on a stack and used
1839 ** to save the Parse.zAuthContext value so that it can be restored later.
1840 */
1841 struct AuthContext {
1842   const char *zAuthContext;   /* Put saved Parse.zAuthContext here */
1843   Parse *pParse;              /* The Parse structure */
1844 };
1845 
1846 /*
1847 ** Bitfield flags for P2 value in OP_Insert and OP_Delete
1848 */
1849 #define OPFLAG_NCHANGE   1    /* Set to update db->nChange */
1850 #define OPFLAG_LASTROWID 2    /* Set to update db->lastRowid */
1851 #define OPFLAG_ISUPDATE  4    /* This OP_Insert is an sql UPDATE */
1852 #define OPFLAG_APPEND    8    /* This is likely to be an append */
1853 
1854 /*
1855  * Each trigger present in the database schema is stored as an instance of
1856  * struct Trigger.
1857  *
1858  * Pointers to instances of struct Trigger are stored in two ways.
1859  * 1. In the "trigHash" hash table (part of the sqlite3* that represents the
1860  *    database). This allows Trigger structures to be retrieved by name.
1861  * 2. All triggers associated with a single table form a linked list, using the
1862  *    pNext member of struct Trigger. A pointer to the first element of the
1863  *    linked list is stored as the "pTrigger" member of the associated
1864  *    struct Table.
1865  *
1866  * The "step_list" member points to the first element of a linked list
1867  * containing the SQL statements specified as the trigger program.
1868  */
1869 struct Trigger {
1870   char *name;             /* The name of the trigger                        */
1871   char *table;            /* The table or view to which the trigger applies */
1872   u8 op;                  /* One of TK_DELETE, TK_UPDATE, TK_INSERT         */
1873   u8 tr_tm;               /* One of TRIGGER_BEFORE, TRIGGER_AFTER */
1874   Expr *pWhen;            /* The WHEN clause of the expression (may be NULL) */
1875   IdList *pColumns;       /* If this is an UPDATE OF <column-list> trigger,
1876                              the <column-list> is stored here */
1877   Token nameToken;        /* Token containing zName. Use during parsing only */
1878   Schema *pSchema;        /* Schema containing the trigger */
1879   Schema *pTabSchema;     /* Schema containing the table */
1880   TriggerStep *step_list; /* Link list of trigger program steps             */
1881   Trigger *pNext;         /* Next trigger associated with the table */
1882 };
1883 
1884 /*
1885 ** A trigger is either a BEFORE or an AFTER trigger.  The following constants
1886 ** determine which.
1887 **
1888 ** If there are multiple triggers, you might of some BEFORE and some AFTER.
1889 ** In that cases, the constants below can be ORed together.
1890 */
1891 #define TRIGGER_BEFORE  1
1892 #define TRIGGER_AFTER   2
1893 
1894 /*
1895  * An instance of struct TriggerStep is used to store a single SQL statement
1896  * that is a part of a trigger-program.
1897  *
1898  * Instances of struct TriggerStep are stored in a singly linked list (linked
1899  * using the "pNext" member) referenced by the "step_list" member of the
1900  * associated struct Trigger instance. The first element of the linked list is
1901  * the first step of the trigger-program.
1902  *
1903  * The "op" member indicates whether this is a "DELETE", "INSERT", "UPDATE" or
1904  * "SELECT" statement. The meanings of the other members is determined by the
1905  * value of "op" as follows:
1906  *
1907  * (op == TK_INSERT)
1908  * orconf    -> stores the ON CONFLICT algorithm
1909  * pSelect   -> If this is an INSERT INTO ... SELECT ... statement, then
1910  *              this stores a pointer to the SELECT statement. Otherwise NULL.
1911  * target    -> A token holding the name of the table to insert into.
1912  * pExprList -> If this is an INSERT INTO ... VALUES ... statement, then
1913  *              this stores values to be inserted. Otherwise NULL.
1914  * pIdList   -> If this is an INSERT INTO ... (<column-names>) VALUES ...
1915  *              statement, then this stores the column-names to be
1916  *              inserted into.
1917  *
1918  * (op == TK_DELETE)
1919  * target    -> A token holding the name of the table to delete from.
1920  * pWhere    -> The WHERE clause of the DELETE statement if one is specified.
1921  *              Otherwise NULL.
1922  *
1923  * (op == TK_UPDATE)
1924  * target    -> A token holding the name of the table to update rows of.
1925  * pWhere    -> The WHERE clause of the UPDATE statement if one is specified.
1926  *              Otherwise NULL.
1927  * pExprList -> A list of the columns to update and the expressions to update
1928  *              them to. See sqlite3Update() documentation of "pChanges"
1929  *              argument.
1930  *
1931  */
1932 struct TriggerStep {
1933   int op;              /* One of TK_DELETE, TK_UPDATE, TK_INSERT, TK_SELECT */
1934   int orconf;          /* OE_Rollback etc. */
1935   Trigger *pTrig;      /* The trigger that this step is a part of */
1936 
1937   Select *pSelect;     /* Valid for SELECT and sometimes
1938                           INSERT steps (when pExprList == 0) */
1939   Token target;        /* Valid for DELETE, UPDATE, INSERT steps */
1940   Expr *pWhere;        /* Valid for DELETE, UPDATE steps */
1941   ExprList *pExprList; /* Valid for UPDATE statements and sometimes
1942                            INSERT steps (when pSelect == 0)         */
1943   IdList *pIdList;     /* Valid for INSERT statements only */
1944   TriggerStep *pNext;  /* Next in the link-list */
1945   TriggerStep *pLast;  /* Last element in link-list. Valid for 1st elem only */
1946 };
1947 
1948 /*
1949  * An instance of struct TriggerStack stores information required during code
1950  * generation of a single trigger program. While the trigger program is being
1951  * coded, its associated TriggerStack instance is pointed to by the
1952  * "pTriggerStack" member of the Parse structure.
1953  *
1954  * The pTab member points to the table that triggers are being coded on. The
1955  * newIdx member contains the index of the vdbe cursor that points at the temp
1956  * table that stores the new.* references. If new.* references are not valid
1957  * for the trigger being coded (for example an ON DELETE trigger), then newIdx
1958  * is set to -1. The oldIdx member is analogous to newIdx, for old.* references.
1959  *
1960  * The ON CONFLICT policy to be used for the trigger program steps is stored
1961  * as the orconf member. If this is OE_Default, then the ON CONFLICT clause
1962  * specified for individual triggers steps is used.
1963  *
1964  * struct TriggerStack has a "pNext" member, to allow linked lists to be
1965  * constructed. When coding nested triggers (triggers fired by other triggers)
1966  * each nested trigger stores its parent trigger's TriggerStack as the "pNext"
1967  * pointer. Once the nested trigger has been coded, the pNext value is restored
1968  * to the pTriggerStack member of the Parse stucture and coding of the parent
1969  * trigger continues.
1970  *
1971  * Before a nested trigger is coded, the linked list pointed to by the
1972  * pTriggerStack is scanned to ensure that the trigger is not about to be coded
1973  * recursively. If this condition is detected, the nested trigger is not coded.
1974  */
1975 struct TriggerStack {
1976   Table *pTab;         /* Table that triggers are currently being coded on */
1977   int newIdx;          /* Index of vdbe cursor to "new" temp table */
1978   int oldIdx;          /* Index of vdbe cursor to "old" temp table */
1979   u32 newColMask;
1980   u32 oldColMask;
1981   int orconf;          /* Current orconf policy */
1982   int ignoreJump;      /* where to jump to for a RAISE(IGNORE) */
1983   Trigger *pTrigger;   /* The trigger currently being coded */
1984   TriggerStack *pNext; /* Next trigger down on the trigger stack */
1985 };
1986 
1987 /*
1988 ** The following structure contains information used by the sqliteFix...
1989 ** routines as they walk the parse tree to make database references
1990 ** explicit.
1991 */
1992 typedef struct DbFixer DbFixer;
1993 struct DbFixer {
1994   Parse *pParse;      /* The parsing context.  Error messages written here */
1995   const char *zDb;    /* Make sure all objects are contained in this database */
1996   const char *zType;  /* Type of the container - used for error messages */
1997   const Token *pName; /* Name of the container - used for error messages */
1998 };
1999 
2000 /*
2001 ** An objected used to accumulate the text of a string where we
2002 ** do not necessarily know how big the string will be in the end.
2003 */
2004 struct StrAccum {
2005   sqlite3 *db;         /* Optional database for lookaside.  Can be NULL */
2006   char *zBase;         /* A base allocation.  Not from malloc. */
2007   char *zText;         /* The string collected so far */
2008   int  nChar;          /* Length of the string so far */
2009   int  nAlloc;         /* Amount of space allocated in zText */
2010   int  mxAlloc;        /* Maximum allowed string length */
2011   u8   mallocFailed;   /* Becomes true if any memory allocation fails */
2012   u8   useMalloc;      /* True if zText is enlargeable using realloc */
2013   u8   tooBig;         /* Becomes true if string size exceeds limits */
2014 };
2015 
2016 /*
2017 ** A pointer to this structure is used to communicate information
2018 ** from sqlite3Init and OP_ParseSchema into the sqlite3InitCallback.
2019 */
2020 typedef struct {
2021   sqlite3 *db;        /* The database being initialized */
2022   int iDb;            /* 0 for main database.  1 for TEMP, 2.. for ATTACHed */
2023   char **pzErrMsg;    /* Error message stored here */
2024   int rc;             /* Result code stored here */
2025 } InitData;
2026 
2027 /*
2028 ** Structure containing global configuration data for the SQLite library.
2029 **
2030 ** This structure also contains some state information.
2031 */
2032 struct Sqlite3Config {
2033   int bMemstat;                     /* True to enable memory status */
2034   int bCoreMutex;                   /* True to enable core mutexing */
2035   int bFullMutex;                   /* True to enable full mutexing */
2036   int mxStrlen;                     /* Maximum string length */
2037   int szLookaside;                  /* Default lookaside buffer size */
2038   int nLookaside;                   /* Default lookaside buffer count */
2039   sqlite3_mem_methods m;            /* Low-level memory allocation interface */
2040   sqlite3_mutex_methods mutex;      /* Low-level mutex interface */
2041   sqlite3_pcache_methods pcache;    /* Low-level page-cache interface */
2042   void *pHeap;                      /* Heap storage space */
2043   int nHeap;                        /* Size of pHeap[] */
2044   int mnReq, mxReq;                 /* Min and max heap requests sizes */
2045   void *pScratch;                   /* Scratch memory */
2046   int szScratch;                    /* Size of each scratch buffer */
2047   int nScratch;                     /* Number of scratch buffers */
2048   void *pPage;                      /* Page cache memory */
2049   int szPage;                       /* Size of each page in pPage[] */
2050   int nPage;                        /* Number of pages in pPage[] */
2051   int mxParserStack;                /* maximum depth of the parser stack */
2052   int sharedCacheEnabled;           /* true if shared-cache mode enabled */
2053   /* The above might be initialized to non-zero.  The following need to always
2054   ** initially be zero, however. */
2055   int isInit;                       /* True after initialization has finished */
2056   int inProgress;                   /* True while initialization in progress */
2057   int isMallocInit;                 /* True after malloc is initialized */
2058   sqlite3_mutex *pInitMutex;        /* Mutex used by sqlite3_initialize() */
2059   int nRefInitMutex;                /* Number of users of pInitMutex */
2060 };
2061 
2062 /*
2063 ** Context pointer passed down through the tree-walk.
2064 */
2065 struct Walker {
2066   int (*xExprCallback)(Walker*, Expr*);     /* Callback for expressions */
2067   int (*xSelectCallback)(Walker*,Select*);  /* Callback for SELECTs */
2068   Parse *pParse;                            /* Parser context.  */
2069   union {                                   /* Extra data for callback */
2070     NameContext *pNC;                          /* Naming context */
2071     int i;                                     /* Integer value */
2072   } u;
2073 };
2074 
2075 /* Forward declarations */
2076 int sqlite3WalkExpr(Walker*, Expr*);
2077 int sqlite3WalkExprList(Walker*, ExprList*);
2078 int sqlite3WalkSelect(Walker*, Select*);
2079 int sqlite3WalkSelectExpr(Walker*, Select*);
2080 int sqlite3WalkSelectFrom(Walker*, Select*);
2081 
2082 /*
2083 ** Return code from the parse-tree walking primitives and their
2084 ** callbacks.
2085 */
2086 #define WRC_Continue    0   /* Continue down into children */
2087 #define WRC_Prune       1   /* Omit children but continue walking siblings */
2088 #define WRC_Abort       2   /* Abandon the tree walk */
2089 
2090 /*
2091 ** Assuming zIn points to the first byte of a UTF-8 character,
2092 ** advance zIn to point to the first byte of the next UTF-8 character.
2093 */
2094 #define SQLITE_SKIP_UTF8(zIn) {                        \
2095   if( (*(zIn++))>=0xc0 ){                              \
2096     while( (*zIn & 0xc0)==0x80 ){ zIn++; }             \
2097   }                                                    \
2098 }
2099 
2100 /*
2101 ** The SQLITE_CORRUPT_BKPT macro can be either a constant (for production
2102 ** builds) or a function call (for debugging).  If it is a function call,
2103 ** it allows the operator to set a breakpoint at the spot where database
2104 ** corruption is first detected.
2105 */
2106 #ifdef SQLITE_DEBUG
2107   int sqlite3Corrupt(void);
2108 # define SQLITE_CORRUPT_BKPT sqlite3Corrupt()
2109 #else
2110 # define SQLITE_CORRUPT_BKPT SQLITE_CORRUPT
2111 #endif
2112 
2113 /*
2114 ** Internal function prototypes
2115 */
2116 int sqlite3StrICmp(const char *, const char *);
2117 int sqlite3StrNICmp(const char *, const char *, int);
2118 int sqlite3IsNumber(const char*, int*, u8);
2119 int sqlite3Strlen(sqlite3*, const char*);
2120 int sqlite3Strlen30(const char*);
2121 
2122 int sqlite3MallocInit(void);
2123 void sqlite3MallocEnd(void);
2124 void *sqlite3Malloc(int);
2125 void *sqlite3MallocZero(int);
2126 void *sqlite3DbMallocZero(sqlite3*, int);
2127 void *sqlite3DbMallocRaw(sqlite3*, int);
2128 char *sqlite3DbStrDup(sqlite3*,const char*);
2129 char *sqlite3DbStrNDup(sqlite3*,const char*, int);
2130 void *sqlite3Realloc(void*, int);
2131 void *sqlite3DbReallocOrFree(sqlite3 *, void *, int);
2132 void *sqlite3DbRealloc(sqlite3 *, void *, int);
2133 void sqlite3DbFree(sqlite3*, void*);
2134 int sqlite3MallocSize(void*);
2135 int sqlite3DbMallocSize(sqlite3*, void*);
2136 void *sqlite3ScratchMalloc(int);
2137 void sqlite3ScratchFree(void*);
2138 void *sqlite3PageMalloc(int);
2139 void sqlite3PageFree(void*);
2140 void sqlite3MemSetDefault(void);
2141 void sqlite3BenignMallocHooks(void (*)(void), void (*)(void));
2142 int sqlite3MemoryAlarm(void (*)(void*, sqlite3_int64, int), void*, sqlite3_int64);
2143 
2144 #ifdef SQLITE_ENABLE_MEMSYS3
2145 const sqlite3_mem_methods *sqlite3MemGetMemsys3(void);
2146 #endif
2147 #ifdef SQLITE_ENABLE_MEMSYS5
2148 const sqlite3_mem_methods *sqlite3MemGetMemsys5(void);
2149 #endif
2150 
2151 
2152 #ifndef SQLITE_MUTEX_OMIT
2153   sqlite3_mutex_methods *sqlite3DefaultMutex(void);
2154   sqlite3_mutex *sqlite3MutexAlloc(int);
2155   int sqlite3MutexInit(void);
2156   int sqlite3MutexEnd(void);
2157 #endif
2158 
2159 int sqlite3StatusValue(int);
2160 void sqlite3StatusAdd(int, int);
2161 void sqlite3StatusSet(int, int);
2162 
2163 int sqlite3IsNaN(double);
2164 
2165 void sqlite3VXPrintf(StrAccum*, int, const char*, va_list);
2166 char *sqlite3MPrintf(sqlite3*,const char*, ...);
2167 char *sqlite3VMPrintf(sqlite3*,const char*, va_list);
2168 char *sqlite3MAppendf(sqlite3*,char*,const char*,...);
2169 #if defined(SQLITE_TEST) || defined(SQLITE_DEBUG)
2170   void sqlite3DebugPrintf(const char*, ...);
2171 #endif
2172 #if defined(SQLITE_TEST)
2173   void *sqlite3TestTextToPtr(const char*);
2174 #endif
2175 void sqlite3SetString(char **, sqlite3*, const char*, ...);
2176 void sqlite3ErrorMsg(Parse*, const char*, ...);
2177 void sqlite3ErrorClear(Parse*);
2178 void sqlite3Dequote(char*);
2179 void sqlite3DequoteExpr(sqlite3*, Expr*);
2180 int sqlite3KeywordCode(const unsigned char*, int);
2181 int sqlite3RunParser(Parse*, const char*, char **);
2182 void sqlite3FinishCoding(Parse*);
2183 int sqlite3GetTempReg(Parse*);
2184 void sqlite3ReleaseTempReg(Parse*,int);
2185 int sqlite3GetTempRange(Parse*,int);
2186 void sqlite3ReleaseTempRange(Parse*,int,int);
2187 Expr *sqlite3Expr(sqlite3*, int, Expr*, Expr*, const Token*);
2188 Expr *sqlite3PExpr(Parse*, int, Expr*, Expr*, const Token*);
2189 Expr *sqlite3RegisterExpr(Parse*,Token*);
2190 Expr *sqlite3ExprAnd(sqlite3*,Expr*, Expr*);
2191 void sqlite3ExprSpan(Expr*,Token*,Token*);
2192 Expr *sqlite3ExprFunction(Parse*,ExprList*, Token*);
2193 void sqlite3ExprAssignVarNumber(Parse*, Expr*);
2194 void sqlite3ExprClear(sqlite3*, Expr*);
2195 void sqlite3ExprDelete(sqlite3*, Expr*);
2196 ExprList *sqlite3ExprListAppend(Parse*,ExprList*,Expr*,Token*);
2197 void sqlite3ExprListDelete(sqlite3*, ExprList*);
2198 int sqlite3Init(sqlite3*, char**);
2199 int sqlite3InitCallback(void*, int, char**, char**);
2200 void sqlite3Pragma(Parse*,Token*,Token*,Token*,int);
2201 void sqlite3ResetInternalSchema(sqlite3*, int);
2202 void sqlite3BeginParse(Parse*,int);
2203 void sqlite3CommitInternalChanges(sqlite3*);
2204 Table *sqlite3ResultSetOfSelect(Parse*,Select*);
2205 void sqlite3OpenMasterTable(Parse *, int);
2206 void sqlite3StartTable(Parse*,Token*,Token*,int,int,int,int);
2207 void sqlite3AddColumn(Parse*,Token*);
2208 void sqlite3AddNotNull(Parse*, int);
2209 void sqlite3AddPrimaryKey(Parse*, ExprList*, int, int, int);
2210 void sqlite3AddCheckConstraint(Parse*, Expr*);
2211 void sqlite3AddColumnType(Parse*,Token*);
2212 void sqlite3AddDefaultValue(Parse*,Expr*);
2213 void sqlite3AddCollateType(Parse*, Token*);
2214 void sqlite3EndTable(Parse*,Token*,Token*,Select*);
2215 
2216 Bitvec *sqlite3BitvecCreate(u32);
2217 int sqlite3BitvecTest(Bitvec*, u32);
2218 int sqlite3BitvecSet(Bitvec*, u32);
2219 void sqlite3BitvecClear(Bitvec*, u32);
2220 void sqlite3BitvecDestroy(Bitvec*);
2221 int sqlite3BitvecBuiltinTest(int,int*);
2222 
2223 RowSet *sqlite3RowSetInit(sqlite3*, void*, unsigned int);
2224 void sqlite3RowSetClear(RowSet*);
2225 void sqlite3RowSetInsert(RowSet*, i64);
2226 int sqlite3RowSetNext(RowSet*, i64*);
2227 
2228 void sqlite3CreateView(Parse*,Token*,Token*,Token*,Select*,int,int);
2229 
2230 #if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE)
2231   int sqlite3ViewGetColumnNames(Parse*,Table*);
2232 #else
2233 # define sqlite3ViewGetColumnNames(A,B) 0
2234 #endif
2235 
2236 void sqlite3DropTable(Parse*, SrcList*, int, int);
2237 void sqlite3DeleteTable(Table*);
2238 void sqlite3Insert(Parse*, SrcList*, ExprList*, Select*, IdList*, int);
2239 void *sqlite3ArrayAllocate(sqlite3*,void*,int,int,int*,int*,int*);
2240 IdList *sqlite3IdListAppend(sqlite3*, IdList*, Token*);
2241 int sqlite3IdListIndex(IdList*,const char*);
2242 SrcList *sqlite3SrcListEnlarge(sqlite3*, SrcList*, int, int);
2243 SrcList *sqlite3SrcListAppend(sqlite3*, SrcList*, Token*, Token*);
2244 SrcList *sqlite3SrcListAppendFromTerm(Parse*, SrcList*, Token*, Token*,
2245                                       Token*, Select*, Expr*, IdList*);
2246 void sqlite3SrcListIndexedBy(Parse *, SrcList *, Token *);
2247 int sqlite3IndexedByLookup(Parse *, struct SrcList_item *);
2248 void sqlite3SrcListShiftJoinType(SrcList*);
2249 void sqlite3SrcListAssignCursors(Parse*, SrcList*);
2250 void sqlite3IdListDelete(sqlite3*, IdList*);
2251 void sqlite3SrcListDelete(sqlite3*, SrcList*);
2252 void sqlite3CreateIndex(Parse*,Token*,Token*,SrcList*,ExprList*,int,Token*,
2253                         Token*, int, int);
2254 void sqlite3DropIndex(Parse*, SrcList*, int);
2255 int sqlite3Select(Parse*, Select*, SelectDest*);
2256 Select *sqlite3SelectNew(Parse*,ExprList*,SrcList*,Expr*,ExprList*,
2257                          Expr*,ExprList*,int,Expr*,Expr*);
2258 void sqlite3SelectDelete(sqlite3*, Select*);
2259 Table *sqlite3SrcListLookup(Parse*, SrcList*);
2260 int sqlite3IsReadOnly(Parse*, Table*, int);
2261 void sqlite3OpenTable(Parse*, int iCur, int iDb, Table*, int);
2262 #if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY)
2263 Expr *sqlite3LimitWhere(Parse *, SrcList *, Expr *, ExprList *, Expr *, Expr *, char *);
2264 #endif
2265 void sqlite3DeleteFrom(Parse*, SrcList*, Expr*);
2266 void sqlite3Update(Parse*, SrcList*, ExprList*, Expr*, int);
2267 WhereInfo *sqlite3WhereBegin(Parse*, SrcList*, Expr*, ExprList**, u8, int);
2268 void sqlite3WhereEnd(WhereInfo*);
2269 int sqlite3ExprCodeGetColumn(Parse*, Table*, int, int, int, int);
2270 void sqlite3ExprCodeMove(Parse*, int, int, int);
2271 void sqlite3ExprCodeCopy(Parse*, int, int, int);
2272 void sqlite3ExprClearColumnCache(Parse*, int);
2273 void sqlite3ExprCacheAffinityChange(Parse*, int, int);
2274 int sqlite3ExprWritableRegister(Parse*,int,int);
2275 void sqlite3ExprHardCopy(Parse*,int,int);
2276 int sqlite3ExprCode(Parse*, Expr*, int);
2277 int sqlite3ExprCodeTemp(Parse*, Expr*, int*);
2278 int sqlite3ExprCodeTarget(Parse*, Expr*, int);
2279 int sqlite3ExprCodeAndCache(Parse*, Expr*, int);
2280 void sqlite3ExprCodeConstants(Parse*, Expr*);
2281 int sqlite3ExprCodeExprList(Parse*, ExprList*, int, int);
2282 void sqlite3ExprIfTrue(Parse*, Expr*, int, int);
2283 void sqlite3ExprIfFalse(Parse*, Expr*, int, int);
2284 Table *sqlite3FindTable(sqlite3*,const char*, const char*);
2285 Table *sqlite3LocateTable(Parse*,int isView,const char*, const char*);
2286 Index *sqlite3FindIndex(sqlite3*,const char*, const char*);
2287 void sqlite3UnlinkAndDeleteTable(sqlite3*,int,const char*);
2288 void sqlite3UnlinkAndDeleteIndex(sqlite3*,int,const char*);
2289 void sqlite3Vacuum(Parse*);
2290 int sqlite3RunVacuum(char**, sqlite3*);
2291 char *sqlite3NameFromToken(sqlite3*, Token*);
2292 int sqlite3ExprCompare(Expr*, Expr*);
2293 void sqlite3ExprAnalyzeAggregates(NameContext*, Expr*);
2294 void sqlite3ExprAnalyzeAggList(NameContext*,ExprList*);
2295 Vdbe *sqlite3GetVdbe(Parse*);
2296 Expr *sqlite3CreateIdExpr(Parse *, const char*);
2297 void sqlite3PrngSaveState(void);
2298 void sqlite3PrngRestoreState(void);
2299 void sqlite3PrngResetState(void);
2300 void sqlite3RollbackAll(sqlite3*);
2301 void sqlite3CodeVerifySchema(Parse*, int);
2302 void sqlite3BeginTransaction(Parse*, int);
2303 void sqlite3CommitTransaction(Parse*);
2304 void sqlite3RollbackTransaction(Parse*);
2305 void sqlite3Savepoint(Parse*, int, Token*);
2306 void sqlite3CloseSavepoints(sqlite3 *);
2307 int sqlite3ExprIsConstant(Expr*);
2308 int sqlite3ExprIsConstantNotJoin(Expr*);
2309 int sqlite3ExprIsConstantOrFunction(Expr*);
2310 int sqlite3ExprIsInteger(Expr*, int*);
2311 int sqlite3IsRowid(const char*);
2312 void sqlite3GenerateRowDelete(Parse*, Table*, int, int, int);
2313 void sqlite3GenerateRowIndexDelete(Parse*, Table*, int, int*);
2314 int sqlite3GenerateIndexKey(Parse*, Index*, int, int, int);
2315 void sqlite3GenerateConstraintChecks(Parse*,Table*,int,int,
2316                                      int*,int,int,int,int);
2317 void sqlite3CompleteInsertion(Parse*, Table*, int, int, int*, int, int, int);
2318 int sqlite3OpenTableAndIndices(Parse*, Table*, int, int);
2319 void sqlite3BeginWriteOperation(Parse*, int, int);
2320 Expr *sqlite3ExprDup(sqlite3*,Expr*);
2321 void sqlite3TokenCopy(sqlite3*,Token*, Token*);
2322 ExprList *sqlite3ExprListDup(sqlite3*,ExprList*);
2323 SrcList *sqlite3SrcListDup(sqlite3*,SrcList*);
2324 IdList *sqlite3IdListDup(sqlite3*,IdList*);
2325 Select *sqlite3SelectDup(sqlite3*,Select*);
2326 void sqlite3FuncDefInsert(FuncDefHash*, FuncDef*);
2327 FuncDef *sqlite3FindFunction(sqlite3*,const char*,int,int,u8,int);
2328 void sqlite3RegisterBuiltinFunctions(sqlite3*);
2329 void sqlite3RegisterDateTimeFunctions(void);
2330 void sqlite3RegisterGlobalFunctions(void);
2331 #ifdef SQLITE_DEBUG
2332   int sqlite3SafetyOn(sqlite3*);
2333   int sqlite3SafetyOff(sqlite3*);
2334 #else
2335 # define sqlite3SafetyOn(A) 0
2336 # define sqlite3SafetyOff(A) 0
2337 #endif
2338 int sqlite3SafetyCheckOk(sqlite3*);
2339 int sqlite3SafetyCheckSickOrOk(sqlite3*);
2340 void sqlite3ChangeCookie(Parse*, int);
2341 
2342 #if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
2343 void sqlite3MaterializeView(Parse*, Table*, Expr*, int);
2344 #endif
2345 
2346 #ifndef SQLITE_OMIT_TRIGGER
2347   void sqlite3BeginTrigger(Parse*, Token*,Token*,int,int,IdList*,SrcList*,
2348                            Expr*,int, int);
2349   void sqlite3FinishTrigger(Parse*, TriggerStep*, Token*);
2350   void sqlite3DropTrigger(Parse*, SrcList*, int);
2351   void sqlite3DropTriggerPtr(Parse*, Trigger*);
2352   int sqlite3TriggersExist(Table*, int, ExprList*);
2353   int sqlite3CodeRowTrigger(Parse*, int, ExprList*, int, Table *, int, int,
2354                            int, int, u32*, u32*);
2355   void sqliteViewTriggers(Parse*, Table*, Expr*, int, ExprList*);
2356   void sqlite3DeleteTriggerStep(sqlite3*, TriggerStep*);
2357   TriggerStep *sqlite3TriggerSelectStep(sqlite3*,Select*);
2358   TriggerStep *sqlite3TriggerInsertStep(sqlite3*,Token*, IdList*,
2359                                         ExprList*,Select*,int);
2360   TriggerStep *sqlite3TriggerUpdateStep(sqlite3*,Token*,ExprList*, Expr*, int);
2361   TriggerStep *sqlite3TriggerDeleteStep(sqlite3*,Token*, Expr*);
2362   void sqlite3DeleteTrigger(sqlite3*, Trigger*);
2363   void sqlite3UnlinkAndDeleteTrigger(sqlite3*,int,const char*);
2364 #else
2365 # define sqlite3TriggersExist(B,C,D,E,F) 0
2366 # define sqlite3DeleteTrigger(A,B)
2367 # define sqlite3DropTriggerPtr(A,B)
2368 # define sqlite3UnlinkAndDeleteTrigger(A,B,C)
2369 # define sqlite3CodeRowTrigger(A,B,C,D,E,F,G,H,I,J,K) 0
2370 #endif
2371 
2372 int sqlite3JoinType(Parse*, Token*, Token*, Token*);
2373 void sqlite3CreateForeignKey(Parse*, ExprList*, Token*, ExprList*, int);
2374 void sqlite3DeferForeignKey(Parse*, int);
2375 #ifndef SQLITE_OMIT_AUTHORIZATION
2376   void sqlite3AuthRead(Parse*,Expr*,Schema*,SrcList*);
2377   int sqlite3AuthCheck(Parse*,int, const char*, const char*, const char*);
2378   void sqlite3AuthContextPush(Parse*, AuthContext*, const char*);
2379   void sqlite3AuthContextPop(AuthContext*);
2380 #else
2381 # define sqlite3AuthRead(a,b,c,d)
2382 # define sqlite3AuthCheck(a,b,c,d,e)    SQLITE_OK
2383 # define sqlite3AuthContextPush(a,b,c)
2384 # define sqlite3AuthContextPop(a)  ((void)(a))
2385 #endif
2386 void sqlite3Attach(Parse*, Expr*, Expr*, Expr*);
2387 void sqlite3Detach(Parse*, Expr*);
2388 int sqlite3BtreeFactory(const sqlite3 *db, const char *zFilename,
2389                        int omitJournal, int nCache, int flags, Btree **ppBtree);
2390 int sqlite3FixInit(DbFixer*, Parse*, int, const char*, const Token*);
2391 int sqlite3FixSrcList(DbFixer*, SrcList*);
2392 int sqlite3FixSelect(DbFixer*, Select*);
2393 int sqlite3FixExpr(DbFixer*, Expr*);
2394 int sqlite3FixExprList(DbFixer*, ExprList*);
2395 int sqlite3FixTriggerStep(DbFixer*, TriggerStep*);
2396 int sqlite3AtoF(const char *z, double*);
2397 int sqlite3GetInt32(const char *, int*);
2398 int sqlite3FitsIn64Bits(const char *, int);
2399 int sqlite3Utf16ByteLen(const void *pData, int nChar);
2400 int sqlite3Utf8CharLen(const char *pData, int nByte);
2401 int sqlite3Utf8Read(const u8*, const u8*, const u8**);
2402 
2403 /*
2404 ** Routines to read and write variable-length integers.  These used to
2405 ** be defined locally, but now we use the varint routines in the util.c
2406 ** file.  Code should use the MACRO forms below, as the Varint32 versions
2407 ** are coded to assume the single byte case is already handled (which
2408 ** the MACRO form does).
2409 */
2410 int sqlite3PutVarint(unsigned char*, u64);
2411 int sqlite3PutVarint32(unsigned char*, u32);
2412 u8 sqlite3GetVarint(const unsigned char *, u64 *);
2413 u8 sqlite3GetVarint32(const unsigned char *, u32 *);
2414 int sqlite3VarintLen(u64 v);
2415 
2416 /*
2417 ** The header of a record consists of a sequence variable-length integers.
2418 ** These integers are almost always small and are encoded as a single byte.
2419 ** The following macros take advantage this fact to provide a fast encode
2420 ** and decode of the integers in a record header.  It is faster for the common
2421 ** case where the integer is a single byte.  It is a little slower when the
2422 ** integer is two or more bytes.  But overall it is faster.
2423 **
2424 ** The following expressions are equivalent:
2425 **
2426 **     x = sqlite3GetVarint32( A, &B );
2427 **     x = sqlite3PutVarint32( A, B );
2428 **
2429 **     x = getVarint32( A, B );
2430 **     x = putVarint32( A, B );
2431 **
2432 */
2433 #define getVarint32(A,B)  (u8)((*(A)<(u8)0x80) ? ((B) = (u32)*(A)),1 : sqlite3GetVarint32((A), (u32 *)&(B)))
2434 #define putVarint32(A,B)  (u8)(((u32)(B)<(u32)0x80) ? (*(A) = (unsigned char)(B)),1 : sqlite3PutVarint32((A), (B)))
2435 #define getVarint    sqlite3GetVarint
2436 #define putVarint    sqlite3PutVarint
2437 
2438 
2439 void sqlite3IndexAffinityStr(Vdbe *, Index *);
2440 void sqlite3TableAffinityStr(Vdbe *, Table *);
2441 char sqlite3CompareAffinity(Expr *pExpr, char aff2);
2442 int sqlite3IndexAffinityOk(Expr *pExpr, char idx_affinity);
2443 char sqlite3ExprAffinity(Expr *pExpr);
2444 int sqlite3Atoi64(const char*, i64*);
2445 void sqlite3Error(sqlite3*, int, const char*,...);
2446 void *sqlite3HexToBlob(sqlite3*, const char *z, int n);
2447 int sqlite3TwoPartName(Parse *, Token *, Token *, Token **);
2448 const char *sqlite3ErrStr(int);
2449 int sqlite3ReadSchema(Parse *pParse);
2450 CollSeq *sqlite3FindCollSeq(sqlite3*,u8 enc, const char *,int,int);
2451 CollSeq *sqlite3LocateCollSeq(Parse *pParse, const char *zName, int nName);
2452 CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr);
2453 Expr *sqlite3ExprSetColl(Parse *pParse, Expr *, Token *);
2454 int sqlite3CheckCollSeq(Parse *, CollSeq *);
2455 int sqlite3CheckObjectName(Parse *, const char *);
2456 void sqlite3VdbeSetChanges(sqlite3 *, int);
2457 
2458 const void *sqlite3ValueText(sqlite3_value*, u8);
2459 int sqlite3ValueBytes(sqlite3_value*, u8);
2460 void sqlite3ValueSetStr(sqlite3_value*, int, const void *,u8,
2461                         void(*)(void*));
2462 void sqlite3ValueFree(sqlite3_value*);
2463 sqlite3_value *sqlite3ValueNew(sqlite3 *);
2464 char *sqlite3Utf16to8(sqlite3 *, const void*, int);
2465 int sqlite3ValueFromExpr(sqlite3 *, Expr *, u8, u8, sqlite3_value **);
2466 void sqlite3ValueApplyAffinity(sqlite3_value *, u8, u8);
2467 #ifndef SQLITE_AMALGAMATION
2468 extern const unsigned char sqlite3UpperToLower[];
2469 extern SQLITE_WSD struct Sqlite3Config sqlite3Config;
2470 extern SQLITE_WSD FuncDefHash sqlite3GlobalFunctions;
2471 #endif
2472 void sqlite3RootPageMoved(Db*, int, int);
2473 void sqlite3Reindex(Parse*, Token*, Token*);
2474 void sqlite3AlterFunctions(sqlite3*);
2475 void sqlite3AlterRenameTable(Parse*, SrcList*, Token*);
2476 int sqlite3GetToken(const unsigned char *, int *);
2477 void sqlite3NestedParse(Parse*, const char*, ...);
2478 void sqlite3ExpirePreparedStatements(sqlite3*);
2479 void sqlite3CodeSubselect(Parse *, Expr *, int, int);
2480 void sqlite3SelectPrep(Parse*, Select*, NameContext*);
2481 int sqlite3ResolveExprNames(NameContext*, Expr*);
2482 void sqlite3ResolveSelectNames(Parse*, Select*, NameContext*);
2483 int sqlite3ResolveOrderGroupBy(Parse*, Select*, ExprList*, const char*);
2484 void sqlite3ColumnDefault(Vdbe *, Table *, int);
2485 void sqlite3AlterFinishAddColumn(Parse *, Token *);
2486 void sqlite3AlterBeginAddColumn(Parse *, SrcList *);
2487 CollSeq *sqlite3GetCollSeq(sqlite3*, CollSeq *, const char *, int);
2488 char sqlite3AffinityType(const Token*);
2489 void sqlite3Analyze(Parse*, Token*, Token*);
2490 int sqlite3InvokeBusyHandler(BusyHandler*);
2491 int sqlite3FindDb(sqlite3*, Token*);
2492 int sqlite3AnalysisLoad(sqlite3*,int iDB);
2493 void sqlite3DefaultRowEst(Index*);
2494 void sqlite3RegisterLikeFunctions(sqlite3*, int);
2495 int sqlite3IsLikeFunction(sqlite3*,Expr*,int*,char*);
2496 void sqlite3MinimumFileFormat(Parse*, int, int);
2497 void sqlite3SchemaFree(void *);
2498 Schema *sqlite3SchemaGet(sqlite3 *, Btree *);
2499 int sqlite3SchemaToIndex(sqlite3 *db, Schema *);
2500 KeyInfo *sqlite3IndexKeyinfo(Parse *, Index *);
2501 int sqlite3CreateFunc(sqlite3 *, const char *, int, int, void *,
2502   void (*)(sqlite3_context*,int,sqlite3_value **),
2503   void (*)(sqlite3_context*,int,sqlite3_value **), void (*)(sqlite3_context*));
2504 int sqlite3ApiExit(sqlite3 *db, int);
2505 int sqlite3OpenTempDatabase(Parse *);
2506 
2507 void sqlite3StrAccumInit(StrAccum*, char*, int, int);
2508 void sqlite3StrAccumAppend(StrAccum*,const char*,int);
2509 char *sqlite3StrAccumFinish(StrAccum*);
2510 void sqlite3StrAccumReset(StrAccum*);
2511 void sqlite3SelectDestInit(SelectDest*,int,int);
2512 
2513 /*
2514 ** The interface to the LEMON-generated parser
2515 */
2516 void *sqlite3ParserAlloc(void*(*)(size_t));
2517 void sqlite3ParserFree(void*, void(*)(void*));
2518 void sqlite3Parser(void*, int, Token, Parse*);
2519 #ifdef YYTRACKMAXSTACKDEPTH
2520   int sqlite3ParserStackPeak(void*);
2521 #endif
2522 
2523 int sqlite3AutoLoadExtensions(sqlite3*);
2524 #ifndef SQLITE_OMIT_LOAD_EXTENSION
2525   void sqlite3CloseExtensions(sqlite3*);
2526 #else
2527 # define sqlite3CloseExtensions(X)
2528 #endif
2529 
2530 #ifndef SQLITE_OMIT_SHARED_CACHE
2531   void sqlite3TableLock(Parse *, int, int, u8, const char *);
2532 #else
2533   #define sqlite3TableLock(v,w,x,y,z)
2534 #endif
2535 
2536 #ifdef SQLITE_TEST
2537   int sqlite3Utf8To8(unsigned char*);
2538 #endif
2539 
2540 #ifdef SQLITE_OMIT_VIRTUALTABLE
2541 #  define sqlite3VtabClear(X)
2542 #  define sqlite3VtabSync(X,Y) SQLITE_OK
2543 #  define sqlite3VtabRollback(X)
2544 #  define sqlite3VtabCommit(X)
2545 #  define sqlite3VtabInSync(db) 0
2546 #else
2547    void sqlite3VtabClear(Table*);
2548    int sqlite3VtabSync(sqlite3 *db, char **);
2549    int sqlite3VtabRollback(sqlite3 *db);
2550    int sqlite3VtabCommit(sqlite3 *db);
2551 #  define sqlite3VtabInSync(db) ((db)->nVTrans>0 && (db)->aVTrans==0)
2552 #endif
2553 void sqlite3VtabMakeWritable(Parse*,Table*);
2554 void sqlite3VtabLock(sqlite3_vtab*);
2555 void sqlite3VtabUnlock(sqlite3*, sqlite3_vtab*);
2556 void sqlite3VtabBeginParse(Parse*, Token*, Token*, Token*);
2557 void sqlite3VtabFinishParse(Parse*, Token*);
2558 void sqlite3VtabArgInit(Parse*);
2559 void sqlite3VtabArgExtend(Parse*, Token*);
2560 int sqlite3VtabCallCreate(sqlite3*, int, const char *, char **);
2561 int sqlite3VtabCallConnect(Parse*, Table*);
2562 int sqlite3VtabCallDestroy(sqlite3*, int, const char *);
2563 int sqlite3VtabBegin(sqlite3 *, sqlite3_vtab *);
2564 FuncDef *sqlite3VtabOverloadFunction(sqlite3 *,FuncDef*, int nArg, Expr*);
2565 void sqlite3InvalidFunction(sqlite3_context*,int,sqlite3_value**);
2566 int sqlite3TransferBindings(sqlite3_stmt *, sqlite3_stmt *);
2567 int sqlite3Reprepare(Vdbe*);
2568 void sqlite3ExprListCheckLength(Parse*, ExprList*, const char*);
2569 CollSeq *sqlite3BinaryCompareCollSeq(Parse *, Expr *, Expr *);
2570 
2571 
2572 /*
2573 ** Available fault injectors.  Should be numbered beginning with 0.
2574 */
2575 #define SQLITE_FAULTINJECTOR_MALLOC     0
2576 #define SQLITE_FAULTINJECTOR_COUNT      1
2577 
2578 /*
2579 ** The interface to the code in fault.c used for identifying "benign"
2580 ** malloc failures. This is only present if SQLITE_OMIT_BUILTIN_TEST
2581 ** is not defined.
2582 */
2583 #ifndef SQLITE_OMIT_BUILTIN_TEST
2584   void sqlite3BeginBenignMalloc(void);
2585   void sqlite3EndBenignMalloc(void);
2586 #else
2587   #define sqlite3BeginBenignMalloc()
2588   #define sqlite3EndBenignMalloc()
2589 #endif
2590 
2591 #define IN_INDEX_ROWID           1
2592 #define IN_INDEX_EPH             2
2593 #define IN_INDEX_INDEX           3
2594 int sqlite3FindInIndex(Parse *, Expr *, int*);
2595 
2596 #ifdef SQLITE_ENABLE_ATOMIC_WRITE
2597   int sqlite3JournalOpen(sqlite3_vfs *, const char *, sqlite3_file *, int, int);
2598   int sqlite3JournalSize(sqlite3_vfs *);
2599   int sqlite3JournalCreate(sqlite3_file *);
2600 #else
2601   #define sqlite3JournalSize(pVfs) ((pVfs)->szOsFile)
2602 #endif
2603 
2604 void sqlite3MemJournalOpen(sqlite3_file *);
2605 int sqlite3MemJournalSize(void);
2606 int sqlite3IsMemJournal(sqlite3_file *);
2607 
2608 #if SQLITE_MAX_EXPR_DEPTH>0
2609   void sqlite3ExprSetHeight(Parse *pParse, Expr *p);
2610   int sqlite3SelectExprHeight(Select *);
2611   int sqlite3ExprCheckHeight(Parse*, int);
2612 #else
2613   #define sqlite3ExprSetHeight(x,y)
2614   #define sqlite3SelectExprHeight(x) 0
2615   #define sqlite3ExprCheckHeight(x,y)
2616 #endif
2617 
2618 u32 sqlite3Get4byte(const u8*);
2619 void sqlite3Put4byte(u8*, u32);
2620 
2621 #ifdef SQLITE_SSE
2622 #include "sseInt.h"
2623 #endif
2624 
2625 #ifdef SQLITE_DEBUG
2626   void sqlite3ParserTrace(FILE*, char *);
2627 #endif
2628 
2629 /*
2630 ** If the SQLITE_ENABLE IOTRACE exists then the global variable
2631 ** sqlite3IoTrace is a pointer to a printf-like routine used to
2632 ** print I/O tracing messages.
2633 */
2634 #ifdef SQLITE_ENABLE_IOTRACE
2635 # define IOTRACE(A)  if( sqlite3IoTrace ){ sqlite3IoTrace A; }
2636   void sqlite3VdbeIOTraceSql(Vdbe*);
2637 SQLITE_EXTERN void (*sqlite3IoTrace)(const char*,...);
2638 #else
2639 # define IOTRACE(A)
2640 # define sqlite3VdbeIOTraceSql(X)
2641 #endif
2642 
2643 #endif
2644