xref: /sqlite-3.40.0/src/sqliteInt.h (revision 78d41832)
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 1.811 2008/12/17 19:22:16 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 WhereInfo WhereInfo;
538 typedef struct WhereLevel WhereLevel;
539 
540 /*
541 ** Defer sourcing vdbe.h and btree.h until after the "u8" and
542 ** "BusyHandler" typedefs. vdbe.h also requires a few of the opaque
543 ** pointer types (i.e. FuncDef) defined above.
544 */
545 #include "btree.h"
546 #include "vdbe.h"
547 #include "pager.h"
548 #include "pcache.h"
549 
550 #include "os.h"
551 #include "mutex.h"
552 
553 
554 /*
555 ** Each database file to be accessed by the system is an instance
556 ** of the following structure.  There are normally two of these structures
557 ** in the sqlite.aDb[] array.  aDb[0] is the main database file and
558 ** aDb[1] is the database file used to hold temporary tables.  Additional
559 ** databases may be attached.
560 */
561 struct Db {
562   char *zName;         /* Name of this database */
563   Btree *pBt;          /* The B*Tree structure for this database file */
564   u8 inTrans;          /* 0: not writable.  1: Transaction.  2: Checkpoint */
565   u8 safety_level;     /* How aggressive at syncing data to disk */
566   void *pAux;               /* Auxiliary data.  Usually NULL */
567   void (*xFreeAux)(void*);  /* Routine to free pAux */
568   Schema *pSchema;     /* Pointer to database schema (possibly shared) */
569 };
570 
571 /*
572 ** An instance of the following structure stores a database schema.
573 **
574 ** If there are no virtual tables configured in this schema, the
575 ** Schema.db variable is set to NULL. After the first virtual table
576 ** has been added, it is set to point to the database connection
577 ** used to create the connection. Once a virtual table has been
578 ** added to the Schema structure and the Schema.db variable populated,
579 ** only that database connection may use the Schema to prepare
580 ** statements.
581 */
582 struct Schema {
583   int schema_cookie;   /* Database schema version number for this file */
584   Hash tblHash;        /* All tables indexed by name */
585   Hash idxHash;        /* All (named) indices indexed by name */
586   Hash trigHash;       /* All triggers indexed by name */
587   Hash aFKey;          /* Foreign keys indexed by to-table */
588   Table *pSeqTab;      /* The sqlite_sequence table used by AUTOINCREMENT */
589   u8 file_format;      /* Schema format version for this file */
590   u8 enc;              /* Text encoding used by this database */
591   u16 flags;           /* Flags associated with this schema */
592   int cache_size;      /* Number of pages to use in the cache */
593 #ifndef SQLITE_OMIT_VIRTUALTABLE
594   sqlite3 *db;         /* "Owner" connection. See comment above */
595 #endif
596 };
597 
598 /*
599 ** These macros can be used to test, set, or clear bits in the
600 ** Db.flags field.
601 */
602 #define DbHasProperty(D,I,P)     (((D)->aDb[I].pSchema->flags&(P))==(P))
603 #define DbHasAnyProperty(D,I,P)  (((D)->aDb[I].pSchema->flags&(P))!=0)
604 #define DbSetProperty(D,I,P)     (D)->aDb[I].pSchema->flags|=(P)
605 #define DbClearProperty(D,I,P)   (D)->aDb[I].pSchema->flags&=~(P)
606 
607 /*
608 ** Allowed values for the DB.flags field.
609 **
610 ** The DB_SchemaLoaded flag is set after the database schema has been
611 ** read into internal hash tables.
612 **
613 ** DB_UnresetViews means that one or more views have column names that
614 ** have been filled out.  If the schema changes, these column names might
615 ** changes and so the view will need to be reset.
616 */
617 #define DB_SchemaLoaded    0x0001  /* The schema has been loaded */
618 #define DB_UnresetViews    0x0002  /* Some views have defined column names */
619 #define DB_Empty           0x0004  /* The file is empty (length 0 bytes) */
620 
621 /*
622 ** The number of different kinds of things that can be limited
623 ** using the sqlite3_limit() interface.
624 */
625 #define SQLITE_N_LIMIT (SQLITE_LIMIT_VARIABLE_NUMBER+1)
626 
627 /*
628 ** Lookaside malloc is a set of fixed-size buffers that can be used
629 ** to satisfy small transient memory allocation requests for objects
630 ** associated with a particular database connection.  The use of
631 ** lookaside malloc provides a significant performance enhancement
632 ** (approx 10%) by avoiding numerous malloc/free requests while parsing
633 ** SQL statements.
634 **
635 ** The Lookaside structure holds configuration information about the
636 ** lookaside malloc subsystem.  Each available memory allocation in
637 ** the lookaside subsystem is stored on a linked list of LookasideSlot
638 ** objects.
639 */
640 struct Lookaside {
641   u16 sz;                 /* Size of each buffer in bytes */
642   u8 bEnabled;            /* True if use lookaside.  False to ignore it */
643   u8 bMalloced;           /* True if pStart obtained from sqlite3_malloc() */
644   int nOut;               /* Number of buffers currently checked out */
645   int mxOut;              /* Highwater mark for nOut */
646   LookasideSlot *pFree;   /* List of available buffers */
647   void *pStart;           /* First byte of available memory space */
648   void *pEnd;             /* First byte past end of available space */
649 };
650 struct LookasideSlot {
651   LookasideSlot *pNext;    /* Next buffer in the list of free buffers */
652 };
653 
654 /*
655 ** A hash table for function definitions.
656 **
657 ** Hash each FuncDef structure into one of the FuncDefHash.a[] slots.
658 ** Collisions are on the FuncDef.pHash chain.
659 */
660 struct FuncDefHash {
661   FuncDef *a[23];       /* Hash table for functions */
662 };
663 
664 /*
665 ** Each database is an instance of the following structure.
666 **
667 ** The sqlite.lastRowid records the last insert rowid generated by an
668 ** insert statement.  Inserts on views do not affect its value.  Each
669 ** trigger has its own context, so that lastRowid can be updated inside
670 ** triggers as usual.  The previous value will be restored once the trigger
671 ** exits.  Upon entering a before or instead of trigger, lastRowid is no
672 ** longer (since after version 2.8.12) reset to -1.
673 **
674 ** The sqlite.nChange does not count changes within triggers and keeps no
675 ** context.  It is reset at start of sqlite3_exec.
676 ** The sqlite.lsChange represents the number of changes made by the last
677 ** insert, update, or delete statement.  It remains constant throughout the
678 ** length of a statement and is then updated by OP_SetCounts.  It keeps a
679 ** context stack just like lastRowid so that the count of changes
680 ** within a trigger is not seen outside the trigger.  Changes to views do not
681 ** affect the value of lsChange.
682 ** The sqlite.csChange keeps track of the number of current changes (since
683 ** the last statement) and is used to update sqlite_lsChange.
684 **
685 ** The member variables sqlite.errCode, sqlite.zErrMsg and sqlite.zErrMsg16
686 ** store the most recent error code and, if applicable, string. The
687 ** internal function sqlite3Error() is used to set these variables
688 ** consistently.
689 */
690 struct sqlite3 {
691   sqlite3_vfs *pVfs;            /* OS Interface */
692   int nDb;                      /* Number of backends currently in use */
693   Db *aDb;                      /* All backends */
694   int flags;                    /* Miscellaneous flags. See below */
695   int openFlags;                /* Flags passed to sqlite3_vfs.xOpen() */
696   int errCode;                  /* Most recent error code (SQLITE_*) */
697   int errMask;                  /* & result codes with this before returning */
698   u8 autoCommit;                /* The auto-commit flag. */
699   u8 temp_store;                /* 1: file 2: memory 0: default */
700   u8 mallocFailed;              /* True if we have seen a malloc failure */
701   u8 dfltLockMode;              /* Default locking-mode for attached dbs */
702   u8 dfltJournalMode;           /* Default journal mode for attached dbs */
703   signed char nextAutovac;      /* Autovac setting after VACUUM if >=0 */
704   int nextPagesize;             /* Pagesize after VACUUM if >0 */
705   int nTable;                   /* Number of tables in the database */
706   CollSeq *pDfltColl;           /* The default collating sequence (BINARY) */
707   i64 lastRowid;                /* ROWID of most recent insert (see above) */
708   i64 priorNewRowid;            /* Last randomly generated ROWID */
709   u32 magic;                    /* Magic number for detect library misuse */
710   int nChange;                  /* Value returned by sqlite3_changes() */
711   int nTotalChange;             /* Value returned by sqlite3_total_changes() */
712   sqlite3_mutex *mutex;         /* Connection mutex */
713   int aLimit[SQLITE_N_LIMIT];   /* Limits */
714   struct sqlite3InitInfo {      /* Information used during initialization */
715     int iDb;                    /* When back is being initialized */
716     int newTnum;                /* Rootpage of table being initialized */
717     u8 busy;                    /* TRUE if currently initializing */
718   } init;
719   int nExtension;               /* Number of loaded extensions */
720   void **aExtension;            /* Array of shared library handles */
721   struct Vdbe *pVdbe;           /* List of active virtual machines */
722   int activeVdbeCnt;            /* Number of VDBEs currently executing */
723   int writeVdbeCnt;             /* Number of active VDBEs that are writing */
724   void (*xTrace)(void*,const char*);        /* Trace function */
725   void *pTraceArg;                          /* Argument to the trace function */
726   void (*xProfile)(void*,const char*,u64);  /* Profiling function */
727   void *pProfileArg;                        /* Argument to profile function */
728   void *pCommitArg;                 /* Argument to xCommitCallback() */
729   int (*xCommitCallback)(void*);    /* Invoked at every commit. */
730   void *pRollbackArg;               /* Argument to xRollbackCallback() */
731   void (*xRollbackCallback)(void*); /* Invoked at every commit. */
732   void *pUpdateArg;
733   void (*xUpdateCallback)(void*,int, const char*,const char*,sqlite_int64);
734   void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*);
735   void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*);
736   void *pCollNeededArg;
737   sqlite3_value *pErr;          /* Most recent error message */
738   char *zErrMsg;                /* Most recent error message (UTF-8 encoded) */
739   char *zErrMsg16;              /* Most recent error message (UTF-16 encoded) */
740   union {
741     volatile int isInterrupted; /* True if sqlite3_interrupt has been called */
742     double notUsed1;            /* Spacer */
743   } u1;
744   Lookaside lookaside;          /* Lookaside malloc configuration */
745 #ifndef SQLITE_OMIT_AUTHORIZATION
746   int (*xAuth)(void*,int,const char*,const char*,const char*,const char*);
747                                 /* Access authorization function */
748   void *pAuthArg;               /* 1st argument to the access auth function */
749 #endif
750 #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
751   int (*xProgress)(void *);     /* The progress callback */
752   void *pProgressArg;           /* Argument to the progress callback */
753   int nProgressOps;             /* Number of opcodes for progress callback */
754 #endif
755 #ifndef SQLITE_OMIT_VIRTUALTABLE
756   Hash aModule;                 /* populated by sqlite3_create_module() */
757   Table *pVTab;                 /* vtab with active Connect/Create method */
758   sqlite3_vtab **aVTrans;       /* Virtual tables with open transactions */
759   int nVTrans;                  /* Allocated size of aVTrans */
760 #endif
761   FuncDefHash aFunc;            /* Hash table of connection functions */
762   Hash aCollSeq;                /* All collating sequences */
763   BusyHandler busyHandler;      /* Busy callback */
764   int busyTimeout;              /* Busy handler timeout, in msec */
765   Db aDbStatic[2];              /* Static space for the 2 default backends */
766 #ifdef SQLITE_SSE
767   sqlite3_stmt *pFetch;         /* Used by SSE to fetch stored statements */
768 #endif
769   Savepoint *pSavepoint;        /* List of active savepoints */
770   int nSavepoint;               /* Number of non-transaction savepoints */
771   u8 isTransactionSavepoint;    /* True if the outermost savepoint is a TS */
772 };
773 
774 /*
775 ** A macro to discover the encoding of a database.
776 */
777 #define ENC(db) ((db)->aDb[0].pSchema->enc)
778 
779 /*
780 ** Possible values for the sqlite.flags and or Db.flags fields.
781 **
782 ** On sqlite.flags, the SQLITE_InTrans value means that we have
783 ** executed a BEGIN.  On Db.flags, SQLITE_InTrans means a statement
784 ** transaction is active on that particular database file.
785 */
786 #define SQLITE_VdbeTrace      0x00000001  /* True to trace VDBE execution */
787 #define SQLITE_InTrans        0x00000008  /* True if in a transaction */
788 #define SQLITE_InternChanges  0x00000010  /* Uncommitted Hash table changes */
789 #define SQLITE_FullColNames   0x00000020  /* Show full column names on SELECT */
790 #define SQLITE_ShortColNames  0x00000040  /* Show short columns names */
791 #define SQLITE_CountRows      0x00000080  /* Count rows changed by INSERT, */
792                                           /*   DELETE, or UPDATE and return */
793                                           /*   the count using a callback. */
794 #define SQLITE_NullCallback   0x00000100  /* Invoke the callback once if the */
795                                           /*   result set is empty */
796 #define SQLITE_SqlTrace       0x00000200  /* Debug print SQL as it executes */
797 #define SQLITE_VdbeListing    0x00000400  /* Debug listings of VDBE programs */
798 #define SQLITE_WriteSchema    0x00000800  /* OK to update SQLITE_MASTER */
799 #define SQLITE_NoReadlock     0x00001000  /* Readlocks are omitted when
800                                           ** accessing read-only databases */
801 #define SQLITE_IgnoreChecks   0x00002000  /* Do not enforce check constraints */
802 #define SQLITE_ReadUncommitted 0x00004000 /* For shared-cache mode */
803 #define SQLITE_LegacyFileFmt  0x00008000  /* Create new databases in format 1 */
804 #define SQLITE_FullFSync      0x00010000  /* Use full fsync on the backend */
805 #define SQLITE_LoadExtension  0x00020000  /* Enable load_extension */
806 
807 #define SQLITE_RecoveryMode   0x00040000  /* Ignore schema errors */
808 #define SQLITE_SharedCache    0x00080000  /* Cache sharing is enabled */
809 #define SQLITE_Vtab           0x00100000  /* There exists a virtual table */
810 
811 /*
812 ** Possible values for the sqlite.magic field.
813 ** The numbers are obtained at random and have no special meaning, other
814 ** than being distinct from one another.
815 */
816 #define SQLITE_MAGIC_OPEN     0xa029a697  /* Database is open */
817 #define SQLITE_MAGIC_CLOSED   0x9f3c2d33  /* Database is closed */
818 #define SQLITE_MAGIC_SICK     0x4b771290  /* Error and awaiting close */
819 #define SQLITE_MAGIC_BUSY     0xf03b7906  /* Database currently in use */
820 #define SQLITE_MAGIC_ERROR    0xb5357930  /* An SQLITE_MISUSE error occurred */
821 
822 /*
823 ** Each SQL function is defined by an instance of the following
824 ** structure.  A pointer to this structure is stored in the sqlite.aFunc
825 ** hash table.  When multiple functions have the same name, the hash table
826 ** points to a linked list of these structures.
827 */
828 struct FuncDef {
829   i16 nArg;            /* Number of arguments.  -1 means unlimited */
830   u8 iPrefEnc;         /* Preferred text encoding (SQLITE_UTF8, 16LE, 16BE) */
831   u8 flags;            /* Some combination of SQLITE_FUNC_* */
832   void *pUserData;     /* User data parameter */
833   FuncDef *pNext;      /* Next function with same name */
834   void (*xFunc)(sqlite3_context*,int,sqlite3_value**); /* Regular function */
835   void (*xStep)(sqlite3_context*,int,sqlite3_value**); /* Aggregate step */
836   void (*xFinalize)(sqlite3_context*);                /* Aggregate finalizer */
837   char *zName;         /* SQL name of the function. */
838   FuncDef *pHash;      /* Next with a different name but the same hash */
839 };
840 
841 /*
842 ** Possible values for FuncDef.flags
843 */
844 #define SQLITE_FUNC_LIKE     0x01 /* Candidate for the LIKE optimization */
845 #define SQLITE_FUNC_CASE     0x02 /* Case-sensitive LIKE-type function */
846 #define SQLITE_FUNC_EPHEM    0x04 /* Ephemeral.  Delete with VDBE */
847 #define SQLITE_FUNC_NEEDCOLL 0x08 /* sqlite3GetFuncCollSeq() might be called */
848 
849 /*
850 ** The following three macros, FUNCTION(), LIKEFUNC() and AGGREGATE() are
851 ** used to create the initializers for the FuncDef structures.
852 **
853 **   FUNCTION(zName, nArg, iArg, bNC, xFunc)
854 **     Used to create a scalar function definition of a function zName
855 **     implemented by C function xFunc that accepts nArg arguments. The
856 **     value passed as iArg is cast to a (void*) and made available
857 **     as the user-data (sqlite3_user_data()) for the function. If
858 **     argument bNC is true, then the FuncDef.needCollate flag is set.
859 **
860 **   AGGREGATE(zName, nArg, iArg, bNC, xStep, xFinal)
861 **     Used to create an aggregate function definition implemented by
862 **     the C functions xStep and xFinal. The first four parameters
863 **     are interpreted in the same way as the first 4 parameters to
864 **     FUNCTION().
865 **
866 **   LIKEFUNC(zName, nArg, pArg, flags)
867 **     Used to create a scalar function definition of a function zName
868 **     that accepts nArg arguments and is implemented by a call to C
869 **     function likeFunc. Argument pArg is cast to a (void *) and made
870 **     available as the function user-data (sqlite3_user_data()). The
871 **     FuncDef.flags variable is set to the value passed as the flags
872 **     parameter.
873 */
874 #define FUNCTION(zName, nArg, iArg, bNC, xFunc) \
875   {nArg, SQLITE_UTF8, bNC*8, SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, 0, #zName, 0}
876 #define STR_FUNCTION(zName, nArg, pArg, bNC, xFunc) \
877   {nArg, SQLITE_UTF8, bNC*8, pArg, 0, xFunc, 0, 0, #zName, 0}
878 #define LIKEFUNC(zName, nArg, arg, flags) \
879   {nArg, SQLITE_UTF8, flags, (void *)arg, 0, likeFunc, 0, 0, #zName, 0}
880 #define AGGREGATE(zName, nArg, arg, nc, xStep, xFinal) \
881   {nArg, SQLITE_UTF8, nc*8, SQLITE_INT_TO_PTR(arg), 0, 0, xStep,xFinal,#zName,0}
882 
883 /*
884 ** All current savepoints are stored in a linked list starting at
885 ** sqlite3.pSavepoint. The first element in the list is the most recently
886 ** opened savepoint. Savepoints are added to the list by the vdbe
887 ** OP_Savepoint instruction.
888 */
889 struct Savepoint {
890   char *zName;                        /* Savepoint name (nul-terminated) */
891   Savepoint *pNext;                   /* Parent savepoint (if any) */
892 };
893 
894 /*
895 ** The following are used as the second parameter to sqlite3Savepoint(),
896 ** and as the P1 argument to the OP_Savepoint instruction.
897 */
898 #define SAVEPOINT_BEGIN      0
899 #define SAVEPOINT_RELEASE    1
900 #define SAVEPOINT_ROLLBACK   2
901 
902 
903 /*
904 ** Each SQLite module (virtual table definition) is defined by an
905 ** instance of the following structure, stored in the sqlite3.aModule
906 ** hash table.
907 */
908 struct Module {
909   const sqlite3_module *pModule;       /* Callback pointers */
910   const char *zName;                   /* Name passed to create_module() */
911   void *pAux;                          /* pAux passed to create_module() */
912   void (*xDestroy)(void *);            /* Module destructor function */
913 };
914 
915 /*
916 ** information about each column of an SQL table is held in an instance
917 ** of this structure.
918 */
919 struct Column {
920   char *zName;     /* Name of this column */
921   Expr *pDflt;     /* Default value of this column */
922   char *zType;     /* Data type for this column */
923   char *zColl;     /* Collating sequence.  If NULL, use the default */
924   u8 notNull;      /* True if there is a NOT NULL constraint */
925   u8 isPrimKey;    /* True if this column is part of the PRIMARY KEY */
926   char affinity;   /* One of the SQLITE_AFF_... values */
927 #ifndef SQLITE_OMIT_VIRTUALTABLE
928   u8 isHidden;     /* True if this column is 'hidden' */
929 #endif
930 };
931 
932 /*
933 ** A "Collating Sequence" is defined by an instance of the following
934 ** structure. Conceptually, a collating sequence consists of a name and
935 ** a comparison routine that defines the order of that sequence.
936 **
937 ** There may two separate implementations of the collation function, one
938 ** that processes text in UTF-8 encoding (CollSeq.xCmp) and another that
939 ** processes text encoded in UTF-16 (CollSeq.xCmp16), using the machine
940 ** native byte order. When a collation sequence is invoked, SQLite selects
941 ** the version that will require the least expensive encoding
942 ** translations, if any.
943 **
944 ** The CollSeq.pUser member variable is an extra parameter that passed in
945 ** as the first argument to the UTF-8 comparison function, xCmp.
946 ** CollSeq.pUser16 is the equivalent for the UTF-16 comparison function,
947 ** xCmp16.
948 **
949 ** If both CollSeq.xCmp and CollSeq.xCmp16 are NULL, it means that the
950 ** collating sequence is undefined.  Indices built on an undefined
951 ** collating sequence may not be read or written.
952 */
953 struct CollSeq {
954   char *zName;          /* Name of the collating sequence, UTF-8 encoded */
955   u8 enc;               /* Text encoding handled by xCmp() */
956   u8 type;              /* One of the SQLITE_COLL_... values below */
957   void *pUser;          /* First argument to xCmp() */
958   int (*xCmp)(void*,int, const void*, int, const void*);
959   void (*xDel)(void*);  /* Destructor for pUser */
960 };
961 
962 /*
963 ** Allowed values of CollSeq.type:
964 */
965 #define SQLITE_COLL_BINARY  1  /* The default memcmp() collating sequence */
966 #define SQLITE_COLL_NOCASE  2  /* The built-in NOCASE collating sequence */
967 #define SQLITE_COLL_REVERSE 3  /* The built-in REVERSE collating sequence */
968 #define SQLITE_COLL_USER    0  /* Any other user-defined collating sequence */
969 
970 /*
971 ** A sort order can be either ASC or DESC.
972 */
973 #define SQLITE_SO_ASC       0  /* Sort in ascending order */
974 #define SQLITE_SO_DESC      1  /* Sort in ascending order */
975 
976 /*
977 ** Column affinity types.
978 **
979 ** These used to have mnemonic name like 'i' for SQLITE_AFF_INTEGER and
980 ** 't' for SQLITE_AFF_TEXT.  But we can save a little space and improve
981 ** the speed a little by numbering the values consecutively.
982 **
983 ** But rather than start with 0 or 1, we begin with 'a'.  That way,
984 ** when multiple affinity types are concatenated into a string and
985 ** used as the P4 operand, they will be more readable.
986 **
987 ** Note also that the numeric types are grouped together so that testing
988 ** for a numeric type is a single comparison.
989 */
990 #define SQLITE_AFF_TEXT     'a'
991 #define SQLITE_AFF_NONE     'b'
992 #define SQLITE_AFF_NUMERIC  'c'
993 #define SQLITE_AFF_INTEGER  'd'
994 #define SQLITE_AFF_REAL     'e'
995 
996 #define sqlite3IsNumericAffinity(X)  ((X)>=SQLITE_AFF_NUMERIC)
997 
998 /*
999 ** The SQLITE_AFF_MASK values masks off the significant bits of an
1000 ** affinity value.
1001 */
1002 #define SQLITE_AFF_MASK     0x67
1003 
1004 /*
1005 ** Additional bit values that can be ORed with an affinity without
1006 ** changing the affinity.
1007 */
1008 #define SQLITE_JUMPIFNULL   0x08  /* jumps if either operand is NULL */
1009 #define SQLITE_STOREP2      0x10  /* Store result in reg[P2] rather than jump */
1010 
1011 /*
1012 ** Each SQL table is represented in memory by an instance of the
1013 ** following structure.
1014 **
1015 ** Table.zName is the name of the table.  The case of the original
1016 ** CREATE TABLE statement is stored, but case is not significant for
1017 ** comparisons.
1018 **
1019 ** Table.nCol is the number of columns in this table.  Table.aCol is a
1020 ** pointer to an array of Column structures, one for each column.
1021 **
1022 ** If the table has an INTEGER PRIMARY KEY, then Table.iPKey is the index of
1023 ** the column that is that key.   Otherwise Table.iPKey is negative.  Note
1024 ** that the datatype of the PRIMARY KEY must be INTEGER for this field to
1025 ** be set.  An INTEGER PRIMARY KEY is used as the rowid for each row of
1026 ** the table.  If a table has no INTEGER PRIMARY KEY, then a random rowid
1027 ** is generated for each row of the table.  TF_HasPrimaryKey is set if
1028 ** the table has any PRIMARY KEY, INTEGER or otherwise.
1029 **
1030 ** Table.tnum is the page number for the root BTree page of the table in the
1031 ** database file.  If Table.iDb is the index of the database table backend
1032 ** in sqlite.aDb[].  0 is for the main database and 1 is for the file that
1033 ** holds temporary tables and indices.  If TF_Ephemeral is set
1034 ** then the table is stored in a file that is automatically deleted
1035 ** when the VDBE cursor to the table is closed.  In this case Table.tnum
1036 ** refers VDBE cursor number that holds the table open, not to the root
1037 ** page number.  Transient tables are used to hold the results of a
1038 ** sub-query that appears instead of a real table name in the FROM clause
1039 ** of a SELECT statement.
1040 */
1041 struct Table {
1042   sqlite3 *db;         /* Associated database connection.  Might be NULL. */
1043   char *zName;         /* Name of the table or view */
1044   int iPKey;           /* If not negative, use aCol[iPKey] as the primary key */
1045   int nCol;            /* Number of columns in this table */
1046   Column *aCol;        /* Information about each column */
1047   Index *pIndex;       /* List of SQL indexes on this table. */
1048   int tnum;            /* Root BTree node for this table (see note above) */
1049   Select *pSelect;     /* NULL for tables.  Points to definition if a view. */
1050   u16 nRef;            /* Number of pointers to this Table */
1051   u8 tabFlags;         /* Mask of TF_* values */
1052   u8 keyConf;          /* What to do in case of uniqueness conflict on iPKey */
1053   Trigger *pTrigger;   /* List of SQL triggers on this table */
1054   FKey *pFKey;         /* Linked list of all foreign keys in this table */
1055   char *zColAff;       /* String defining the affinity of each column */
1056 #ifndef SQLITE_OMIT_CHECK
1057   Expr *pCheck;        /* The AND of all CHECK constraints */
1058 #endif
1059 #ifndef SQLITE_OMIT_ALTERTABLE
1060   int addColOffset;    /* Offset in CREATE TABLE stmt to add a new column */
1061 #endif
1062 #ifndef SQLITE_OMIT_VIRTUALTABLE
1063   Module *pMod;        /* Pointer to the implementation of the module */
1064   sqlite3_vtab *pVtab; /* Pointer to the module instance */
1065   int nModuleArg;      /* Number of arguments to the module */
1066   char **azModuleArg;  /* Text of all module args. [0] is module name */
1067 #endif
1068   Schema *pSchema;     /* Schema that contains this table */
1069   Table *pNextZombie;  /* Next on the Parse.pZombieTab list */
1070 };
1071 
1072 /*
1073 ** Allowed values for Tabe.tabFlags.
1074 */
1075 #define TF_Readonly        0x01    /* Read-only system table */
1076 #define TF_Ephemeral       0x02    /* An ephemeral table */
1077 #define TF_HasPrimaryKey   0x04    /* Table has a primary key */
1078 #define TF_Autoincrement   0x08    /* Integer primary key is autoincrement */
1079 #define TF_Virtual         0x10    /* Is a virtual table */
1080 #define TF_NeedMetadata    0x20    /* aCol[].zType and aCol[].pColl missing */
1081 
1082 
1083 
1084 /*
1085 ** Test to see whether or not a table is a virtual table.  This is
1086 ** done as a macro so that it will be optimized out when virtual
1087 ** table support is omitted from the build.
1088 */
1089 #ifndef SQLITE_OMIT_VIRTUALTABLE
1090 #  define IsVirtual(X)      (((X)->tabFlags & TF_Virtual)!=0)
1091 #  define IsHiddenColumn(X) ((X)->isHidden)
1092 #else
1093 #  define IsVirtual(X)      0
1094 #  define IsHiddenColumn(X) 0
1095 #endif
1096 
1097 /*
1098 ** Each foreign key constraint is an instance of the following structure.
1099 **
1100 ** A foreign key is associated with two tables.  The "from" table is
1101 ** the table that contains the REFERENCES clause that creates the foreign
1102 ** key.  The "to" table is the table that is named in the REFERENCES clause.
1103 ** Consider this example:
1104 **
1105 **     CREATE TABLE ex1(
1106 **       a INTEGER PRIMARY KEY,
1107 **       b INTEGER CONSTRAINT fk1 REFERENCES ex2(x)
1108 **     );
1109 **
1110 ** For foreign key "fk1", the from-table is "ex1" and the to-table is "ex2".
1111 **
1112 ** Each REFERENCES clause generates an instance of the following structure
1113 ** which is attached to the from-table.  The to-table need not exist when
1114 ** the from-table is created.  The existence of the to-table is not checked
1115 ** until an attempt is made to insert data into the from-table.
1116 **
1117 ** The sqlite.aFKey hash table stores pointers to this structure
1118 ** given the name of a to-table.  For each to-table, all foreign keys
1119 ** associated with that table are on a linked list using the FKey.pNextTo
1120 ** field.
1121 */
1122 struct FKey {
1123   Table *pFrom;     /* The table that contains the REFERENCES clause */
1124   FKey *pNextFrom;  /* Next foreign key in pFrom */
1125   char *zTo;        /* Name of table that the key points to */
1126   FKey *pNextTo;    /* Next foreign key that points to zTo */
1127   int nCol;         /* Number of columns in this key */
1128   struct sColMap {  /* Mapping of columns in pFrom to columns in zTo */
1129     int iFrom;         /* Index of column in pFrom */
1130     char *zCol;        /* Name of column in zTo.  If 0 use PRIMARY KEY */
1131   } *aCol;          /* One entry for each of nCol column s */
1132   u8 isDeferred;    /* True if constraint checking is deferred till COMMIT */
1133   u8 updateConf;    /* How to resolve conflicts that occur on UPDATE */
1134   u8 deleteConf;    /* How to resolve conflicts that occur on DELETE */
1135   u8 insertConf;    /* How to resolve conflicts that occur on INSERT */
1136 };
1137 
1138 /*
1139 ** SQLite supports many different ways to resolve a constraint
1140 ** error.  ROLLBACK processing means that a constraint violation
1141 ** causes the operation in process to fail and for the current transaction
1142 ** to be rolled back.  ABORT processing means the operation in process
1143 ** fails and any prior changes from that one operation are backed out,
1144 ** but the transaction is not rolled back.  FAIL processing means that
1145 ** the operation in progress stops and returns an error code.  But prior
1146 ** changes due to the same operation are not backed out and no rollback
1147 ** occurs.  IGNORE means that the particular row that caused the constraint
1148 ** error is not inserted or updated.  Processing continues and no error
1149 ** is returned.  REPLACE means that preexisting database rows that caused
1150 ** a UNIQUE constraint violation are removed so that the new insert or
1151 ** update can proceed.  Processing continues and no error is reported.
1152 **
1153 ** RESTRICT, SETNULL, and CASCADE actions apply only to foreign keys.
1154 ** RESTRICT is the same as ABORT for IMMEDIATE foreign keys and the
1155 ** same as ROLLBACK for DEFERRED keys.  SETNULL means that the foreign
1156 ** key is set to NULL.  CASCADE means that a DELETE or UPDATE of the
1157 ** referenced table row is propagated into the row that holds the
1158 ** foreign key.
1159 **
1160 ** The following symbolic values are used to record which type
1161 ** of action to take.
1162 */
1163 #define OE_None     0   /* There is no constraint to check */
1164 #define OE_Rollback 1   /* Fail the operation and rollback the transaction */
1165 #define OE_Abort    2   /* Back out changes but do no rollback transaction */
1166 #define OE_Fail     3   /* Stop the operation but leave all prior changes */
1167 #define OE_Ignore   4   /* Ignore the error. Do not do the INSERT or UPDATE */
1168 #define OE_Replace  5   /* Delete existing record, then do INSERT or UPDATE */
1169 
1170 #define OE_Restrict 6   /* OE_Abort for IMMEDIATE, OE_Rollback for DEFERRED */
1171 #define OE_SetNull  7   /* Set the foreign key value to NULL */
1172 #define OE_SetDflt  8   /* Set the foreign key value to its default */
1173 #define OE_Cascade  9   /* Cascade the changes */
1174 
1175 #define OE_Default  99  /* Do whatever the default action is */
1176 
1177 
1178 /*
1179 ** An instance of the following structure is passed as the first
1180 ** argument to sqlite3VdbeKeyCompare and is used to control the
1181 ** comparison of the two index keys.
1182 */
1183 struct KeyInfo {
1184   sqlite3 *db;        /* The database connection */
1185   u8 enc;             /* Text encoding - one of the TEXT_Utf* values */
1186   u16 nField;         /* Number of entries in aColl[] */
1187   u8 *aSortOrder;     /* If defined an aSortOrder[i] is true, sort DESC */
1188   CollSeq *aColl[1];  /* Collating sequence for each term of the key */
1189 };
1190 
1191 /*
1192 ** An instance of the following structure holds information about a
1193 ** single index record that has already been parsed out into individual
1194 ** values.
1195 **
1196 ** A record is an object that contains one or more fields of data.
1197 ** Records are used to store the content of a table row and to store
1198 ** the key of an index.  A blob encoding of a record is created by
1199 ** the OP_MakeRecord opcode of the VDBE and is disassembled by the
1200 ** OP_Column opcode.
1201 **
1202 ** This structure holds a record that has already been disassembled
1203 ** into its constituent fields.
1204 */
1205 struct UnpackedRecord {
1206   KeyInfo *pKeyInfo;  /* Collation and sort-order information */
1207   u16 nField;         /* Number of entries in apMem[] */
1208   u16 flags;          /* Boolean settings.  UNPACKED_... below */
1209   Mem *aMem;          /* Values */
1210 };
1211 
1212 /*
1213 ** Allowed values of UnpackedRecord.flags
1214 */
1215 #define UNPACKED_NEED_FREE     0x0001  /* Memory is from sqlite3Malloc() */
1216 #define UNPACKED_NEED_DESTROY  0x0002  /* apMem[]s should all be destroyed */
1217 #define UNPACKED_IGNORE_ROWID  0x0004  /* Ignore trailing rowid on key1 */
1218 #define UNPACKED_INCRKEY       0x0008  /* Make this key an epsilon larger */
1219 #define UNPACKED_PREFIX_MATCH  0x0010  /* A prefix match is considered OK */
1220 
1221 /*
1222 ** Each SQL index is represented in memory by an
1223 ** instance of the following structure.
1224 **
1225 ** The columns of the table that are to be indexed are described
1226 ** by the aiColumn[] field of this structure.  For example, suppose
1227 ** we have the following table and index:
1228 **
1229 **     CREATE TABLE Ex1(c1 int, c2 int, c3 text);
1230 **     CREATE INDEX Ex2 ON Ex1(c3,c1);
1231 **
1232 ** In the Table structure describing Ex1, nCol==3 because there are
1233 ** three columns in the table.  In the Index structure describing
1234 ** Ex2, nColumn==2 since 2 of the 3 columns of Ex1 are indexed.
1235 ** The value of aiColumn is {2, 0}.  aiColumn[0]==2 because the
1236 ** first column to be indexed (c3) has an index of 2 in Ex1.aCol[].
1237 ** The second column to be indexed (c1) has an index of 0 in
1238 ** Ex1.aCol[], hence Ex2.aiColumn[1]==0.
1239 **
1240 ** The Index.onError field determines whether or not the indexed columns
1241 ** must be unique and what to do if they are not.  When Index.onError=OE_None,
1242 ** it means this is not a unique index.  Otherwise it is a unique index
1243 ** and the value of Index.onError indicate the which conflict resolution
1244 ** algorithm to employ whenever an attempt is made to insert a non-unique
1245 ** element.
1246 */
1247 struct Index {
1248   char *zName;     /* Name of this index */
1249   int nColumn;     /* Number of columns in the table used by this index */
1250   int *aiColumn;   /* Which columns are used by this index.  1st is 0 */
1251   unsigned *aiRowEst; /* Result of ANALYZE: Est. rows selected by each column */
1252   Table *pTable;   /* The SQL table being indexed */
1253   int tnum;        /* Page containing root of this index in database file */
1254   u8 onError;      /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
1255   u8 autoIndex;    /* True if is automatically created (ex: by UNIQUE) */
1256   char *zColAff;   /* String defining the affinity of each column */
1257   Index *pNext;    /* The next index associated with the same table */
1258   Schema *pSchema; /* Schema containing this index */
1259   u8 *aSortOrder;  /* Array of size Index.nColumn. True==DESC, False==ASC */
1260   char **azColl;   /* Array of collation sequence names for index */
1261 };
1262 
1263 /*
1264 ** Each token coming out of the lexer is an instance of
1265 ** this structure.  Tokens are also used as part of an expression.
1266 **
1267 ** Note if Token.z==0 then Token.dyn and Token.n are undefined and
1268 ** may contain random values.  Do not make any assumptions about Token.dyn
1269 ** and Token.n when Token.z==0.
1270 */
1271 struct Token {
1272   const unsigned char *z; /* Text of the token.  Not NULL-terminated! */
1273   unsigned dyn  : 1;      /* True for malloced memory, false for static */
1274   unsigned n    : 31;     /* Number of characters in this token */
1275 };
1276 
1277 /*
1278 ** An instance of this structure contains information needed to generate
1279 ** code for a SELECT that contains aggregate functions.
1280 **
1281 ** If Expr.op==TK_AGG_COLUMN or TK_AGG_FUNCTION then Expr.pAggInfo is a
1282 ** pointer to this structure.  The Expr.iColumn field is the index in
1283 ** AggInfo.aCol[] or AggInfo.aFunc[] of information needed to generate
1284 ** code for that node.
1285 **
1286 ** AggInfo.pGroupBy and AggInfo.aFunc.pExpr point to fields within the
1287 ** original Select structure that describes the SELECT statement.  These
1288 ** fields do not need to be freed when deallocating the AggInfo structure.
1289 */
1290 struct AggInfo {
1291   u8 directMode;          /* Direct rendering mode means take data directly
1292                           ** from source tables rather than from accumulators */
1293   u8 useSortingIdx;       /* In direct mode, reference the sorting index rather
1294                           ** than the source table */
1295   int sortingIdx;         /* Cursor number of the sorting index */
1296   ExprList *pGroupBy;     /* The group by clause */
1297   int nSortingColumn;     /* Number of columns in the sorting index */
1298   struct AggInfo_col {    /* For each column used in source tables */
1299     Table *pTab;             /* Source table */
1300     int iTable;              /* Cursor number of the source table */
1301     int iColumn;             /* Column number within the source table */
1302     int iSorterColumn;       /* Column number in the sorting index */
1303     int iMem;                /* Memory location that acts as accumulator */
1304     Expr *pExpr;             /* The original expression */
1305   } *aCol;
1306   int nColumn;            /* Number of used entries in aCol[] */
1307   int nColumnAlloc;       /* Number of slots allocated for aCol[] */
1308   int nAccumulator;       /* Number of columns that show through to the output.
1309                           ** Additional columns are used only as parameters to
1310                           ** aggregate functions */
1311   struct AggInfo_func {   /* For each aggregate function */
1312     Expr *pExpr;             /* Expression encoding the function */
1313     FuncDef *pFunc;          /* The aggregate function implementation */
1314     int iMem;                /* Memory location that acts as accumulator */
1315     int iDistinct;           /* Ephemeral table used to enforce DISTINCT */
1316   } *aFunc;
1317   int nFunc;              /* Number of entries in aFunc[] */
1318   int nFuncAlloc;         /* Number of slots allocated for aFunc[] */
1319 };
1320 
1321 /*
1322 ** Each node of an expression in the parse tree is an instance
1323 ** of this structure.
1324 **
1325 ** Expr.op is the opcode.  The integer parser token codes are reused
1326 ** as opcodes here.  For example, the parser defines TK_GE to be an integer
1327 ** code representing the ">=" operator.  This same integer code is reused
1328 ** to represent the greater-than-or-equal-to operator in the expression
1329 ** tree.
1330 **
1331 ** Expr.pRight and Expr.pLeft are subexpressions.  Expr.pList is a list
1332 ** of argument if the expression is a function.
1333 **
1334 ** Expr.token is the operator token for this node.  For some expressions
1335 ** that have subexpressions, Expr.token can be the complete text that gave
1336 ** rise to the Expr.  In the latter case, the token is marked as being
1337 ** a compound token.
1338 **
1339 ** An expression of the form ID or ID.ID refers to a column in a table.
1340 ** For such expressions, Expr.op is set to TK_COLUMN and Expr.iTable is
1341 ** the integer cursor number of a VDBE cursor pointing to that table and
1342 ** Expr.iColumn is the column number for the specific column.  If the
1343 ** expression is used as a result in an aggregate SELECT, then the
1344 ** value is also stored in the Expr.iAgg column in the aggregate so that
1345 ** it can be accessed after all aggregates are computed.
1346 **
1347 ** If the expression is a function, the Expr.iTable is an integer code
1348 ** representing which function.  If the expression is an unbound variable
1349 ** marker (a question mark character '?' in the original SQL) then the
1350 ** Expr.iTable holds the index number for that variable.
1351 **
1352 ** If the expression is a subquery then Expr.iColumn holds an integer
1353 ** register number containing the result of the subquery.  If the
1354 ** subquery gives a constant result, then iTable is -1.  If the subquery
1355 ** gives a different answer at different times during statement processing
1356 ** then iTable is the address of a subroutine that computes the subquery.
1357 **
1358 ** The Expr.pSelect field points to a SELECT statement.  The SELECT might
1359 ** be the right operand of an IN operator.  Or, if a scalar SELECT appears
1360 ** in an expression the opcode is TK_SELECT and Expr.pSelect is the only
1361 ** operand.
1362 **
1363 ** If the Expr is of type OP_Column, and the table it is selecting from
1364 ** is a disk table or the "old.*" pseudo-table, then pTab points to the
1365 ** corresponding table definition.
1366 */
1367 struct Expr {
1368   u8 op;                 /* Operation performed by this node */
1369   char affinity;         /* The affinity of the column or 0 if not a column */
1370   u16 flags;             /* Various flags.  See below */
1371   CollSeq *pColl;        /* The collation type of the column or 0 */
1372   Expr *pLeft, *pRight;  /* Left and right subnodes */
1373   ExprList *pList;       /* A list of expressions used as function arguments
1374                          ** or in "<expr> IN (<expr-list)" */
1375   Token token;           /* An operand token */
1376   Token span;            /* Complete text of the expression */
1377   int iTable, iColumn;   /* When op==TK_COLUMN, then this expr node means the
1378                          ** iColumn-th field of the iTable-th table. */
1379   AggInfo *pAggInfo;     /* Used by TK_AGG_COLUMN and TK_AGG_FUNCTION */
1380   int iAgg;              /* Which entry in pAggInfo->aCol[] or ->aFunc[] */
1381   int iRightJoinTable;   /* If EP_FromJoin, the right table of the join */
1382   Select *pSelect;       /* When the expression is a sub-select.  Also the
1383                          ** right side of "<expr> IN (<select>)" */
1384   Table *pTab;           /* Table for TK_COLUMN expressions. */
1385 #if SQLITE_MAX_EXPR_DEPTH>0
1386   int nHeight;           /* Height of the tree headed by this node */
1387 #endif
1388 };
1389 
1390 /*
1391 ** The following are the meanings of bits in the Expr.flags field.
1392 */
1393 #define EP_FromJoin   0x0001  /* Originated in ON or USING clause of a join */
1394 #define EP_Agg        0x0002  /* Contains one or more aggregate functions */
1395 #define EP_Resolved   0x0004  /* IDs have been resolved to COLUMNs */
1396 #define EP_Error      0x0008  /* Expression contains one or more errors */
1397 #define EP_Distinct   0x0010  /* Aggregate function with DISTINCT keyword */
1398 #define EP_VarSelect  0x0020  /* pSelect is correlated, not constant */
1399 #define EP_Dequoted   0x0040  /* True if the string has been dequoted */
1400 #define EP_InfixFunc  0x0080  /* True for an infix function: LIKE, GLOB, etc */
1401 #define EP_ExpCollate 0x0100  /* Collating sequence specified explicitly */
1402 #define EP_AnyAff     0x0200  /* Can take a cached column of any affinity */
1403 #define EP_FixedDest  0x0400  /* Result needed in a specific register */
1404 #define EP_IntValue   0x0800  /* Integer value contained in iTable */
1405 /*
1406 ** These macros can be used to test, set, or clear bits in the
1407 ** Expr.flags field.
1408 */
1409 #define ExprHasProperty(E,P)     (((E)->flags&(P))==(P))
1410 #define ExprHasAnyProperty(E,P)  (((E)->flags&(P))!=0)
1411 #define ExprSetProperty(E,P)     (E)->flags|=(P)
1412 #define ExprClearProperty(E,P)   (E)->flags&=~(P)
1413 
1414 /*
1415 ** A list of expressions.  Each expression may optionally have a
1416 ** name.  An expr/name combination can be used in several ways, such
1417 ** as the list of "expr AS ID" fields following a "SELECT" or in the
1418 ** list of "ID = expr" items in an UPDATE.  A list of expressions can
1419 ** also be used as the argument to a function, in which case the a.zName
1420 ** field is not used.
1421 */
1422 struct ExprList {
1423   int nExpr;             /* Number of expressions on the list */
1424   int nAlloc;            /* Number of entries allocated below */
1425   int iECursor;          /* VDBE Cursor associated with this ExprList */
1426   struct ExprList_item {
1427     Expr *pExpr;           /* The list of expressions */
1428     char *zName;           /* Token associated with this expression */
1429     u8 sortOrder;          /* 1 for DESC or 0 for ASC */
1430     u8 done;               /* A flag to indicate when processing is finished */
1431     u16 iCol;              /* For ORDER BY, column number in result set */
1432     u16 iAlias;            /* Index into Parse.aAlias[] for zName */
1433   } *a;                  /* One entry for each expression */
1434 };
1435 
1436 /*
1437 ** An instance of this structure can hold a simple list of identifiers,
1438 ** such as the list "a,b,c" in the following statements:
1439 **
1440 **      INSERT INTO t(a,b,c) VALUES ...;
1441 **      CREATE INDEX idx ON t(a,b,c);
1442 **      CREATE TRIGGER trig BEFORE UPDATE ON t(a,b,c) ...;
1443 **
1444 ** The IdList.a.idx field is used when the IdList represents the list of
1445 ** column names after a table name in an INSERT statement.  In the statement
1446 **
1447 **     INSERT INTO t(a,b,c) ...
1448 **
1449 ** If "a" is the k-th column of table "t", then IdList.a[0].idx==k.
1450 */
1451 struct IdList {
1452   struct IdList_item {
1453     char *zName;      /* Name of the identifier */
1454     int idx;          /* Index in some Table.aCol[] of a column named zName */
1455   } *a;
1456   int nId;         /* Number of identifiers on the list */
1457   int nAlloc;      /* Number of entries allocated for a[] below */
1458 };
1459 
1460 /*
1461 ** The bitmask datatype defined below is used for various optimizations.
1462 **
1463 ** Changing this from a 64-bit to a 32-bit type limits the number of
1464 ** tables in a join to 32 instead of 64.  But it also reduces the size
1465 ** of the library by 738 bytes on ix86.
1466 */
1467 typedef u64 Bitmask;
1468 
1469 /*
1470 ** The number of bits in a Bitmask.  "BMS" means "BitMask Size".
1471 */
1472 #define BMS  ((int)(sizeof(Bitmask)*8))
1473 
1474 /*
1475 ** The following structure describes the FROM clause of a SELECT statement.
1476 ** Each table or subquery in the FROM clause is a separate element of
1477 ** the SrcList.a[] array.
1478 **
1479 ** With the addition of multiple database support, the following structure
1480 ** can also be used to describe a particular table such as the table that
1481 ** is modified by an INSERT, DELETE, or UPDATE statement.  In standard SQL,
1482 ** such a table must be a simple name: ID.  But in SQLite, the table can
1483 ** now be identified by a database name, a dot, then the table name: ID.ID.
1484 **
1485 ** The jointype starts out showing the join type between the current table
1486 ** and the next table on the list.  The parser builds the list this way.
1487 ** But sqlite3SrcListShiftJoinType() later shifts the jointypes so that each
1488 ** jointype expresses the join between the table and the previous table.
1489 */
1490 struct SrcList {
1491   i16 nSrc;        /* Number of tables or subqueries in the FROM clause */
1492   i16 nAlloc;      /* Number of entries allocated in a[] below */
1493   struct SrcList_item {
1494     char *zDatabase;  /* Name of database holding this table */
1495     char *zName;      /* Name of the table */
1496     char *zAlias;     /* The "B" part of a "A AS B" phrase.  zName is the "A" */
1497     Table *pTab;      /* An SQL table corresponding to zName */
1498     Select *pSelect;  /* A SELECT statement used in place of a table name */
1499     u8 isPopulated;   /* Temporary table associated with SELECT is populated */
1500     u8 jointype;      /* Type of join between this able and the previous */
1501     int iCursor;      /* The VDBE cursor number used to access this table */
1502     Expr *pOn;        /* The ON clause of a join */
1503     IdList *pUsing;   /* The USING clause of a join */
1504     Bitmask colUsed;  /* Bit N (1<<N) set if column N or pTab is used */
1505     u8 notIndexed;    /* True if there is a NOT INDEXED clause */
1506     char *zIndex;     /* Identifier from "INDEXED BY <zIndex>" clause */
1507     Index *pIndex;    /* Index structure corresponding to zIndex, if any */
1508   } a[1];             /* One entry for each identifier on the list */
1509 };
1510 
1511 /*
1512 ** Permitted values of the SrcList.a.jointype field
1513 */
1514 #define JT_INNER     0x0001    /* Any kind of inner or cross join */
1515 #define JT_CROSS     0x0002    /* Explicit use of the CROSS keyword */
1516 #define JT_NATURAL   0x0004    /* True for a "natural" join */
1517 #define JT_LEFT      0x0008    /* Left outer join */
1518 #define JT_RIGHT     0x0010    /* Right outer join */
1519 #define JT_OUTER     0x0020    /* The "OUTER" keyword is present */
1520 #define JT_ERROR     0x0040    /* unknown or unsupported join type */
1521 
1522 /*
1523 ** For each nested loop in a WHERE clause implementation, the WhereInfo
1524 ** structure contains a single instance of this structure.  This structure
1525 ** is intended to be private the the where.c module and should not be
1526 ** access or modified by other modules.
1527 **
1528 ** The pIdxInfo and pBestIdx fields are used to help pick the best
1529 ** index on a virtual table.  The pIdxInfo pointer contains indexing
1530 ** information for the i-th table in the FROM clause before reordering.
1531 ** All the pIdxInfo pointers are freed by whereInfoFree() in where.c.
1532 ** The pBestIdx pointer is a copy of pIdxInfo for the i-th table after
1533 ** FROM clause ordering.  This is a little confusing so I will repeat
1534 ** it in different words.  WhereInfo.a[i].pIdxInfo is index information
1535 ** for WhereInfo.pTabList.a[i].  WhereInfo.a[i].pBestInfo is the
1536 ** index information for the i-th loop of the join.  pBestInfo is always
1537 ** either NULL or a copy of some pIdxInfo.  So for cleanup it is
1538 ** sufficient to free all of the pIdxInfo pointers.
1539 **
1540 */
1541 struct WhereLevel {
1542   u32 wsFlags;          /* "Where-Scan" flags show the choosen scan strategy */
1543   int iLeftJoin;        /* Memory cell used to implement LEFT OUTER JOIN */
1544   Index *pIdx;          /* Index used.  NULL if no index */
1545   struct WhereTerm *pTerm; /* Where term containing OR clause */
1546   int iTabCur;          /* The VDBE cursor used to access the table */
1547   int iIdxCur;          /* The VDBE cursor used to access pIdx */
1548   int addrBrk;          /* Jump here to break out of the loop */
1549   int addrNxt;          /* Jump here to start the next IN combination */
1550   int addrCont;         /* Jump here to continue with the next loop cycle */
1551   int addrFirst;        /* First instruction of interior of the loop */
1552   int op, p1, p2;       /* Opcode used to terminate the loop */
1553   u8 p5;                /* P5 operand of the opcode that terminates the loop */
1554   u8 iFrom;             /* Which entry in the FROM clause */
1555   u16 nEq;              /* Number of == or IN constraints on this loop */
1556   u16 nIn;              /* Number of IN operators constraining this loop */
1557   struct InLoop {
1558     int iCur;              /* The VDBE cursor used by this IN operator */
1559     int addrInTop;         /* Top of the IN loop */
1560   } *aInLoop;           /* Information about each nested IN operator */
1561   sqlite3_index_info *pBestIdx;  /* Index information for this level */
1562 
1563   /* The following field is really not part of the current level.  But
1564   ** we need a place to cache index information for each table in the
1565   ** FROM clause and the WhereLevel structure is a convenient place.
1566   */
1567   sqlite3_index_info *pIdxInfo;  /* Index info for n-th source table */
1568 };
1569 
1570 /*
1571 ** Flags appropriate for the wctrlFlags parameter of sqlite3WhereBegin().
1572 */
1573 #define WHERE_ORDERBY_NORMAL     0   /* No-op */
1574 #define WHERE_ORDERBY_MIN        1   /* ORDER BY processing for min() func */
1575 #define WHERE_ORDERBY_MAX        2   /* ORDER BY processing for max() func */
1576 #define WHERE_ONEPASS_DESIRED    4   /* Want to do one-pass UPDATE/DELETE */
1577 
1578 /*
1579 ** The WHERE clause processing routine has two halves.  The
1580 ** first part does the start of the WHERE loop and the second
1581 ** half does the tail of the WHERE loop.  An instance of
1582 ** this structure is returned by the first half and passed
1583 ** into the second half to give some continuity.
1584 */
1585 struct WhereInfo {
1586   Parse *pParse;       /* Parsing and code generating context */
1587   u8 okOnePass;        /* Ok to use one-pass algorithm for UPDATE or DELETE */
1588   SrcList *pTabList;   /* List of tables in the join */
1589   int iTop;            /* The very beginning of the WHERE loop */
1590   int iContinue;       /* Jump here to continue with next record */
1591   int iBreak;          /* Jump here to break out of the loop */
1592   int nLevel;          /* Number of nested loop */
1593   sqlite3_index_info **apInfo;  /* Array of pointers to index info structures */
1594   WhereLevel a[1];     /* Information about each nest loop in the WHERE */
1595 };
1596 
1597 /*
1598 ** A NameContext defines a context in which to resolve table and column
1599 ** names.  The context consists of a list of tables (the pSrcList) field and
1600 ** a list of named expression (pEList).  The named expression list may
1601 ** be NULL.  The pSrc corresponds to the FROM clause of a SELECT or
1602 ** to the table being operated on by INSERT, UPDATE, or DELETE.  The
1603 ** pEList corresponds to the result set of a SELECT and is NULL for
1604 ** other statements.
1605 **
1606 ** NameContexts can be nested.  When resolving names, the inner-most
1607 ** context is searched first.  If no match is found, the next outer
1608 ** context is checked.  If there is still no match, the next context
1609 ** is checked.  This process continues until either a match is found
1610 ** or all contexts are check.  When a match is found, the nRef member of
1611 ** the context containing the match is incremented.
1612 **
1613 ** Each subquery gets a new NameContext.  The pNext field points to the
1614 ** NameContext in the parent query.  Thus the process of scanning the
1615 ** NameContext list corresponds to searching through successively outer
1616 ** subqueries looking for a match.
1617 */
1618 struct NameContext {
1619   Parse *pParse;       /* The parser */
1620   SrcList *pSrcList;   /* One or more tables used to resolve names */
1621   ExprList *pEList;    /* Optional list of named expressions */
1622   int nRef;            /* Number of names resolved by this context */
1623   int nErr;            /* Number of errors encountered while resolving names */
1624   u8 allowAgg;         /* Aggregate functions allowed here */
1625   u8 hasAgg;           /* True if aggregates are seen */
1626   u8 isCheck;          /* True if resolving names in a CHECK constraint */
1627   int nDepth;          /* Depth of subquery recursion. 1 for no recursion */
1628   AggInfo *pAggInfo;   /* Information about aggregates at this level */
1629   NameContext *pNext;  /* Next outer name context.  NULL for outermost */
1630 };
1631 
1632 /*
1633 ** An instance of the following structure contains all information
1634 ** needed to generate code for a single SELECT statement.
1635 **
1636 ** nLimit is set to -1 if there is no LIMIT clause.  nOffset is set to 0.
1637 ** If there is a LIMIT clause, the parser sets nLimit to the value of the
1638 ** limit and nOffset to the value of the offset (or 0 if there is not
1639 ** offset).  But later on, nLimit and nOffset become the memory locations
1640 ** in the VDBE that record the limit and offset counters.
1641 **
1642 ** addrOpenEphm[] entries contain the address of OP_OpenEphemeral opcodes.
1643 ** These addresses must be stored so that we can go back and fill in
1644 ** the P4_KEYINFO and P2 parameters later.  Neither the KeyInfo nor
1645 ** the number of columns in P2 can be computed at the same time
1646 ** as the OP_OpenEphm instruction is coded because not
1647 ** enough information about the compound query is known at that point.
1648 ** The KeyInfo for addrOpenTran[0] and [1] contains collating sequences
1649 ** for the result set.  The KeyInfo for addrOpenTran[2] contains collating
1650 ** sequences for the ORDER BY clause.
1651 */
1652 struct Select {
1653   ExprList *pEList;      /* The fields of the result */
1654   u8 op;                 /* One of: TK_UNION TK_ALL TK_INTERSECT TK_EXCEPT */
1655   char affinity;         /* MakeRecord with this affinity for SRT_Set */
1656   u16 selFlags;          /* Various SF_* values */
1657   SrcList *pSrc;         /* The FROM clause */
1658   Expr *pWhere;          /* The WHERE clause */
1659   ExprList *pGroupBy;    /* The GROUP BY clause */
1660   Expr *pHaving;         /* The HAVING clause */
1661   ExprList *pOrderBy;    /* The ORDER BY clause */
1662   Select *pPrior;        /* Prior select in a compound select statement */
1663   Select *pNext;         /* Next select to the left in a compound */
1664   Select *pRightmost;    /* Right-most select in a compound select statement */
1665   Expr *pLimit;          /* LIMIT expression. NULL means not used. */
1666   Expr *pOffset;         /* OFFSET expression. NULL means not used. */
1667   int iLimit, iOffset;   /* Memory registers holding LIMIT & OFFSET counters */
1668   int addrOpenEphm[3];   /* OP_OpenEphem opcodes related to this select */
1669 };
1670 
1671 /*
1672 ** Allowed values for Select.selFlags.  The "SF" prefix stands for
1673 ** "Select Flag".
1674 */
1675 #define SF_Distinct        0x0001  /* Output should be DISTINCT */
1676 #define SF_Resolved        0x0002  /* Identifiers have been resolved */
1677 #define SF_Aggregate       0x0004  /* Contains aggregate functions */
1678 #define SF_UsesEphemeral   0x0008  /* Uses the OpenEphemeral opcode */
1679 #define SF_Expanded        0x0010  /* sqlite3SelectExpand() called on this */
1680 #define SF_HasTypeInfo     0x0020  /* FROM subqueries have Table metadata */
1681 
1682 
1683 /*
1684 ** The results of a select can be distributed in several ways.  The
1685 ** "SRT" prefix means "SELECT Result Type".
1686 */
1687 #define SRT_Union        1  /* Store result as keys in an index */
1688 #define SRT_Except       2  /* Remove result from a UNION index */
1689 #define SRT_Exists       3  /* Store 1 if the result is not empty */
1690 #define SRT_Discard      4  /* Do not save the results anywhere */
1691 
1692 /* The ORDER BY clause is ignored for all of the above */
1693 #define IgnorableOrderby(X) ((X->eDest)<=SRT_Discard)
1694 
1695 #define SRT_Output       5  /* Output each row of result */
1696 #define SRT_Mem          6  /* Store result in a memory cell */
1697 #define SRT_Set          7  /* Store results as keys in an index */
1698 #define SRT_Table        8  /* Store result as data with an automatic rowid */
1699 #define SRT_EphemTab     9  /* Create transient tab and store like SRT_Table */
1700 #define SRT_Coroutine   10  /* Generate a single row of result */
1701 
1702 /*
1703 ** A structure used to customize the behavior of sqlite3Select(). See
1704 ** comments above sqlite3Select() for details.
1705 */
1706 typedef struct SelectDest SelectDest;
1707 struct SelectDest {
1708   u8 eDest;         /* How to dispose of the results */
1709   u8 affinity;      /* Affinity used when eDest==SRT_Set */
1710   int iParm;        /* A parameter used by the eDest disposal method */
1711   int iMem;         /* Base register where results are written */
1712   int nMem;         /* Number of registers allocated */
1713 };
1714 
1715 /*
1716 ** An SQL parser context.  A copy of this structure is passed through
1717 ** the parser and down into all the parser action routine in order to
1718 ** carry around information that is global to the entire parse.
1719 **
1720 ** The structure is divided into two parts.  When the parser and code
1721 ** generate call themselves recursively, the first part of the structure
1722 ** is constant but the second part is reset at the beginning and end of
1723 ** each recursion.
1724 **
1725 ** The nTableLock and aTableLock variables are only used if the shared-cache
1726 ** feature is enabled (if sqlite3Tsd()->useSharedData is true). They are
1727 ** used to store the set of table-locks required by the statement being
1728 ** compiled. Function sqlite3TableLock() is used to add entries to the
1729 ** list.
1730 */
1731 struct Parse {
1732   sqlite3 *db;         /* The main database structure */
1733   int rc;              /* Return code from execution */
1734   char *zErrMsg;       /* An error message */
1735   Vdbe *pVdbe;         /* An engine for executing database bytecode */
1736   u8 colNamesSet;      /* TRUE after OP_ColumnName has been issued to pVdbe */
1737   u8 nameClash;        /* A permanent table name clashes with temp table name */
1738   u8 checkSchema;      /* Causes schema cookie check after an error */
1739   u8 nested;           /* Number of nested calls to the parser/code generator */
1740   u8 parseError;       /* True after a parsing error.  Ticket #1794 */
1741   u8 nTempReg;         /* Number of temporary registers in aTempReg[] */
1742   u8 nTempInUse;       /* Number of aTempReg[] currently checked out */
1743   int aTempReg[8];     /* Holding area for temporary registers */
1744   int nRangeReg;       /* Size of the temporary register block */
1745   int iRangeReg;       /* First register in temporary register block */
1746   int nErr;            /* Number of errors seen */
1747   int nTab;            /* Number of previously allocated VDBE cursors */
1748   int nMem;            /* Number of memory cells used so far */
1749   int nSet;            /* Number of sets used so far */
1750   int ckBase;          /* Base register of data during check constraints */
1751   int disableColCache; /* True to disable adding to column cache */
1752   int nColCache;       /* Number of entries in the column cache */
1753   int iColCache;       /* Next entry of the cache to replace */
1754   struct yColCache {
1755     int iTable;           /* Table cursor number */
1756     int iColumn;          /* Table column number */
1757     char affChange;       /* True if this register has had an affinity change */
1758     int iReg;             /* Register holding value of this column */
1759   } aColCache[10];     /* One for each valid column cache entry */
1760   u32 writeMask;       /* Start a write transaction on these databases */
1761   u32 cookieMask;      /* Bitmask of schema verified databases */
1762   int cookieGoto;      /* Address of OP_Goto to cookie verifier subroutine */
1763   int cookieValue[SQLITE_MAX_ATTACHED+2];  /* Values of cookies to verify */
1764 #ifndef SQLITE_OMIT_SHARED_CACHE
1765   int nTableLock;        /* Number of locks in aTableLock */
1766   TableLock *aTableLock; /* Required table locks for shared-cache mode */
1767 #endif
1768   int regRowid;        /* Register holding rowid of CREATE TABLE entry */
1769   int regRoot;         /* Register holding root page number for new objects */
1770 
1771   /* Above is constant between recursions.  Below is reset before and after
1772   ** each recursion */
1773 
1774   int nVar;            /* Number of '?' variables seen in the SQL so far */
1775   int nVarExpr;        /* Number of used slots in apVarExpr[] */
1776   int nVarExprAlloc;   /* Number of allocated slots in apVarExpr[] */
1777   Expr **apVarExpr;    /* Pointers to :aaa and $aaaa wildcard expressions */
1778   int nAlias;          /* Number of aliased result set columns */
1779   int nAliasAlloc;     /* Number of allocated slots for aAlias[] */
1780   int *aAlias;         /* Register used to hold aliased result */
1781   u8 explain;          /* True if the EXPLAIN flag is found on the query */
1782   Token sErrToken;     /* The token at which the error occurred */
1783   Token sNameToken;    /* Token with unqualified schema object name */
1784   Token sLastToken;    /* The last token parsed */
1785   const char *zSql;    /* All SQL text */
1786   const char *zTail;   /* All SQL text past the last semicolon parsed */
1787   Table *pNewTable;    /* A table being constructed by CREATE TABLE */
1788   Trigger *pNewTrigger;     /* Trigger under construct by a CREATE TRIGGER */
1789   TriggerStack *trigStack;  /* Trigger actions being coded */
1790   const char *zAuthContext; /* The 6th parameter to db->xAuth callbacks */
1791 #ifndef SQLITE_OMIT_VIRTUALTABLE
1792   Token sArg;                /* Complete text of a module argument */
1793   u8 declareVtab;            /* True if inside sqlite3_declare_vtab() */
1794   int nVtabLock;             /* Number of virtual tables to lock */
1795   Table **apVtabLock;        /* Pointer to virtual tables needing locking */
1796 #endif
1797   int nHeight;            /* Expression tree height of current sub-select */
1798   Table *pZombieTab;      /* List of Table objects to delete after code gen */
1799 };
1800 
1801 #ifdef SQLITE_OMIT_VIRTUALTABLE
1802   #define IN_DECLARE_VTAB 0
1803 #else
1804   #define IN_DECLARE_VTAB (pParse->declareVtab)
1805 #endif
1806 
1807 /*
1808 ** An instance of the following structure can be declared on a stack and used
1809 ** to save the Parse.zAuthContext value so that it can be restored later.
1810 */
1811 struct AuthContext {
1812   const char *zAuthContext;   /* Put saved Parse.zAuthContext here */
1813   Parse *pParse;              /* The Parse structure */
1814 };
1815 
1816 /*
1817 ** Bitfield flags for P2 value in OP_Insert and OP_Delete
1818 */
1819 #define OPFLAG_NCHANGE   1    /* Set to update db->nChange */
1820 #define OPFLAG_LASTROWID 2    /* Set to update db->lastRowid */
1821 #define OPFLAG_ISUPDATE  4    /* This OP_Insert is an sql UPDATE */
1822 #define OPFLAG_APPEND    8    /* This is likely to be an append */
1823 
1824 /*
1825  * Each trigger present in the database schema is stored as an instance of
1826  * struct Trigger.
1827  *
1828  * Pointers to instances of struct Trigger are stored in two ways.
1829  * 1. In the "trigHash" hash table (part of the sqlite3* that represents the
1830  *    database). This allows Trigger structures to be retrieved by name.
1831  * 2. All triggers associated with a single table form a linked list, using the
1832  *    pNext member of struct Trigger. A pointer to the first element of the
1833  *    linked list is stored as the "pTrigger" member of the associated
1834  *    struct Table.
1835  *
1836  * The "step_list" member points to the first element of a linked list
1837  * containing the SQL statements specified as the trigger program.
1838  */
1839 struct Trigger {
1840   char *name;             /* The name of the trigger                        */
1841   char *table;            /* The table or view to which the trigger applies */
1842   u8 op;                  /* One of TK_DELETE, TK_UPDATE, TK_INSERT         */
1843   u8 tr_tm;               /* One of TRIGGER_BEFORE, TRIGGER_AFTER */
1844   Expr *pWhen;            /* The WHEN clause of the expression (may be NULL) */
1845   IdList *pColumns;       /* If this is an UPDATE OF <column-list> trigger,
1846                              the <column-list> is stored here */
1847   Token nameToken;        /* Token containing zName. Use during parsing only */
1848   Schema *pSchema;        /* Schema containing the trigger */
1849   Schema *pTabSchema;     /* Schema containing the table */
1850   TriggerStep *step_list; /* Link list of trigger program steps             */
1851   Trigger *pNext;         /* Next trigger associated with the table */
1852 };
1853 
1854 /*
1855 ** A trigger is either a BEFORE or an AFTER trigger.  The following constants
1856 ** determine which.
1857 **
1858 ** If there are multiple triggers, you might of some BEFORE and some AFTER.
1859 ** In that cases, the constants below can be ORed together.
1860 */
1861 #define TRIGGER_BEFORE  1
1862 #define TRIGGER_AFTER   2
1863 
1864 /*
1865  * An instance of struct TriggerStep is used to store a single SQL statement
1866  * that is a part of a trigger-program.
1867  *
1868  * Instances of struct TriggerStep are stored in a singly linked list (linked
1869  * using the "pNext" member) referenced by the "step_list" member of the
1870  * associated struct Trigger instance. The first element of the linked list is
1871  * the first step of the trigger-program.
1872  *
1873  * The "op" member indicates whether this is a "DELETE", "INSERT", "UPDATE" or
1874  * "SELECT" statement. The meanings of the other members is determined by the
1875  * value of "op" as follows:
1876  *
1877  * (op == TK_INSERT)
1878  * orconf    -> stores the ON CONFLICT algorithm
1879  * pSelect   -> If this is an INSERT INTO ... SELECT ... statement, then
1880  *              this stores a pointer to the SELECT statement. Otherwise NULL.
1881  * target    -> A token holding the name of the table to insert into.
1882  * pExprList -> If this is an INSERT INTO ... VALUES ... statement, then
1883  *              this stores values to be inserted. Otherwise NULL.
1884  * pIdList   -> If this is an INSERT INTO ... (<column-names>) VALUES ...
1885  *              statement, then this stores the column-names to be
1886  *              inserted into.
1887  *
1888  * (op == TK_DELETE)
1889  * target    -> A token holding the name of the table to delete from.
1890  * pWhere    -> The WHERE clause of the DELETE statement if one is specified.
1891  *              Otherwise NULL.
1892  *
1893  * (op == TK_UPDATE)
1894  * target    -> A token holding the name of the table to update rows of.
1895  * pWhere    -> The WHERE clause of the UPDATE statement if one is specified.
1896  *              Otherwise NULL.
1897  * pExprList -> A list of the columns to update and the expressions to update
1898  *              them to. See sqlite3Update() documentation of "pChanges"
1899  *              argument.
1900  *
1901  */
1902 struct TriggerStep {
1903   int op;              /* One of TK_DELETE, TK_UPDATE, TK_INSERT, TK_SELECT */
1904   int orconf;          /* OE_Rollback etc. */
1905   Trigger *pTrig;      /* The trigger that this step is a part of */
1906 
1907   Select *pSelect;     /* Valid for SELECT and sometimes
1908                           INSERT steps (when pExprList == 0) */
1909   Token target;        /* Valid for DELETE, UPDATE, INSERT steps */
1910   Expr *pWhere;        /* Valid for DELETE, UPDATE steps */
1911   ExprList *pExprList; /* Valid for UPDATE statements and sometimes
1912                            INSERT steps (when pSelect == 0)         */
1913   IdList *pIdList;     /* Valid for INSERT statements only */
1914   TriggerStep *pNext;  /* Next in the link-list */
1915   TriggerStep *pLast;  /* Last element in link-list. Valid for 1st elem only */
1916 };
1917 
1918 /*
1919  * An instance of struct TriggerStack stores information required during code
1920  * generation of a single trigger program. While the trigger program is being
1921  * coded, its associated TriggerStack instance is pointed to by the
1922  * "pTriggerStack" member of the Parse structure.
1923  *
1924  * The pTab member points to the table that triggers are being coded on. The
1925  * newIdx member contains the index of the vdbe cursor that points at the temp
1926  * table that stores the new.* references. If new.* references are not valid
1927  * for the trigger being coded (for example an ON DELETE trigger), then newIdx
1928  * is set to -1. The oldIdx member is analogous to newIdx, for old.* references.
1929  *
1930  * The ON CONFLICT policy to be used for the trigger program steps is stored
1931  * as the orconf member. If this is OE_Default, then the ON CONFLICT clause
1932  * specified for individual triggers steps is used.
1933  *
1934  * struct TriggerStack has a "pNext" member, to allow linked lists to be
1935  * constructed. When coding nested triggers (triggers fired by other triggers)
1936  * each nested trigger stores its parent trigger's TriggerStack as the "pNext"
1937  * pointer. Once the nested trigger has been coded, the pNext value is restored
1938  * to the pTriggerStack member of the Parse stucture and coding of the parent
1939  * trigger continues.
1940  *
1941  * Before a nested trigger is coded, the linked list pointed to by the
1942  * pTriggerStack is scanned to ensure that the trigger is not about to be coded
1943  * recursively. If this condition is detected, the nested trigger is not coded.
1944  */
1945 struct TriggerStack {
1946   Table *pTab;         /* Table that triggers are currently being coded on */
1947   int newIdx;          /* Index of vdbe cursor to "new" temp table */
1948   int oldIdx;          /* Index of vdbe cursor to "old" temp table */
1949   u32 newColMask;
1950   u32 oldColMask;
1951   int orconf;          /* Current orconf policy */
1952   int ignoreJump;      /* where to jump to for a RAISE(IGNORE) */
1953   Trigger *pTrigger;   /* The trigger currently being coded */
1954   TriggerStack *pNext; /* Next trigger down on the trigger stack */
1955 };
1956 
1957 /*
1958 ** The following structure contains information used by the sqliteFix...
1959 ** routines as they walk the parse tree to make database references
1960 ** explicit.
1961 */
1962 typedef struct DbFixer DbFixer;
1963 struct DbFixer {
1964   Parse *pParse;      /* The parsing context.  Error messages written here */
1965   const char *zDb;    /* Make sure all objects are contained in this database */
1966   const char *zType;  /* Type of the container - used for error messages */
1967   const Token *pName; /* Name of the container - used for error messages */
1968 };
1969 
1970 /*
1971 ** An objected used to accumulate the text of a string where we
1972 ** do not necessarily know how big the string will be in the end.
1973 */
1974 struct StrAccum {
1975   sqlite3 *db;         /* Optional database for lookaside.  Can be NULL */
1976   char *zBase;         /* A base allocation.  Not from malloc. */
1977   char *zText;         /* The string collected so far */
1978   int  nChar;          /* Length of the string so far */
1979   int  nAlloc;         /* Amount of space allocated in zText */
1980   int  mxAlloc;        /* Maximum allowed string length */
1981   u8   mallocFailed;   /* Becomes true if any memory allocation fails */
1982   u8   useMalloc;      /* True if zText is enlargeable using realloc */
1983   u8   tooBig;         /* Becomes true if string size exceeds limits */
1984 };
1985 
1986 /*
1987 ** A pointer to this structure is used to communicate information
1988 ** from sqlite3Init and OP_ParseSchema into the sqlite3InitCallback.
1989 */
1990 typedef struct {
1991   sqlite3 *db;        /* The database being initialized */
1992   int iDb;            /* 0 for main database.  1 for TEMP, 2.. for ATTACHed */
1993   char **pzErrMsg;    /* Error message stored here */
1994   int rc;             /* Result code stored here */
1995 } InitData;
1996 
1997 /*
1998 ** Structure containing global configuration data for the SQLite library.
1999 **
2000 ** This structure also contains some state information.
2001 */
2002 struct Sqlite3Config {
2003   int bMemstat;                     /* True to enable memory status */
2004   int bCoreMutex;                   /* True to enable core mutexing */
2005   int bFullMutex;                   /* True to enable full mutexing */
2006   int mxStrlen;                     /* Maximum string length */
2007   int szLookaside;                  /* Default lookaside buffer size */
2008   int nLookaside;                   /* Default lookaside buffer count */
2009   sqlite3_mem_methods m;            /* Low-level memory allocation interface */
2010   sqlite3_mutex_methods mutex;      /* Low-level mutex interface */
2011   sqlite3_pcache_methods pcache;    /* Low-level page-cache interface */
2012   void *pHeap;                      /* Heap storage space */
2013   int nHeap;                        /* Size of pHeap[] */
2014   int mnReq, mxReq;                 /* Min and max heap requests sizes */
2015   void *pScratch;                   /* Scratch memory */
2016   int szScratch;                    /* Size of each scratch buffer */
2017   int nScratch;                     /* Number of scratch buffers */
2018   void *pPage;                      /* Page cache memory */
2019   int szPage;                       /* Size of each page in pPage[] */
2020   int nPage;                        /* Number of pages in pPage[] */
2021   int mxParserStack;                /* maximum depth of the parser stack */
2022   int sharedCacheEnabled;           /* true if shared-cache mode enabled */
2023   /* The above might be initialized to non-zero.  The following need to always
2024   ** initially be zero, however. */
2025   int isInit;                       /* True after initialization has finished */
2026   int inProgress;                   /* True while initialization in progress */
2027   int isMallocInit;                 /* True after malloc is initialized */
2028   sqlite3_mutex *pInitMutex;        /* Mutex used by sqlite3_initialize() */
2029   int nRefInitMutex;                /* Number of users of pInitMutex */
2030 };
2031 
2032 /*
2033 ** Context pointer passed down through the tree-walk.
2034 */
2035 struct Walker {
2036   int (*xExprCallback)(Walker*, Expr*);     /* Callback for expressions */
2037   int (*xSelectCallback)(Walker*,Select*);  /* Callback for SELECTs */
2038   Parse *pParse;                            /* Parser context.  */
2039   union {                                   /* Extra data for callback */
2040     NameContext *pNC;                          /* Naming context */
2041     int i;                                     /* Integer value */
2042   } u;
2043 };
2044 
2045 /* Forward declarations */
2046 int sqlite3WalkExpr(Walker*, Expr*);
2047 int sqlite3WalkExprList(Walker*, ExprList*);
2048 int sqlite3WalkSelect(Walker*, Select*);
2049 int sqlite3WalkSelectExpr(Walker*, Select*);
2050 int sqlite3WalkSelectFrom(Walker*, Select*);
2051 
2052 /*
2053 ** Return code from the parse-tree walking primitives and their
2054 ** callbacks.
2055 */
2056 #define WRC_Continue    0   /* Continue down into children */
2057 #define WRC_Prune       1   /* Omit children but continue walking siblings */
2058 #define WRC_Abort       2   /* Abandon the tree walk */
2059 
2060 /*
2061 ** Assuming zIn points to the first byte of a UTF-8 character,
2062 ** advance zIn to point to the first byte of the next UTF-8 character.
2063 */
2064 #define SQLITE_SKIP_UTF8(zIn) {                        \
2065   if( (*(zIn++))>=0xc0 ){                              \
2066     while( (*zIn & 0xc0)==0x80 ){ zIn++; }             \
2067   }                                                    \
2068 }
2069 
2070 /*
2071 ** The SQLITE_CORRUPT_BKPT macro can be either a constant (for production
2072 ** builds) or a function call (for debugging).  If it is a function call,
2073 ** it allows the operator to set a breakpoint at the spot where database
2074 ** corruption is first detected.
2075 */
2076 #ifdef SQLITE_DEBUG
2077   int sqlite3Corrupt(void);
2078 # define SQLITE_CORRUPT_BKPT sqlite3Corrupt()
2079 #else
2080 # define SQLITE_CORRUPT_BKPT SQLITE_CORRUPT
2081 #endif
2082 
2083 /*
2084 ** Internal function prototypes
2085 */
2086 int sqlite3StrICmp(const char *, const char *);
2087 int sqlite3StrNICmp(const char *, const char *, int);
2088 int sqlite3IsNumber(const char*, int*, u8);
2089 int sqlite3Strlen(sqlite3*, const char*);
2090 int sqlite3Strlen30(const char*);
2091 
2092 int sqlite3MallocInit(void);
2093 void sqlite3MallocEnd(void);
2094 void *sqlite3Malloc(int);
2095 void *sqlite3MallocZero(int);
2096 void *sqlite3DbMallocZero(sqlite3*, int);
2097 void *sqlite3DbMallocRaw(sqlite3*, int);
2098 char *sqlite3DbStrDup(sqlite3*,const char*);
2099 char *sqlite3DbStrNDup(sqlite3*,const char*, int);
2100 void *sqlite3Realloc(void*, int);
2101 void *sqlite3DbReallocOrFree(sqlite3 *, void *, int);
2102 void *sqlite3DbRealloc(sqlite3 *, void *, int);
2103 void sqlite3DbFree(sqlite3*, void*);
2104 int sqlite3MallocSize(void*);
2105 int sqlite3DbMallocSize(sqlite3*, void*);
2106 void *sqlite3ScratchMalloc(int);
2107 void sqlite3ScratchFree(void*);
2108 void *sqlite3PageMalloc(int);
2109 void sqlite3PageFree(void*);
2110 void sqlite3MemSetDefault(void);
2111 void sqlite3BenignMallocHooks(void (*)(void), void (*)(void));
2112 int sqlite3MemoryAlarm(void (*)(void*, sqlite3_int64, int), void*, sqlite3_int64);
2113 
2114 #ifdef SQLITE_ENABLE_MEMSYS3
2115 const sqlite3_mem_methods *sqlite3MemGetMemsys3(void);
2116 #endif
2117 #ifdef SQLITE_ENABLE_MEMSYS5
2118 const sqlite3_mem_methods *sqlite3MemGetMemsys5(void);
2119 #endif
2120 
2121 
2122 #ifndef SQLITE_MUTEX_OMIT
2123   sqlite3_mutex_methods *sqlite3DefaultMutex(void);
2124   sqlite3_mutex *sqlite3MutexAlloc(int);
2125   int sqlite3MutexInit(void);
2126   int sqlite3MutexEnd(void);
2127 #endif
2128 
2129 int sqlite3StatusValue(int);
2130 void sqlite3StatusAdd(int, int);
2131 void sqlite3StatusSet(int, int);
2132 
2133 int sqlite3IsNaN(double);
2134 
2135 void sqlite3VXPrintf(StrAccum*, int, const char*, va_list);
2136 char *sqlite3MPrintf(sqlite3*,const char*, ...);
2137 char *sqlite3VMPrintf(sqlite3*,const char*, va_list);
2138 char *sqlite3MAppendf(sqlite3*,char*,const char*,...);
2139 #if defined(SQLITE_TEST) || defined(SQLITE_DEBUG)
2140   void sqlite3DebugPrintf(const char*, ...);
2141 #endif
2142 #if defined(SQLITE_TEST)
2143   void *sqlite3TestTextToPtr(const char*);
2144 #endif
2145 void sqlite3SetString(char **, sqlite3*, const char*, ...);
2146 void sqlite3ErrorMsg(Parse*, const char*, ...);
2147 void sqlite3ErrorClear(Parse*);
2148 void sqlite3Dequote(char*);
2149 void sqlite3DequoteExpr(sqlite3*, Expr*);
2150 int sqlite3KeywordCode(const unsigned char*, int);
2151 int sqlite3RunParser(Parse*, const char*, char **);
2152 void sqlite3FinishCoding(Parse*);
2153 int sqlite3GetTempReg(Parse*);
2154 void sqlite3ReleaseTempReg(Parse*,int);
2155 int sqlite3GetTempRange(Parse*,int);
2156 void sqlite3ReleaseTempRange(Parse*,int,int);
2157 Expr *sqlite3Expr(sqlite3*, int, Expr*, Expr*, const Token*);
2158 Expr *sqlite3PExpr(Parse*, int, Expr*, Expr*, const Token*);
2159 Expr *sqlite3RegisterExpr(Parse*,Token*);
2160 Expr *sqlite3ExprAnd(sqlite3*,Expr*, Expr*);
2161 void sqlite3ExprSpan(Expr*,Token*,Token*);
2162 Expr *sqlite3ExprFunction(Parse*,ExprList*, Token*);
2163 void sqlite3ExprAssignVarNumber(Parse*, Expr*);
2164 void sqlite3ExprClear(sqlite3*, Expr*);
2165 void sqlite3ExprDelete(sqlite3*, Expr*);
2166 ExprList *sqlite3ExprListAppend(Parse*,ExprList*,Expr*,Token*);
2167 void sqlite3ExprListDelete(sqlite3*, ExprList*);
2168 int sqlite3Init(sqlite3*, char**);
2169 int sqlite3InitCallback(void*, int, char**, char**);
2170 void sqlite3Pragma(Parse*,Token*,Token*,Token*,int);
2171 void sqlite3ResetInternalSchema(sqlite3*, int);
2172 void sqlite3BeginParse(Parse*,int);
2173 void sqlite3CommitInternalChanges(sqlite3*);
2174 Table *sqlite3ResultSetOfSelect(Parse*,Select*);
2175 void sqlite3OpenMasterTable(Parse *, int);
2176 void sqlite3StartTable(Parse*,Token*,Token*,int,int,int,int);
2177 void sqlite3AddColumn(Parse*,Token*);
2178 void sqlite3AddNotNull(Parse*, int);
2179 void sqlite3AddPrimaryKey(Parse*, ExprList*, int, int, int);
2180 void sqlite3AddCheckConstraint(Parse*, Expr*);
2181 void sqlite3AddColumnType(Parse*,Token*);
2182 void sqlite3AddDefaultValue(Parse*,Expr*);
2183 void sqlite3AddCollateType(Parse*, Token*);
2184 void sqlite3EndTable(Parse*,Token*,Token*,Select*);
2185 
2186 Bitvec *sqlite3BitvecCreate(u32);
2187 int sqlite3BitvecTest(Bitvec*, u32);
2188 int sqlite3BitvecSet(Bitvec*, u32);
2189 void sqlite3BitvecClear(Bitvec*, u32);
2190 void sqlite3BitvecDestroy(Bitvec*);
2191 int sqlite3BitvecBuiltinTest(int,int*);
2192 
2193 RowSet *sqlite3RowSetInit(sqlite3*, void*, unsigned int);
2194 void sqlite3RowSetClear(RowSet*);
2195 void sqlite3RowSetInsert(RowSet*, i64);
2196 int sqlite3RowSetNext(RowSet*, i64*);
2197 
2198 void sqlite3CreateView(Parse*,Token*,Token*,Token*,Select*,int,int);
2199 
2200 #if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE)
2201   int sqlite3ViewGetColumnNames(Parse*,Table*);
2202 #else
2203 # define sqlite3ViewGetColumnNames(A,B) 0
2204 #endif
2205 
2206 void sqlite3DropTable(Parse*, SrcList*, int, int);
2207 void sqlite3DeleteTable(Table*);
2208 void sqlite3Insert(Parse*, SrcList*, ExprList*, Select*, IdList*, int);
2209 void *sqlite3ArrayAllocate(sqlite3*,void*,int,int,int*,int*,int*);
2210 IdList *sqlite3IdListAppend(sqlite3*, IdList*, Token*);
2211 int sqlite3IdListIndex(IdList*,const char*);
2212 SrcList *sqlite3SrcListEnlarge(sqlite3*, SrcList*, int, int);
2213 SrcList *sqlite3SrcListAppend(sqlite3*, SrcList*, Token*, Token*);
2214 SrcList *sqlite3SrcListAppendFromTerm(Parse*, SrcList*, Token*, Token*,
2215                                       Token*, Select*, Expr*, IdList*);
2216 void sqlite3SrcListIndexedBy(Parse *, SrcList *, Token *);
2217 int sqlite3IndexedByLookup(Parse *, struct SrcList_item *);
2218 void sqlite3SrcListShiftJoinType(SrcList*);
2219 void sqlite3SrcListAssignCursors(Parse*, SrcList*);
2220 void sqlite3IdListDelete(sqlite3*, IdList*);
2221 void sqlite3SrcListDelete(sqlite3*, SrcList*);
2222 void sqlite3CreateIndex(Parse*,Token*,Token*,SrcList*,ExprList*,int,Token*,
2223                         Token*, int, int);
2224 void sqlite3DropIndex(Parse*, SrcList*, int);
2225 int sqlite3Select(Parse*, Select*, SelectDest*);
2226 Select *sqlite3SelectNew(Parse*,ExprList*,SrcList*,Expr*,ExprList*,
2227                          Expr*,ExprList*,int,Expr*,Expr*);
2228 void sqlite3SelectDelete(sqlite3*, Select*);
2229 Table *sqlite3SrcListLookup(Parse*, SrcList*);
2230 int sqlite3IsReadOnly(Parse*, Table*, int);
2231 void sqlite3OpenTable(Parse*, int iCur, int iDb, Table*, int);
2232 #if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY)
2233 Expr *sqlite3LimitWhere(Parse *, SrcList *, Expr *, ExprList *, Expr *, Expr *, char *);
2234 #endif
2235 void sqlite3DeleteFrom(Parse*, SrcList*, Expr*);
2236 void sqlite3Update(Parse*, SrcList*, ExprList*, Expr*, int);
2237 WhereInfo *sqlite3WhereBegin(Parse*, SrcList*, Expr*, ExprList**, u8);
2238 void sqlite3WhereEnd(WhereInfo*);
2239 int sqlite3ExprCodeGetColumn(Parse*, Table*, int, int, int, int);
2240 void sqlite3ExprCodeMove(Parse*, int, int, int);
2241 void sqlite3ExprCodeCopy(Parse*, int, int, int);
2242 void sqlite3ExprClearColumnCache(Parse*, int);
2243 void sqlite3ExprCacheAffinityChange(Parse*, int, int);
2244 int sqlite3ExprWritableRegister(Parse*,int,int);
2245 void sqlite3ExprHardCopy(Parse*,int,int);
2246 int sqlite3ExprCode(Parse*, Expr*, int);
2247 int sqlite3ExprCodeTemp(Parse*, Expr*, int*);
2248 int sqlite3ExprCodeTarget(Parse*, Expr*, int);
2249 int sqlite3ExprCodeAndCache(Parse*, Expr*, int);
2250 void sqlite3ExprCodeConstants(Parse*, Expr*);
2251 int sqlite3ExprCodeExprList(Parse*, ExprList*, int, int);
2252 void sqlite3ExprIfTrue(Parse*, Expr*, int, int);
2253 void sqlite3ExprIfFalse(Parse*, Expr*, int, int);
2254 Table *sqlite3FindTable(sqlite3*,const char*, const char*);
2255 Table *sqlite3LocateTable(Parse*,int isView,const char*, const char*);
2256 Index *sqlite3FindIndex(sqlite3*,const char*, const char*);
2257 void sqlite3UnlinkAndDeleteTable(sqlite3*,int,const char*);
2258 void sqlite3UnlinkAndDeleteIndex(sqlite3*,int,const char*);
2259 void sqlite3Vacuum(Parse*);
2260 int sqlite3RunVacuum(char**, sqlite3*);
2261 char *sqlite3NameFromToken(sqlite3*, Token*);
2262 int sqlite3ExprCompare(Expr*, Expr*);
2263 void sqlite3ExprAnalyzeAggregates(NameContext*, Expr*);
2264 void sqlite3ExprAnalyzeAggList(NameContext*,ExprList*);
2265 Vdbe *sqlite3GetVdbe(Parse*);
2266 Expr *sqlite3CreateIdExpr(Parse *, const char*);
2267 void sqlite3PrngSaveState(void);
2268 void sqlite3PrngRestoreState(void);
2269 void sqlite3PrngResetState(void);
2270 void sqlite3RollbackAll(sqlite3*);
2271 void sqlite3CodeVerifySchema(Parse*, int);
2272 void sqlite3BeginTransaction(Parse*, int);
2273 void sqlite3CommitTransaction(Parse*);
2274 void sqlite3RollbackTransaction(Parse*);
2275 void sqlite3Savepoint(Parse*, int, Token*);
2276 void sqlite3CloseSavepoints(sqlite3 *);
2277 int sqlite3ExprIsConstant(Expr*);
2278 int sqlite3ExprIsConstantNotJoin(Expr*);
2279 int sqlite3ExprIsConstantOrFunction(Expr*);
2280 int sqlite3ExprIsInteger(Expr*, int*);
2281 int sqlite3IsRowid(const char*);
2282 void sqlite3GenerateRowDelete(Parse*, Table*, int, int, int);
2283 void sqlite3GenerateRowIndexDelete(Parse*, Table*, int, int*);
2284 int sqlite3GenerateIndexKey(Parse*, Index*, int, int, int);
2285 void sqlite3GenerateConstraintChecks(Parse*,Table*,int,int,
2286                                      int*,int,int,int,int);
2287 void sqlite3CompleteInsertion(Parse*, Table*, int, int, int*, int, int, int);
2288 int sqlite3OpenTableAndIndices(Parse*, Table*, int, int);
2289 void sqlite3BeginWriteOperation(Parse*, int, int);
2290 Expr *sqlite3ExprDup(sqlite3*,Expr*);
2291 void sqlite3TokenCopy(sqlite3*,Token*, Token*);
2292 ExprList *sqlite3ExprListDup(sqlite3*,ExprList*);
2293 SrcList *sqlite3SrcListDup(sqlite3*,SrcList*);
2294 IdList *sqlite3IdListDup(sqlite3*,IdList*);
2295 Select *sqlite3SelectDup(sqlite3*,Select*);
2296 void sqlite3FuncDefInsert(FuncDefHash*, FuncDef*);
2297 FuncDef *sqlite3FindFunction(sqlite3*,const char*,int,int,u8,int);
2298 void sqlite3RegisterBuiltinFunctions(sqlite3*);
2299 void sqlite3RegisterDateTimeFunctions(void);
2300 void sqlite3RegisterGlobalFunctions(void);
2301 #ifdef SQLITE_DEBUG
2302   int sqlite3SafetyOn(sqlite3*);
2303   int sqlite3SafetyOff(sqlite3*);
2304 #else
2305 # define sqlite3SafetyOn(A) 0
2306 # define sqlite3SafetyOff(A) 0
2307 #endif
2308 int sqlite3SafetyCheckOk(sqlite3*);
2309 int sqlite3SafetyCheckSickOrOk(sqlite3*);
2310 void sqlite3ChangeCookie(Parse*, int);
2311 
2312 #if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
2313 void sqlite3MaterializeView(Parse*, Table*, Expr*, int);
2314 #endif
2315 
2316 #ifndef SQLITE_OMIT_TRIGGER
2317   void sqlite3BeginTrigger(Parse*, Token*,Token*,int,int,IdList*,SrcList*,
2318                            Expr*,int, int);
2319   void sqlite3FinishTrigger(Parse*, TriggerStep*, Token*);
2320   void sqlite3DropTrigger(Parse*, SrcList*, int);
2321   void sqlite3DropTriggerPtr(Parse*, Trigger*);
2322   int sqlite3TriggersExist(Table*, int, ExprList*);
2323   int sqlite3CodeRowTrigger(Parse*, int, ExprList*, int, Table *, int, int,
2324                            int, int, u32*, u32*);
2325   void sqliteViewTriggers(Parse*, Table*, Expr*, int, ExprList*);
2326   void sqlite3DeleteTriggerStep(sqlite3*, TriggerStep*);
2327   TriggerStep *sqlite3TriggerSelectStep(sqlite3*,Select*);
2328   TriggerStep *sqlite3TriggerInsertStep(sqlite3*,Token*, IdList*,
2329                                         ExprList*,Select*,int);
2330   TriggerStep *sqlite3TriggerUpdateStep(sqlite3*,Token*,ExprList*, Expr*, int);
2331   TriggerStep *sqlite3TriggerDeleteStep(sqlite3*,Token*, Expr*);
2332   void sqlite3DeleteTrigger(sqlite3*, Trigger*);
2333   void sqlite3UnlinkAndDeleteTrigger(sqlite3*,int,const char*);
2334 #else
2335 # define sqlite3TriggersExist(B,C,D,E,F) 0
2336 # define sqlite3DeleteTrigger(A,B)
2337 # define sqlite3DropTriggerPtr(A,B)
2338 # define sqlite3UnlinkAndDeleteTrigger(A,B,C)
2339 # define sqlite3CodeRowTrigger(A,B,C,D,E,F,G,H,I,J,K) 0
2340 #endif
2341 
2342 int sqlite3JoinType(Parse*, Token*, Token*, Token*);
2343 void sqlite3CreateForeignKey(Parse*, ExprList*, Token*, ExprList*, int);
2344 void sqlite3DeferForeignKey(Parse*, int);
2345 #ifndef SQLITE_OMIT_AUTHORIZATION
2346   void sqlite3AuthRead(Parse*,Expr*,Schema*,SrcList*);
2347   int sqlite3AuthCheck(Parse*,int, const char*, const char*, const char*);
2348   void sqlite3AuthContextPush(Parse*, AuthContext*, const char*);
2349   void sqlite3AuthContextPop(AuthContext*);
2350 #else
2351 # define sqlite3AuthRead(a,b,c,d)
2352 # define sqlite3AuthCheck(a,b,c,d,e)    SQLITE_OK
2353 # define sqlite3AuthContextPush(a,b,c)
2354 # define sqlite3AuthContextPop(a)  ((void)(a))
2355 #endif
2356 void sqlite3Attach(Parse*, Expr*, Expr*, Expr*);
2357 void sqlite3Detach(Parse*, Expr*);
2358 int sqlite3BtreeFactory(const sqlite3 *db, const char *zFilename,
2359                        int omitJournal, int nCache, int flags, Btree **ppBtree);
2360 int sqlite3FixInit(DbFixer*, Parse*, int, const char*, const Token*);
2361 int sqlite3FixSrcList(DbFixer*, SrcList*);
2362 int sqlite3FixSelect(DbFixer*, Select*);
2363 int sqlite3FixExpr(DbFixer*, Expr*);
2364 int sqlite3FixExprList(DbFixer*, ExprList*);
2365 int sqlite3FixTriggerStep(DbFixer*, TriggerStep*);
2366 int sqlite3AtoF(const char *z, double*);
2367 int sqlite3GetInt32(const char *, int*);
2368 int sqlite3FitsIn64Bits(const char *, int);
2369 int sqlite3Utf16ByteLen(const void *pData, int nChar);
2370 int sqlite3Utf8CharLen(const char *pData, int nByte);
2371 int sqlite3Utf8Read(const u8*, const u8*, const u8**);
2372 
2373 /*
2374 ** Routines to read and write variable-length integers.  These used to
2375 ** be defined locally, but now we use the varint routines in the util.c
2376 ** file.  Code should use the MACRO forms below, as the Varint32 versions
2377 ** are coded to assume the single byte case is already handled (which
2378 ** the MACRO form does).
2379 */
2380 int sqlite3PutVarint(unsigned char*, u64);
2381 int sqlite3PutVarint32(unsigned char*, u32);
2382 u8 sqlite3GetVarint(const unsigned char *, u64 *);
2383 u8 sqlite3GetVarint32(const unsigned char *, u32 *);
2384 int sqlite3VarintLen(u64 v);
2385 
2386 /*
2387 ** The header of a record consists of a sequence variable-length integers.
2388 ** These integers are almost always small and are encoded as a single byte.
2389 ** The following macros take advantage this fact to provide a fast encode
2390 ** and decode of the integers in a record header.  It is faster for the common
2391 ** case where the integer is a single byte.  It is a little slower when the
2392 ** integer is two or more bytes.  But overall it is faster.
2393 **
2394 ** The following expressions are equivalent:
2395 **
2396 **     x = sqlite3GetVarint32( A, &B );
2397 **     x = sqlite3PutVarint32( A, B );
2398 **
2399 **     x = getVarint32( A, B );
2400 **     x = putVarint32( A, B );
2401 **
2402 */
2403 #define getVarint32(A,B)  (u8)((*(A)<(u8)0x80) ? ((B) = (u32)*(A)),1 : sqlite3GetVarint32((A), (u32 *)&(B)))
2404 #define putVarint32(A,B)  (u8)(((u32)(B)<(u32)0x80) ? (*(A) = (unsigned char)(B)),1 : sqlite3PutVarint32((A), (B)))
2405 #define getVarint    sqlite3GetVarint
2406 #define putVarint    sqlite3PutVarint
2407 
2408 
2409 void sqlite3IndexAffinityStr(Vdbe *, Index *);
2410 void sqlite3TableAffinityStr(Vdbe *, Table *);
2411 char sqlite3CompareAffinity(Expr *pExpr, char aff2);
2412 int sqlite3IndexAffinityOk(Expr *pExpr, char idx_affinity);
2413 char sqlite3ExprAffinity(Expr *pExpr);
2414 int sqlite3Atoi64(const char*, i64*);
2415 void sqlite3Error(sqlite3*, int, const char*,...);
2416 void *sqlite3HexToBlob(sqlite3*, const char *z, int n);
2417 int sqlite3TwoPartName(Parse *, Token *, Token *, Token **);
2418 const char *sqlite3ErrStr(int);
2419 int sqlite3ReadSchema(Parse *pParse);
2420 CollSeq *sqlite3FindCollSeq(sqlite3*,u8 enc, const char *,int,int);
2421 CollSeq *sqlite3LocateCollSeq(Parse *pParse, const char *zName, int nName);
2422 CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr);
2423 Expr *sqlite3ExprSetColl(Parse *pParse, Expr *, Token *);
2424 int sqlite3CheckCollSeq(Parse *, CollSeq *);
2425 int sqlite3CheckObjectName(Parse *, const char *);
2426 void sqlite3VdbeSetChanges(sqlite3 *, int);
2427 
2428 const void *sqlite3ValueText(sqlite3_value*, u8);
2429 int sqlite3ValueBytes(sqlite3_value*, u8);
2430 void sqlite3ValueSetStr(sqlite3_value*, int, const void *,u8,
2431                         void(*)(void*));
2432 void sqlite3ValueFree(sqlite3_value*);
2433 sqlite3_value *sqlite3ValueNew(sqlite3 *);
2434 char *sqlite3Utf16to8(sqlite3 *, const void*, int);
2435 int sqlite3ValueFromExpr(sqlite3 *, Expr *, u8, u8, sqlite3_value **);
2436 void sqlite3ValueApplyAffinity(sqlite3_value *, u8, u8);
2437 #ifndef SQLITE_AMALGAMATION
2438 extern const unsigned char sqlite3UpperToLower[];
2439 extern SQLITE_WSD struct Sqlite3Config sqlite3Config;
2440 extern SQLITE_WSD FuncDefHash sqlite3GlobalFunctions;
2441 #endif
2442 void sqlite3RootPageMoved(Db*, int, int);
2443 void sqlite3Reindex(Parse*, Token*, Token*);
2444 void sqlite3AlterFunctions(sqlite3*);
2445 void sqlite3AlterRenameTable(Parse*, SrcList*, Token*);
2446 int sqlite3GetToken(const unsigned char *, int *);
2447 void sqlite3NestedParse(Parse*, const char*, ...);
2448 void sqlite3ExpirePreparedStatements(sqlite3*);
2449 void sqlite3CodeSubselect(Parse *, Expr *, int, int);
2450 void sqlite3SelectPrep(Parse*, Select*, NameContext*);
2451 int sqlite3ResolveExprNames(NameContext*, Expr*);
2452 void sqlite3ResolveSelectNames(Parse*, Select*, NameContext*);
2453 int sqlite3ResolveOrderGroupBy(Parse*, Select*, ExprList*, const char*);
2454 void sqlite3ColumnDefault(Vdbe *, Table *, int);
2455 void sqlite3AlterFinishAddColumn(Parse *, Token *);
2456 void sqlite3AlterBeginAddColumn(Parse *, SrcList *);
2457 CollSeq *sqlite3GetCollSeq(sqlite3*, CollSeq *, const char *, int);
2458 char sqlite3AffinityType(const Token*);
2459 void sqlite3Analyze(Parse*, Token*, Token*);
2460 int sqlite3InvokeBusyHandler(BusyHandler*);
2461 int sqlite3FindDb(sqlite3*, Token*);
2462 int sqlite3AnalysisLoad(sqlite3*,int iDB);
2463 void sqlite3DefaultRowEst(Index*);
2464 void sqlite3RegisterLikeFunctions(sqlite3*, int);
2465 int sqlite3IsLikeFunction(sqlite3*,Expr*,int*,char*);
2466 void sqlite3MinimumFileFormat(Parse*, int, int);
2467 void sqlite3SchemaFree(void *);
2468 Schema *sqlite3SchemaGet(sqlite3 *, Btree *);
2469 int sqlite3SchemaToIndex(sqlite3 *db, Schema *);
2470 KeyInfo *sqlite3IndexKeyinfo(Parse *, Index *);
2471 int sqlite3CreateFunc(sqlite3 *, const char *, int, int, void *,
2472   void (*)(sqlite3_context*,int,sqlite3_value **),
2473   void (*)(sqlite3_context*,int,sqlite3_value **), void (*)(sqlite3_context*));
2474 int sqlite3ApiExit(sqlite3 *db, int);
2475 int sqlite3OpenTempDatabase(Parse *);
2476 
2477 void sqlite3StrAccumInit(StrAccum*, char*, int, int);
2478 void sqlite3StrAccumAppend(StrAccum*,const char*,int);
2479 char *sqlite3StrAccumFinish(StrAccum*);
2480 void sqlite3StrAccumReset(StrAccum*);
2481 void sqlite3SelectDestInit(SelectDest*,int,int);
2482 
2483 /*
2484 ** The interface to the LEMON-generated parser
2485 */
2486 void *sqlite3ParserAlloc(void*(*)(size_t));
2487 void sqlite3ParserFree(void*, void(*)(void*));
2488 void sqlite3Parser(void*, int, Token, Parse*);
2489 #ifdef YYTRACKMAXSTACKDEPTH
2490   int sqlite3ParserStackPeak(void*);
2491 #endif
2492 
2493 int sqlite3AutoLoadExtensions(sqlite3*);
2494 #ifndef SQLITE_OMIT_LOAD_EXTENSION
2495   void sqlite3CloseExtensions(sqlite3*);
2496 #else
2497 # define sqlite3CloseExtensions(X)
2498 #endif
2499 
2500 #ifndef SQLITE_OMIT_SHARED_CACHE
2501   void sqlite3TableLock(Parse *, int, int, u8, const char *);
2502 #else
2503   #define sqlite3TableLock(v,w,x,y,z)
2504 #endif
2505 
2506 #ifdef SQLITE_TEST
2507   int sqlite3Utf8To8(unsigned char*);
2508 #endif
2509 
2510 #ifdef SQLITE_OMIT_VIRTUALTABLE
2511 #  define sqlite3VtabClear(X)
2512 #  define sqlite3VtabSync(X,Y) SQLITE_OK
2513 #  define sqlite3VtabRollback(X)
2514 #  define sqlite3VtabCommit(X)
2515 #  define sqlite3VtabInSync(db) 0
2516 #else
2517    void sqlite3VtabClear(Table*);
2518    int sqlite3VtabSync(sqlite3 *db, char **);
2519    int sqlite3VtabRollback(sqlite3 *db);
2520    int sqlite3VtabCommit(sqlite3 *db);
2521 #  define sqlite3VtabInSync(db) ((db)->nVTrans>0 && (db)->aVTrans==0)
2522 #endif
2523 void sqlite3VtabMakeWritable(Parse*,Table*);
2524 void sqlite3VtabLock(sqlite3_vtab*);
2525 void sqlite3VtabUnlock(sqlite3*, sqlite3_vtab*);
2526 void sqlite3VtabBeginParse(Parse*, Token*, Token*, Token*);
2527 void sqlite3VtabFinishParse(Parse*, Token*);
2528 void sqlite3VtabArgInit(Parse*);
2529 void sqlite3VtabArgExtend(Parse*, Token*);
2530 int sqlite3VtabCallCreate(sqlite3*, int, const char *, char **);
2531 int sqlite3VtabCallConnect(Parse*, Table*);
2532 int sqlite3VtabCallDestroy(sqlite3*, int, const char *);
2533 int sqlite3VtabBegin(sqlite3 *, sqlite3_vtab *);
2534 FuncDef *sqlite3VtabOverloadFunction(sqlite3 *,FuncDef*, int nArg, Expr*);
2535 void sqlite3InvalidFunction(sqlite3_context*,int,sqlite3_value**);
2536 int sqlite3TransferBindings(sqlite3_stmt *, sqlite3_stmt *);
2537 int sqlite3Reprepare(Vdbe*);
2538 void sqlite3ExprListCheckLength(Parse*, ExprList*, const char*);
2539 CollSeq *sqlite3BinaryCompareCollSeq(Parse *, Expr *, Expr *);
2540 
2541 
2542 /*
2543 ** Available fault injectors.  Should be numbered beginning with 0.
2544 */
2545 #define SQLITE_FAULTINJECTOR_MALLOC     0
2546 #define SQLITE_FAULTINJECTOR_COUNT      1
2547 
2548 /*
2549 ** The interface to the code in fault.c used for identifying "benign"
2550 ** malloc failures. This is only present if SQLITE_OMIT_BUILTIN_TEST
2551 ** is not defined.
2552 */
2553 #ifndef SQLITE_OMIT_BUILTIN_TEST
2554   void sqlite3BeginBenignMalloc(void);
2555   void sqlite3EndBenignMalloc(void);
2556 #else
2557   #define sqlite3BeginBenignMalloc()
2558   #define sqlite3EndBenignMalloc()
2559 #endif
2560 
2561 #define IN_INDEX_ROWID           1
2562 #define IN_INDEX_EPH             2
2563 #define IN_INDEX_INDEX           3
2564 int sqlite3FindInIndex(Parse *, Expr *, int*);
2565 
2566 #ifdef SQLITE_ENABLE_ATOMIC_WRITE
2567   int sqlite3JournalOpen(sqlite3_vfs *, const char *, sqlite3_file *, int, int);
2568   int sqlite3JournalSize(sqlite3_vfs *);
2569   int sqlite3JournalCreate(sqlite3_file *);
2570 #else
2571   #define sqlite3JournalSize(pVfs) ((pVfs)->szOsFile)
2572 #endif
2573 
2574 void sqlite3MemJournalOpen(sqlite3_file *);
2575 int sqlite3MemJournalSize();
2576 int sqlite3IsMemJournal(sqlite3_file *);
2577 
2578 #if SQLITE_MAX_EXPR_DEPTH>0
2579   void sqlite3ExprSetHeight(Parse *pParse, Expr *p);
2580   int sqlite3SelectExprHeight(Select *);
2581   int sqlite3ExprCheckHeight(Parse*, int);
2582 #else
2583   #define sqlite3ExprSetHeight(x,y)
2584   #define sqlite3SelectExprHeight(x) 0
2585   #define sqlite3ExprCheckHeight(x,y)
2586 #endif
2587 
2588 u32 sqlite3Get4byte(const u8*);
2589 void sqlite3Put4byte(u8*, u32);
2590 
2591 #ifdef SQLITE_SSE
2592 #include "sseInt.h"
2593 #endif
2594 
2595 #ifdef SQLITE_DEBUG
2596   void sqlite3ParserTrace(FILE*, char *);
2597 #endif
2598 
2599 /*
2600 ** If the SQLITE_ENABLE IOTRACE exists then the global variable
2601 ** sqlite3IoTrace is a pointer to a printf-like routine used to
2602 ** print I/O tracing messages.
2603 */
2604 #ifdef SQLITE_ENABLE_IOTRACE
2605 # define IOTRACE(A)  if( sqlite3IoTrace ){ sqlite3IoTrace A; }
2606   void sqlite3VdbeIOTraceSql(Vdbe*);
2607 SQLITE_EXTERN void (*sqlite3IoTrace)(const char*,...);
2608 #else
2609 # define IOTRACE(A)
2610 # define sqlite3VdbeIOTraceSql(X)
2611 #endif
2612 
2613 #endif
2614