xref: /sqlite-3.40.0/src/sqliteInt.h (revision 6f050aa2)
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 1.861 2009/04/24 15:46:22 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  * This macro is used to "hide" some ugliness in casting an int
55  * value to a ptr value under the MSVC 64-bit compiler.   Casting
56  * non 64-bit values to ptr types results in a "hard" error with
57  * the MSVC 64-bit compiler which this attempts to avoid.
58  *
59  * A simple compiler pragma or casting sequence could not be found
60  * to correct this in all situations, so this macro was introduced.
61  *
62  * It could be argued that the intptr_t type could be used in this
63  * case, but that type is not available on all compilers, or
64  * requires the #include of specific headers which differs between
65  * platforms.
66  */
67 #define SQLITE_INT_TO_PTR(X)   ((void*)&((char*)0)[X])
68 #define SQLITE_PTR_TO_INT(X)   ((int)(((char*)X)-(char*)0))
69 
70 /*
71 ** These #defines should enable >2GB file support on POSIX if the
72 ** underlying operating system supports it.  If the OS lacks
73 ** large file support, or if the OS is windows, these should be no-ops.
74 **
75 ** Ticket #2739:  The _LARGEFILE_SOURCE macro must appear before any
76 ** system #includes.  Hence, this block of code must be the very first
77 ** code in all source files.
78 **
79 ** Large file support can be disabled using the -DSQLITE_DISABLE_LFS switch
80 ** on the compiler command line.  This is necessary if you are compiling
81 ** on a recent machine (ex: Red Hat 7.2) but you want your code to work
82 ** on an older machine (ex: Red Hat 6.0).  If you compile on Red Hat 7.2
83 ** without this option, LFS is enable.  But LFS does not exist in the kernel
84 ** in Red Hat 6.0, so the code won't work.  Hence, for maximum binary
85 ** portability you should omit LFS.
86 **
87 ** Similar is true for Mac OS X.  LFS is only supported on Mac OS X 9 and later.
88 */
89 #ifndef SQLITE_DISABLE_LFS
90 # define _LARGE_FILE       1
91 # ifndef _FILE_OFFSET_BITS
92 #   define _FILE_OFFSET_BITS 64
93 # endif
94 # define _LARGEFILE_SOURCE 1
95 #endif
96 
97 
98 /*
99 ** The SQLITE_THREADSAFE macro must be defined as either 0 or 1.
100 ** Older versions of SQLite used an optional THREADSAFE macro.
101 ** We support that for legacy
102 */
103 #if !defined(SQLITE_THREADSAFE)
104 #if defined(THREADSAFE)
105 # define SQLITE_THREADSAFE THREADSAFE
106 #else
107 # define SQLITE_THREADSAFE 1
108 #endif
109 #endif
110 
111 /*
112 ** The SQLITE_DEFAULT_MEMSTATUS macro must be defined as either 0 or 1.
113 ** It determines whether or not the features related to
114 ** SQLITE_CONFIG_MEMSTATUS are available by default or not. This value can
115 ** be overridden at runtime using the sqlite3_config() API.
116 */
117 #if !defined(SQLITE_DEFAULT_MEMSTATUS)
118 # define SQLITE_DEFAULT_MEMSTATUS 1
119 #endif
120 
121 /*
122 ** Exactly one of the following macros must be defined in order to
123 ** specify which memory allocation subsystem to use.
124 **
125 **     SQLITE_SYSTEM_MALLOC          // Use normal system malloc()
126 **     SQLITE_MEMDEBUG               // Debugging version of system malloc()
127 **     SQLITE_MEMORY_SIZE            // internal allocator #1
128 **     SQLITE_MMAP_HEAP_SIZE         // internal mmap() allocator
129 **     SQLITE_POW2_MEMORY_SIZE       // internal power-of-two allocator
130 **
131 ** If none of the above are defined, then set SQLITE_SYSTEM_MALLOC as
132 ** the default.
133 */
134 #if defined(SQLITE_SYSTEM_MALLOC)+defined(SQLITE_MEMDEBUG)+\
135     defined(SQLITE_MEMORY_SIZE)+defined(SQLITE_MMAP_HEAP_SIZE)+\
136     defined(SQLITE_POW2_MEMORY_SIZE)>1
137 # error "At most one of the following compile-time configuration options\
138  is allows: SQLITE_SYSTEM_MALLOC, SQLITE_MEMDEBUG, SQLITE_MEMORY_SIZE,\
139  SQLITE_MMAP_HEAP_SIZE, SQLITE_POW2_MEMORY_SIZE"
140 #endif
141 #if defined(SQLITE_SYSTEM_MALLOC)+defined(SQLITE_MEMDEBUG)+\
142     defined(SQLITE_MEMORY_SIZE)+defined(SQLITE_MMAP_HEAP_SIZE)+\
143     defined(SQLITE_POW2_MEMORY_SIZE)==0
144 # define SQLITE_SYSTEM_MALLOC 1
145 #endif
146 
147 /*
148 ** If SQLITE_MALLOC_SOFT_LIMIT is defined, then try to keep the
149 ** sizes of memory allocations below this value where possible.
150 */
151 #if defined(SQLITE_POW2_MEMORY_SIZE) && !defined(SQLITE_MALLOC_SOFT_LIMIT)
152 # define SQLITE_MALLOC_SOFT_LIMIT 1024
153 #endif
154 
155 /*
156 ** We need to define _XOPEN_SOURCE as follows in order to enable
157 ** recursive mutexes on most Unix systems.  But Mac OS X is different.
158 ** The _XOPEN_SOURCE define causes problems for Mac OS X we are told,
159 ** so it is omitted there.  See ticket #2673.
160 **
161 ** Later we learn that _XOPEN_SOURCE is poorly or incorrectly
162 ** implemented on some systems.  So we avoid defining it at all
163 ** if it is already defined or if it is unneeded because we are
164 ** not doing a threadsafe build.  Ticket #2681.
165 **
166 ** See also ticket #2741.
167 */
168 #if !defined(_XOPEN_SOURCE) && !defined(__DARWIN__) && !defined(__APPLE__) && SQLITE_THREADSAFE
169 #  define _XOPEN_SOURCE 500  /* Needed to enable pthread recursive mutexes */
170 #endif
171 
172 /*
173 ** The TCL headers are only needed when compiling the TCL bindings.
174 */
175 #if defined(SQLITE_TCL) || defined(TCLSH)
176 # include <tcl.h>
177 #endif
178 
179 /*
180 ** Many people are failing to set -DNDEBUG=1 when compiling SQLite.
181 ** Setting NDEBUG makes the code smaller and run faster.  So the following
182 ** lines are added to automatically set NDEBUG unless the -DSQLITE_DEBUG=1
183 ** option is set.  Thus NDEBUG becomes an opt-in rather than an opt-out
184 ** feature.
185 */
186 #if !defined(NDEBUG) && !defined(SQLITE_DEBUG)
187 # define NDEBUG 1
188 #endif
189 
190 /*
191 ** The testcase() macro is used to aid in coverage testing.  When
192 ** doing coverage testing, the condition inside the argument to
193 ** testcase() must be evaluated both true and false in order to
194 ** get full branch coverage.  The testcase() macro is inserted
195 ** to help ensure adequate test coverage in places where simple
196 ** condition/decision coverage is inadequate.  For example, testcase()
197 ** can be used to make sure boundary values are tested.  For
198 ** bitmask tests, testcase() can be used to make sure each bit
199 ** is significant and used at least once.  On switch statements
200 ** where multiple cases go to the same block of code, testcase()
201 ** can insure that all cases are evaluated.
202 **
203 */
204 #ifdef SQLITE_COVERAGE_TEST
205   void sqlite3Coverage(int);
206 # define testcase(X)  if( X ){ sqlite3Coverage(__LINE__); }
207 #else
208 # define testcase(X)
209 #endif
210 
211 /*
212 ** The TESTONLY macro is used to enclose variable declarations or
213 ** other bits of code that are needed to support the arguments
214 ** within testcase() and assert() macros.
215 */
216 #if !defined(NDEBUG) || defined(SQLITE_COVERAGE_TEST)
217 # define TESTONLY(X)  X
218 #else
219 # define TESTONLY(X)
220 #endif
221 
222 /*
223 ** Sometimes we need a small amount of code such as a variable initialization
224 ** to setup for a later assert() statement.  We do not want this code to
225 ** appear when assert() is disabled.  The following macro is therefore
226 ** used to contain that setup code.  The "VVA" acronym stands for
227 ** "Verification, Validation, and Accreditation".  In other words, the
228 ** code within VVA_ONLY() will only run during verification processes.
229 */
230 #ifndef NDEBUG
231 # define VVA_ONLY(X)  X
232 #else
233 # define VVA_ONLY(X)
234 #endif
235 
236 /*
237 ** The ALWAYS and NEVER macros surround boolean expressions which
238 ** are intended to always be true or false, respectively.  Such
239 ** expressions could be omitted from the code completely.  But they
240 ** are included in a few cases in order to enhance the resilience
241 ** of SQLite to unexpected behavior - to make the code "self-healing"
242 ** or "ductile" rather than being "brittle" and crashing at the first
243 ** hint of unplanned behavior.
244 **
245 ** In other words, ALWAYS and NEVER are added for defensive code.
246 **
247 ** When doing coverage testing ALWAYS and NEVER are hard-coded to
248 ** be true and false so that the unreachable code then specify will
249 ** not be counted as untested code.
250 */
251 #if defined(SQLITE_COVERAGE_TEST)
252 # define ALWAYS(X)      (1)
253 # define NEVER(X)       (0)
254 #elif !defined(NDEBUG)
255   int sqlite3Assert(void);
256 # define ALWAYS(X)      ((X)?1:sqlite3Assert())
257 # define NEVER(X)       ((X)?sqlite3Assert():0)
258 #else
259 # define ALWAYS(X)      (X)
260 # define NEVER(X)       (X)
261 #endif
262 
263 /*
264 ** The macro unlikely() is a hint that surrounds a boolean
265 ** expression that is usually false.  Macro likely() surrounds
266 ** a boolean expression that is usually true.  GCC is able to
267 ** use these hints to generate better code, sometimes.
268 */
269 #if defined(__GNUC__) && 0
270 # define likely(X)    __builtin_expect((X),1)
271 # define unlikely(X)  __builtin_expect((X),0)
272 #else
273 # define likely(X)    !!(X)
274 # define unlikely(X)  !!(X)
275 #endif
276 
277 #include "sqlite3.h"
278 #include "hash.h"
279 #include "parse.h"
280 #include <stdio.h>
281 #include <stdlib.h>
282 #include <string.h>
283 #include <assert.h>
284 #include <stddef.h>
285 
286 /*
287 ** If compiling for a processor that lacks floating point support,
288 ** substitute integer for floating-point
289 */
290 #ifdef SQLITE_OMIT_FLOATING_POINT
291 # define double sqlite_int64
292 # define LONGDOUBLE_TYPE sqlite_int64
293 # ifndef SQLITE_BIG_DBL
294 #   define SQLITE_BIG_DBL (0x7fffffffffffffff)
295 # endif
296 # define SQLITE_OMIT_DATETIME_FUNCS 1
297 # define SQLITE_OMIT_TRACE 1
298 # undef SQLITE_MIXED_ENDIAN_64BIT_FLOAT
299 #endif
300 #ifndef SQLITE_BIG_DBL
301 # define SQLITE_BIG_DBL (1e99)
302 #endif
303 
304 /*
305 ** OMIT_TEMPDB is set to 1 if SQLITE_OMIT_TEMPDB is defined, or 0
306 ** afterward. Having this macro allows us to cause the C compiler
307 ** to omit code used by TEMP tables without messy #ifndef statements.
308 */
309 #ifdef SQLITE_OMIT_TEMPDB
310 #define OMIT_TEMPDB 1
311 #else
312 #define OMIT_TEMPDB 0
313 #endif
314 
315 /*
316 ** If the following macro is set to 1, then NULL values are considered
317 ** distinct when determining whether or not two entries are the same
318 ** in a UNIQUE index.  This is the way PostgreSQL, Oracle, DB2, MySQL,
319 ** OCELOT, and Firebird all work.  The SQL92 spec explicitly says this
320 ** is the way things are suppose to work.
321 **
322 ** If the following macro is set to 0, the NULLs are indistinct for
323 ** a UNIQUE index.  In this mode, you can only have a single NULL entry
324 ** for a column declared UNIQUE.  This is the way Informix and SQL Server
325 ** work.
326 */
327 #define NULL_DISTINCT_FOR_UNIQUE 1
328 
329 /*
330 ** The "file format" number is an integer that is incremented whenever
331 ** the VDBE-level file format changes.  The following macros define the
332 ** the default file format for new databases and the maximum file format
333 ** that the library can read.
334 */
335 #define SQLITE_MAX_FILE_FORMAT 4
336 #ifndef SQLITE_DEFAULT_FILE_FORMAT
337 # define SQLITE_DEFAULT_FILE_FORMAT 1
338 #endif
339 
340 /*
341 ** Provide a default value for SQLITE_TEMP_STORE in case it is not specified
342 ** on the command-line
343 */
344 #ifndef SQLITE_TEMP_STORE
345 # define SQLITE_TEMP_STORE 1
346 #endif
347 
348 /*
349 ** GCC does not define the offsetof() macro so we'll have to do it
350 ** ourselves.
351 */
352 #ifndef offsetof
353 #define offsetof(STRUCTURE,FIELD) ((int)((char*)&((STRUCTURE*)0)->FIELD))
354 #endif
355 
356 /*
357 ** Check to see if this machine uses EBCDIC.  (Yes, believe it or
358 ** not, there are still machines out there that use EBCDIC.)
359 */
360 #if 'A' == '\301'
361 # define SQLITE_EBCDIC 1
362 #else
363 # define SQLITE_ASCII 1
364 #endif
365 
366 /*
367 ** Integers of known sizes.  These typedefs might change for architectures
368 ** where the sizes very.  Preprocessor macros are available so that the
369 ** types can be conveniently redefined at compile-type.  Like this:
370 **
371 **         cc '-DUINTPTR_TYPE=long long int' ...
372 */
373 #ifndef UINT32_TYPE
374 # ifdef HAVE_UINT32_T
375 #  define UINT32_TYPE uint32_t
376 # else
377 #  define UINT32_TYPE unsigned int
378 # endif
379 #endif
380 #ifndef UINT16_TYPE
381 # ifdef HAVE_UINT16_T
382 #  define UINT16_TYPE uint16_t
383 # else
384 #  define UINT16_TYPE unsigned short int
385 # endif
386 #endif
387 #ifndef INT16_TYPE
388 # ifdef HAVE_INT16_T
389 #  define INT16_TYPE int16_t
390 # else
391 #  define INT16_TYPE short int
392 # endif
393 #endif
394 #ifndef UINT8_TYPE
395 # ifdef HAVE_UINT8_T
396 #  define UINT8_TYPE uint8_t
397 # else
398 #  define UINT8_TYPE unsigned char
399 # endif
400 #endif
401 #ifndef INT8_TYPE
402 # ifdef HAVE_INT8_T
403 #  define INT8_TYPE int8_t
404 # else
405 #  define INT8_TYPE signed char
406 # endif
407 #endif
408 #ifndef LONGDOUBLE_TYPE
409 # define LONGDOUBLE_TYPE long double
410 #endif
411 typedef sqlite_int64 i64;          /* 8-byte signed integer */
412 typedef sqlite_uint64 u64;         /* 8-byte unsigned integer */
413 typedef UINT32_TYPE u32;           /* 4-byte unsigned integer */
414 typedef UINT16_TYPE u16;           /* 2-byte unsigned integer */
415 typedef INT16_TYPE i16;            /* 2-byte signed integer */
416 typedef UINT8_TYPE u8;             /* 1-byte unsigned integer */
417 typedef INT8_TYPE i8;              /* 1-byte signed integer */
418 
419 /*
420 ** Macros to determine whether the machine is big or little endian,
421 ** evaluated at runtime.
422 */
423 #ifdef SQLITE_AMALGAMATION
424 const int sqlite3one = 1;
425 #else
426 extern const int sqlite3one;
427 #endif
428 #if defined(i386) || defined(__i386__) || defined(_M_IX86)\
429                              || defined(__x86_64) || defined(__x86_64__)
430 # define SQLITE_BIGENDIAN    0
431 # define SQLITE_LITTLEENDIAN 1
432 # define SQLITE_UTF16NATIVE  SQLITE_UTF16LE
433 #else
434 # define SQLITE_BIGENDIAN    (*(char *)(&sqlite3one)==0)
435 # define SQLITE_LITTLEENDIAN (*(char *)(&sqlite3one)==1)
436 # define SQLITE_UTF16NATIVE (SQLITE_BIGENDIAN?SQLITE_UTF16BE:SQLITE_UTF16LE)
437 #endif
438 
439 /*
440 ** Constants for the largest and smallest possible 64-bit signed integers.
441 ** These macros are designed to work correctly on both 32-bit and 64-bit
442 ** compilers.
443 */
444 #define LARGEST_INT64  (0xffffffff|(((i64)0x7fffffff)<<32))
445 #define SMALLEST_INT64 (((i64)-1) - LARGEST_INT64)
446 
447 /*
448 ** Round up a number to the next larger multiple of 8.  This is used
449 ** to force 8-byte alignment on 64-bit architectures.
450 */
451 #define ROUND8(x)     (((x)+7)&~7)
452 
453 /*
454 ** Round down to the nearest multiple of 8
455 */
456 #define ROUNDDOWN8(x) ((x)&~7)
457 
458 /*
459 ** Assert that the pointer X is aligned to an 8-byte boundary.
460 */
461 #define EIGHT_BYTE_ALIGNMENT(X)   ((((char*)(X) - (char*)0)&7)==0)
462 
463 /*
464 ** An instance of the following structure is used to store the busy-handler
465 ** callback for a given sqlite handle.
466 **
467 ** The sqlite.busyHandler member of the sqlite struct contains the busy
468 ** callback for the database handle. Each pager opened via the sqlite
469 ** handle is passed a pointer to sqlite.busyHandler. The busy-handler
470 ** callback is currently invoked only from within pager.c.
471 */
472 typedef struct BusyHandler BusyHandler;
473 struct BusyHandler {
474   int (*xFunc)(void *,int);  /* The busy callback */
475   void *pArg;                /* First arg to busy callback */
476   int nBusy;                 /* Incremented with each busy call */
477 };
478 
479 /*
480 ** Name of the master database table.  The master database table
481 ** is a special table that holds the names and attributes of all
482 ** user tables and indices.
483 */
484 #define MASTER_NAME       "sqlite_master"
485 #define TEMP_MASTER_NAME  "sqlite_temp_master"
486 
487 /*
488 ** The root-page of the master database table.
489 */
490 #define MASTER_ROOT       1
491 
492 /*
493 ** The name of the schema table.
494 */
495 #define SCHEMA_TABLE(x)  ((!OMIT_TEMPDB)&&(x==1)?TEMP_MASTER_NAME:MASTER_NAME)
496 
497 /*
498 ** A convenience macro that returns the number of elements in
499 ** an array.
500 */
501 #define ArraySize(X)    ((int)(sizeof(X)/sizeof(X[0])))
502 
503 /*
504 ** The following value as a destructor means to use sqlite3DbFree().
505 ** This is an internal extension to SQLITE_STATIC and SQLITE_TRANSIENT.
506 */
507 #define SQLITE_DYNAMIC   ((sqlite3_destructor_type)sqlite3DbFree)
508 
509 /*
510 ** When SQLITE_OMIT_WSD is defined, it means that the target platform does
511 ** not support Writable Static Data (WSD) such as global and static variables.
512 ** All variables must either be on the stack or dynamically allocated from
513 ** the heap.  When WSD is unsupported, the variable declarations scattered
514 ** throughout the SQLite code must become constants instead.  The SQLITE_WSD
515 ** macro is used for this purpose.  And instead of referencing the variable
516 ** directly, we use its constant as a key to lookup the run-time allocated
517 ** buffer that holds real variable.  The constant is also the initializer
518 ** for the run-time allocated buffer.
519 **
520 ** In the usual case where WSD is supported, the SQLITE_WSD and GLOBAL
521 ** macros become no-ops and have zero performance impact.
522 */
523 #ifdef SQLITE_OMIT_WSD
524   #define SQLITE_WSD const
525   #define GLOBAL(t,v) (*(t*)sqlite3_wsd_find((void*)&(v), sizeof(v)))
526   #define sqlite3GlobalConfig GLOBAL(struct Sqlite3Config, sqlite3Config)
527   int sqlite3_wsd_init(int N, int J);
528   void *sqlite3_wsd_find(void *K, int L);
529 #else
530   #define SQLITE_WSD
531   #define GLOBAL(t,v) v
532   #define sqlite3GlobalConfig sqlite3Config
533 #endif
534 
535 /*
536 ** The following macros are used to suppress compiler warnings and to
537 ** make it clear to human readers when a function parameter is deliberately
538 ** left unused within the body of a function. This usually happens when
539 ** a function is called via a function pointer. For example the
540 ** implementation of an SQL aggregate step callback may not use the
541 ** parameter indicating the number of arguments passed to the aggregate,
542 ** if it knows that this is enforced elsewhere.
543 **
544 ** When a function parameter is not used at all within the body of a function,
545 ** it is generally named "NotUsed" or "NotUsed2" to make things even clearer.
546 ** However, these macros may also be used to suppress warnings related to
547 ** parameters that may or may not be used depending on compilation options.
548 ** For example those parameters only used in assert() statements. In these
549 ** cases the parameters are named as per the usual conventions.
550 */
551 #define UNUSED_PARAMETER(x) (void)(x)
552 #define UNUSED_PARAMETER2(x,y) UNUSED_PARAMETER(x),UNUSED_PARAMETER(y)
553 
554 /*
555 ** Forward references to structures
556 */
557 typedef struct AggInfo AggInfo;
558 typedef struct AuthContext AuthContext;
559 typedef struct Bitvec Bitvec;
560 typedef struct RowSet RowSet;
561 typedef struct CollSeq CollSeq;
562 typedef struct Column Column;
563 typedef struct Db Db;
564 typedef struct Schema Schema;
565 typedef struct Expr Expr;
566 typedef struct ExprList ExprList;
567 typedef struct FKey FKey;
568 typedef struct FuncDef FuncDef;
569 typedef struct FuncDefHash FuncDefHash;
570 typedef struct IdList IdList;
571 typedef struct Index Index;
572 typedef struct KeyClass KeyClass;
573 typedef struct KeyInfo KeyInfo;
574 typedef struct Lookaside Lookaside;
575 typedef struct LookasideSlot LookasideSlot;
576 typedef struct Module Module;
577 typedef struct NameContext NameContext;
578 typedef struct Parse Parse;
579 typedef struct Savepoint Savepoint;
580 typedef struct Select Select;
581 typedef struct SrcList SrcList;
582 typedef struct StrAccum StrAccum;
583 typedef struct Table Table;
584 typedef struct TableLock TableLock;
585 typedef struct Token Token;
586 typedef struct TriggerStack TriggerStack;
587 typedef struct TriggerStep TriggerStep;
588 typedef struct Trigger Trigger;
589 typedef struct UnpackedRecord UnpackedRecord;
590 typedef struct Walker Walker;
591 typedef struct WherePlan WherePlan;
592 typedef struct WhereInfo WhereInfo;
593 typedef struct WhereLevel WhereLevel;
594 
595 /*
596 ** Defer sourcing vdbe.h and btree.h until after the "u8" and
597 ** "BusyHandler" typedefs. vdbe.h also requires a few of the opaque
598 ** pointer types (i.e. FuncDef) defined above.
599 */
600 #include "btree.h"
601 #include "vdbe.h"
602 #include "pager.h"
603 #include "pcache.h"
604 
605 #include "os.h"
606 #include "mutex.h"
607 
608 
609 /*
610 ** Each database file to be accessed by the system is an instance
611 ** of the following structure.  There are normally two of these structures
612 ** in the sqlite.aDb[] array.  aDb[0] is the main database file and
613 ** aDb[1] is the database file used to hold temporary tables.  Additional
614 ** databases may be attached.
615 */
616 struct Db {
617   char *zName;         /* Name of this database */
618   Btree *pBt;          /* The B*Tree structure for this database file */
619   u8 inTrans;          /* 0: not writable.  1: Transaction.  2: Checkpoint */
620   u8 safety_level;     /* How aggressive at syncing data to disk */
621   void *pAux;               /* Auxiliary data.  Usually NULL */
622   void (*xFreeAux)(void*);  /* Routine to free pAux */
623   Schema *pSchema;     /* Pointer to database schema (possibly shared) */
624 };
625 
626 /*
627 ** An instance of the following structure stores a database schema.
628 **
629 ** If there are no virtual tables configured in this schema, the
630 ** Schema.db variable is set to NULL. After the first virtual table
631 ** has been added, it is set to point to the database connection
632 ** used to create the connection. Once a virtual table has been
633 ** added to the Schema structure and the Schema.db variable populated,
634 ** only that database connection may use the Schema to prepare
635 ** statements.
636 */
637 struct Schema {
638   int schema_cookie;   /* Database schema version number for this file */
639   Hash tblHash;        /* All tables indexed by name */
640   Hash idxHash;        /* All (named) indices indexed by name */
641   Hash trigHash;       /* All triggers indexed by name */
642   Hash aFKey;          /* Foreign keys indexed by to-table */
643   Table *pSeqTab;      /* The sqlite_sequence table used by AUTOINCREMENT */
644   u8 file_format;      /* Schema format version for this file */
645   u8 enc;              /* Text encoding used by this database */
646   u16 flags;           /* Flags associated with this schema */
647   int cache_size;      /* Number of pages to use in the cache */
648 #ifndef SQLITE_OMIT_VIRTUALTABLE
649   sqlite3 *db;         /* "Owner" connection. See comment above */
650 #endif
651 };
652 
653 /*
654 ** These macros can be used to test, set, or clear bits in the
655 ** Db.flags field.
656 */
657 #define DbHasProperty(D,I,P)     (((D)->aDb[I].pSchema->flags&(P))==(P))
658 #define DbHasAnyProperty(D,I,P)  (((D)->aDb[I].pSchema->flags&(P))!=0)
659 #define DbSetProperty(D,I,P)     (D)->aDb[I].pSchema->flags|=(P)
660 #define DbClearProperty(D,I,P)   (D)->aDb[I].pSchema->flags&=~(P)
661 
662 /*
663 ** Allowed values for the DB.flags field.
664 **
665 ** The DB_SchemaLoaded flag is set after the database schema has been
666 ** read into internal hash tables.
667 **
668 ** DB_UnresetViews means that one or more views have column names that
669 ** have been filled out.  If the schema changes, these column names might
670 ** changes and so the view will need to be reset.
671 */
672 #define DB_SchemaLoaded    0x0001  /* The schema has been loaded */
673 #define DB_UnresetViews    0x0002  /* Some views have defined column names */
674 #define DB_Empty           0x0004  /* The file is empty (length 0 bytes) */
675 
676 /*
677 ** The number of different kinds of things that can be limited
678 ** using the sqlite3_limit() interface.
679 */
680 #define SQLITE_N_LIMIT (SQLITE_LIMIT_VARIABLE_NUMBER+1)
681 
682 /*
683 ** Lookaside malloc is a set of fixed-size buffers that can be used
684 ** to satisfy small transient memory allocation requests for objects
685 ** associated with a particular database connection.  The use of
686 ** lookaside malloc provides a significant performance enhancement
687 ** (approx 10%) by avoiding numerous malloc/free requests while parsing
688 ** SQL statements.
689 **
690 ** The Lookaside structure holds configuration information about the
691 ** lookaside malloc subsystem.  Each available memory allocation in
692 ** the lookaside subsystem is stored on a linked list of LookasideSlot
693 ** objects.
694 **
695 ** Lookaside allocations are only allowed for objects that are associated
696 ** with a particular database connection.  Hence, schema information cannot
697 ** be stored in lookaside because in shared cache mode the schema information
698 ** is shared by multiple database connections.  Therefore, while parsing
699 ** schema information, the Lookaside.bEnabled flag is cleared so that
700 ** lookaside allocations are not used to construct the schema objects.
701 */
702 struct Lookaside {
703   u16 sz;                 /* Size of each buffer in bytes */
704   u8 bEnabled;            /* False to disable new lookaside allocations */
705   u8 bMalloced;           /* True if pStart obtained from sqlite3_malloc() */
706   int nOut;               /* Number of buffers currently checked out */
707   int mxOut;              /* Highwater mark for nOut */
708   LookasideSlot *pFree;   /* List of available buffers */
709   void *pStart;           /* First byte of available memory space */
710   void *pEnd;             /* First byte past end of available space */
711 };
712 struct LookasideSlot {
713   LookasideSlot *pNext;    /* Next buffer in the list of free buffers */
714 };
715 
716 /*
717 ** A hash table for function definitions.
718 **
719 ** Hash each FuncDef structure into one of the FuncDefHash.a[] slots.
720 ** Collisions are on the FuncDef.pHash chain.
721 */
722 struct FuncDefHash {
723   FuncDef *a[23];       /* Hash table for functions */
724 };
725 
726 /*
727 ** Each database is an instance of the following structure.
728 **
729 ** The sqlite.lastRowid records the last insert rowid generated by an
730 ** insert statement.  Inserts on views do not affect its value.  Each
731 ** trigger has its own context, so that lastRowid can be updated inside
732 ** triggers as usual.  The previous value will be restored once the trigger
733 ** exits.  Upon entering a before or instead of trigger, lastRowid is no
734 ** longer (since after version 2.8.12) reset to -1.
735 **
736 ** The sqlite.nChange does not count changes within triggers and keeps no
737 ** context.  It is reset at start of sqlite3_exec.
738 ** The sqlite.lsChange represents the number of changes made by the last
739 ** insert, update, or delete statement.  It remains constant throughout the
740 ** length of a statement and is then updated by OP_SetCounts.  It keeps a
741 ** context stack just like lastRowid so that the count of changes
742 ** within a trigger is not seen outside the trigger.  Changes to views do not
743 ** affect the value of lsChange.
744 ** The sqlite.csChange keeps track of the number of current changes (since
745 ** the last statement) and is used to update sqlite_lsChange.
746 **
747 ** The member variables sqlite.errCode, sqlite.zErrMsg and sqlite.zErrMsg16
748 ** store the most recent error code and, if applicable, string. The
749 ** internal function sqlite3Error() is used to set these variables
750 ** consistently.
751 */
752 struct sqlite3 {
753   sqlite3_vfs *pVfs;            /* OS Interface */
754   int nDb;                      /* Number of backends currently in use */
755   Db *aDb;                      /* All backends */
756   int flags;                    /* Miscellaneous flags. See below */
757   int openFlags;                /* Flags passed to sqlite3_vfs.xOpen() */
758   int errCode;                  /* Most recent error code (SQLITE_*) */
759   int errMask;                  /* & result codes with this before returning */
760   u8 autoCommit;                /* The auto-commit flag. */
761   u8 temp_store;                /* 1: file 2: memory 0: default */
762   u8 mallocFailed;              /* True if we have seen a malloc failure */
763   u8 dfltLockMode;              /* Default locking-mode for attached dbs */
764   u8 dfltJournalMode;           /* Default journal mode for attached dbs */
765   signed char nextAutovac;      /* Autovac setting after VACUUM if >=0 */
766   int nextPagesize;             /* Pagesize after VACUUM if >0 */
767   int nTable;                   /* Number of tables in the database */
768   CollSeq *pDfltColl;           /* The default collating sequence (BINARY) */
769   i64 lastRowid;                /* ROWID of most recent insert (see above) */
770   i64 priorNewRowid;            /* Last randomly generated ROWID */
771   u32 magic;                    /* Magic number for detect library misuse */
772   int nChange;                  /* Value returned by sqlite3_changes() */
773   int nTotalChange;             /* Value returned by sqlite3_total_changes() */
774   sqlite3_mutex *mutex;         /* Connection mutex */
775   int aLimit[SQLITE_N_LIMIT];   /* Limits */
776   struct sqlite3InitInfo {      /* Information used during initialization */
777     int iDb;                    /* When back is being initialized */
778     int newTnum;                /* Rootpage of table being initialized */
779     u8 busy;                    /* TRUE if currently initializing */
780   } init;
781   int nExtension;               /* Number of loaded extensions */
782   void **aExtension;            /* Array of shared library handles */
783   struct Vdbe *pVdbe;           /* List of active virtual machines */
784   int activeVdbeCnt;            /* Number of VDBEs currently executing */
785   int writeVdbeCnt;             /* Number of active VDBEs that are writing */
786   void (*xTrace)(void*,const char*);        /* Trace function */
787   void *pTraceArg;                          /* Argument to the trace function */
788   void (*xProfile)(void*,const char*,u64);  /* Profiling function */
789   void *pProfileArg;                        /* Argument to profile function */
790   void *pCommitArg;                 /* Argument to xCommitCallback() */
791   int (*xCommitCallback)(void*);    /* Invoked at every commit. */
792   void *pRollbackArg;               /* Argument to xRollbackCallback() */
793   void (*xRollbackCallback)(void*); /* Invoked at every commit. */
794   void *pUpdateArg;
795   void (*xUpdateCallback)(void*,int, const char*,const char*,sqlite_int64);
796   void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*);
797   void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*);
798   void *pCollNeededArg;
799   sqlite3_value *pErr;          /* Most recent error message */
800   char *zErrMsg;                /* Most recent error message (UTF-8 encoded) */
801   char *zErrMsg16;              /* Most recent error message (UTF-16 encoded) */
802   union {
803     volatile int isInterrupted; /* True if sqlite3_interrupt has been called */
804     double notUsed1;            /* Spacer */
805   } u1;
806   Lookaside lookaside;          /* Lookaside malloc configuration */
807 #ifndef SQLITE_OMIT_AUTHORIZATION
808   int (*xAuth)(void*,int,const char*,const char*,const char*,const char*);
809                                 /* Access authorization function */
810   void *pAuthArg;               /* 1st argument to the access auth function */
811 #endif
812 #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
813   int (*xProgress)(void *);     /* The progress callback */
814   void *pProgressArg;           /* Argument to the progress callback */
815   int nProgressOps;             /* Number of opcodes for progress callback */
816 #endif
817 #ifndef SQLITE_OMIT_VIRTUALTABLE
818   Hash aModule;                 /* populated by sqlite3_create_module() */
819   Table *pVTab;                 /* vtab with active Connect/Create method */
820   sqlite3_vtab **aVTrans;       /* Virtual tables with open transactions */
821   int nVTrans;                  /* Allocated size of aVTrans */
822 #endif
823   FuncDefHash aFunc;            /* Hash table of connection functions */
824   Hash aCollSeq;                /* All collating sequences */
825   BusyHandler busyHandler;      /* Busy callback */
826   int busyTimeout;              /* Busy handler timeout, in msec */
827   Db aDbStatic[2];              /* Static space for the 2 default backends */
828 #ifdef SQLITE_SSE
829   sqlite3_stmt *pFetch;         /* Used by SSE to fetch stored statements */
830 #endif
831   Savepoint *pSavepoint;        /* List of active savepoints */
832   int nSavepoint;               /* Number of non-transaction savepoints */
833   int nStatement;               /* Number of nested statement-transactions  */
834   u8 isTransactionSavepoint;    /* True if the outermost savepoint is a TS */
835 
836 #ifdef SQLITE_ENABLE_UNLOCK_NOTIFY
837   /* The following variables are all protected by the STATIC_MASTER
838   ** mutex, not by sqlite3.mutex. They are used by code in notify.c.
839   **
840   ** When X.pUnlockConnection==Y, that means that X is waiting for Y to
841   ** unlock so that it can proceed.
842   **
843   ** When X.pBlockingConnection==Y, that means that something that X tried
844   ** tried to do recently failed with an SQLITE_LOCKED error due to locks
845   ** held by Y.
846   */
847   sqlite3 *pBlockingConnection; /* Connection that caused SQLITE_LOCKED */
848   sqlite3 *pUnlockConnection;           /* Connection to watch for unlock */
849   void *pUnlockArg;                     /* Argument to xUnlockNotify */
850   void (*xUnlockNotify)(void **, int);  /* Unlock notify callback */
851   sqlite3 *pNextBlocked;        /* Next in list of all blocked connections */
852 #endif
853 };
854 
855 /*
856 ** A macro to discover the encoding of a database.
857 */
858 #define ENC(db) ((db)->aDb[0].pSchema->enc)
859 
860 /*
861 ** Possible values for the sqlite.flags and or Db.flags fields.
862 **
863 ** On sqlite.flags, the SQLITE_InTrans value means that we have
864 ** executed a BEGIN.  On Db.flags, SQLITE_InTrans means a statement
865 ** transaction is active on that particular database file.
866 */
867 #define SQLITE_VdbeTrace      0x00000001  /* True to trace VDBE execution */
868 #define SQLITE_InTrans        0x00000008  /* True if in a transaction */
869 #define SQLITE_InternChanges  0x00000010  /* Uncommitted Hash table changes */
870 #define SQLITE_FullColNames   0x00000020  /* Show full column names on SELECT */
871 #define SQLITE_ShortColNames  0x00000040  /* Show short columns names */
872 #define SQLITE_CountRows      0x00000080  /* Count rows changed by INSERT, */
873                                           /*   DELETE, or UPDATE and return */
874                                           /*   the count using a callback. */
875 #define SQLITE_NullCallback   0x00000100  /* Invoke the callback once if the */
876                                           /*   result set is empty */
877 #define SQLITE_SqlTrace       0x00000200  /* Debug print SQL as it executes */
878 #define SQLITE_VdbeListing    0x00000400  /* Debug listings of VDBE programs */
879 #define SQLITE_WriteSchema    0x00000800  /* OK to update SQLITE_MASTER */
880 #define SQLITE_NoReadlock     0x00001000  /* Readlocks are omitted when
881                                           ** accessing read-only databases */
882 #define SQLITE_IgnoreChecks   0x00002000  /* Do not enforce check constraints */
883 #define SQLITE_ReadUncommitted 0x00004000 /* For shared-cache mode */
884 #define SQLITE_LegacyFileFmt  0x00008000  /* Create new databases in format 1 */
885 #define SQLITE_FullFSync      0x00010000  /* Use full fsync on the backend */
886 #define SQLITE_LoadExtension  0x00020000  /* Enable load_extension */
887 
888 #define SQLITE_RecoveryMode   0x00040000  /* Ignore schema errors */
889 #define SQLITE_SharedCache    0x00080000  /* Cache sharing is enabled */
890 #define SQLITE_CommitBusy     0x00200000  /* In the process of committing */
891 #define SQLITE_ReverseOrder   0x00400000  /* Reverse unordered SELECTs */
892 
893 /*
894 ** Possible values for the sqlite.magic field.
895 ** The numbers are obtained at random and have no special meaning, other
896 ** than being distinct from one another.
897 */
898 #define SQLITE_MAGIC_OPEN     0xa029a697  /* Database is open */
899 #define SQLITE_MAGIC_CLOSED   0x9f3c2d33  /* Database is closed */
900 #define SQLITE_MAGIC_SICK     0x4b771290  /* Error and awaiting close */
901 #define SQLITE_MAGIC_BUSY     0xf03b7906  /* Database currently in use */
902 #define SQLITE_MAGIC_ERROR    0xb5357930  /* An SQLITE_MISUSE error occurred */
903 
904 /*
905 ** Each SQL function is defined by an instance of the following
906 ** structure.  A pointer to this structure is stored in the sqlite.aFunc
907 ** hash table.  When multiple functions have the same name, the hash table
908 ** points to a linked list of these structures.
909 */
910 struct FuncDef {
911   i16 nArg;            /* Number of arguments.  -1 means unlimited */
912   u8 iPrefEnc;         /* Preferred text encoding (SQLITE_UTF8, 16LE, 16BE) */
913   u8 flags;            /* Some combination of SQLITE_FUNC_* */
914   void *pUserData;     /* User data parameter */
915   FuncDef *pNext;      /* Next function with same name */
916   void (*xFunc)(sqlite3_context*,int,sqlite3_value**); /* Regular function */
917   void (*xStep)(sqlite3_context*,int,sqlite3_value**); /* Aggregate step */
918   void (*xFinalize)(sqlite3_context*);                /* Aggregate finalizer */
919   char *zName;         /* SQL name of the function. */
920   FuncDef *pHash;      /* Next with a different name but the same hash */
921 };
922 
923 /*
924 ** Possible values for FuncDef.flags
925 */
926 #define SQLITE_FUNC_LIKE     0x01 /* Candidate for the LIKE optimization */
927 #define SQLITE_FUNC_CASE     0x02 /* Case-sensitive LIKE-type function */
928 #define SQLITE_FUNC_EPHEM    0x04 /* Ephemeral.  Delete with VDBE */
929 #define SQLITE_FUNC_NEEDCOLL 0x08 /* sqlite3GetFuncCollSeq() might be called */
930 #define SQLITE_FUNC_PRIVATE  0x10 /* Allowed for internal use only */
931 #define SQLITE_FUNC_COUNT    0x20 /* Built-in count(*) aggregate */
932 
933 /*
934 ** The following three macros, FUNCTION(), LIKEFUNC() and AGGREGATE() are
935 ** used to create the initializers for the FuncDef structures.
936 **
937 **   FUNCTION(zName, nArg, iArg, bNC, xFunc)
938 **     Used to create a scalar function definition of a function zName
939 **     implemented by C function xFunc that accepts nArg arguments. The
940 **     value passed as iArg is cast to a (void*) and made available
941 **     as the user-data (sqlite3_user_data()) for the function. If
942 **     argument bNC is true, then the FuncDef.needCollate flag is set.
943 **
944 **   AGGREGATE(zName, nArg, iArg, bNC, xStep, xFinal)
945 **     Used to create an aggregate function definition implemented by
946 **     the C functions xStep and xFinal. The first four parameters
947 **     are interpreted in the same way as the first 4 parameters to
948 **     FUNCTION().
949 **
950 **   LIKEFUNC(zName, nArg, pArg, flags)
951 **     Used to create a scalar function definition of a function zName
952 **     that accepts nArg arguments and is implemented by a call to C
953 **     function likeFunc. Argument pArg is cast to a (void *) and made
954 **     available as the function user-data (sqlite3_user_data()). The
955 **     FuncDef.flags variable is set to the value passed as the flags
956 **     parameter.
957 */
958 #define FUNCTION(zName, nArg, iArg, bNC, xFunc) \
959   {nArg, SQLITE_UTF8, bNC*8, SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, 0, #zName, 0}
960 #define STR_FUNCTION(zName, nArg, pArg, bNC, xFunc) \
961   {nArg, SQLITE_UTF8, bNC*8, pArg, 0, xFunc, 0, 0, #zName, 0}
962 #define LIKEFUNC(zName, nArg, arg, flags) \
963   {nArg, SQLITE_UTF8, flags, (void *)arg, 0, likeFunc, 0, 0, #zName, 0}
964 #define AGGREGATE(zName, nArg, arg, nc, xStep, xFinal) \
965   {nArg, SQLITE_UTF8, nc*8, SQLITE_INT_TO_PTR(arg), 0, 0, xStep,xFinal,#zName,0}
966 
967 /*
968 ** All current savepoints are stored in a linked list starting at
969 ** sqlite3.pSavepoint. The first element in the list is the most recently
970 ** opened savepoint. Savepoints are added to the list by the vdbe
971 ** OP_Savepoint instruction.
972 */
973 struct Savepoint {
974   char *zName;                        /* Savepoint name (nul-terminated) */
975   Savepoint *pNext;                   /* Parent savepoint (if any) */
976 };
977 
978 /*
979 ** The following are used as the second parameter to sqlite3Savepoint(),
980 ** and as the P1 argument to the OP_Savepoint instruction.
981 */
982 #define SAVEPOINT_BEGIN      0
983 #define SAVEPOINT_RELEASE    1
984 #define SAVEPOINT_ROLLBACK   2
985 
986 
987 /*
988 ** Each SQLite module (virtual table definition) is defined by an
989 ** instance of the following structure, stored in the sqlite3.aModule
990 ** hash table.
991 */
992 struct Module {
993   const sqlite3_module *pModule;       /* Callback pointers */
994   const char *zName;                   /* Name passed to create_module() */
995   void *pAux;                          /* pAux passed to create_module() */
996   void (*xDestroy)(void *);            /* Module destructor function */
997 };
998 
999 /*
1000 ** information about each column of an SQL table is held in an instance
1001 ** of this structure.
1002 */
1003 struct Column {
1004   char *zName;     /* Name of this column */
1005   Expr *pDflt;     /* Default value of this column */
1006   char *zType;     /* Data type for this column */
1007   char *zColl;     /* Collating sequence.  If NULL, use the default */
1008   u8 notNull;      /* True if there is a NOT NULL constraint */
1009   u8 isPrimKey;    /* True if this column is part of the PRIMARY KEY */
1010   char affinity;   /* One of the SQLITE_AFF_... values */
1011 #ifndef SQLITE_OMIT_VIRTUALTABLE
1012   u8 isHidden;     /* True if this column is 'hidden' */
1013 #endif
1014 };
1015 
1016 /*
1017 ** A "Collating Sequence" is defined by an instance of the following
1018 ** structure. Conceptually, a collating sequence consists of a name and
1019 ** a comparison routine that defines the order of that sequence.
1020 **
1021 ** There may two separate implementations of the collation function, one
1022 ** that processes text in UTF-8 encoding (CollSeq.xCmp) and another that
1023 ** processes text encoded in UTF-16 (CollSeq.xCmp16), using the machine
1024 ** native byte order. When a collation sequence is invoked, SQLite selects
1025 ** the version that will require the least expensive encoding
1026 ** translations, if any.
1027 **
1028 ** The CollSeq.pUser member variable is an extra parameter that passed in
1029 ** as the first argument to the UTF-8 comparison function, xCmp.
1030 ** CollSeq.pUser16 is the equivalent for the UTF-16 comparison function,
1031 ** xCmp16.
1032 **
1033 ** If both CollSeq.xCmp and CollSeq.xCmp16 are NULL, it means that the
1034 ** collating sequence is undefined.  Indices built on an undefined
1035 ** collating sequence may not be read or written.
1036 */
1037 struct CollSeq {
1038   char *zName;          /* Name of the collating sequence, UTF-8 encoded */
1039   u8 enc;               /* Text encoding handled by xCmp() */
1040   u8 type;              /* One of the SQLITE_COLL_... values below */
1041   void *pUser;          /* First argument to xCmp() */
1042   int (*xCmp)(void*,int, const void*, int, const void*);
1043   void (*xDel)(void*);  /* Destructor for pUser */
1044 };
1045 
1046 /*
1047 ** Allowed values of CollSeq.type:
1048 */
1049 #define SQLITE_COLL_BINARY  1  /* The default memcmp() collating sequence */
1050 #define SQLITE_COLL_NOCASE  2  /* The built-in NOCASE collating sequence */
1051 #define SQLITE_COLL_REVERSE 3  /* The built-in REVERSE collating sequence */
1052 #define SQLITE_COLL_USER    0  /* Any other user-defined collating sequence */
1053 
1054 /*
1055 ** A sort order can be either ASC or DESC.
1056 */
1057 #define SQLITE_SO_ASC       0  /* Sort in ascending order */
1058 #define SQLITE_SO_DESC      1  /* Sort in ascending order */
1059 
1060 /*
1061 ** Column affinity types.
1062 **
1063 ** These used to have mnemonic name like 'i' for SQLITE_AFF_INTEGER and
1064 ** 't' for SQLITE_AFF_TEXT.  But we can save a little space and improve
1065 ** the speed a little by numbering the values consecutively.
1066 **
1067 ** But rather than start with 0 or 1, we begin with 'a'.  That way,
1068 ** when multiple affinity types are concatenated into a string and
1069 ** used as the P4 operand, they will be more readable.
1070 **
1071 ** Note also that the numeric types are grouped together so that testing
1072 ** for a numeric type is a single comparison.
1073 */
1074 #define SQLITE_AFF_TEXT     'a'
1075 #define SQLITE_AFF_NONE     'b'
1076 #define SQLITE_AFF_NUMERIC  'c'
1077 #define SQLITE_AFF_INTEGER  'd'
1078 #define SQLITE_AFF_REAL     'e'
1079 
1080 #define sqlite3IsNumericAffinity(X)  ((X)>=SQLITE_AFF_NUMERIC)
1081 
1082 /*
1083 ** The SQLITE_AFF_MASK values masks off the significant bits of an
1084 ** affinity value.
1085 */
1086 #define SQLITE_AFF_MASK     0x67
1087 
1088 /*
1089 ** Additional bit values that can be ORed with an affinity without
1090 ** changing the affinity.
1091 */
1092 #define SQLITE_JUMPIFNULL   0x08  /* jumps if either operand is NULL */
1093 #define SQLITE_STOREP2      0x10  /* Store result in reg[P2] rather than jump */
1094 
1095 /*
1096 ** Each SQL table is represented in memory by an instance of the
1097 ** following structure.
1098 **
1099 ** Table.zName is the name of the table.  The case of the original
1100 ** CREATE TABLE statement is stored, but case is not significant for
1101 ** comparisons.
1102 **
1103 ** Table.nCol is the number of columns in this table.  Table.aCol is a
1104 ** pointer to an array of Column structures, one for each column.
1105 **
1106 ** If the table has an INTEGER PRIMARY KEY, then Table.iPKey is the index of
1107 ** the column that is that key.   Otherwise Table.iPKey is negative.  Note
1108 ** that the datatype of the PRIMARY KEY must be INTEGER for this field to
1109 ** be set.  An INTEGER PRIMARY KEY is used as the rowid for each row of
1110 ** the table.  If a table has no INTEGER PRIMARY KEY, then a random rowid
1111 ** is generated for each row of the table.  TF_HasPrimaryKey is set if
1112 ** the table has any PRIMARY KEY, INTEGER or otherwise.
1113 **
1114 ** Table.tnum is the page number for the root BTree page of the table in the
1115 ** database file.  If Table.iDb is the index of the database table backend
1116 ** in sqlite.aDb[].  0 is for the main database and 1 is for the file that
1117 ** holds temporary tables and indices.  If TF_Ephemeral is set
1118 ** then the table is stored in a file that is automatically deleted
1119 ** when the VDBE cursor to the table is closed.  In this case Table.tnum
1120 ** refers VDBE cursor number that holds the table open, not to the root
1121 ** page number.  Transient tables are used to hold the results of a
1122 ** sub-query that appears instead of a real table name in the FROM clause
1123 ** of a SELECT statement.
1124 */
1125 struct Table {
1126   sqlite3 *dbMem;      /* DB connection used for lookaside allocations. */
1127   char *zName;         /* Name of the table or view */
1128   int iPKey;           /* If not negative, use aCol[iPKey] as the primary key */
1129   int nCol;            /* Number of columns in this table */
1130   Column *aCol;        /* Information about each column */
1131   Index *pIndex;       /* List of SQL indexes on this table. */
1132   int tnum;            /* Root BTree node for this table (see note above) */
1133   Select *pSelect;     /* NULL for tables.  Points to definition if a view. */
1134   u16 nRef;            /* Number of pointers to this Table */
1135   u8 tabFlags;         /* Mask of TF_* values */
1136   u8 keyConf;          /* What to do in case of uniqueness conflict on iPKey */
1137   FKey *pFKey;         /* Linked list of all foreign keys in this table */
1138   char *zColAff;       /* String defining the affinity of each column */
1139 #ifndef SQLITE_OMIT_CHECK
1140   Expr *pCheck;        /* The AND of all CHECK constraints */
1141 #endif
1142 #ifndef SQLITE_OMIT_ALTERTABLE
1143   int addColOffset;    /* Offset in CREATE TABLE stmt to add a new column */
1144 #endif
1145 #ifndef SQLITE_OMIT_VIRTUALTABLE
1146   Module *pMod;        /* Pointer to the implementation of the module */
1147   sqlite3_vtab *pVtab; /* Pointer to the module instance */
1148   int nModuleArg;      /* Number of arguments to the module */
1149   char **azModuleArg;  /* Text of all module args. [0] is module name */
1150 #endif
1151   Trigger *pTrigger;   /* List of triggers stored in pSchema */
1152   Schema *pSchema;     /* Schema that contains this table */
1153   Table *pNextZombie;  /* Next on the Parse.pZombieTab list */
1154 };
1155 
1156 /*
1157 ** Allowed values for Tabe.tabFlags.
1158 */
1159 #define TF_Readonly        0x01    /* Read-only system table */
1160 #define TF_Ephemeral       0x02    /* An ephemeral table */
1161 #define TF_HasPrimaryKey   0x04    /* Table has a primary key */
1162 #define TF_Autoincrement   0x08    /* Integer primary key is autoincrement */
1163 #define TF_Virtual         0x10    /* Is a virtual table */
1164 #define TF_NeedMetadata    0x20    /* aCol[].zType and aCol[].pColl missing */
1165 
1166 
1167 
1168 /*
1169 ** Test to see whether or not a table is a virtual table.  This is
1170 ** done as a macro so that it will be optimized out when virtual
1171 ** table support is omitted from the build.
1172 */
1173 #ifndef SQLITE_OMIT_VIRTUALTABLE
1174 #  define IsVirtual(X)      (((X)->tabFlags & TF_Virtual)!=0)
1175 #  define IsHiddenColumn(X) ((X)->isHidden)
1176 #else
1177 #  define IsVirtual(X)      0
1178 #  define IsHiddenColumn(X) 0
1179 #endif
1180 
1181 /*
1182 ** Each foreign key constraint is an instance of the following structure.
1183 **
1184 ** A foreign key is associated with two tables.  The "from" table is
1185 ** the table that contains the REFERENCES clause that creates the foreign
1186 ** key.  The "to" table is the table that is named in the REFERENCES clause.
1187 ** Consider this example:
1188 **
1189 **     CREATE TABLE ex1(
1190 **       a INTEGER PRIMARY KEY,
1191 **       b INTEGER CONSTRAINT fk1 REFERENCES ex2(x)
1192 **     );
1193 **
1194 ** For foreign key "fk1", the from-table is "ex1" and the to-table is "ex2".
1195 **
1196 ** Each REFERENCES clause generates an instance of the following structure
1197 ** which is attached to the from-table.  The to-table need not exist when
1198 ** the from-table is created.  The existence of the to-table is not checked
1199 ** until an attempt is made to insert data into the from-table.
1200 **
1201 ** The sqlite.aFKey hash table stores pointers to this structure
1202 ** given the name of a to-table.  For each to-table, all foreign keys
1203 ** associated with that table are on a linked list using the FKey.pNextTo
1204 ** field.
1205 */
1206 struct FKey {
1207   Table *pFrom;     /* The table that contains the REFERENCES clause */
1208   FKey *pNextFrom;  /* Next foreign key in pFrom */
1209   char *zTo;        /* Name of table that the key points to */
1210   FKey *pNextTo;    /* Next foreign key that points to zTo */
1211   int nCol;         /* Number of columns in this key */
1212   struct sColMap {  /* Mapping of columns in pFrom to columns in zTo */
1213     int iFrom;         /* Index of column in pFrom */
1214     char *zCol;        /* Name of column in zTo.  If 0 use PRIMARY KEY */
1215   } *aCol;          /* One entry for each of nCol column s */
1216   u8 isDeferred;    /* True if constraint checking is deferred till COMMIT */
1217   u8 updateConf;    /* How to resolve conflicts that occur on UPDATE */
1218   u8 deleteConf;    /* How to resolve conflicts that occur on DELETE */
1219   u8 insertConf;    /* How to resolve conflicts that occur on INSERT */
1220 };
1221 
1222 /*
1223 ** SQLite supports many different ways to resolve a constraint
1224 ** error.  ROLLBACK processing means that a constraint violation
1225 ** causes the operation in process to fail and for the current transaction
1226 ** to be rolled back.  ABORT processing means the operation in process
1227 ** fails and any prior changes from that one operation are backed out,
1228 ** but the transaction is not rolled back.  FAIL processing means that
1229 ** the operation in progress stops and returns an error code.  But prior
1230 ** changes due to the same operation are not backed out and no rollback
1231 ** occurs.  IGNORE means that the particular row that caused the constraint
1232 ** error is not inserted or updated.  Processing continues and no error
1233 ** is returned.  REPLACE means that preexisting database rows that caused
1234 ** a UNIQUE constraint violation are removed so that the new insert or
1235 ** update can proceed.  Processing continues and no error is reported.
1236 **
1237 ** RESTRICT, SETNULL, and CASCADE actions apply only to foreign keys.
1238 ** RESTRICT is the same as ABORT for IMMEDIATE foreign keys and the
1239 ** same as ROLLBACK for DEFERRED keys.  SETNULL means that the foreign
1240 ** key is set to NULL.  CASCADE means that a DELETE or UPDATE of the
1241 ** referenced table row is propagated into the row that holds the
1242 ** foreign key.
1243 **
1244 ** The following symbolic values are used to record which type
1245 ** of action to take.
1246 */
1247 #define OE_None     0   /* There is no constraint to check */
1248 #define OE_Rollback 1   /* Fail the operation and rollback the transaction */
1249 #define OE_Abort    2   /* Back out changes but do no rollback transaction */
1250 #define OE_Fail     3   /* Stop the operation but leave all prior changes */
1251 #define OE_Ignore   4   /* Ignore the error. Do not do the INSERT or UPDATE */
1252 #define OE_Replace  5   /* Delete existing record, then do INSERT or UPDATE */
1253 
1254 #define OE_Restrict 6   /* OE_Abort for IMMEDIATE, OE_Rollback for DEFERRED */
1255 #define OE_SetNull  7   /* Set the foreign key value to NULL */
1256 #define OE_SetDflt  8   /* Set the foreign key value to its default */
1257 #define OE_Cascade  9   /* Cascade the changes */
1258 
1259 #define OE_Default  99  /* Do whatever the default action is */
1260 
1261 
1262 /*
1263 ** An instance of the following structure is passed as the first
1264 ** argument to sqlite3VdbeKeyCompare and is used to control the
1265 ** comparison of the two index keys.
1266 */
1267 struct KeyInfo {
1268   sqlite3 *db;        /* The database connection */
1269   u8 enc;             /* Text encoding - one of the TEXT_Utf* values */
1270   u16 nField;         /* Number of entries in aColl[] */
1271   u8 *aSortOrder;     /* If defined an aSortOrder[i] is true, sort DESC */
1272   CollSeq *aColl[1];  /* Collating sequence for each term of the key */
1273 };
1274 
1275 /*
1276 ** An instance of the following structure holds information about a
1277 ** single index record that has already been parsed out into individual
1278 ** values.
1279 **
1280 ** A record is an object that contains one or more fields of data.
1281 ** Records are used to store the content of a table row and to store
1282 ** the key of an index.  A blob encoding of a record is created by
1283 ** the OP_MakeRecord opcode of the VDBE and is disassembled by the
1284 ** OP_Column opcode.
1285 **
1286 ** This structure holds a record that has already been disassembled
1287 ** into its constituent fields.
1288 */
1289 struct UnpackedRecord {
1290   KeyInfo *pKeyInfo;  /* Collation and sort-order information */
1291   u16 nField;         /* Number of entries in apMem[] */
1292   u16 flags;          /* Boolean settings.  UNPACKED_... below */
1293   Mem *aMem;          /* Values */
1294 };
1295 
1296 /*
1297 ** Allowed values of UnpackedRecord.flags
1298 */
1299 #define UNPACKED_NEED_FREE     0x0001  /* Memory is from sqlite3Malloc() */
1300 #define UNPACKED_NEED_DESTROY  0x0002  /* apMem[]s should all be destroyed */
1301 #define UNPACKED_IGNORE_ROWID  0x0004  /* Ignore trailing rowid on key1 */
1302 #define UNPACKED_INCRKEY       0x0008  /* Make this key an epsilon larger */
1303 #define UNPACKED_PREFIX_MATCH  0x0010  /* A prefix match is considered OK */
1304 
1305 /*
1306 ** Each SQL index is represented in memory by an
1307 ** instance of the following structure.
1308 **
1309 ** The columns of the table that are to be indexed are described
1310 ** by the aiColumn[] field of this structure.  For example, suppose
1311 ** we have the following table and index:
1312 **
1313 **     CREATE TABLE Ex1(c1 int, c2 int, c3 text);
1314 **     CREATE INDEX Ex2 ON Ex1(c3,c1);
1315 **
1316 ** In the Table structure describing Ex1, nCol==3 because there are
1317 ** three columns in the table.  In the Index structure describing
1318 ** Ex2, nColumn==2 since 2 of the 3 columns of Ex1 are indexed.
1319 ** The value of aiColumn is {2, 0}.  aiColumn[0]==2 because the
1320 ** first column to be indexed (c3) has an index of 2 in Ex1.aCol[].
1321 ** The second column to be indexed (c1) has an index of 0 in
1322 ** Ex1.aCol[], hence Ex2.aiColumn[1]==0.
1323 **
1324 ** The Index.onError field determines whether or not the indexed columns
1325 ** must be unique and what to do if they are not.  When Index.onError=OE_None,
1326 ** it means this is not a unique index.  Otherwise it is a unique index
1327 ** and the value of Index.onError indicate the which conflict resolution
1328 ** algorithm to employ whenever an attempt is made to insert a non-unique
1329 ** element.
1330 */
1331 struct Index {
1332   char *zName;     /* Name of this index */
1333   int nColumn;     /* Number of columns in the table used by this index */
1334   int *aiColumn;   /* Which columns are used by this index.  1st is 0 */
1335   unsigned *aiRowEst; /* Result of ANALYZE: Est. rows selected by each column */
1336   Table *pTable;   /* The SQL table being indexed */
1337   int tnum;        /* Page containing root of this index in database file */
1338   u8 onError;      /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
1339   u8 autoIndex;    /* True if is automatically created (ex: by UNIQUE) */
1340   char *zColAff;   /* String defining the affinity of each column */
1341   Index *pNext;    /* The next index associated with the same table */
1342   Schema *pSchema; /* Schema containing this index */
1343   u8 *aSortOrder;  /* Array of size Index.nColumn. True==DESC, False==ASC */
1344   char **azColl;   /* Array of collation sequence names for index */
1345 };
1346 
1347 /*
1348 ** Each token coming out of the lexer is an instance of
1349 ** this structure.  Tokens are also used as part of an expression.
1350 **
1351 ** Note if Token.z==0 then Token.dyn and Token.n are undefined and
1352 ** may contain random values.  Do not make any assumptions about Token.dyn
1353 ** and Token.n when Token.z==0.
1354 */
1355 struct Token {
1356   const unsigned char *z; /* Text of the token.  Not NULL-terminated! */
1357   unsigned dyn  : 1;      /* True for malloced memory, false for static */
1358   unsigned n    : 31;     /* Number of characters in this token */
1359 };
1360 
1361 /*
1362 ** An instance of this structure contains information needed to generate
1363 ** code for a SELECT that contains aggregate functions.
1364 **
1365 ** If Expr.op==TK_AGG_COLUMN or TK_AGG_FUNCTION then Expr.pAggInfo is a
1366 ** pointer to this structure.  The Expr.iColumn field is the index in
1367 ** AggInfo.aCol[] or AggInfo.aFunc[] of information needed to generate
1368 ** code for that node.
1369 **
1370 ** AggInfo.pGroupBy and AggInfo.aFunc.pExpr point to fields within the
1371 ** original Select structure that describes the SELECT statement.  These
1372 ** fields do not need to be freed when deallocating the AggInfo structure.
1373 */
1374 struct AggInfo {
1375   u8 directMode;          /* Direct rendering mode means take data directly
1376                           ** from source tables rather than from accumulators */
1377   u8 useSortingIdx;       /* In direct mode, reference the sorting index rather
1378                           ** than the source table */
1379   int sortingIdx;         /* Cursor number of the sorting index */
1380   ExprList *pGroupBy;     /* The group by clause */
1381   int nSortingColumn;     /* Number of columns in the sorting index */
1382   struct AggInfo_col {    /* For each column used in source tables */
1383     Table *pTab;             /* Source table */
1384     int iTable;              /* Cursor number of the source table */
1385     int iColumn;             /* Column number within the source table */
1386     int iSorterColumn;       /* Column number in the sorting index */
1387     int iMem;                /* Memory location that acts as accumulator */
1388     Expr *pExpr;             /* The original expression */
1389   } *aCol;
1390   int nColumn;            /* Number of used entries in aCol[] */
1391   int nColumnAlloc;       /* Number of slots allocated for aCol[] */
1392   int nAccumulator;       /* Number of columns that show through to the output.
1393                           ** Additional columns are used only as parameters to
1394                           ** aggregate functions */
1395   struct AggInfo_func {   /* For each aggregate function */
1396     Expr *pExpr;             /* Expression encoding the function */
1397     FuncDef *pFunc;          /* The aggregate function implementation */
1398     int iMem;                /* Memory location that acts as accumulator */
1399     int iDistinct;           /* Ephemeral table used to enforce DISTINCT */
1400   } *aFunc;
1401   int nFunc;              /* Number of entries in aFunc[] */
1402   int nFuncAlloc;         /* Number of slots allocated for aFunc[] */
1403 };
1404 
1405 /*
1406 ** Each node of an expression in the parse tree is an instance
1407 ** of this structure.
1408 **
1409 ** Expr.op is the opcode. The integer parser token codes are reused
1410 ** as opcodes here. For example, the parser defines TK_GE to be an integer
1411 ** code representing the ">=" operator. This same integer code is reused
1412 ** to represent the greater-than-or-equal-to operator in the expression
1413 ** tree.
1414 **
1415 ** If the expression is an SQL literal (TK_INTEGER, TK_FLOAT, TK_BLOB,
1416 ** or TK_STRING), then Expr.token contains the text of the SQL literal. If
1417 ** the expression is a variable (TK_VARIABLE), then Expr.token contains the
1418 ** variable name. Finally, if the expression is an SQL function (TK_FUNCTION),
1419 ** then Expr.token contains the name of the function.
1420 **
1421 ** Expr.pRight and Expr.pLeft are the left and right subexpressions of a
1422 ** binary operator. Either or both may be NULL.
1423 **
1424 ** Expr.x.pList is a list of arguments if the expression is an SQL function,
1425 ** a CASE expression or an IN expression of the form "<lhs> IN (<y>, <z>...)".
1426 ** Expr.x.pSelect is used if the expression is a sub-select or an expression of
1427 ** the form "<lhs> IN (SELECT ...)". If the EP_xIsSelect bit is set in the
1428 ** Expr.flags mask, then Expr.x.pSelect is valid. Otherwise, Expr.x.pList is
1429 ** valid.
1430 **
1431 ** An expression of the form ID or ID.ID refers to a column in a table.
1432 ** For such expressions, Expr.op is set to TK_COLUMN and Expr.iTable is
1433 ** the integer cursor number of a VDBE cursor pointing to that table and
1434 ** Expr.iColumn is the column number for the specific column.  If the
1435 ** expression is used as a result in an aggregate SELECT, then the
1436 ** value is also stored in the Expr.iAgg column in the aggregate so that
1437 ** it can be accessed after all aggregates are computed.
1438 **
1439 ** If the expression is an unbound variable marker (a question mark
1440 ** character '?' in the original SQL) then the Expr.iTable holds the index
1441 ** number for that variable.
1442 **
1443 ** If the expression is a subquery then Expr.iColumn holds an integer
1444 ** register number containing the result of the subquery.  If the
1445 ** subquery gives a constant result, then iTable is -1.  If the subquery
1446 ** gives a different answer at different times during statement processing
1447 ** then iTable is the address of a subroutine that computes the subquery.
1448 **
1449 ** If the Expr is of type OP_Column, and the table it is selecting from
1450 ** is a disk table or the "old.*" pseudo-table, then pTab points to the
1451 ** corresponding table definition.
1452 **
1453 ** ALLOCATION NOTES:
1454 **
1455 ** Expr objects can use a lot of memory space in database schema.  To
1456 ** help reduce memory requirements, sometimes an Expr object will be
1457 ** truncated.  And to reduce the number of memory allocations, sometimes
1458 ** two or more Expr objects will be stored in a single memory allocation,
1459 ** together with Expr.token and/or Expr.span strings.
1460 **
1461 ** If the EP_Reduced, EP_SpanToken, and EP_TokenOnly flags are set when
1462 ** an Expr object is truncated.  When EP_Reduced is set, then all
1463 ** the child Expr objects in the Expr.pLeft and Expr.pRight subtrees
1464 ** are contained within the same memory allocation.  Note, however, that
1465 ** the subtrees in Expr.x.pList or Expr.x.pSelect are always separately
1466 ** allocated, regardless of whether or not EP_Reduced is set.
1467 */
1468 struct Expr {
1469   u8 op;                 /* Operation performed by this node */
1470   char affinity;         /* The affinity of the column or 0 if not a column */
1471   VVA_ONLY(u8 vvaFlags;) /* Flags used for VV&A only.  EVVA_* below. */
1472   u16 flags;             /* Various flags.  EP_* See below */
1473   Token token;           /* An operand token */
1474 
1475   /* If the EP_TokenOnly flag is set in the Expr.flags mask, then no
1476   ** space is allocated for the fields below this point. An attempt to
1477   ** access them will result in a segfault or malfunction.
1478   *********************************************************************/
1479 
1480   Token span;            /* Complete text of the expression */
1481 
1482   /* If the EP_SpanToken flag is set in the Expr.flags mask, then no
1483   ** space is allocated for the fields below this point. An attempt to
1484   ** access them will result in a segfault or malfunction.
1485   *********************************************************************/
1486 
1487   Expr *pLeft;           /* Left subnode */
1488   Expr *pRight;          /* Right subnode */
1489   union {
1490     ExprList *pList;     /* Function arguments or in "<expr> IN (<expr-list)" */
1491     Select *pSelect;     /* Used for sub-selects and "<expr> IN (<select>)" */
1492   } x;
1493   CollSeq *pColl;        /* The collation type of the column or 0 */
1494 
1495   /* If the EP_Reduced flag is set in the Expr.flags mask, then no
1496   ** space is allocated for the fields below this point. An attempt to
1497   ** access them will result in a segfault or malfunction.
1498   *********************************************************************/
1499 
1500   int iTable, iColumn;   /* When op==TK_COLUMN, then this expr node means the
1501                          ** iColumn-th field of the iTable-th table. */
1502   AggInfo *pAggInfo;     /* Used by TK_AGG_COLUMN and TK_AGG_FUNCTION */
1503   int iAgg;              /* Which entry in pAggInfo->aCol[] or ->aFunc[] */
1504   int iRightJoinTable;   /* If EP_FromJoin, the right table of the join */
1505   Table *pTab;           /* Table for TK_COLUMN expressions. */
1506 #if SQLITE_MAX_EXPR_DEPTH>0
1507   int nHeight;           /* Height of the tree headed by this node */
1508 #endif
1509 };
1510 
1511 /*
1512 ** The following are the meanings of bits in the Expr.flags field.
1513 */
1514 #define EP_FromJoin   0x0001  /* Originated in ON or USING clause of a join */
1515 #define EP_Agg        0x0002  /* Contains one or more aggregate functions */
1516 #define EP_Resolved   0x0004  /* IDs have been resolved to COLUMNs */
1517 #define EP_Error      0x0008  /* Expression contains one or more errors */
1518 #define EP_Distinct   0x0010  /* Aggregate function with DISTINCT keyword */
1519 #define EP_VarSelect  0x0020  /* pSelect is correlated, not constant */
1520 #define EP_Dequoted   0x0040  /* True if the string has been dequoted */
1521 #define EP_InfixFunc  0x0080  /* True for an infix function: LIKE, GLOB, etc */
1522 #define EP_ExpCollate 0x0100  /* Collating sequence specified explicitly */
1523 #define EP_AnyAff     0x0200  /* Can take a cached column of any affinity */
1524 #define EP_FixedDest  0x0400  /* Result needed in a specific register */
1525 #define EP_IntValue   0x0800  /* Integer value contained in iTable */
1526 #define EP_xIsSelect  0x1000  /* x.pSelect is valid (otherwise x.pList is) */
1527 
1528 #define EP_Reduced    0x2000  /* Expr struct is EXPR_REDUCEDSIZE bytes only */
1529 #define EP_TokenOnly  0x4000  /* Expr struct is EXPR_TOKENONLYSIZE bytes only */
1530 #define EP_SpanToken  0x8000  /* Expr size is EXPR_SPANTOKENSIZE bytes */
1531 
1532 /*
1533 ** The following are the meanings of bits in the Expr.vvaFlags field.
1534 ** This information is only used when SQLite is compiled with
1535 ** SQLITE_DEBUG defined.
1536 */
1537 #ifndef NDEBUG
1538 #define EVVA_ReadOnlyToken  0x01  /* Expr.token.z is read-only */
1539 #endif
1540 
1541 /*
1542 ** These macros can be used to test, set, or clear bits in the
1543 ** Expr.flags field.
1544 */
1545 #define ExprHasProperty(E,P)     (((E)->flags&(P))==(P))
1546 #define ExprHasAnyProperty(E,P)  (((E)->flags&(P))!=0)
1547 #define ExprSetProperty(E,P)     (E)->flags|=(P)
1548 #define ExprClearProperty(E,P)   (E)->flags&=~(P)
1549 
1550 /*
1551 ** Macros to determine the number of bytes required by a normal Expr
1552 ** struct, an Expr struct with the EP_Reduced flag set in Expr.flags
1553 ** and an Expr struct with the EP_TokenOnly flag set.
1554 */
1555 #define EXPR_FULLSIZE           sizeof(Expr)           /* Full size */
1556 #define EXPR_REDUCEDSIZE        offsetof(Expr,iTable)  /* Common features */
1557 #define EXPR_SPANTOKENSIZE      offsetof(Expr,pLeft)   /* Fewer features */
1558 #define EXPR_TOKENONLYSIZE      offsetof(Expr,span)    /* Smallest possible */
1559 
1560 /*
1561 ** Flags passed to the sqlite3ExprDup() function. See the header comment
1562 ** above sqlite3ExprDup() for details.
1563 */
1564 #define EXPRDUP_REDUCE         0x0001  /* Used reduced-size Expr nodes */
1565 #define EXPRDUP_SPAN           0x0002  /* Make a copy of Expr.span */
1566 
1567 /*
1568 ** A list of expressions.  Each expression may optionally have a
1569 ** name.  An expr/name combination can be used in several ways, such
1570 ** as the list of "expr AS ID" fields following a "SELECT" or in the
1571 ** list of "ID = expr" items in an UPDATE.  A list of expressions can
1572 ** also be used as the argument to a function, in which case the a.zName
1573 ** field is not used.
1574 */
1575 struct ExprList {
1576   int nExpr;             /* Number of expressions on the list */
1577   int nAlloc;            /* Number of entries allocated below */
1578   int iECursor;          /* VDBE Cursor associated with this ExprList */
1579   struct ExprList_item {
1580     Expr *pExpr;           /* The list of expressions */
1581     char *zName;           /* Token associated with this expression */
1582     u8 sortOrder;          /* 1 for DESC or 0 for ASC */
1583     u8 done;               /* A flag to indicate when processing is finished */
1584     u16 iCol;              /* For ORDER BY, column number in result set */
1585     u16 iAlias;            /* Index into Parse.aAlias[] for zName */
1586   } *a;                  /* One entry for each expression */
1587 };
1588 
1589 /*
1590 ** An instance of this structure can hold a simple list of identifiers,
1591 ** such as the list "a,b,c" in the following statements:
1592 **
1593 **      INSERT INTO t(a,b,c) VALUES ...;
1594 **      CREATE INDEX idx ON t(a,b,c);
1595 **      CREATE TRIGGER trig BEFORE UPDATE ON t(a,b,c) ...;
1596 **
1597 ** The IdList.a.idx field is used when the IdList represents the list of
1598 ** column names after a table name in an INSERT statement.  In the statement
1599 **
1600 **     INSERT INTO t(a,b,c) ...
1601 **
1602 ** If "a" is the k-th column of table "t", then IdList.a[0].idx==k.
1603 */
1604 struct IdList {
1605   struct IdList_item {
1606     char *zName;      /* Name of the identifier */
1607     int idx;          /* Index in some Table.aCol[] of a column named zName */
1608   } *a;
1609   int nId;         /* Number of identifiers on the list */
1610   int nAlloc;      /* Number of entries allocated for a[] below */
1611 };
1612 
1613 /*
1614 ** The bitmask datatype defined below is used for various optimizations.
1615 **
1616 ** Changing this from a 64-bit to a 32-bit type limits the number of
1617 ** tables in a join to 32 instead of 64.  But it also reduces the size
1618 ** of the library by 738 bytes on ix86.
1619 */
1620 typedef u64 Bitmask;
1621 
1622 /*
1623 ** The number of bits in a Bitmask.  "BMS" means "BitMask Size".
1624 */
1625 #define BMS  ((int)(sizeof(Bitmask)*8))
1626 
1627 /*
1628 ** The following structure describes the FROM clause of a SELECT statement.
1629 ** Each table or subquery in the FROM clause is a separate element of
1630 ** the SrcList.a[] array.
1631 **
1632 ** With the addition of multiple database support, the following structure
1633 ** can also be used to describe a particular table such as the table that
1634 ** is modified by an INSERT, DELETE, or UPDATE statement.  In standard SQL,
1635 ** such a table must be a simple name: ID.  But in SQLite, the table can
1636 ** now be identified by a database name, a dot, then the table name: ID.ID.
1637 **
1638 ** The jointype starts out showing the join type between the current table
1639 ** and the next table on the list.  The parser builds the list this way.
1640 ** But sqlite3SrcListShiftJoinType() later shifts the jointypes so that each
1641 ** jointype expresses the join between the table and the previous table.
1642 */
1643 struct SrcList {
1644   i16 nSrc;        /* Number of tables or subqueries in the FROM clause */
1645   i16 nAlloc;      /* Number of entries allocated in a[] below */
1646   struct SrcList_item {
1647     char *zDatabase;  /* Name of database holding this table */
1648     char *zName;      /* Name of the table */
1649     char *zAlias;     /* The "B" part of a "A AS B" phrase.  zName is the "A" */
1650     Table *pTab;      /* An SQL table corresponding to zName */
1651     Select *pSelect;  /* A SELECT statement used in place of a table name */
1652     u8 isPopulated;   /* Temporary table associated with SELECT is populated */
1653     u8 jointype;      /* Type of join between this able and the previous */
1654     u8 notIndexed;    /* True if there is a NOT INDEXED clause */
1655     int iCursor;      /* The VDBE cursor number used to access this table */
1656     Expr *pOn;        /* The ON clause of a join */
1657     IdList *pUsing;   /* The USING clause of a join */
1658     Bitmask colUsed;  /* Bit N (1<<N) set if column N of pTab is used */
1659     char *zIndex;     /* Identifier from "INDEXED BY <zIndex>" clause */
1660     Index *pIndex;    /* Index structure corresponding to zIndex, if any */
1661   } a[1];             /* One entry for each identifier on the list */
1662 };
1663 
1664 /*
1665 ** Permitted values of the SrcList.a.jointype field
1666 */
1667 #define JT_INNER     0x0001    /* Any kind of inner or cross join */
1668 #define JT_CROSS     0x0002    /* Explicit use of the CROSS keyword */
1669 #define JT_NATURAL   0x0004    /* True for a "natural" join */
1670 #define JT_LEFT      0x0008    /* Left outer join */
1671 #define JT_RIGHT     0x0010    /* Right outer join */
1672 #define JT_OUTER     0x0020    /* The "OUTER" keyword is present */
1673 #define JT_ERROR     0x0040    /* unknown or unsupported join type */
1674 
1675 
1676 /*
1677 ** A WherePlan object holds information that describes a lookup
1678 ** strategy.
1679 **
1680 ** This object is intended to be opaque outside of the where.c module.
1681 ** It is included here only so that that compiler will know how big it
1682 ** is.  None of the fields in this object should be used outside of
1683 ** the where.c module.
1684 **
1685 ** Within the union, pIdx is only used when wsFlags&WHERE_INDEXED is true.
1686 ** pTerm is only used when wsFlags&WHERE_MULTI_OR is true.  And pVtabIdx
1687 ** is only used when wsFlags&WHERE_VIRTUALTABLE is true.  It is never the
1688 ** case that more than one of these conditions is true.
1689 */
1690 struct WherePlan {
1691   u32 wsFlags;                   /* WHERE_* flags that describe the strategy */
1692   u32 nEq;                       /* Number of == constraints */
1693   union {
1694     Index *pIdx;                   /* Index when WHERE_INDEXED is true */
1695     struct WhereTerm *pTerm;       /* WHERE clause term for OR-search */
1696     sqlite3_index_info *pVtabIdx;  /* Virtual table index to use */
1697   } u;
1698 };
1699 
1700 /*
1701 ** For each nested loop in a WHERE clause implementation, the WhereInfo
1702 ** structure contains a single instance of this structure.  This structure
1703 ** is intended to be private the the where.c module and should not be
1704 ** access or modified by other modules.
1705 **
1706 ** The pIdxInfo field is used to help pick the best index on a
1707 ** virtual table.  The pIdxInfo pointer contains indexing
1708 ** information for the i-th table in the FROM clause before reordering.
1709 ** All the pIdxInfo pointers are freed by whereInfoFree() in where.c.
1710 ** All other information in the i-th WhereLevel object for the i-th table
1711 ** after FROM clause ordering.
1712 */
1713 struct WhereLevel {
1714   WherePlan plan;       /* query plan for this element of the FROM clause */
1715   int iLeftJoin;        /* Memory cell used to implement LEFT OUTER JOIN */
1716   int iTabCur;          /* The VDBE cursor used to access the table */
1717   int iIdxCur;          /* The VDBE cursor used to access pIdx */
1718   int addrBrk;          /* Jump here to break out of the loop */
1719   int addrNxt;          /* Jump here to start the next IN combination */
1720   int addrCont;         /* Jump here to continue with the next loop cycle */
1721   int addrFirst;        /* First instruction of interior of the loop */
1722   u8 iFrom;             /* Which entry in the FROM clause */
1723   u8 op, p5;            /* Opcode and P5 of the opcode that ends the loop */
1724   int p1, p2;           /* Operands of the opcode used to ends the loop */
1725   union {               /* Information that depends on plan.wsFlags */
1726     struct {
1727       int nIn;              /* Number of entries in aInLoop[] */
1728       struct InLoop {
1729         int iCur;              /* The VDBE cursor used by this IN operator */
1730         int addrInTop;         /* Top of the IN loop */
1731       } *aInLoop;           /* Information about each nested IN operator */
1732     } in;                 /* Used when plan.wsFlags&WHERE_IN_ABLE */
1733   } u;
1734 
1735   /* The following field is really not part of the current level.  But
1736   ** we need a place to cache virtual table index information for each
1737   ** virtual table in the FROM clause and the WhereLevel structure is
1738   ** a convenient place since there is one WhereLevel for each FROM clause
1739   ** element.
1740   */
1741   sqlite3_index_info *pIdxInfo;  /* Index info for n-th source table */
1742 };
1743 
1744 /*
1745 ** Flags appropriate for the wctrlFlags parameter of sqlite3WhereBegin()
1746 ** and the WhereInfo.wctrlFlags member.
1747 */
1748 #define WHERE_ORDERBY_NORMAL   0x0000 /* No-op */
1749 #define WHERE_ORDERBY_MIN      0x0001 /* ORDER BY processing for min() func */
1750 #define WHERE_ORDERBY_MAX      0x0002 /* ORDER BY processing for max() func */
1751 #define WHERE_ONEPASS_DESIRED  0x0004 /* Want to do one-pass UPDATE/DELETE */
1752 #define WHERE_DUPLICATES_OK    0x0008 /* Ok to return a row more than once */
1753 #define WHERE_OMIT_OPEN        0x0010 /* Table cursor are already open */
1754 #define WHERE_OMIT_CLOSE       0x0020 /* Omit close of table & index cursors */
1755 #define WHERE_FORCE_TABLE      0x0040 /* Do not use an index-only search */
1756 
1757 /*
1758 ** The WHERE clause processing routine has two halves.  The
1759 ** first part does the start of the WHERE loop and the second
1760 ** half does the tail of the WHERE loop.  An instance of
1761 ** this structure is returned by the first half and passed
1762 ** into the second half to give some continuity.
1763 */
1764 struct WhereInfo {
1765   Parse *pParse;       /* Parsing and code generating context */
1766   u16 wctrlFlags;      /* Flags originally passed to sqlite3WhereBegin() */
1767   u8 okOnePass;        /* Ok to use one-pass algorithm for UPDATE or DELETE */
1768   SrcList *pTabList;             /* List of tables in the join */
1769   int iTop;                      /* The very beginning of the WHERE loop */
1770   int iContinue;                 /* Jump here to continue with next record */
1771   int iBreak;                    /* Jump here to break out of the loop */
1772   int nLevel;                    /* Number of nested loop */
1773   struct WhereClause *pWC;       /* Decomposition of the WHERE clause */
1774   WhereLevel a[1];               /* Information about each nest loop in WHERE */
1775 };
1776 
1777 /*
1778 ** A NameContext defines a context in which to resolve table and column
1779 ** names.  The context consists of a list of tables (the pSrcList) field and
1780 ** a list of named expression (pEList).  The named expression list may
1781 ** be NULL.  The pSrc corresponds to the FROM clause of a SELECT or
1782 ** to the table being operated on by INSERT, UPDATE, or DELETE.  The
1783 ** pEList corresponds to the result set of a SELECT and is NULL for
1784 ** other statements.
1785 **
1786 ** NameContexts can be nested.  When resolving names, the inner-most
1787 ** context is searched first.  If no match is found, the next outer
1788 ** context is checked.  If there is still no match, the next context
1789 ** is checked.  This process continues until either a match is found
1790 ** or all contexts are check.  When a match is found, the nRef member of
1791 ** the context containing the match is incremented.
1792 **
1793 ** Each subquery gets a new NameContext.  The pNext field points to the
1794 ** NameContext in the parent query.  Thus the process of scanning the
1795 ** NameContext list corresponds to searching through successively outer
1796 ** subqueries looking for a match.
1797 */
1798 struct NameContext {
1799   Parse *pParse;       /* The parser */
1800   SrcList *pSrcList;   /* One or more tables used to resolve names */
1801   ExprList *pEList;    /* Optional list of named expressions */
1802   int nRef;            /* Number of names resolved by this context */
1803   int nErr;            /* Number of errors encountered while resolving names */
1804   u8 allowAgg;         /* Aggregate functions allowed here */
1805   u8 hasAgg;           /* True if aggregates are seen */
1806   u8 isCheck;          /* True if resolving names in a CHECK constraint */
1807   int nDepth;          /* Depth of subquery recursion. 1 for no recursion */
1808   AggInfo *pAggInfo;   /* Information about aggregates at this level */
1809   NameContext *pNext;  /* Next outer name context.  NULL for outermost */
1810 };
1811 
1812 /*
1813 ** An instance of the following structure contains all information
1814 ** needed to generate code for a single SELECT statement.
1815 **
1816 ** nLimit is set to -1 if there is no LIMIT clause.  nOffset is set to 0.
1817 ** If there is a LIMIT clause, the parser sets nLimit to the value of the
1818 ** limit and nOffset to the value of the offset (or 0 if there is not
1819 ** offset).  But later on, nLimit and nOffset become the memory locations
1820 ** in the VDBE that record the limit and offset counters.
1821 **
1822 ** addrOpenEphm[] entries contain the address of OP_OpenEphemeral opcodes.
1823 ** These addresses must be stored so that we can go back and fill in
1824 ** the P4_KEYINFO and P2 parameters later.  Neither the KeyInfo nor
1825 ** the number of columns in P2 can be computed at the same time
1826 ** as the OP_OpenEphm instruction is coded because not
1827 ** enough information about the compound query is known at that point.
1828 ** The KeyInfo for addrOpenTran[0] and [1] contains collating sequences
1829 ** for the result set.  The KeyInfo for addrOpenTran[2] contains collating
1830 ** sequences for the ORDER BY clause.
1831 */
1832 struct Select {
1833   ExprList *pEList;      /* The fields of the result */
1834   u8 op;                 /* One of: TK_UNION TK_ALL TK_INTERSECT TK_EXCEPT */
1835   char affinity;         /* MakeRecord with this affinity for SRT_Set */
1836   u16 selFlags;          /* Various SF_* values */
1837   SrcList *pSrc;         /* The FROM clause */
1838   Expr *pWhere;          /* The WHERE clause */
1839   ExprList *pGroupBy;    /* The GROUP BY clause */
1840   Expr *pHaving;         /* The HAVING clause */
1841   ExprList *pOrderBy;    /* The ORDER BY clause */
1842   Select *pPrior;        /* Prior select in a compound select statement */
1843   Select *pNext;         /* Next select to the left in a compound */
1844   Select *pRightmost;    /* Right-most select in a compound select statement */
1845   Expr *pLimit;          /* LIMIT expression. NULL means not used. */
1846   Expr *pOffset;         /* OFFSET expression. NULL means not used. */
1847   int iLimit, iOffset;   /* Memory registers holding LIMIT & OFFSET counters */
1848   int addrOpenEphm[3];   /* OP_OpenEphem opcodes related to this select */
1849 };
1850 
1851 /*
1852 ** Allowed values for Select.selFlags.  The "SF" prefix stands for
1853 ** "Select Flag".
1854 */
1855 #define SF_Distinct        0x0001  /* Output should be DISTINCT */
1856 #define SF_Resolved        0x0002  /* Identifiers have been resolved */
1857 #define SF_Aggregate       0x0004  /* Contains aggregate functions */
1858 #define SF_UsesEphemeral   0x0008  /* Uses the OpenEphemeral opcode */
1859 #define SF_Expanded        0x0010  /* sqlite3SelectExpand() called on this */
1860 #define SF_HasTypeInfo     0x0020  /* FROM subqueries have Table metadata */
1861 
1862 
1863 /*
1864 ** The results of a select can be distributed in several ways.  The
1865 ** "SRT" prefix means "SELECT Result Type".
1866 */
1867 #define SRT_Union        1  /* Store result as keys in an index */
1868 #define SRT_Except       2  /* Remove result from a UNION index */
1869 #define SRT_Exists       3  /* Store 1 if the result is not empty */
1870 #define SRT_Discard      4  /* Do not save the results anywhere */
1871 
1872 /* The ORDER BY clause is ignored for all of the above */
1873 #define IgnorableOrderby(X) ((X->eDest)<=SRT_Discard)
1874 
1875 #define SRT_Output       5  /* Output each row of result */
1876 #define SRT_Mem          6  /* Store result in a memory cell */
1877 #define SRT_Set          7  /* Store results as keys in an index */
1878 #define SRT_Table        8  /* Store result as data with an automatic rowid */
1879 #define SRT_EphemTab     9  /* Create transient tab and store like SRT_Table */
1880 #define SRT_Coroutine   10  /* Generate a single row of result */
1881 
1882 /*
1883 ** A structure used to customize the behavior of sqlite3Select(). See
1884 ** comments above sqlite3Select() for details.
1885 */
1886 typedef struct SelectDest SelectDest;
1887 struct SelectDest {
1888   u8 eDest;         /* How to dispose of the results */
1889   u8 affinity;      /* Affinity used when eDest==SRT_Set */
1890   int iParm;        /* A parameter used by the eDest disposal method */
1891   int iMem;         /* Base register where results are written */
1892   int nMem;         /* Number of registers allocated */
1893 };
1894 
1895 /*
1896 ** Size of the column cache
1897 */
1898 #ifndef SQLITE_N_COLCACHE
1899 # define SQLITE_N_COLCACHE 10
1900 #endif
1901 
1902 /*
1903 ** An SQL parser context.  A copy of this structure is passed through
1904 ** the parser and down into all the parser action routine in order to
1905 ** carry around information that is global to the entire parse.
1906 **
1907 ** The structure is divided into two parts.  When the parser and code
1908 ** generate call themselves recursively, the first part of the structure
1909 ** is constant but the second part is reset at the beginning and end of
1910 ** each recursion.
1911 **
1912 ** The nTableLock and aTableLock variables are only used if the shared-cache
1913 ** feature is enabled (if sqlite3Tsd()->useSharedData is true). They are
1914 ** used to store the set of table-locks required by the statement being
1915 ** compiled. Function sqlite3TableLock() is used to add entries to the
1916 ** list.
1917 */
1918 struct Parse {
1919   sqlite3 *db;         /* The main database structure */
1920   int rc;              /* Return code from execution */
1921   char *zErrMsg;       /* An error message */
1922   Vdbe *pVdbe;         /* An engine for executing database bytecode */
1923   u8 colNamesSet;      /* TRUE after OP_ColumnName has been issued to pVdbe */
1924   u8 nameClash;        /* A permanent table name clashes with temp table name */
1925   u8 checkSchema;      /* Causes schema cookie check after an error */
1926   u8 nested;           /* Number of nested calls to the parser/code generator */
1927   u8 parseError;       /* True after a parsing error.  Ticket #1794 */
1928   u8 nTempReg;         /* Number of temporary registers in aTempReg[] */
1929   u8 nTempInUse;       /* Number of aTempReg[] currently checked out */
1930   int aTempReg[8];     /* Holding area for temporary registers */
1931   int nRangeReg;       /* Size of the temporary register block */
1932   int iRangeReg;       /* First register in temporary register block */
1933   int nErr;            /* Number of errors seen */
1934   int nTab;            /* Number of previously allocated VDBE cursors */
1935   int nMem;            /* Number of memory cells used so far */
1936   int nSet;            /* Number of sets used so far */
1937   int ckBase;          /* Base register of data during check constraints */
1938   int iCacheLevel;     /* ColCache valid when aColCache[].iLevel<=iCacheLevel */
1939   int iCacheCnt;       /* Counter used to generate aColCache[].lru values */
1940   u8 nColCache;        /* Number of entries in the column cache */
1941   u8 iColCache;        /* Next entry of the cache to replace */
1942   struct yColCache {
1943     int iTable;           /* Table cursor number */
1944     int iColumn;          /* Table column number */
1945     u8 affChange;         /* True if this register has had an affinity change */
1946     u8 tempReg;           /* iReg is a temp register that needs to be freed */
1947     int iLevel;           /* Nesting level */
1948     int iReg;             /* Reg with value of this column. 0 means none. */
1949     int lru;              /* Least recently used entry has the smallest value */
1950   } aColCache[SQLITE_N_COLCACHE];  /* One for each column cache entry */
1951   u32 writeMask;       /* Start a write transaction on these databases */
1952   u32 cookieMask;      /* Bitmask of schema verified databases */
1953   int cookieGoto;      /* Address of OP_Goto to cookie verifier subroutine */
1954   int cookieValue[SQLITE_MAX_ATTACHED+2];  /* Values of cookies to verify */
1955 #ifndef SQLITE_OMIT_SHARED_CACHE
1956   int nTableLock;        /* Number of locks in aTableLock */
1957   TableLock *aTableLock; /* Required table locks for shared-cache mode */
1958 #endif
1959   int regRowid;        /* Register holding rowid of CREATE TABLE entry */
1960   int regRoot;         /* Register holding root page number for new objects */
1961 
1962   /* Above is constant between recursions.  Below is reset before and after
1963   ** each recursion */
1964 
1965   int nVar;            /* Number of '?' variables seen in the SQL so far */
1966   int nVarExpr;        /* Number of used slots in apVarExpr[] */
1967   int nVarExprAlloc;   /* Number of allocated slots in apVarExpr[] */
1968   Expr **apVarExpr;    /* Pointers to :aaa and $aaaa wildcard expressions */
1969   int nAlias;          /* Number of aliased result set columns */
1970   int nAliasAlloc;     /* Number of allocated slots for aAlias[] */
1971   int *aAlias;         /* Register used to hold aliased result */
1972   u8 explain;          /* True if the EXPLAIN flag is found on the query */
1973   Token sErrToken;     /* The token at which the error occurred */
1974   Token sNameToken;    /* Token with unqualified schema object name */
1975   Token sLastToken;    /* The last token parsed */
1976   const char *zSql;    /* All SQL text */
1977   const char *zTail;   /* All SQL text past the last semicolon parsed */
1978   Table *pNewTable;    /* A table being constructed by CREATE TABLE */
1979   Trigger *pNewTrigger;     /* Trigger under construct by a CREATE TRIGGER */
1980   TriggerStack *trigStack;  /* Trigger actions being coded */
1981   const char *zAuthContext; /* The 6th parameter to db->xAuth callbacks */
1982 #ifndef SQLITE_OMIT_VIRTUALTABLE
1983   Token sArg;                /* Complete text of a module argument */
1984   u8 declareVtab;            /* True if inside sqlite3_declare_vtab() */
1985   int nVtabLock;             /* Number of virtual tables to lock */
1986   Table **apVtabLock;        /* Pointer to virtual tables needing locking */
1987 #endif
1988   int nHeight;            /* Expression tree height of current sub-select */
1989   Table *pZombieTab;      /* List of Table objects to delete after code gen */
1990 };
1991 
1992 #ifdef SQLITE_OMIT_VIRTUALTABLE
1993   #define IN_DECLARE_VTAB 0
1994 #else
1995   #define IN_DECLARE_VTAB (pParse->declareVtab)
1996 #endif
1997 
1998 /*
1999 ** An instance of the following structure can be declared on a stack and used
2000 ** to save the Parse.zAuthContext value so that it can be restored later.
2001 */
2002 struct AuthContext {
2003   const char *zAuthContext;   /* Put saved Parse.zAuthContext here */
2004   Parse *pParse;              /* The Parse structure */
2005 };
2006 
2007 /*
2008 ** Bitfield flags for P2 value in OP_Insert and OP_Delete
2009 */
2010 #define OPFLAG_NCHANGE   1    /* Set to update db->nChange */
2011 #define OPFLAG_LASTROWID 2    /* Set to update db->lastRowid */
2012 #define OPFLAG_ISUPDATE  4    /* This OP_Insert is an sql UPDATE */
2013 #define OPFLAG_APPEND    8    /* This is likely to be an append */
2014 
2015 /*
2016  * Each trigger present in the database schema is stored as an instance of
2017  * struct Trigger.
2018  *
2019  * Pointers to instances of struct Trigger are stored in two ways.
2020  * 1. In the "trigHash" hash table (part of the sqlite3* that represents the
2021  *    database). This allows Trigger structures to be retrieved by name.
2022  * 2. All triggers associated with a single table form a linked list, using the
2023  *    pNext member of struct Trigger. A pointer to the first element of the
2024  *    linked list is stored as the "pTrigger" member of the associated
2025  *    struct Table.
2026  *
2027  * The "step_list" member points to the first element of a linked list
2028  * containing the SQL statements specified as the trigger program.
2029  */
2030 struct Trigger {
2031   char *name;             /* The name of the trigger                        */
2032   char *table;            /* The table or view to which the trigger applies */
2033   u8 op;                  /* One of TK_DELETE, TK_UPDATE, TK_INSERT         */
2034   u8 tr_tm;               /* One of TRIGGER_BEFORE, TRIGGER_AFTER */
2035   Expr *pWhen;            /* The WHEN clause of the expression (may be NULL) */
2036   IdList *pColumns;       /* If this is an UPDATE OF <column-list> trigger,
2037                              the <column-list> is stored here */
2038   Token nameToken;        /* Token containing zName. Use during parsing only */
2039   Schema *pSchema;        /* Schema containing the trigger */
2040   Schema *pTabSchema;     /* Schema containing the table */
2041   TriggerStep *step_list; /* Link list of trigger program steps             */
2042   Trigger *pNext;         /* Next trigger associated with the table */
2043 };
2044 
2045 /*
2046 ** A trigger is either a BEFORE or an AFTER trigger.  The following constants
2047 ** determine which.
2048 **
2049 ** If there are multiple triggers, you might of some BEFORE and some AFTER.
2050 ** In that cases, the constants below can be ORed together.
2051 */
2052 #define TRIGGER_BEFORE  1
2053 #define TRIGGER_AFTER   2
2054 
2055 /*
2056  * An instance of struct TriggerStep is used to store a single SQL statement
2057  * that is a part of a trigger-program.
2058  *
2059  * Instances of struct TriggerStep are stored in a singly linked list (linked
2060  * using the "pNext" member) referenced by the "step_list" member of the
2061  * associated struct Trigger instance. The first element of the linked list is
2062  * the first step of the trigger-program.
2063  *
2064  * The "op" member indicates whether this is a "DELETE", "INSERT", "UPDATE" or
2065  * "SELECT" statement. The meanings of the other members is determined by the
2066  * value of "op" as follows:
2067  *
2068  * (op == TK_INSERT)
2069  * orconf    -> stores the ON CONFLICT algorithm
2070  * pSelect   -> If this is an INSERT INTO ... SELECT ... statement, then
2071  *              this stores a pointer to the SELECT statement. Otherwise NULL.
2072  * target    -> A token holding the name of the table to insert into.
2073  * pExprList -> If this is an INSERT INTO ... VALUES ... statement, then
2074  *              this stores values to be inserted. Otherwise NULL.
2075  * pIdList   -> If this is an INSERT INTO ... (<column-names>) VALUES ...
2076  *              statement, then this stores the column-names to be
2077  *              inserted into.
2078  *
2079  * (op == TK_DELETE)
2080  * target    -> A token holding the name of the table to delete from.
2081  * pWhere    -> The WHERE clause of the DELETE statement if one is specified.
2082  *              Otherwise NULL.
2083  *
2084  * (op == TK_UPDATE)
2085  * target    -> A token holding the name of the table to update rows of.
2086  * pWhere    -> The WHERE clause of the UPDATE statement if one is specified.
2087  *              Otherwise NULL.
2088  * pExprList -> A list of the columns to update and the expressions to update
2089  *              them to. See sqlite3Update() documentation of "pChanges"
2090  *              argument.
2091  *
2092  */
2093 struct TriggerStep {
2094   int op;              /* One of TK_DELETE, TK_UPDATE, TK_INSERT, TK_SELECT */
2095   int orconf;          /* OE_Rollback etc. */
2096   Trigger *pTrig;      /* The trigger that this step is a part of */
2097 
2098   Select *pSelect;     /* Valid for SELECT and sometimes
2099                           INSERT steps (when pExprList == 0) */
2100   Token target;        /* Valid for DELETE, UPDATE, INSERT steps */
2101   Expr *pWhere;        /* Valid for DELETE, UPDATE steps */
2102   ExprList *pExprList; /* Valid for UPDATE statements and sometimes
2103                            INSERT steps (when pSelect == 0)         */
2104   IdList *pIdList;     /* Valid for INSERT statements only */
2105   TriggerStep *pNext;  /* Next in the link-list */
2106   TriggerStep *pLast;  /* Last element in link-list. Valid for 1st elem only */
2107 };
2108 
2109 /*
2110  * An instance of struct TriggerStack stores information required during code
2111  * generation of a single trigger program. While the trigger program is being
2112  * coded, its associated TriggerStack instance is pointed to by the
2113  * "pTriggerStack" member of the Parse structure.
2114  *
2115  * The pTab member points to the table that triggers are being coded on. The
2116  * newIdx member contains the index of the vdbe cursor that points at the temp
2117  * table that stores the new.* references. If new.* references are not valid
2118  * for the trigger being coded (for example an ON DELETE trigger), then newIdx
2119  * is set to -1. The oldIdx member is analogous to newIdx, for old.* references.
2120  *
2121  * The ON CONFLICT policy to be used for the trigger program steps is stored
2122  * as the orconf member. If this is OE_Default, then the ON CONFLICT clause
2123  * specified for individual triggers steps is used.
2124  *
2125  * struct TriggerStack has a "pNext" member, to allow linked lists to be
2126  * constructed. When coding nested triggers (triggers fired by other triggers)
2127  * each nested trigger stores its parent trigger's TriggerStack as the "pNext"
2128  * pointer. Once the nested trigger has been coded, the pNext value is restored
2129  * to the pTriggerStack member of the Parse stucture and coding of the parent
2130  * trigger continues.
2131  *
2132  * Before a nested trigger is coded, the linked list pointed to by the
2133  * pTriggerStack is scanned to ensure that the trigger is not about to be coded
2134  * recursively. If this condition is detected, the nested trigger is not coded.
2135  */
2136 struct TriggerStack {
2137   Table *pTab;         /* Table that triggers are currently being coded on */
2138   int newIdx;          /* Index of vdbe cursor to "new" temp table */
2139   int oldIdx;          /* Index of vdbe cursor to "old" temp table */
2140   u32 newColMask;
2141   u32 oldColMask;
2142   int orconf;          /* Current orconf policy */
2143   int ignoreJump;      /* where to jump to for a RAISE(IGNORE) */
2144   Trigger *pTrigger;   /* The trigger currently being coded */
2145   TriggerStack *pNext; /* Next trigger down on the trigger stack */
2146 };
2147 
2148 /*
2149 ** The following structure contains information used by the sqliteFix...
2150 ** routines as they walk the parse tree to make database references
2151 ** explicit.
2152 */
2153 typedef struct DbFixer DbFixer;
2154 struct DbFixer {
2155   Parse *pParse;      /* The parsing context.  Error messages written here */
2156   const char *zDb;    /* Make sure all objects are contained in this database */
2157   const char *zType;  /* Type of the container - used for error messages */
2158   const Token *pName; /* Name of the container - used for error messages */
2159 };
2160 
2161 /*
2162 ** An objected used to accumulate the text of a string where we
2163 ** do not necessarily know how big the string will be in the end.
2164 */
2165 struct StrAccum {
2166   sqlite3 *db;         /* Optional database for lookaside.  Can be NULL */
2167   char *zBase;         /* A base allocation.  Not from malloc. */
2168   char *zText;         /* The string collected so far */
2169   int  nChar;          /* Length of the string so far */
2170   int  nAlloc;         /* Amount of space allocated in zText */
2171   int  mxAlloc;        /* Maximum allowed string length */
2172   u8   mallocFailed;   /* Becomes true if any memory allocation fails */
2173   u8   useMalloc;      /* True if zText is enlargeable using realloc */
2174   u8   tooBig;         /* Becomes true if string size exceeds limits */
2175 };
2176 
2177 /*
2178 ** A pointer to this structure is used to communicate information
2179 ** from sqlite3Init and OP_ParseSchema into the sqlite3InitCallback.
2180 */
2181 typedef struct {
2182   sqlite3 *db;        /* The database being initialized */
2183   int iDb;            /* 0 for main database.  1 for TEMP, 2.. for ATTACHed */
2184   char **pzErrMsg;    /* Error message stored here */
2185   int rc;             /* Result code stored here */
2186 } InitData;
2187 
2188 /*
2189 ** Structure containing global configuration data for the SQLite library.
2190 **
2191 ** This structure also contains some state information.
2192 */
2193 struct Sqlite3Config {
2194   int bMemstat;                     /* True to enable memory status */
2195   int bCoreMutex;                   /* True to enable core mutexing */
2196   int bFullMutex;                   /* True to enable full mutexing */
2197   int mxStrlen;                     /* Maximum string length */
2198   int szLookaside;                  /* Default lookaside buffer size */
2199   int nLookaside;                   /* Default lookaside buffer count */
2200   sqlite3_mem_methods m;            /* Low-level memory allocation interface */
2201   sqlite3_mutex_methods mutex;      /* Low-level mutex interface */
2202   sqlite3_pcache_methods pcache;    /* Low-level page-cache interface */
2203   void *pHeap;                      /* Heap storage space */
2204   int nHeap;                        /* Size of pHeap[] */
2205   int mnReq, mxReq;                 /* Min and max heap requests sizes */
2206   void *pScratch;                   /* Scratch memory */
2207   int szScratch;                    /* Size of each scratch buffer */
2208   int nScratch;                     /* Number of scratch buffers */
2209   void *pPage;                      /* Page cache memory */
2210   int szPage;                       /* Size of each page in pPage[] */
2211   int nPage;                        /* Number of pages in pPage[] */
2212   int mxParserStack;                /* maximum depth of the parser stack */
2213   int sharedCacheEnabled;           /* true if shared-cache mode enabled */
2214   /* The above might be initialized to non-zero.  The following need to always
2215   ** initially be zero, however. */
2216   int isInit;                       /* True after initialization has finished */
2217   int inProgress;                   /* True while initialization in progress */
2218   int isMallocInit;                 /* True after malloc is initialized */
2219   sqlite3_mutex *pInitMutex;        /* Mutex used by sqlite3_initialize() */
2220   int nRefInitMutex;                /* Number of users of pInitMutex */
2221 };
2222 
2223 /*
2224 ** Context pointer passed down through the tree-walk.
2225 */
2226 struct Walker {
2227   int (*xExprCallback)(Walker*, Expr*);     /* Callback for expressions */
2228   int (*xSelectCallback)(Walker*,Select*);  /* Callback for SELECTs */
2229   Parse *pParse;                            /* Parser context.  */
2230   union {                                   /* Extra data for callback */
2231     NameContext *pNC;                          /* Naming context */
2232     int i;                                     /* Integer value */
2233   } u;
2234 };
2235 
2236 /* Forward declarations */
2237 int sqlite3WalkExpr(Walker*, Expr*);
2238 int sqlite3WalkExprList(Walker*, ExprList*);
2239 int sqlite3WalkSelect(Walker*, Select*);
2240 int sqlite3WalkSelectExpr(Walker*, Select*);
2241 int sqlite3WalkSelectFrom(Walker*, Select*);
2242 
2243 /*
2244 ** Return code from the parse-tree walking primitives and their
2245 ** callbacks.
2246 */
2247 #define WRC_Continue    0   /* Continue down into children */
2248 #define WRC_Prune       1   /* Omit children but continue walking siblings */
2249 #define WRC_Abort       2   /* Abandon the tree walk */
2250 
2251 /*
2252 ** Assuming zIn points to the first byte of a UTF-8 character,
2253 ** advance zIn to point to the first byte of the next UTF-8 character.
2254 */
2255 #define SQLITE_SKIP_UTF8(zIn) {                        \
2256   if( (*(zIn++))>=0xc0 ){                              \
2257     while( (*zIn & 0xc0)==0x80 ){ zIn++; }             \
2258   }                                                    \
2259 }
2260 
2261 /*
2262 ** The SQLITE_CORRUPT_BKPT macro can be either a constant (for production
2263 ** builds) or a function call (for debugging).  If it is a function call,
2264 ** it allows the operator to set a breakpoint at the spot where database
2265 ** corruption is first detected.
2266 */
2267 #ifdef SQLITE_DEBUG
2268   int sqlite3Corrupt(void);
2269 # define SQLITE_CORRUPT_BKPT sqlite3Corrupt()
2270 #else
2271 # define SQLITE_CORRUPT_BKPT SQLITE_CORRUPT
2272 #endif
2273 
2274 /*
2275 ** The following macros mimic the standard library functions toupper(),
2276 ** isspace(), isalnum(), isdigit() and isxdigit(), respectively. The
2277 ** sqlite versions only work for ASCII characters, regardless of locale.
2278 */
2279 #ifdef SQLITE_ASCII
2280 # define sqlite3Toupper(x)  ((x)&~(sqlite3CtypeMap[(unsigned char)(x)]&0x20))
2281 # define sqlite3Isspace(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x01)
2282 # define sqlite3Isalnum(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x06)
2283 # define sqlite3Isalpha(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x02)
2284 # define sqlite3Isdigit(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x04)
2285 # define sqlite3Isxdigit(x)  (sqlite3CtypeMap[(unsigned char)(x)]&0x08)
2286 # define sqlite3Tolower(x)   (sqlite3UpperToLower[(unsigned char)(x)])
2287 #else
2288 # include <ctype.h>
2289 # define sqlite3Toupper(x)   toupper((unsigned char)(x))
2290 # define sqlite3Isspace(x)   isspace((unsigned char)(x))
2291 # define sqlite3Isalnum(x)   isalnum((unsigned char)(x))
2292 # define sqlite3Isalpha(x)   isalpha((unsigned char)(x))
2293 # define sqlite3Isdigit(x)   isdigit((unsigned char)(x))
2294 # define sqlite3Isxdigit(x)  isxdigit((unsigned char)(x))
2295 # define sqlite3Tolower(x)   tolower((unsigned char)(x))
2296 #endif
2297 
2298 /*
2299 ** Internal function prototypes
2300 */
2301 int sqlite3StrICmp(const char *, const char *);
2302 int sqlite3StrNICmp(const char *, const char *, int);
2303 int sqlite3IsNumber(const char*, int*, u8);
2304 int sqlite3Strlen(sqlite3*, const char*);
2305 int sqlite3Strlen30(const char*);
2306 
2307 int sqlite3MallocInit(void);
2308 void sqlite3MallocEnd(void);
2309 void *sqlite3Malloc(int);
2310 void *sqlite3MallocZero(int);
2311 void *sqlite3DbMallocZero(sqlite3*, int);
2312 void *sqlite3DbMallocRaw(sqlite3*, int);
2313 char *sqlite3DbStrDup(sqlite3*,const char*);
2314 char *sqlite3DbStrNDup(sqlite3*,const char*, int);
2315 void *sqlite3Realloc(void*, int);
2316 void *sqlite3DbReallocOrFree(sqlite3 *, void *, int);
2317 void *sqlite3DbRealloc(sqlite3 *, void *, int);
2318 void sqlite3DbFree(sqlite3*, void*);
2319 int sqlite3MallocSize(void*);
2320 int sqlite3DbMallocSize(sqlite3*, void*);
2321 void *sqlite3ScratchMalloc(int);
2322 void sqlite3ScratchFree(void*);
2323 void *sqlite3PageMalloc(int);
2324 void sqlite3PageFree(void*);
2325 void sqlite3MemSetDefault(void);
2326 void sqlite3BenignMallocHooks(void (*)(void), void (*)(void));
2327 int sqlite3MemoryAlarm(void (*)(void*, sqlite3_int64, int), void*, sqlite3_int64);
2328 
2329 #ifdef SQLITE_ENABLE_MEMSYS3
2330 const sqlite3_mem_methods *sqlite3MemGetMemsys3(void);
2331 #endif
2332 #ifdef SQLITE_ENABLE_MEMSYS5
2333 const sqlite3_mem_methods *sqlite3MemGetMemsys5(void);
2334 #endif
2335 
2336 
2337 #ifndef SQLITE_MUTEX_OMIT
2338   sqlite3_mutex_methods *sqlite3DefaultMutex(void);
2339   sqlite3_mutex *sqlite3MutexAlloc(int);
2340   int sqlite3MutexInit(void);
2341   int sqlite3MutexEnd(void);
2342 #endif
2343 
2344 int sqlite3StatusValue(int);
2345 void sqlite3StatusAdd(int, int);
2346 void sqlite3StatusSet(int, int);
2347 
2348 int sqlite3IsNaN(double);
2349 
2350 void sqlite3VXPrintf(StrAccum*, int, const char*, va_list);
2351 char *sqlite3MPrintf(sqlite3*,const char*, ...);
2352 char *sqlite3VMPrintf(sqlite3*,const char*, va_list);
2353 char *sqlite3MAppendf(sqlite3*,char*,const char*,...);
2354 #if defined(SQLITE_TEST) || defined(SQLITE_DEBUG)
2355   void sqlite3DebugPrintf(const char*, ...);
2356 #endif
2357 #if defined(SQLITE_TEST)
2358   void *sqlite3TestTextToPtr(const char*);
2359 #endif
2360 void sqlite3SetString(char **, sqlite3*, const char*, ...);
2361 void sqlite3ErrorMsg(Parse*, const char*, ...);
2362 void sqlite3ErrorClear(Parse*);
2363 void sqlite3Dequote(char*);
2364 void sqlite3DequoteExpr(Expr*);
2365 int sqlite3KeywordCode(const unsigned char*, int);
2366 int sqlite3RunParser(Parse*, const char*, char **);
2367 void sqlite3FinishCoding(Parse*);
2368 int sqlite3GetTempReg(Parse*);
2369 void sqlite3ReleaseTempReg(Parse*,int);
2370 int sqlite3GetTempRange(Parse*,int);
2371 void sqlite3ReleaseTempRange(Parse*,int,int);
2372 Expr *sqlite3Expr(sqlite3*, int, Expr*, Expr*, const Token*);
2373 Expr *sqlite3PExpr(Parse*, int, Expr*, Expr*, const Token*);
2374 Expr *sqlite3RegisterExpr(Parse*,Token*);
2375 Expr *sqlite3ExprAnd(sqlite3*,Expr*, Expr*);
2376 void sqlite3ExprSpan(Expr*,Token*,Token*);
2377 Expr *sqlite3ExprFunction(Parse*,ExprList*, Token*);
2378 void sqlite3ExprAssignVarNumber(Parse*, Expr*);
2379 void sqlite3ExprClear(sqlite3*, Expr*);
2380 void sqlite3ExprDelete(sqlite3*, Expr*);
2381 ExprList *sqlite3ExprListAppend(Parse*,ExprList*,Expr*,Token*);
2382 void sqlite3ExprListDelete(sqlite3*, ExprList*);
2383 int sqlite3Init(sqlite3*, char**);
2384 int sqlite3InitCallback(void*, int, char**, char**);
2385 void sqlite3Pragma(Parse*,Token*,Token*,Token*,int);
2386 void sqlite3ResetInternalSchema(sqlite3*, int);
2387 void sqlite3BeginParse(Parse*,int);
2388 void sqlite3CommitInternalChanges(sqlite3*);
2389 Table *sqlite3ResultSetOfSelect(Parse*,Select*);
2390 void sqlite3OpenMasterTable(Parse *, int);
2391 void sqlite3StartTable(Parse*,Token*,Token*,int,int,int,int);
2392 void sqlite3AddColumn(Parse*,Token*);
2393 void sqlite3AddNotNull(Parse*, int);
2394 void sqlite3AddPrimaryKey(Parse*, ExprList*, int, int, int);
2395 void sqlite3AddCheckConstraint(Parse*, Expr*);
2396 void sqlite3AddColumnType(Parse*,Token*);
2397 void sqlite3AddDefaultValue(Parse*,Expr*);
2398 void sqlite3AddCollateType(Parse*, Token*);
2399 void sqlite3EndTable(Parse*,Token*,Token*,Select*);
2400 
2401 Bitvec *sqlite3BitvecCreate(u32);
2402 int sqlite3BitvecTest(Bitvec*, u32);
2403 int sqlite3BitvecSet(Bitvec*, u32);
2404 void sqlite3BitvecClear(Bitvec*, u32);
2405 void sqlite3BitvecDestroy(Bitvec*);
2406 u32 sqlite3BitvecSize(Bitvec*);
2407 int sqlite3BitvecBuiltinTest(int,int*);
2408 
2409 RowSet *sqlite3RowSetInit(sqlite3*, void*, unsigned int);
2410 void sqlite3RowSetClear(RowSet*);
2411 void sqlite3RowSetInsert(RowSet*, i64);
2412 int sqlite3RowSetTest(RowSet*, u8 iBatch, i64);
2413 int sqlite3RowSetNext(RowSet*, i64*);
2414 
2415 void sqlite3CreateView(Parse*,Token*,Token*,Token*,Select*,int,int);
2416 
2417 #if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE)
2418   int sqlite3ViewGetColumnNames(Parse*,Table*);
2419 #else
2420 # define sqlite3ViewGetColumnNames(A,B) 0
2421 #endif
2422 
2423 void sqlite3DropTable(Parse*, SrcList*, int, int);
2424 void sqlite3DeleteTable(Table*);
2425 void sqlite3Insert(Parse*, SrcList*, ExprList*, Select*, IdList*, int);
2426 void *sqlite3ArrayAllocate(sqlite3*,void*,int,int,int*,int*,int*);
2427 IdList *sqlite3IdListAppend(sqlite3*, IdList*, Token*);
2428 int sqlite3IdListIndex(IdList*,const char*);
2429 SrcList *sqlite3SrcListEnlarge(sqlite3*, SrcList*, int, int);
2430 SrcList *sqlite3SrcListAppend(sqlite3*, SrcList*, Token*, Token*);
2431 SrcList *sqlite3SrcListAppendFromTerm(Parse*, SrcList*, Token*, Token*,
2432                                       Token*, Select*, Expr*, IdList*);
2433 void sqlite3SrcListIndexedBy(Parse *, SrcList *, Token *);
2434 int sqlite3IndexedByLookup(Parse *, struct SrcList_item *);
2435 void sqlite3SrcListShiftJoinType(SrcList*);
2436 void sqlite3SrcListAssignCursors(Parse*, SrcList*);
2437 void sqlite3IdListDelete(sqlite3*, IdList*);
2438 void sqlite3SrcListDelete(sqlite3*, SrcList*);
2439 void sqlite3CreateIndex(Parse*,Token*,Token*,SrcList*,ExprList*,int,Token*,
2440                         Token*, int, int);
2441 void sqlite3DropIndex(Parse*, SrcList*, int);
2442 int sqlite3Select(Parse*, Select*, SelectDest*);
2443 Select *sqlite3SelectNew(Parse*,ExprList*,SrcList*,Expr*,ExprList*,
2444                          Expr*,ExprList*,int,Expr*,Expr*);
2445 void sqlite3SelectDelete(sqlite3*, Select*);
2446 Table *sqlite3SrcListLookup(Parse*, SrcList*);
2447 int sqlite3IsReadOnly(Parse*, Table*, int);
2448 void sqlite3OpenTable(Parse*, int iCur, int iDb, Table*, int);
2449 #if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY)
2450 Expr *sqlite3LimitWhere(Parse *, SrcList *, Expr *, ExprList *, Expr *, Expr *, char *);
2451 #endif
2452 void sqlite3DeleteFrom(Parse*, SrcList*, Expr*);
2453 void sqlite3Update(Parse*, SrcList*, ExprList*, Expr*, int);
2454 WhereInfo *sqlite3WhereBegin(Parse*, SrcList*, Expr*, ExprList**, u16);
2455 void sqlite3WhereEnd(WhereInfo*);
2456 int sqlite3ExprCodeGetColumn(Parse*, Table*, int, int, int, int);
2457 void sqlite3ExprCodeMove(Parse*, int, int, int);
2458 void sqlite3ExprCodeCopy(Parse*, int, int, int);
2459 void sqlite3ExprCacheStore(Parse*, int, int, int);
2460 void sqlite3ExprCachePush(Parse*);
2461 void sqlite3ExprCachePop(Parse*, int);
2462 void sqlite3ExprCacheRemove(Parse*, int);
2463 void sqlite3ExprCacheClear(Parse*);
2464 void sqlite3ExprCacheAffinityChange(Parse*, int, int);
2465 void sqlite3ExprHardCopy(Parse*,int,int);
2466 int sqlite3ExprCode(Parse*, Expr*, int);
2467 int sqlite3ExprCodeTemp(Parse*, Expr*, int*);
2468 int sqlite3ExprCodeTarget(Parse*, Expr*, int);
2469 int sqlite3ExprCodeAndCache(Parse*, Expr*, int);
2470 void sqlite3ExprCodeConstants(Parse*, Expr*);
2471 int sqlite3ExprCodeExprList(Parse*, ExprList*, int, int);
2472 void sqlite3ExprIfTrue(Parse*, Expr*, int, int);
2473 void sqlite3ExprIfFalse(Parse*, Expr*, int, int);
2474 Table *sqlite3FindTable(sqlite3*,const char*, const char*);
2475 Table *sqlite3LocateTable(Parse*,int isView,const char*, const char*);
2476 Index *sqlite3FindIndex(sqlite3*,const char*, const char*);
2477 void sqlite3UnlinkAndDeleteTable(sqlite3*,int,const char*);
2478 void sqlite3UnlinkAndDeleteIndex(sqlite3*,int,const char*);
2479 void sqlite3Vacuum(Parse*);
2480 int sqlite3RunVacuum(char**, sqlite3*);
2481 char *sqlite3NameFromToken(sqlite3*, Token*);
2482 int sqlite3ExprCompare(Expr*, Expr*);
2483 void sqlite3ExprAnalyzeAggregates(NameContext*, Expr*);
2484 void sqlite3ExprAnalyzeAggList(NameContext*,ExprList*);
2485 Vdbe *sqlite3GetVdbe(Parse*);
2486 Expr *sqlite3CreateIdExpr(Parse *, const char*);
2487 void sqlite3PrngSaveState(void);
2488 void sqlite3PrngRestoreState(void);
2489 void sqlite3PrngResetState(void);
2490 void sqlite3RollbackAll(sqlite3*);
2491 void sqlite3CodeVerifySchema(Parse*, int);
2492 void sqlite3BeginTransaction(Parse*, int);
2493 void sqlite3CommitTransaction(Parse*);
2494 void sqlite3RollbackTransaction(Parse*);
2495 void sqlite3Savepoint(Parse*, int, Token*);
2496 void sqlite3CloseSavepoints(sqlite3 *);
2497 int sqlite3ExprIsConstant(Expr*);
2498 int sqlite3ExprIsConstantNotJoin(Expr*);
2499 int sqlite3ExprIsConstantOrFunction(Expr*);
2500 int sqlite3ExprIsInteger(Expr*, int*);
2501 int sqlite3IsRowid(const char*);
2502 void sqlite3GenerateRowDelete(Parse*, Table*, int, int, int);
2503 void sqlite3GenerateRowIndexDelete(Parse*, Table*, int, int*);
2504 int sqlite3GenerateIndexKey(Parse*, Index*, int, int, int);
2505 void sqlite3GenerateConstraintChecks(Parse*,Table*,int,int,
2506                                      int*,int,int,int,int);
2507 void sqlite3CompleteInsertion(Parse*, Table*, int, int, int*, int, int, int);
2508 int sqlite3OpenTableAndIndices(Parse*, Table*, int, int);
2509 void sqlite3BeginWriteOperation(Parse*, int, int);
2510 Expr *sqlite3ExprDup(sqlite3*,Expr*,int);
2511 void sqlite3TokenCopy(sqlite3*,Token*,const Token*);
2512 ExprList *sqlite3ExprListDup(sqlite3*,ExprList*,int);
2513 SrcList *sqlite3SrcListDup(sqlite3*,SrcList*,int);
2514 IdList *sqlite3IdListDup(sqlite3*,IdList*);
2515 Select *sqlite3SelectDup(sqlite3*,Select*,int);
2516 void sqlite3FuncDefInsert(FuncDefHash*, FuncDef*);
2517 FuncDef *sqlite3FindFunction(sqlite3*,const char*,int,int,u8,int);
2518 void sqlite3RegisterBuiltinFunctions(sqlite3*);
2519 void sqlite3RegisterDateTimeFunctions(void);
2520 void sqlite3RegisterGlobalFunctions(void);
2521 #ifdef SQLITE_DEBUG
2522   int sqlite3SafetyOn(sqlite3*);
2523   int sqlite3SafetyOff(sqlite3*);
2524 #else
2525 # define sqlite3SafetyOn(A) 0
2526 # define sqlite3SafetyOff(A) 0
2527 #endif
2528 int sqlite3SafetyCheckOk(sqlite3*);
2529 int sqlite3SafetyCheckSickOrOk(sqlite3*);
2530 void sqlite3ChangeCookie(Parse*, int);
2531 
2532 #if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
2533 void sqlite3MaterializeView(Parse*, Table*, Expr*, int);
2534 #endif
2535 
2536 #ifndef SQLITE_OMIT_TRIGGER
2537   void sqlite3BeginTrigger(Parse*, Token*,Token*,int,int,IdList*,SrcList*,
2538                            Expr*,int, int);
2539   void sqlite3FinishTrigger(Parse*, TriggerStep*, Token*);
2540   void sqlite3DropTrigger(Parse*, SrcList*, int);
2541   void sqlite3DropTriggerPtr(Parse*, Trigger*);
2542   Trigger *sqlite3TriggersExist(Parse *, Table*, int, ExprList*, int *pMask);
2543   Trigger *sqlite3TriggerList(Parse *, Table *);
2544   int sqlite3CodeRowTrigger(Parse*, Trigger *, int, ExprList*, int, Table *,
2545                             int, int, int, int, u32*, u32*);
2546   void sqliteViewTriggers(Parse*, Table*, Expr*, int, ExprList*);
2547   void sqlite3DeleteTriggerStep(sqlite3*, TriggerStep*);
2548   TriggerStep *sqlite3TriggerSelectStep(sqlite3*,Select*);
2549   TriggerStep *sqlite3TriggerInsertStep(sqlite3*,Token*, IdList*,
2550                                         ExprList*,Select*,int);
2551   TriggerStep *sqlite3TriggerUpdateStep(sqlite3*,Token*,ExprList*, Expr*, int);
2552   TriggerStep *sqlite3TriggerDeleteStep(sqlite3*,Token*, Expr*);
2553   void sqlite3DeleteTrigger(sqlite3*, Trigger*);
2554   void sqlite3UnlinkAndDeleteTrigger(sqlite3*,int,const char*);
2555 #else
2556 # define sqlite3TriggersExist(B,C,D,E,F) 0
2557 # define sqlite3DeleteTrigger(A,B)
2558 # define sqlite3DropTriggerPtr(A,B)
2559 # define sqlite3UnlinkAndDeleteTrigger(A,B,C)
2560 # define sqlite3CodeRowTrigger(A,B,C,D,E,F,G,H,I,J,K,L) 0
2561 # define sqlite3TriggerList(X, Y) 0
2562 #endif
2563 
2564 int sqlite3JoinType(Parse*, Token*, Token*, Token*);
2565 void sqlite3CreateForeignKey(Parse*, ExprList*, Token*, ExprList*, int);
2566 void sqlite3DeferForeignKey(Parse*, int);
2567 #ifndef SQLITE_OMIT_AUTHORIZATION
2568   void sqlite3AuthRead(Parse*,Expr*,Schema*,SrcList*);
2569   int sqlite3AuthCheck(Parse*,int, const char*, const char*, const char*);
2570   void sqlite3AuthContextPush(Parse*, AuthContext*, const char*);
2571   void sqlite3AuthContextPop(AuthContext*);
2572 #else
2573 # define sqlite3AuthRead(a,b,c,d)
2574 # define sqlite3AuthCheck(a,b,c,d,e)    SQLITE_OK
2575 # define sqlite3AuthContextPush(a,b,c)
2576 # define sqlite3AuthContextPop(a)  ((void)(a))
2577 #endif
2578 void sqlite3Attach(Parse*, Expr*, Expr*, Expr*);
2579 void sqlite3Detach(Parse*, Expr*);
2580 int sqlite3BtreeFactory(const sqlite3 *db, const char *zFilename,
2581                        int omitJournal, int nCache, int flags, Btree **ppBtree);
2582 int sqlite3FixInit(DbFixer*, Parse*, int, const char*, const Token*);
2583 int sqlite3FixSrcList(DbFixer*, SrcList*);
2584 int sqlite3FixSelect(DbFixer*, Select*);
2585 int sqlite3FixExpr(DbFixer*, Expr*);
2586 int sqlite3FixExprList(DbFixer*, ExprList*);
2587 int sqlite3FixTriggerStep(DbFixer*, TriggerStep*);
2588 int sqlite3AtoF(const char *z, double*);
2589 int sqlite3GetInt32(const char *, int*);
2590 int sqlite3FitsIn64Bits(const char *, int);
2591 int sqlite3Utf16ByteLen(const void *pData, int nChar);
2592 int sqlite3Utf8CharLen(const char *pData, int nByte);
2593 int sqlite3Utf8Read(const u8*, const u8**);
2594 
2595 /*
2596 ** Routines to read and write variable-length integers.  These used to
2597 ** be defined locally, but now we use the varint routines in the util.c
2598 ** file.  Code should use the MACRO forms below, as the Varint32 versions
2599 ** are coded to assume the single byte case is already handled (which
2600 ** the MACRO form does).
2601 */
2602 int sqlite3PutVarint(unsigned char*, u64);
2603 int sqlite3PutVarint32(unsigned char*, u32);
2604 u8 sqlite3GetVarint(const unsigned char *, u64 *);
2605 u8 sqlite3GetVarint32(const unsigned char *, u32 *);
2606 int sqlite3VarintLen(u64 v);
2607 
2608 /*
2609 ** The header of a record consists of a sequence variable-length integers.
2610 ** These integers are almost always small and are encoded as a single byte.
2611 ** The following macros take advantage this fact to provide a fast encode
2612 ** and decode of the integers in a record header.  It is faster for the common
2613 ** case where the integer is a single byte.  It is a little slower when the
2614 ** integer is two or more bytes.  But overall it is faster.
2615 **
2616 ** The following expressions are equivalent:
2617 **
2618 **     x = sqlite3GetVarint32( A, &B );
2619 **     x = sqlite3PutVarint32( A, B );
2620 **
2621 **     x = getVarint32( A, B );
2622 **     x = putVarint32( A, B );
2623 **
2624 */
2625 #define getVarint32(A,B)  (u8)((*(A)<(u8)0x80) ? ((B) = (u32)*(A)),1 : sqlite3GetVarint32((A), (u32 *)&(B)))
2626 #define putVarint32(A,B)  (u8)(((u32)(B)<(u32)0x80) ? (*(A) = (unsigned char)(B)),1 : sqlite3PutVarint32((A), (B)))
2627 #define getVarint    sqlite3GetVarint
2628 #define putVarint    sqlite3PutVarint
2629 
2630 
2631 void sqlite3IndexAffinityStr(Vdbe *, Index *);
2632 void sqlite3TableAffinityStr(Vdbe *, Table *);
2633 char sqlite3CompareAffinity(Expr *pExpr, char aff2);
2634 int sqlite3IndexAffinityOk(Expr *pExpr, char idx_affinity);
2635 char sqlite3ExprAffinity(Expr *pExpr);
2636 int sqlite3Atoi64(const char*, i64*);
2637 void sqlite3Error(sqlite3*, int, const char*,...);
2638 void *sqlite3HexToBlob(sqlite3*, const char *z, int n);
2639 int sqlite3TwoPartName(Parse *, Token *, Token *, Token **);
2640 const char *sqlite3ErrStr(int);
2641 int sqlite3ReadSchema(Parse *pParse);
2642 CollSeq *sqlite3FindCollSeq(sqlite3*,u8 enc, const char *,int,int);
2643 CollSeq *sqlite3LocateCollSeq(Parse *pParse, const char *zName, int nName);
2644 CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr);
2645 Expr *sqlite3ExprSetColl(Parse *pParse, Expr *, Token *);
2646 int sqlite3CheckCollSeq(Parse *, CollSeq *);
2647 int sqlite3CheckObjectName(Parse *, const char *);
2648 void sqlite3VdbeSetChanges(sqlite3 *, int);
2649 
2650 const void *sqlite3ValueText(sqlite3_value*, u8);
2651 int sqlite3ValueBytes(sqlite3_value*, u8);
2652 void sqlite3ValueSetStr(sqlite3_value*, int, const void *,u8,
2653                         void(*)(void*));
2654 void sqlite3ValueFree(sqlite3_value*);
2655 sqlite3_value *sqlite3ValueNew(sqlite3 *);
2656 char *sqlite3Utf16to8(sqlite3 *, const void*, int);
2657 int sqlite3ValueFromExpr(sqlite3 *, Expr *, u8, u8, sqlite3_value **);
2658 void sqlite3ValueApplyAffinity(sqlite3_value *, u8, u8);
2659 #ifndef SQLITE_AMALGAMATION
2660 extern const unsigned char sqlite3UpperToLower[];
2661 extern const unsigned char sqlite3CtypeMap[];
2662 extern SQLITE_WSD struct Sqlite3Config sqlite3Config;
2663 extern SQLITE_WSD FuncDefHash sqlite3GlobalFunctions;
2664 extern int sqlite3PendingByte;
2665 #endif
2666 void sqlite3RootPageMoved(Db*, int, int);
2667 void sqlite3Reindex(Parse*, Token*, Token*);
2668 void sqlite3AlterFunctions(sqlite3*);
2669 void sqlite3AlterRenameTable(Parse*, SrcList*, Token*);
2670 int sqlite3GetToken(const unsigned char *, int *);
2671 void sqlite3NestedParse(Parse*, const char*, ...);
2672 void sqlite3ExpirePreparedStatements(sqlite3*);
2673 void sqlite3CodeSubselect(Parse *, Expr *, int, int);
2674 void sqlite3SelectPrep(Parse*, Select*, NameContext*);
2675 int sqlite3ResolveExprNames(NameContext*, Expr*);
2676 void sqlite3ResolveSelectNames(Parse*, Select*, NameContext*);
2677 int sqlite3ResolveOrderGroupBy(Parse*, Select*, ExprList*, const char*);
2678 void sqlite3ColumnDefault(Vdbe *, Table *, int);
2679 void sqlite3AlterFinishAddColumn(Parse *, Token *);
2680 void sqlite3AlterBeginAddColumn(Parse *, SrcList *);
2681 CollSeq *sqlite3GetCollSeq(sqlite3*, CollSeq *, const char *, int);
2682 char sqlite3AffinityType(const Token*);
2683 void sqlite3Analyze(Parse*, Token*, Token*);
2684 int sqlite3InvokeBusyHandler(BusyHandler*);
2685 int sqlite3FindDb(sqlite3*, Token*);
2686 int sqlite3FindDbName(sqlite3 *, const char *);
2687 int sqlite3AnalysisLoad(sqlite3*,int iDB);
2688 void sqlite3DefaultRowEst(Index*);
2689 void sqlite3RegisterLikeFunctions(sqlite3*, int);
2690 int sqlite3IsLikeFunction(sqlite3*,Expr*,int*,char*);
2691 void sqlite3MinimumFileFormat(Parse*, int, int);
2692 void sqlite3SchemaFree(void *);
2693 Schema *sqlite3SchemaGet(sqlite3 *, Btree *);
2694 int sqlite3SchemaToIndex(sqlite3 *db, Schema *);
2695 KeyInfo *sqlite3IndexKeyinfo(Parse *, Index *);
2696 int sqlite3CreateFunc(sqlite3 *, const char *, int, int, void *,
2697   void (*)(sqlite3_context*,int,sqlite3_value **),
2698   void (*)(sqlite3_context*,int,sqlite3_value **), void (*)(sqlite3_context*));
2699 int sqlite3ApiExit(sqlite3 *db, int);
2700 int sqlite3OpenTempDatabase(Parse *);
2701 
2702 void sqlite3StrAccumInit(StrAccum*, char*, int, int);
2703 void sqlite3StrAccumAppend(StrAccum*,const char*,int);
2704 char *sqlite3StrAccumFinish(StrAccum*);
2705 void sqlite3StrAccumReset(StrAccum*);
2706 void sqlite3SelectDestInit(SelectDest*,int,int);
2707 
2708 void sqlite3BackupRestart(sqlite3_backup *);
2709 void sqlite3BackupUpdate(sqlite3_backup *, Pgno, const u8 *);
2710 
2711 /*
2712 ** The interface to the LEMON-generated parser
2713 */
2714 void *sqlite3ParserAlloc(void*(*)(size_t));
2715 void sqlite3ParserFree(void*, void(*)(void*));
2716 void sqlite3Parser(void*, int, Token, Parse*);
2717 #ifdef YYTRACKMAXSTACKDEPTH
2718   int sqlite3ParserStackPeak(void*);
2719 #endif
2720 
2721 int sqlite3AutoLoadExtensions(sqlite3*);
2722 #ifndef SQLITE_OMIT_LOAD_EXTENSION
2723   void sqlite3CloseExtensions(sqlite3*);
2724 #else
2725 # define sqlite3CloseExtensions(X)
2726 #endif
2727 
2728 #ifndef SQLITE_OMIT_SHARED_CACHE
2729   void sqlite3TableLock(Parse *, int, int, u8, const char *);
2730 #else
2731   #define sqlite3TableLock(v,w,x,y,z)
2732 #endif
2733 
2734 #ifdef SQLITE_TEST
2735   int sqlite3Utf8To8(unsigned char*);
2736 #endif
2737 
2738 #ifdef SQLITE_OMIT_VIRTUALTABLE
2739 #  define sqlite3VtabClear(X)
2740 #  define sqlite3VtabSync(X,Y) SQLITE_OK
2741 #  define sqlite3VtabRollback(X)
2742 #  define sqlite3VtabCommit(X)
2743 #  define sqlite3VtabInSync(db) 0
2744 #else
2745    void sqlite3VtabClear(Table*);
2746    int sqlite3VtabSync(sqlite3 *db, char **);
2747    int sqlite3VtabRollback(sqlite3 *db);
2748    int sqlite3VtabCommit(sqlite3 *db);
2749 #  define sqlite3VtabInSync(db) ((db)->nVTrans>0 && (db)->aVTrans==0)
2750 #endif
2751 void sqlite3VtabMakeWritable(Parse*,Table*);
2752 void sqlite3VtabLock(sqlite3_vtab*);
2753 void sqlite3VtabUnlock(sqlite3*, sqlite3_vtab*);
2754 void sqlite3VtabBeginParse(Parse*, Token*, Token*, Token*);
2755 void sqlite3VtabFinishParse(Parse*, Token*);
2756 void sqlite3VtabArgInit(Parse*);
2757 void sqlite3VtabArgExtend(Parse*, Token*);
2758 int sqlite3VtabCallCreate(sqlite3*, int, const char *, char **);
2759 int sqlite3VtabCallConnect(Parse*, Table*);
2760 int sqlite3VtabCallDestroy(sqlite3*, int, const char *);
2761 int sqlite3VtabBegin(sqlite3 *, sqlite3_vtab *);
2762 FuncDef *sqlite3VtabOverloadFunction(sqlite3 *,FuncDef*, int nArg, Expr*);
2763 void sqlite3InvalidFunction(sqlite3_context*,int,sqlite3_value**);
2764 int sqlite3TransferBindings(sqlite3_stmt *, sqlite3_stmt *);
2765 int sqlite3Reprepare(Vdbe*);
2766 void sqlite3ExprListCheckLength(Parse*, ExprList*, const char*);
2767 CollSeq *sqlite3BinaryCompareCollSeq(Parse *, Expr *, Expr *);
2768 
2769 
2770 /*
2771 ** Available fault injectors.  Should be numbered beginning with 0.
2772 */
2773 #define SQLITE_FAULTINJECTOR_MALLOC     0
2774 #define SQLITE_FAULTINJECTOR_COUNT      1
2775 
2776 /*
2777 ** The interface to the code in fault.c used for identifying "benign"
2778 ** malloc failures. This is only present if SQLITE_OMIT_BUILTIN_TEST
2779 ** is not defined.
2780 */
2781 #ifndef SQLITE_OMIT_BUILTIN_TEST
2782   void sqlite3BeginBenignMalloc(void);
2783   void sqlite3EndBenignMalloc(void);
2784 #else
2785   #define sqlite3BeginBenignMalloc()
2786   #define sqlite3EndBenignMalloc()
2787 #endif
2788 
2789 #define IN_INDEX_ROWID           1
2790 #define IN_INDEX_EPH             2
2791 #define IN_INDEX_INDEX           3
2792 int sqlite3FindInIndex(Parse *, Expr *, int*);
2793 
2794 #ifdef SQLITE_ENABLE_ATOMIC_WRITE
2795   int sqlite3JournalOpen(sqlite3_vfs *, const char *, sqlite3_file *, int, int);
2796   int sqlite3JournalSize(sqlite3_vfs *);
2797   int sqlite3JournalCreate(sqlite3_file *);
2798 #else
2799   #define sqlite3JournalSize(pVfs) ((pVfs)->szOsFile)
2800 #endif
2801 
2802 void sqlite3MemJournalOpen(sqlite3_file *);
2803 int sqlite3MemJournalSize(void);
2804 int sqlite3IsMemJournal(sqlite3_file *);
2805 
2806 #if SQLITE_MAX_EXPR_DEPTH>0
2807   void sqlite3ExprSetHeight(Parse *pParse, Expr *p);
2808   int sqlite3SelectExprHeight(Select *);
2809   int sqlite3ExprCheckHeight(Parse*, int);
2810 #else
2811   #define sqlite3ExprSetHeight(x,y)
2812   #define sqlite3SelectExprHeight(x) 0
2813   #define sqlite3ExprCheckHeight(x,y)
2814 #endif
2815 
2816 u32 sqlite3Get4byte(const u8*);
2817 void sqlite3Put4byte(u8*, u32);
2818 
2819 #ifdef SQLITE_ENABLE_UNLOCK_NOTIFY
2820   void sqlite3ConnectionBlocked(sqlite3 *, sqlite3 *);
2821   void sqlite3ConnectionUnlocked(sqlite3 *db);
2822   void sqlite3ConnectionClosed(sqlite3 *db);
2823 #else
2824   #define sqlite3ConnectionBlocked(x,y)
2825   #define sqlite3ConnectionUnlocked(x)
2826   #define sqlite3ConnectionClosed(x)
2827 #endif
2828 
2829 
2830 #ifdef SQLITE_SSE
2831 #include "sseInt.h"
2832 #endif
2833 
2834 #ifdef SQLITE_DEBUG
2835   void sqlite3ParserTrace(FILE*, char *);
2836 #endif
2837 
2838 /*
2839 ** If the SQLITE_ENABLE IOTRACE exists then the global variable
2840 ** sqlite3IoTrace is a pointer to a printf-like routine used to
2841 ** print I/O tracing messages.
2842 */
2843 #ifdef SQLITE_ENABLE_IOTRACE
2844 # define IOTRACE(A)  if( sqlite3IoTrace ){ sqlite3IoTrace A; }
2845   void sqlite3VdbeIOTraceSql(Vdbe*);
2846 SQLITE_EXTERN void (*sqlite3IoTrace)(const char*,...);
2847 #else
2848 # define IOTRACE(A)
2849 # define sqlite3VdbeIOTraceSql(X)
2850 #endif
2851 
2852 #endif
2853