xref: /sqlite-3.40.0/src/sqliteInt.h (revision fd3b2226)
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 */
15 #ifndef _SQLITEINT_H_
16 #define _SQLITEINT_H_
17 
18 /*
19 ** These #defines should enable >2GB file support on POSIX if the
20 ** underlying operating system supports it.  If the OS lacks
21 ** large file support, or if the OS is windows, these should be no-ops.
22 **
23 ** Ticket #2739:  The _LARGEFILE_SOURCE macro must appear before any
24 ** system #includes.  Hence, this block of code must be the very first
25 ** code in all source files.
26 **
27 ** Large file support can be disabled using the -DSQLITE_DISABLE_LFS switch
28 ** on the compiler command line.  This is necessary if you are compiling
29 ** on a recent machine (ex: Red Hat 7.2) but you want your code to work
30 ** on an older machine (ex: Red Hat 6.0).  If you compile on Red Hat 7.2
31 ** without this option, LFS is enable.  But LFS does not exist in the kernel
32 ** in Red Hat 6.0, so the code won't work.  Hence, for maximum binary
33 ** portability you should omit LFS.
34 **
35 ** Similar is true for Mac OS X.  LFS is only supported on Mac OS X 9 and later.
36 */
37 #ifndef SQLITE_DISABLE_LFS
38 # define _LARGE_FILE       1
39 # ifndef _FILE_OFFSET_BITS
40 #   define _FILE_OFFSET_BITS 64
41 # endif
42 # define _LARGEFILE_SOURCE 1
43 #endif
44 
45 /*
46 ** Include the configuration header output by 'configure' if we're using the
47 ** autoconf-based build
48 */
49 #ifdef _HAVE_SQLITE_CONFIG_H
50 #include "config.h"
51 #endif
52 
53 #include "sqliteLimit.h"
54 
55 /* Disable nuisance warnings on Borland compilers */
56 #if defined(__BORLANDC__)
57 #pragma warn -rch /* unreachable code */
58 #pragma warn -ccc /* Condition is always true or false */
59 #pragma warn -aus /* Assigned value is never used */
60 #pragma warn -csu /* Comparing signed and unsigned */
61 #pragma warn -spa /* Suspicious pointer arithmetic */
62 #endif
63 
64 /* Needed for various definitions... */
65 #ifndef _GNU_SOURCE
66 # define _GNU_SOURCE
67 #endif
68 
69 /*
70 ** Include standard header files as necessary
71 */
72 #ifdef HAVE_STDINT_H
73 #include <stdint.h>
74 #endif
75 #ifdef HAVE_INTTYPES_H
76 #include <inttypes.h>
77 #endif
78 
79 #define SQLITE_INDEX_SAMPLES 10
80 
81 /*
82 ** This macro is used to "hide" some ugliness in casting an int
83 ** value to a ptr value under the MSVC 64-bit compiler.   Casting
84 ** non 64-bit values to ptr types results in a "hard" error with
85 ** the MSVC 64-bit compiler which this attempts to avoid.
86 **
87 ** A simple compiler pragma or casting sequence could not be found
88 ** to correct this in all situations, so this macro was introduced.
89 **
90 ** It could be argued that the intptr_t type could be used in this
91 ** case, but that type is not available on all compilers, or
92 ** requires the #include of specific headers which differs between
93 ** platforms.
94 **
95 ** Ticket #3860:  The llvm-gcc-4.2 compiler from Apple chokes on
96 ** the ((void*)&((char*)0)[X]) construct.  But MSVC chokes on ((void*)(X)).
97 ** So we have to define the macros in different ways depending on the
98 ** compiler.
99 */
100 #if defined(__GNUC__)
101 # if defined(HAVE_STDINT_H)
102 #   define SQLITE_INT_TO_PTR(X)  ((void*)(intptr_t)(X))
103 #   define SQLITE_PTR_TO_INT(X)  ((int)(intptr_t)(X))
104 # else
105 #   define SQLITE_INT_TO_PTR(X)  ((void*)(X))
106 #   define SQLITE_PTR_TO_INT(X)  ((int)(X))
107 # endif
108 #else
109 # define SQLITE_INT_TO_PTR(X)   ((void*)&((char*)0)[X])
110 # define SQLITE_PTR_TO_INT(X)   ((int)(((char*)X)-(char*)0))
111 #endif
112 
113 
114 /*
115 ** The SQLITE_THREADSAFE macro must be defined as either 0 or 1.
116 ** Older versions of SQLite used an optional THREADSAFE macro.
117 ** We support that for legacy
118 */
119 #if !defined(SQLITE_THREADSAFE)
120 #if defined(THREADSAFE)
121 # define SQLITE_THREADSAFE THREADSAFE
122 #else
123 # define SQLITE_THREADSAFE 1
124 #endif
125 #endif
126 
127 /*
128 ** The SQLITE_DEFAULT_MEMSTATUS macro must be defined as either 0 or 1.
129 ** It determines whether or not the features related to
130 ** SQLITE_CONFIG_MEMSTATUS are available by default or not. This value can
131 ** be overridden at runtime using the sqlite3_config() API.
132 */
133 #if !defined(SQLITE_DEFAULT_MEMSTATUS)
134 # define SQLITE_DEFAULT_MEMSTATUS 1
135 #endif
136 
137 /*
138 ** Exactly one of the following macros must be defined in order to
139 ** specify which memory allocation subsystem to use.
140 **
141 **     SQLITE_SYSTEM_MALLOC          // Use normal system malloc()
142 **     SQLITE_MEMDEBUG               // Debugging version of system malloc()
143 **     SQLITE_MEMORY_SIZE            // internal allocator #1
144 **     SQLITE_MMAP_HEAP_SIZE         // internal mmap() allocator
145 **     SQLITE_POW2_MEMORY_SIZE       // internal power-of-two allocator
146 **
147 ** If none of the above are defined, then set SQLITE_SYSTEM_MALLOC as
148 ** the default.
149 */
150 #if defined(SQLITE_SYSTEM_MALLOC)+defined(SQLITE_MEMDEBUG)+\
151     defined(SQLITE_MEMORY_SIZE)+defined(SQLITE_MMAP_HEAP_SIZE)+\
152     defined(SQLITE_POW2_MEMORY_SIZE)>1
153 # error "At most one of the following compile-time configuration options\
154  is allows: SQLITE_SYSTEM_MALLOC, SQLITE_MEMDEBUG, SQLITE_MEMORY_SIZE,\
155  SQLITE_MMAP_HEAP_SIZE, SQLITE_POW2_MEMORY_SIZE"
156 #endif
157 #if defined(SQLITE_SYSTEM_MALLOC)+defined(SQLITE_MEMDEBUG)+\
158     defined(SQLITE_MEMORY_SIZE)+defined(SQLITE_MMAP_HEAP_SIZE)+\
159     defined(SQLITE_POW2_MEMORY_SIZE)==0
160 # define SQLITE_SYSTEM_MALLOC 1
161 #endif
162 
163 /*
164 ** If SQLITE_MALLOC_SOFT_LIMIT is not zero, then try to keep the
165 ** sizes of memory allocations below this value where possible.
166 */
167 #if !defined(SQLITE_MALLOC_SOFT_LIMIT)
168 # define SQLITE_MALLOC_SOFT_LIMIT 1024
169 #endif
170 
171 /*
172 ** We need to define _XOPEN_SOURCE as follows in order to enable
173 ** recursive mutexes on most Unix systems.  But Mac OS X is different.
174 ** The _XOPEN_SOURCE define causes problems for Mac OS X we are told,
175 ** so it is omitted there.  See ticket #2673.
176 **
177 ** Later we learn that _XOPEN_SOURCE is poorly or incorrectly
178 ** implemented on some systems.  So we avoid defining it at all
179 ** if it is already defined or if it is unneeded because we are
180 ** not doing a threadsafe build.  Ticket #2681.
181 **
182 ** See also ticket #2741.
183 */
184 #if !defined(_XOPEN_SOURCE) && !defined(__DARWIN__) && !defined(__APPLE__) && SQLITE_THREADSAFE
185 #  define _XOPEN_SOURCE 500  /* Needed to enable pthread recursive mutexes */
186 #endif
187 
188 /*
189 ** The TCL headers are only needed when compiling the TCL bindings.
190 */
191 #if defined(SQLITE_TCL) || defined(TCLSH)
192 # include <tcl.h>
193 #endif
194 
195 /*
196 ** Many people are failing to set -DNDEBUG=1 when compiling SQLite.
197 ** Setting NDEBUG makes the code smaller and run faster.  So the following
198 ** lines are added to automatically set NDEBUG unless the -DSQLITE_DEBUG=1
199 ** option is set.  Thus NDEBUG becomes an opt-in rather than an opt-out
200 ** feature.
201 */
202 #if !defined(NDEBUG) && !defined(SQLITE_DEBUG)
203 # define NDEBUG 1
204 #endif
205 
206 /*
207 ** The testcase() macro is used to aid in coverage testing.  When
208 ** doing coverage testing, the condition inside the argument to
209 ** testcase() must be evaluated both true and false in order to
210 ** get full branch coverage.  The testcase() macro is inserted
211 ** to help ensure adequate test coverage in places where simple
212 ** condition/decision coverage is inadequate.  For example, testcase()
213 ** can be used to make sure boundary values are tested.  For
214 ** bitmask tests, testcase() can be used to make sure each bit
215 ** is significant and used at least once.  On switch statements
216 ** where multiple cases go to the same block of code, testcase()
217 ** can insure that all cases are evaluated.
218 **
219 */
220 #ifdef SQLITE_COVERAGE_TEST
221   void sqlite3Coverage(int);
222 # define testcase(X)  if( X ){ sqlite3Coverage(__LINE__); }
223 #else
224 # define testcase(X)
225 #endif
226 
227 /*
228 ** The TESTONLY macro is used to enclose variable declarations or
229 ** other bits of code that are needed to support the arguments
230 ** within testcase() and assert() macros.
231 */
232 #if !defined(NDEBUG) || defined(SQLITE_COVERAGE_TEST)
233 # define TESTONLY(X)  X
234 #else
235 # define TESTONLY(X)
236 #endif
237 
238 /*
239 ** Sometimes we need a small amount of code such as a variable initialization
240 ** to setup for a later assert() statement.  We do not want this code to
241 ** appear when assert() is disabled.  The following macro is therefore
242 ** used to contain that setup code.  The "VVA" acronym stands for
243 ** "Verification, Validation, and Accreditation".  In other words, the
244 ** code within VVA_ONLY() will only run during verification processes.
245 */
246 #ifndef NDEBUG
247 # define VVA_ONLY(X)  X
248 #else
249 # define VVA_ONLY(X)
250 #endif
251 
252 /*
253 ** The ALWAYS and NEVER macros surround boolean expressions which
254 ** are intended to always be true or false, respectively.  Such
255 ** expressions could be omitted from the code completely.  But they
256 ** are included in a few cases in order to enhance the resilience
257 ** of SQLite to unexpected behavior - to make the code "self-healing"
258 ** or "ductile" rather than being "brittle" and crashing at the first
259 ** hint of unplanned behavior.
260 **
261 ** In other words, ALWAYS and NEVER are added for defensive code.
262 **
263 ** When doing coverage testing ALWAYS and NEVER are hard-coded to
264 ** be true and false so that the unreachable code then specify will
265 ** not be counted as untested code.
266 */
267 #if defined(SQLITE_COVERAGE_TEST)
268 # define ALWAYS(X)      (1)
269 # define NEVER(X)       (0)
270 #elif !defined(NDEBUG)
271 # define ALWAYS(X)      ((X)?1:(assert(0),0))
272 # define NEVER(X)       ((X)?(assert(0),1):0)
273 #else
274 # define ALWAYS(X)      (X)
275 # define NEVER(X)       (X)
276 #endif
277 
278 /*
279 ** The macro unlikely() is a hint that surrounds a boolean
280 ** expression that is usually false.  Macro likely() surrounds
281 ** a boolean expression that is usually true.  GCC is able to
282 ** use these hints to generate better code, sometimes.
283 */
284 #if defined(__GNUC__) && 0
285 # define likely(X)    __builtin_expect((X),1)
286 # define unlikely(X)  __builtin_expect((X),0)
287 #else
288 # define likely(X)    !!(X)
289 # define unlikely(X)  !!(X)
290 #endif
291 
292 #include "sqlite3.h"
293 #include "hash.h"
294 #include "parse.h"
295 #include <stdio.h>
296 #include <stdlib.h>
297 #include <string.h>
298 #include <assert.h>
299 #include <stddef.h>
300 
301 /*
302 ** If compiling for a processor that lacks floating point support,
303 ** substitute integer for floating-point
304 */
305 #ifdef SQLITE_OMIT_FLOATING_POINT
306 # define double sqlite_int64
307 # define LONGDOUBLE_TYPE sqlite_int64
308 # ifndef SQLITE_BIG_DBL
309 #   define SQLITE_BIG_DBL (((sqlite3_int64)1)<<50)
310 # endif
311 # define SQLITE_OMIT_DATETIME_FUNCS 1
312 # define SQLITE_OMIT_TRACE 1
313 # undef SQLITE_MIXED_ENDIAN_64BIT_FLOAT
314 # undef SQLITE_HAVE_ISNAN
315 #endif
316 #ifndef SQLITE_BIG_DBL
317 # define SQLITE_BIG_DBL (1e99)
318 #endif
319 
320 /*
321 ** OMIT_TEMPDB is set to 1 if SQLITE_OMIT_TEMPDB is defined, or 0
322 ** afterward. Having this macro allows us to cause the C compiler
323 ** to omit code used by TEMP tables without messy #ifndef statements.
324 */
325 #ifdef SQLITE_OMIT_TEMPDB
326 #define OMIT_TEMPDB 1
327 #else
328 #define OMIT_TEMPDB 0
329 #endif
330 
331 /*
332 ** If the following macro is set to 1, then NULL values are considered
333 ** distinct when determining whether or not two entries are the same
334 ** in a UNIQUE index.  This is the way PostgreSQL, Oracle, DB2, MySQL,
335 ** OCELOT, and Firebird all work.  The SQL92 spec explicitly says this
336 ** is the way things are suppose to work.
337 **
338 ** If the following macro is set to 0, the NULLs are indistinct for
339 ** a UNIQUE index.  In this mode, you can only have a single NULL entry
340 ** for a column declared UNIQUE.  This is the way Informix and SQL Server
341 ** work.
342 */
343 #define NULL_DISTINCT_FOR_UNIQUE 1
344 
345 /*
346 ** The "file format" number is an integer that is incremented whenever
347 ** the VDBE-level file format changes.  The following macros define the
348 ** the default file format for new databases and the maximum file format
349 ** that the library can read.
350 */
351 #define SQLITE_MAX_FILE_FORMAT 4
352 #ifndef SQLITE_DEFAULT_FILE_FORMAT
353 # define SQLITE_DEFAULT_FILE_FORMAT 1
354 #endif
355 
356 #ifndef SQLITE_DEFAULT_RECURSIVE_TRIGGERS
357 # define SQLITE_DEFAULT_RECURSIVE_TRIGGERS 0
358 #endif
359 
360 /*
361 ** Provide a default value for SQLITE_TEMP_STORE in case it is not specified
362 ** on the command-line
363 */
364 #ifndef SQLITE_TEMP_STORE
365 # define SQLITE_TEMP_STORE 1
366 #endif
367 
368 /*
369 ** GCC does not define the offsetof() macro so we'll have to do it
370 ** ourselves.
371 */
372 #ifndef offsetof
373 #define offsetof(STRUCTURE,FIELD) ((int)((char*)&((STRUCTURE*)0)->FIELD))
374 #endif
375 
376 /*
377 ** Check to see if this machine uses EBCDIC.  (Yes, believe it or
378 ** not, there are still machines out there that use EBCDIC.)
379 */
380 #if 'A' == '\301'
381 # define SQLITE_EBCDIC 1
382 #else
383 # define SQLITE_ASCII 1
384 #endif
385 
386 /*
387 ** Integers of known sizes.  These typedefs might change for architectures
388 ** where the sizes very.  Preprocessor macros are available so that the
389 ** types can be conveniently redefined at compile-type.  Like this:
390 **
391 **         cc '-DUINTPTR_TYPE=long long int' ...
392 */
393 #ifndef UINT32_TYPE
394 # ifdef HAVE_UINT32_T
395 #  define UINT32_TYPE uint32_t
396 # else
397 #  define UINT32_TYPE unsigned int
398 # endif
399 #endif
400 #ifndef UINT16_TYPE
401 # ifdef HAVE_UINT16_T
402 #  define UINT16_TYPE uint16_t
403 # else
404 #  define UINT16_TYPE unsigned short int
405 # endif
406 #endif
407 #ifndef INT16_TYPE
408 # ifdef HAVE_INT16_T
409 #  define INT16_TYPE int16_t
410 # else
411 #  define INT16_TYPE short int
412 # endif
413 #endif
414 #ifndef UINT8_TYPE
415 # ifdef HAVE_UINT8_T
416 #  define UINT8_TYPE uint8_t
417 # else
418 #  define UINT8_TYPE unsigned char
419 # endif
420 #endif
421 #ifndef INT8_TYPE
422 # ifdef HAVE_INT8_T
423 #  define INT8_TYPE int8_t
424 # else
425 #  define INT8_TYPE signed char
426 # endif
427 #endif
428 #ifndef LONGDOUBLE_TYPE
429 # define LONGDOUBLE_TYPE long double
430 #endif
431 typedef sqlite_int64 i64;          /* 8-byte signed integer */
432 typedef sqlite_uint64 u64;         /* 8-byte unsigned integer */
433 typedef UINT32_TYPE u32;           /* 4-byte unsigned integer */
434 typedef UINT16_TYPE u16;           /* 2-byte unsigned integer */
435 typedef INT16_TYPE i16;            /* 2-byte signed integer */
436 typedef UINT8_TYPE u8;             /* 1-byte unsigned integer */
437 typedef INT8_TYPE i8;              /* 1-byte signed integer */
438 
439 /*
440 ** SQLITE_MAX_U32 is a u64 constant that is the maximum u64 value
441 ** that can be stored in a u32 without loss of data.  The value
442 ** is 0x00000000ffffffff.  But because of quirks of some compilers, we
443 ** have to specify the value in the less intuitive manner shown:
444 */
445 #define SQLITE_MAX_U32  ((((u64)1)<<32)-1)
446 
447 /*
448 ** Macros to determine whether the machine is big or little endian,
449 ** evaluated at runtime.
450 */
451 #ifdef SQLITE_AMALGAMATION
452 const int sqlite3one = 1;
453 #else
454 extern const int sqlite3one;
455 #endif
456 #if defined(i386) || defined(__i386__) || defined(_M_IX86)\
457                              || defined(__x86_64) || defined(__x86_64__)
458 # define SQLITE_BIGENDIAN    0
459 # define SQLITE_LITTLEENDIAN 1
460 # define SQLITE_UTF16NATIVE  SQLITE_UTF16LE
461 #else
462 # define SQLITE_BIGENDIAN    (*(char *)(&sqlite3one)==0)
463 # define SQLITE_LITTLEENDIAN (*(char *)(&sqlite3one)==1)
464 # define SQLITE_UTF16NATIVE (SQLITE_BIGENDIAN?SQLITE_UTF16BE:SQLITE_UTF16LE)
465 #endif
466 
467 /*
468 ** Constants for the largest and smallest possible 64-bit signed integers.
469 ** These macros are designed to work correctly on both 32-bit and 64-bit
470 ** compilers.
471 */
472 #define LARGEST_INT64  (0xffffffff|(((i64)0x7fffffff)<<32))
473 #define SMALLEST_INT64 (((i64)-1) - LARGEST_INT64)
474 
475 /*
476 ** Round up a number to the next larger multiple of 8.  This is used
477 ** to force 8-byte alignment on 64-bit architectures.
478 */
479 #define ROUND8(x)     (((x)+7)&~7)
480 
481 /*
482 ** Round down to the nearest multiple of 8
483 */
484 #define ROUNDDOWN8(x) ((x)&~7)
485 
486 /*
487 ** Assert that the pointer X is aligned to an 8-byte boundary.
488 */
489 #define EIGHT_BYTE_ALIGNMENT(X)   ((((char*)(X) - (char*)0)&7)==0)
490 
491 
492 /*
493 ** An instance of the following structure is used to store the busy-handler
494 ** callback for a given sqlite handle.
495 **
496 ** The sqlite.busyHandler member of the sqlite struct contains the busy
497 ** callback for the database handle. Each pager opened via the sqlite
498 ** handle is passed a pointer to sqlite.busyHandler. The busy-handler
499 ** callback is currently invoked only from within pager.c.
500 */
501 typedef struct BusyHandler BusyHandler;
502 struct BusyHandler {
503   int (*xFunc)(void *,int);  /* The busy callback */
504   void *pArg;                /* First arg to busy callback */
505   int nBusy;                 /* Incremented with each busy call */
506 };
507 
508 /*
509 ** Name of the master database table.  The master database table
510 ** is a special table that holds the names and attributes of all
511 ** user tables and indices.
512 */
513 #define MASTER_NAME       "sqlite_master"
514 #define TEMP_MASTER_NAME  "sqlite_temp_master"
515 
516 /*
517 ** The root-page of the master database table.
518 */
519 #define MASTER_ROOT       1
520 
521 /*
522 ** The name of the schema table.
523 */
524 #define SCHEMA_TABLE(x)  ((!OMIT_TEMPDB)&&(x==1)?TEMP_MASTER_NAME:MASTER_NAME)
525 
526 /*
527 ** A convenience macro that returns the number of elements in
528 ** an array.
529 */
530 #define ArraySize(X)    ((int)(sizeof(X)/sizeof(X[0])))
531 
532 /*
533 ** The following value as a destructor means to use sqlite3DbFree().
534 ** This is an internal extension to SQLITE_STATIC and SQLITE_TRANSIENT.
535 */
536 #define SQLITE_DYNAMIC   ((sqlite3_destructor_type)sqlite3DbFree)
537 
538 /*
539 ** When SQLITE_OMIT_WSD is defined, it means that the target platform does
540 ** not support Writable Static Data (WSD) such as global and static variables.
541 ** All variables must either be on the stack or dynamically allocated from
542 ** the heap.  When WSD is unsupported, the variable declarations scattered
543 ** throughout the SQLite code must become constants instead.  The SQLITE_WSD
544 ** macro is used for this purpose.  And instead of referencing the variable
545 ** directly, we use its constant as a key to lookup the run-time allocated
546 ** buffer that holds real variable.  The constant is also the initializer
547 ** for the run-time allocated buffer.
548 **
549 ** In the usual case where WSD is supported, the SQLITE_WSD and GLOBAL
550 ** macros become no-ops and have zero performance impact.
551 */
552 #ifdef SQLITE_OMIT_WSD
553   #define SQLITE_WSD const
554   #define GLOBAL(t,v) (*(t*)sqlite3_wsd_find((void*)&(v), sizeof(v)))
555   #define sqlite3GlobalConfig GLOBAL(struct Sqlite3Config, sqlite3Config)
556   int sqlite3_wsd_init(int N, int J);
557   void *sqlite3_wsd_find(void *K, int L);
558 #else
559   #define SQLITE_WSD
560   #define GLOBAL(t,v) v
561   #define sqlite3GlobalConfig sqlite3Config
562 #endif
563 
564 /*
565 ** The following macros are used to suppress compiler warnings and to
566 ** make it clear to human readers when a function parameter is deliberately
567 ** left unused within the body of a function. This usually happens when
568 ** a function is called via a function pointer. For example the
569 ** implementation of an SQL aggregate step callback may not use the
570 ** parameter indicating the number of arguments passed to the aggregate,
571 ** if it knows that this is enforced elsewhere.
572 **
573 ** When a function parameter is not used at all within the body of a function,
574 ** it is generally named "NotUsed" or "NotUsed2" to make things even clearer.
575 ** However, these macros may also be used to suppress warnings related to
576 ** parameters that may or may not be used depending on compilation options.
577 ** For example those parameters only used in assert() statements. In these
578 ** cases the parameters are named as per the usual conventions.
579 */
580 #define UNUSED_PARAMETER(x) (void)(x)
581 #define UNUSED_PARAMETER2(x,y) UNUSED_PARAMETER(x),UNUSED_PARAMETER(y)
582 
583 /*
584 ** Forward references to structures
585 */
586 typedef struct AggInfo AggInfo;
587 typedef struct AuthContext AuthContext;
588 typedef struct AutoincInfo AutoincInfo;
589 typedef struct Bitvec Bitvec;
590 typedef struct RowSet RowSet;
591 typedef struct CollSeq CollSeq;
592 typedef struct Column Column;
593 typedef struct Db Db;
594 typedef struct Schema Schema;
595 typedef struct Expr Expr;
596 typedef struct ExprList ExprList;
597 typedef struct ExprSpan ExprSpan;
598 typedef struct FKey FKey;
599 typedef struct FuncDef FuncDef;
600 typedef struct FuncDefHash FuncDefHash;
601 typedef struct IdList IdList;
602 typedef struct Index Index;
603 typedef struct IndexSample IndexSample;
604 typedef struct KeyClass KeyClass;
605 typedef struct KeyInfo KeyInfo;
606 typedef struct Lookaside Lookaside;
607 typedef struct LookasideSlot LookasideSlot;
608 typedef struct Module Module;
609 typedef struct NameContext NameContext;
610 typedef struct Parse Parse;
611 typedef struct Savepoint Savepoint;
612 typedef struct Select Select;
613 typedef struct SrcList SrcList;
614 typedef struct StrAccum StrAccum;
615 typedef struct Table Table;
616 typedef struct TableLock TableLock;
617 typedef struct Token Token;
618 typedef struct TriggerPrg TriggerPrg;
619 typedef struct TriggerStep TriggerStep;
620 typedef struct Trigger Trigger;
621 typedef struct UnpackedRecord UnpackedRecord;
622 typedef struct VTable VTable;
623 typedef struct Walker Walker;
624 typedef struct WherePlan WherePlan;
625 typedef struct WhereInfo WhereInfo;
626 typedef struct WhereLevel WhereLevel;
627 
628 /*
629 ** Defer sourcing vdbe.h and btree.h until after the "u8" and
630 ** "BusyHandler" typedefs. vdbe.h also requires a few of the opaque
631 ** pointer types (i.e. FuncDef) defined above.
632 */
633 #include "btree.h"
634 #include "vdbe.h"
635 #include "pager.h"
636 #include "pcache.h"
637 
638 #include "os.h"
639 #include "mutex.h"
640 
641 
642 /*
643 ** Each database file to be accessed by the system is an instance
644 ** of the following structure.  There are normally two of these structures
645 ** in the sqlite.aDb[] array.  aDb[0] is the main database file and
646 ** aDb[1] is the database file used to hold temporary tables.  Additional
647 ** databases may be attached.
648 */
649 struct Db {
650   char *zName;         /* Name of this database */
651   Btree *pBt;          /* The B*Tree structure for this database file */
652   u8 inTrans;          /* 0: not writable.  1: Transaction.  2: Checkpoint */
653   u8 safety_level;     /* How aggressive at syncing data to disk */
654   Schema *pSchema;     /* Pointer to database schema (possibly shared) */
655 };
656 
657 /*
658 ** An instance of the following structure stores a database schema.
659 **
660 ** If there are no virtual tables configured in this schema, the
661 ** Schema.db variable is set to NULL. After the first virtual table
662 ** has been added, it is set to point to the database connection
663 ** used to create the connection. Once a virtual table has been
664 ** added to the Schema structure and the Schema.db variable populated,
665 ** only that database connection may use the Schema to prepare
666 ** statements.
667 */
668 struct Schema {
669   int schema_cookie;   /* Database schema version number for this file */
670   Hash tblHash;        /* All tables indexed by name */
671   Hash idxHash;        /* All (named) indices indexed by name */
672   Hash trigHash;       /* All triggers indexed by name */
673   Hash fkeyHash;       /* All foreign keys by referenced table name */
674   Table *pSeqTab;      /* The sqlite_sequence table used by AUTOINCREMENT */
675   u8 file_format;      /* Schema format version for this file */
676   u8 enc;              /* Text encoding used by this database */
677   u16 flags;           /* Flags associated with this schema */
678   int cache_size;      /* Number of pages to use in the cache */
679 #ifndef SQLITE_OMIT_VIRTUALTABLE
680   sqlite3 *db;         /* "Owner" connection. See comment above */
681 #endif
682 };
683 
684 /*
685 ** These macros can be used to test, set, or clear bits in the
686 ** Db.flags field.
687 */
688 #define DbHasProperty(D,I,P)     (((D)->aDb[I].pSchema->flags&(P))==(P))
689 #define DbHasAnyProperty(D,I,P)  (((D)->aDb[I].pSchema->flags&(P))!=0)
690 #define DbSetProperty(D,I,P)     (D)->aDb[I].pSchema->flags|=(P)
691 #define DbClearProperty(D,I,P)   (D)->aDb[I].pSchema->flags&=~(P)
692 
693 /*
694 ** Allowed values for the DB.flags field.
695 **
696 ** The DB_SchemaLoaded flag is set after the database schema has been
697 ** read into internal hash tables.
698 **
699 ** DB_UnresetViews means that one or more views have column names that
700 ** have been filled out.  If the schema changes, these column names might
701 ** changes and so the view will need to be reset.
702 */
703 #define DB_SchemaLoaded    0x0001  /* The schema has been loaded */
704 #define DB_UnresetViews    0x0002  /* Some views have defined column names */
705 #define DB_Empty           0x0004  /* The file is empty (length 0 bytes) */
706 
707 /*
708 ** The number of different kinds of things that can be limited
709 ** using the sqlite3_limit() interface.
710 */
711 #define SQLITE_N_LIMIT (SQLITE_LIMIT_TRIGGER_DEPTH+1)
712 
713 /*
714 ** Lookaside malloc is a set of fixed-size buffers that can be used
715 ** to satisfy small transient memory allocation requests for objects
716 ** associated with a particular database connection.  The use of
717 ** lookaside malloc provides a significant performance enhancement
718 ** (approx 10%) by avoiding numerous malloc/free requests while parsing
719 ** SQL statements.
720 **
721 ** The Lookaside structure holds configuration information about the
722 ** lookaside malloc subsystem.  Each available memory allocation in
723 ** the lookaside subsystem is stored on a linked list of LookasideSlot
724 ** objects.
725 **
726 ** Lookaside allocations are only allowed for objects that are associated
727 ** with a particular database connection.  Hence, schema information cannot
728 ** be stored in lookaside because in shared cache mode the schema information
729 ** is shared by multiple database connections.  Therefore, while parsing
730 ** schema information, the Lookaside.bEnabled flag is cleared so that
731 ** lookaside allocations are not used to construct the schema objects.
732 */
733 struct Lookaside {
734   u16 sz;                 /* Size of each buffer in bytes */
735   u8 bEnabled;            /* False to disable new lookaside allocations */
736   u8 bMalloced;           /* True if pStart obtained from sqlite3_malloc() */
737   int nOut;               /* Number of buffers currently checked out */
738   int mxOut;              /* Highwater mark for nOut */
739   LookasideSlot *pFree;   /* List of available buffers */
740   void *pStart;           /* First byte of available memory space */
741   void *pEnd;             /* First byte past end of available space */
742 };
743 struct LookasideSlot {
744   LookasideSlot *pNext;    /* Next buffer in the list of free buffers */
745 };
746 
747 /*
748 ** A hash table for function definitions.
749 **
750 ** Hash each FuncDef structure into one of the FuncDefHash.a[] slots.
751 ** Collisions are on the FuncDef.pHash chain.
752 */
753 struct FuncDefHash {
754   FuncDef *a[23];       /* Hash table for functions */
755 };
756 
757 /*
758 ** Each database is an instance of the following structure.
759 **
760 ** The sqlite.lastRowid records the last insert rowid generated by an
761 ** insert statement.  Inserts on views do not affect its value.  Each
762 ** trigger has its own context, so that lastRowid can be updated inside
763 ** triggers as usual.  The previous value will be restored once the trigger
764 ** exits.  Upon entering a before or instead of trigger, lastRowid is no
765 ** longer (since after version 2.8.12) reset to -1.
766 **
767 ** The sqlite.nChange does not count changes within triggers and keeps no
768 ** context.  It is reset at start of sqlite3_exec.
769 ** The sqlite.lsChange represents the number of changes made by the last
770 ** insert, update, or delete statement.  It remains constant throughout the
771 ** length of a statement and is then updated by OP_SetCounts.  It keeps a
772 ** context stack just like lastRowid so that the count of changes
773 ** within a trigger is not seen outside the trigger.  Changes to views do not
774 ** affect the value of lsChange.
775 ** The sqlite.csChange keeps track of the number of current changes (since
776 ** the last statement) and is used to update sqlite_lsChange.
777 **
778 ** The member variables sqlite.errCode, sqlite.zErrMsg and sqlite.zErrMsg16
779 ** store the most recent error code and, if applicable, string. The
780 ** internal function sqlite3Error() is used to set these variables
781 ** consistently.
782 */
783 struct sqlite3 {
784   sqlite3_vfs *pVfs;            /* OS Interface */
785   int nDb;                      /* Number of backends currently in use */
786   Db *aDb;                      /* All backends */
787   int flags;                    /* Miscellaneous flags. See below */
788   int openFlags;                /* Flags passed to sqlite3_vfs.xOpen() */
789   int errCode;                  /* Most recent error code (SQLITE_*) */
790   int errMask;                  /* & result codes with this before returning */
791   u8 autoCommit;                /* The auto-commit flag. */
792   u8 temp_store;                /* 1: file 2: memory 0: default */
793   u8 mallocFailed;              /* True if we have seen a malloc failure */
794   u8 dfltLockMode;              /* Default locking-mode for attached dbs */
795   u8 dfltJournalMode;           /* Default journal mode for attached dbs */
796   signed char nextAutovac;      /* Autovac setting after VACUUM if >=0 */
797   int nextPagesize;             /* Pagesize after VACUUM if >0 */
798   int nTable;                   /* Number of tables in the database */
799   CollSeq *pDfltColl;           /* The default collating sequence (BINARY) */
800   i64 lastRowid;                /* ROWID of most recent insert (see above) */
801   u32 magic;                    /* Magic number for detect library misuse */
802   int nChange;                  /* Value returned by sqlite3_changes() */
803   int nTotalChange;             /* Value returned by sqlite3_total_changes() */
804   sqlite3_mutex *mutex;         /* Connection mutex */
805   int aLimit[SQLITE_N_LIMIT];   /* Limits */
806   struct sqlite3InitInfo {      /* Information used during initialization */
807     int iDb;                    /* When back is being initialized */
808     int newTnum;                /* Rootpage of table being initialized */
809     u8 busy;                    /* TRUE if currently initializing */
810     u8 orphanTrigger;           /* Last statement is orphaned TEMP trigger */
811   } init;
812   int nExtension;               /* Number of loaded extensions */
813   void **aExtension;            /* Array of shared library handles */
814   struct Vdbe *pVdbe;           /* List of active virtual machines */
815   int activeVdbeCnt;            /* Number of VDBEs currently executing */
816   int writeVdbeCnt;             /* Number of active VDBEs that are writing */
817   void (*xTrace)(void*,const char*);        /* Trace function */
818   void *pTraceArg;                          /* Argument to the trace function */
819   void (*xProfile)(void*,const char*,u64);  /* Profiling function */
820   void *pProfileArg;                        /* Argument to profile function */
821   void *pCommitArg;                 /* Argument to xCommitCallback() */
822   int (*xCommitCallback)(void*);    /* Invoked at every commit. */
823   void *pRollbackArg;               /* Argument to xRollbackCallback() */
824   void (*xRollbackCallback)(void*); /* Invoked at every commit. */
825   void *pUpdateArg;
826   void (*xUpdateCallback)(void*,int, const char*,const char*,sqlite_int64);
827   void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*);
828   void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*);
829   void *pCollNeededArg;
830   sqlite3_value *pErr;          /* Most recent error message */
831   char *zErrMsg;                /* Most recent error message (UTF-8 encoded) */
832   char *zErrMsg16;              /* Most recent error message (UTF-16 encoded) */
833   union {
834     volatile int isInterrupted; /* True if sqlite3_interrupt has been called */
835     double notUsed1;            /* Spacer */
836   } u1;
837   Lookaside lookaside;          /* Lookaside malloc configuration */
838 #ifndef SQLITE_OMIT_AUTHORIZATION
839   int (*xAuth)(void*,int,const char*,const char*,const char*,const char*);
840                                 /* Access authorization function */
841   void *pAuthArg;               /* 1st argument to the access auth function */
842 #endif
843 #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
844   int (*xProgress)(void *);     /* The progress callback */
845   void *pProgressArg;           /* Argument to the progress callback */
846   int nProgressOps;             /* Number of opcodes for progress callback */
847 #endif
848 #ifndef SQLITE_OMIT_VIRTUALTABLE
849   Hash aModule;                 /* populated by sqlite3_create_module() */
850   Table *pVTab;                 /* vtab with active Connect/Create method */
851   VTable **aVTrans;             /* Virtual tables with open transactions */
852   int nVTrans;                  /* Allocated size of aVTrans */
853   VTable *pDisconnect;    /* Disconnect these in next sqlite3_prepare() */
854 #endif
855   FuncDefHash aFunc;            /* Hash table of connection functions */
856   Hash aCollSeq;                /* All collating sequences */
857   BusyHandler busyHandler;      /* Busy callback */
858   int busyTimeout;              /* Busy handler timeout, in msec */
859   Db aDbStatic[2];              /* Static space for the 2 default backends */
860   Savepoint *pSavepoint;        /* List of active savepoints */
861   int nSavepoint;               /* Number of non-transaction savepoints */
862   int nStatement;               /* Number of nested statement-transactions  */
863   u8 isTransactionSavepoint;    /* True if the outermost savepoint is a TS */
864   i64 nDeferredCons;            /* Net deferred constraints this transaction. */
865 
866 #ifdef SQLITE_ENABLE_UNLOCK_NOTIFY
867   /* The following variables are all protected by the STATIC_MASTER
868   ** mutex, not by sqlite3.mutex. They are used by code in notify.c.
869   **
870   ** When X.pUnlockConnection==Y, that means that X is waiting for Y to
871   ** unlock so that it can proceed.
872   **
873   ** When X.pBlockingConnection==Y, that means that something that X tried
874   ** tried to do recently failed with an SQLITE_LOCKED error due to locks
875   ** held by Y.
876   */
877   sqlite3 *pBlockingConnection; /* Connection that caused SQLITE_LOCKED */
878   sqlite3 *pUnlockConnection;           /* Connection to watch for unlock */
879   void *pUnlockArg;                     /* Argument to xUnlockNotify */
880   void (*xUnlockNotify)(void **, int);  /* Unlock notify callback */
881   sqlite3 *pNextBlocked;        /* Next in list of all blocked connections */
882 #endif
883 };
884 
885 /*
886 ** A macro to discover the encoding of a database.
887 */
888 #define ENC(db) ((db)->aDb[0].pSchema->enc)
889 
890 /*
891 ** Possible values for the sqlite.flags and or Db.flags fields.
892 **
893 ** On sqlite.flags, the SQLITE_InTrans value means that we have
894 ** executed a BEGIN.  On Db.flags, SQLITE_InTrans means a statement
895 ** transaction is active on that particular database file.
896 */
897 #define SQLITE_VdbeTrace      0x00000001  /* True to trace VDBE execution */
898 #define SQLITE_InTrans        0x00000008  /* True if in a transaction */
899 #define SQLITE_InternChanges  0x00000010  /* Uncommitted Hash table changes */
900 #define SQLITE_FullColNames   0x00000020  /* Show full column names on SELECT */
901 #define SQLITE_ShortColNames  0x00000040  /* Show short columns names */
902 #define SQLITE_CountRows      0x00000080  /* Count rows changed by INSERT, */
903                                           /*   DELETE, or UPDATE and return */
904                                           /*   the count using a callback. */
905 #define SQLITE_NullCallback   0x00000100  /* Invoke the callback once if the */
906                                           /*   result set is empty */
907 #define SQLITE_SqlTrace       0x00000200  /* Debug print SQL as it executes */
908 #define SQLITE_VdbeListing    0x00000400  /* Debug listings of VDBE programs */
909 #define SQLITE_WriteSchema    0x00000800  /* OK to update SQLITE_MASTER */
910 #define SQLITE_NoReadlock     0x00001000  /* Readlocks are omitted when
911                                           ** accessing read-only databases */
912 #define SQLITE_IgnoreChecks   0x00002000  /* Do not enforce check constraints */
913 #define SQLITE_ReadUncommitted 0x00004000 /* For shared-cache mode */
914 #define SQLITE_LegacyFileFmt  0x00008000  /* Create new databases in format 1 */
915 #define SQLITE_FullFSync      0x00010000  /* Use full fsync on the backend */
916 #define SQLITE_LoadExtension  0x00020000  /* Enable load_extension */
917 
918 #define SQLITE_RecoveryMode   0x00040000  /* Ignore schema errors */
919 #define SQLITE_ReverseOrder   0x00100000  /* Reverse unordered SELECTs */
920 #define SQLITE_RecTriggers    0x00200000  /* Enable recursive triggers */
921 #define SQLITE_ForeignKeys    0x00400000  /* Enforce foreign key constraints  */
922 
923 /*
924 ** Possible values for the sqlite.magic field.
925 ** The numbers are obtained at random and have no special meaning, other
926 ** than being distinct from one another.
927 */
928 #define SQLITE_MAGIC_OPEN     0xa029a697  /* Database is open */
929 #define SQLITE_MAGIC_CLOSED   0x9f3c2d33  /* Database is closed */
930 #define SQLITE_MAGIC_SICK     0x4b771290  /* Error and awaiting close */
931 #define SQLITE_MAGIC_BUSY     0xf03b7906  /* Database currently in use */
932 #define SQLITE_MAGIC_ERROR    0xb5357930  /* An SQLITE_MISUSE error occurred */
933 
934 /*
935 ** Each SQL function is defined by an instance of the following
936 ** structure.  A pointer to this structure is stored in the sqlite.aFunc
937 ** hash table.  When multiple functions have the same name, the hash table
938 ** points to a linked list of these structures.
939 */
940 struct FuncDef {
941   i16 nArg;            /* Number of arguments.  -1 means unlimited */
942   u8 iPrefEnc;         /* Preferred text encoding (SQLITE_UTF8, 16LE, 16BE) */
943   u8 flags;            /* Some combination of SQLITE_FUNC_* */
944   void *pUserData;     /* User data parameter */
945   FuncDef *pNext;      /* Next function with same name */
946   void (*xFunc)(sqlite3_context*,int,sqlite3_value**); /* Regular function */
947   void (*xStep)(sqlite3_context*,int,sqlite3_value**); /* Aggregate step */
948   void (*xFinalize)(sqlite3_context*);                /* Aggregate finalizer */
949   char *zName;         /* SQL name of the function. */
950   FuncDef *pHash;      /* Next with a different name but the same hash */
951 };
952 
953 /*
954 ** Possible values for FuncDef.flags
955 */
956 #define SQLITE_FUNC_LIKE     0x01 /* Candidate for the LIKE optimization */
957 #define SQLITE_FUNC_CASE     0x02 /* Case-sensitive LIKE-type function */
958 #define SQLITE_FUNC_EPHEM    0x04 /* Ephemeral.  Delete with VDBE */
959 #define SQLITE_FUNC_NEEDCOLL 0x08 /* sqlite3GetFuncCollSeq() might be called */
960 #define SQLITE_FUNC_PRIVATE  0x10 /* Allowed for internal use only */
961 #define SQLITE_FUNC_COUNT    0x20 /* Built-in count(*) aggregate */
962 
963 /*
964 ** The following three macros, FUNCTION(), LIKEFUNC() and AGGREGATE() are
965 ** used to create the initializers for the FuncDef structures.
966 **
967 **   FUNCTION(zName, nArg, iArg, bNC, xFunc)
968 **     Used to create a scalar function definition of a function zName
969 **     implemented by C function xFunc that accepts nArg arguments. The
970 **     value passed as iArg is cast to a (void*) and made available
971 **     as the user-data (sqlite3_user_data()) for the function. If
972 **     argument bNC is true, then the SQLITE_FUNC_NEEDCOLL flag is set.
973 **
974 **   AGGREGATE(zName, nArg, iArg, bNC, xStep, xFinal)
975 **     Used to create an aggregate function definition implemented by
976 **     the C functions xStep and xFinal. The first four parameters
977 **     are interpreted in the same way as the first 4 parameters to
978 **     FUNCTION().
979 **
980 **   LIKEFUNC(zName, nArg, pArg, flags)
981 **     Used to create a scalar function definition of a function zName
982 **     that accepts nArg arguments and is implemented by a call to C
983 **     function likeFunc. Argument pArg is cast to a (void *) and made
984 **     available as the function user-data (sqlite3_user_data()). The
985 **     FuncDef.flags variable is set to the value passed as the flags
986 **     parameter.
987 */
988 #define FUNCTION(zName, nArg, iArg, bNC, xFunc) \
989   {nArg, SQLITE_UTF8, bNC*SQLITE_FUNC_NEEDCOLL, \
990    SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, 0, #zName, 0}
991 #define STR_FUNCTION(zName, nArg, pArg, bNC, xFunc) \
992   {nArg, SQLITE_UTF8, bNC*SQLITE_FUNC_NEEDCOLL, \
993    pArg, 0, xFunc, 0, 0, #zName, 0}
994 #define LIKEFUNC(zName, nArg, arg, flags) \
995   {nArg, SQLITE_UTF8, flags, (void *)arg, 0, likeFunc, 0, 0, #zName, 0}
996 #define AGGREGATE(zName, nArg, arg, nc, xStep, xFinal) \
997   {nArg, SQLITE_UTF8, nc*SQLITE_FUNC_NEEDCOLL, \
998    SQLITE_INT_TO_PTR(arg), 0, 0, xStep,xFinal,#zName,0}
999 
1000 /*
1001 ** All current savepoints are stored in a linked list starting at
1002 ** sqlite3.pSavepoint. The first element in the list is the most recently
1003 ** opened savepoint. Savepoints are added to the list by the vdbe
1004 ** OP_Savepoint instruction.
1005 */
1006 struct Savepoint {
1007   char *zName;                        /* Savepoint name (nul-terminated) */
1008   i64 nDeferredCons;                  /* Number of deferred fk violations */
1009   Savepoint *pNext;                   /* Parent savepoint (if any) */
1010 };
1011 
1012 /*
1013 ** The following are used as the second parameter to sqlite3Savepoint(),
1014 ** and as the P1 argument to the OP_Savepoint instruction.
1015 */
1016 #define SAVEPOINT_BEGIN      0
1017 #define SAVEPOINT_RELEASE    1
1018 #define SAVEPOINT_ROLLBACK   2
1019 
1020 
1021 /*
1022 ** Each SQLite module (virtual table definition) is defined by an
1023 ** instance of the following structure, stored in the sqlite3.aModule
1024 ** hash table.
1025 */
1026 struct Module {
1027   const sqlite3_module *pModule;       /* Callback pointers */
1028   const char *zName;                   /* Name passed to create_module() */
1029   void *pAux;                          /* pAux passed to create_module() */
1030   void (*xDestroy)(void *);            /* Module destructor function */
1031 };
1032 
1033 /*
1034 ** information about each column of an SQL table is held in an instance
1035 ** of this structure.
1036 */
1037 struct Column {
1038   char *zName;     /* Name of this column */
1039   Expr *pDflt;     /* Default value of this column */
1040   char *zDflt;     /* Original text of the default value */
1041   char *zType;     /* Data type for this column */
1042   char *zColl;     /* Collating sequence.  If NULL, use the default */
1043   u8 notNull;      /* True if there is a NOT NULL constraint */
1044   u8 isPrimKey;    /* True if this column is part of the PRIMARY KEY */
1045   char affinity;   /* One of the SQLITE_AFF_... values */
1046 #ifndef SQLITE_OMIT_VIRTUALTABLE
1047   u8 isHidden;     /* True if this column is 'hidden' */
1048 #endif
1049 };
1050 
1051 /*
1052 ** A "Collating Sequence" is defined by an instance of the following
1053 ** structure. Conceptually, a collating sequence consists of a name and
1054 ** a comparison routine that defines the order of that sequence.
1055 **
1056 ** There may two separate implementations of the collation function, one
1057 ** that processes text in UTF-8 encoding (CollSeq.xCmp) and another that
1058 ** processes text encoded in UTF-16 (CollSeq.xCmp16), using the machine
1059 ** native byte order. When a collation sequence is invoked, SQLite selects
1060 ** the version that will require the least expensive encoding
1061 ** translations, if any.
1062 **
1063 ** The CollSeq.pUser member variable is an extra parameter that passed in
1064 ** as the first argument to the UTF-8 comparison function, xCmp.
1065 ** CollSeq.pUser16 is the equivalent for the UTF-16 comparison function,
1066 ** xCmp16.
1067 **
1068 ** If both CollSeq.xCmp and CollSeq.xCmp16 are NULL, it means that the
1069 ** collating sequence is undefined.  Indices built on an undefined
1070 ** collating sequence may not be read or written.
1071 */
1072 struct CollSeq {
1073   char *zName;          /* Name of the collating sequence, UTF-8 encoded */
1074   u8 enc;               /* Text encoding handled by xCmp() */
1075   u8 type;              /* One of the SQLITE_COLL_... values below */
1076   void *pUser;          /* First argument to xCmp() */
1077   int (*xCmp)(void*,int, const void*, int, const void*);
1078   void (*xDel)(void*);  /* Destructor for pUser */
1079 };
1080 
1081 /*
1082 ** Allowed values of CollSeq.type:
1083 */
1084 #define SQLITE_COLL_BINARY  1  /* The default memcmp() collating sequence */
1085 #define SQLITE_COLL_NOCASE  2  /* The built-in NOCASE collating sequence */
1086 #define SQLITE_COLL_REVERSE 3  /* The built-in REVERSE collating sequence */
1087 #define SQLITE_COLL_USER    0  /* Any other user-defined collating sequence */
1088 
1089 /*
1090 ** A sort order can be either ASC or DESC.
1091 */
1092 #define SQLITE_SO_ASC       0  /* Sort in ascending order */
1093 #define SQLITE_SO_DESC      1  /* Sort in ascending order */
1094 
1095 /*
1096 ** Column affinity types.
1097 **
1098 ** These used to have mnemonic name like 'i' for SQLITE_AFF_INTEGER and
1099 ** 't' for SQLITE_AFF_TEXT.  But we can save a little space and improve
1100 ** the speed a little by numbering the values consecutively.
1101 **
1102 ** But rather than start with 0 or 1, we begin with 'a'.  That way,
1103 ** when multiple affinity types are concatenated into a string and
1104 ** used as the P4 operand, they will be more readable.
1105 **
1106 ** Note also that the numeric types are grouped together so that testing
1107 ** for a numeric type is a single comparison.
1108 */
1109 #define SQLITE_AFF_TEXT     'a'
1110 #define SQLITE_AFF_NONE     'b'
1111 #define SQLITE_AFF_NUMERIC  'c'
1112 #define SQLITE_AFF_INTEGER  'd'
1113 #define SQLITE_AFF_REAL     'e'
1114 
1115 #define sqlite3IsNumericAffinity(X)  ((X)>=SQLITE_AFF_NUMERIC)
1116 
1117 /*
1118 ** The SQLITE_AFF_MASK values masks off the significant bits of an
1119 ** affinity value.
1120 */
1121 #define SQLITE_AFF_MASK     0x67
1122 
1123 /*
1124 ** Additional bit values that can be ORed with an affinity without
1125 ** changing the affinity.
1126 */
1127 #define SQLITE_JUMPIFNULL   0x08  /* jumps if either operand is NULL */
1128 #define SQLITE_STOREP2      0x10  /* Store result in reg[P2] rather than jump */
1129 #define SQLITE_NULLEQ       0x80  /* NULL=NULL */
1130 
1131 /*
1132 ** An object of this type is created for each virtual table present in
1133 ** the database schema.
1134 **
1135 ** If the database schema is shared, then there is one instance of this
1136 ** structure for each database connection (sqlite3*) that uses the shared
1137 ** schema. This is because each database connection requires its own unique
1138 ** instance of the sqlite3_vtab* handle used to access the virtual table
1139 ** implementation. sqlite3_vtab* handles can not be shared between
1140 ** database connections, even when the rest of the in-memory database
1141 ** schema is shared, as the implementation often stores the database
1142 ** connection handle passed to it via the xConnect() or xCreate() method
1143 ** during initialization internally. This database connection handle may
1144 ** then used by the virtual table implementation to access real tables
1145 ** within the database. So that they appear as part of the callers
1146 ** transaction, these accesses need to be made via the same database
1147 ** connection as that used to execute SQL operations on the virtual table.
1148 **
1149 ** All VTable objects that correspond to a single table in a shared
1150 ** database schema are initially stored in a linked-list pointed to by
1151 ** the Table.pVTable member variable of the corresponding Table object.
1152 ** When an sqlite3_prepare() operation is required to access the virtual
1153 ** table, it searches the list for the VTable that corresponds to the
1154 ** database connection doing the preparing so as to use the correct
1155 ** sqlite3_vtab* handle in the compiled query.
1156 **
1157 ** When an in-memory Table object is deleted (for example when the
1158 ** schema is being reloaded for some reason), the VTable objects are not
1159 ** deleted and the sqlite3_vtab* handles are not xDisconnect()ed
1160 ** immediately. Instead, they are moved from the Table.pVTable list to
1161 ** another linked list headed by the sqlite3.pDisconnect member of the
1162 ** corresponding sqlite3 structure. They are then deleted/xDisconnected
1163 ** next time a statement is prepared using said sqlite3*. This is done
1164 ** to avoid deadlock issues involving multiple sqlite3.mutex mutexes.
1165 ** Refer to comments above function sqlite3VtabUnlockList() for an
1166 ** explanation as to why it is safe to add an entry to an sqlite3.pDisconnect
1167 ** list without holding the corresponding sqlite3.mutex mutex.
1168 **
1169 ** The memory for objects of this type is always allocated by
1170 ** sqlite3DbMalloc(), using the connection handle stored in VTable.db as
1171 ** the first argument.
1172 */
1173 struct VTable {
1174   sqlite3 *db;              /* Database connection associated with this table */
1175   Module *pMod;             /* Pointer to module implementation */
1176   sqlite3_vtab *pVtab;      /* Pointer to vtab instance */
1177   int nRef;                 /* Number of pointers to this structure */
1178   VTable *pNext;            /* Next in linked list (see above) */
1179 };
1180 
1181 /*
1182 ** Each SQL table is represented in memory by an instance of the
1183 ** following structure.
1184 **
1185 ** Table.zName is the name of the table.  The case of the original
1186 ** CREATE TABLE statement is stored, but case is not significant for
1187 ** comparisons.
1188 **
1189 ** Table.nCol is the number of columns in this table.  Table.aCol is a
1190 ** pointer to an array of Column structures, one for each column.
1191 **
1192 ** If the table has an INTEGER PRIMARY KEY, then Table.iPKey is the index of
1193 ** the column that is that key.   Otherwise Table.iPKey is negative.  Note
1194 ** that the datatype of the PRIMARY KEY must be INTEGER for this field to
1195 ** be set.  An INTEGER PRIMARY KEY is used as the rowid for each row of
1196 ** the table.  If a table has no INTEGER PRIMARY KEY, then a random rowid
1197 ** is generated for each row of the table.  TF_HasPrimaryKey is set if
1198 ** the table has any PRIMARY KEY, INTEGER or otherwise.
1199 **
1200 ** Table.tnum is the page number for the root BTree page of the table in the
1201 ** database file.  If Table.iDb is the index of the database table backend
1202 ** in sqlite.aDb[].  0 is for the main database and 1 is for the file that
1203 ** holds temporary tables and indices.  If TF_Ephemeral is set
1204 ** then the table is stored in a file that is automatically deleted
1205 ** when the VDBE cursor to the table is closed.  In this case Table.tnum
1206 ** refers VDBE cursor number that holds the table open, not to the root
1207 ** page number.  Transient tables are used to hold the results of a
1208 ** sub-query that appears instead of a real table name in the FROM clause
1209 ** of a SELECT statement.
1210 */
1211 struct Table {
1212   sqlite3 *dbMem;      /* DB connection used for lookaside allocations. */
1213   char *zName;         /* Name of the table or view */
1214   int iPKey;           /* If not negative, use aCol[iPKey] as the primary key */
1215   int nCol;            /* Number of columns in this table */
1216   Column *aCol;        /* Information about each column */
1217   Index *pIndex;       /* List of SQL indexes on this table. */
1218   int tnum;            /* Root BTree node for this table (see note above) */
1219   Select *pSelect;     /* NULL for tables.  Points to definition if a view. */
1220   u16 nRef;            /* Number of pointers to this Table */
1221   u8 tabFlags;         /* Mask of TF_* values */
1222   u8 keyConf;          /* What to do in case of uniqueness conflict on iPKey */
1223   FKey *pFKey;         /* Linked list of all foreign keys in this table */
1224   char *zColAff;       /* String defining the affinity of each column */
1225 #ifndef SQLITE_OMIT_CHECK
1226   Expr *pCheck;        /* The AND of all CHECK constraints */
1227 #endif
1228 #ifndef SQLITE_OMIT_ALTERTABLE
1229   int addColOffset;    /* Offset in CREATE TABLE stmt to add a new column */
1230 #endif
1231 #ifndef SQLITE_OMIT_VIRTUALTABLE
1232   VTable *pVTable;     /* List of VTable objects. */
1233   int nModuleArg;      /* Number of arguments to the module */
1234   char **azModuleArg;  /* Text of all module args. [0] is module name */
1235 #endif
1236   Trigger *pTrigger;   /* List of triggers stored in pSchema */
1237   Schema *pSchema;     /* Schema that contains this table */
1238   Table *pNextZombie;  /* Next on the Parse.pZombieTab list */
1239 };
1240 
1241 /*
1242 ** Allowed values for Tabe.tabFlags.
1243 */
1244 #define TF_Readonly        0x01    /* Read-only system table */
1245 #define TF_Ephemeral       0x02    /* An ephemeral table */
1246 #define TF_HasPrimaryKey   0x04    /* Table has a primary key */
1247 #define TF_Autoincrement   0x08    /* Integer primary key is autoincrement */
1248 #define TF_Virtual         0x10    /* Is a virtual table */
1249 #define TF_NeedMetadata    0x20    /* aCol[].zType and aCol[].pColl missing */
1250 
1251 
1252 
1253 /*
1254 ** Test to see whether or not a table is a virtual table.  This is
1255 ** done as a macro so that it will be optimized out when virtual
1256 ** table support is omitted from the build.
1257 */
1258 #ifndef SQLITE_OMIT_VIRTUALTABLE
1259 #  define IsVirtual(X)      (((X)->tabFlags & TF_Virtual)!=0)
1260 #  define IsHiddenColumn(X) ((X)->isHidden)
1261 #else
1262 #  define IsVirtual(X)      0
1263 #  define IsHiddenColumn(X) 0
1264 #endif
1265 
1266 /*
1267 ** Each foreign key constraint is an instance of the following structure.
1268 **
1269 ** A foreign key is associated with two tables.  The "from" table is
1270 ** the table that contains the REFERENCES clause that creates the foreign
1271 ** key.  The "to" table is the table that is named in the REFERENCES clause.
1272 ** Consider this example:
1273 **
1274 **     CREATE TABLE ex1(
1275 **       a INTEGER PRIMARY KEY,
1276 **       b INTEGER CONSTRAINT fk1 REFERENCES ex2(x)
1277 **     );
1278 **
1279 ** For foreign key "fk1", the from-table is "ex1" and the to-table is "ex2".
1280 **
1281 ** Each REFERENCES clause generates an instance of the following structure
1282 ** which is attached to the from-table.  The to-table need not exist when
1283 ** the from-table is created.  The existence of the to-table is not checked.
1284 */
1285 struct FKey {
1286   Table *pFrom;     /* Table containing the REFERENCES clause (aka: Child) */
1287   FKey *pNextFrom;  /* Next foreign key in pFrom */
1288   char *zTo;        /* Name of table that the key points to (aka: Parent) */
1289   FKey *pNextTo;    /* Next foreign key on table named zTo */
1290   FKey *pPrevTo;    /* Previous foreign key on table named zTo */
1291   int nCol;         /* Number of columns in this key */
1292   /* EV: R-30323-21917 */
1293   u8 isDeferred;    /* True if constraint checking is deferred till COMMIT */
1294   u8 aAction[2];          /* ON DELETE and ON UPDATE actions, respectively */
1295   Trigger *apTrigger[2];  /* Triggers for aAction[] actions */
1296   struct sColMap {  /* Mapping of columns in pFrom to columns in zTo */
1297     int iFrom;         /* Index of column in pFrom */
1298     char *zCol;        /* Name of column in zTo.  If 0 use PRIMARY KEY */
1299   } aCol[1];        /* One entry for each of nCol column s */
1300 };
1301 
1302 /*
1303 ** SQLite supports many different ways to resolve a constraint
1304 ** error.  ROLLBACK processing means that a constraint violation
1305 ** causes the operation in process to fail and for the current transaction
1306 ** to be rolled back.  ABORT processing means the operation in process
1307 ** fails and any prior changes from that one operation are backed out,
1308 ** but the transaction is not rolled back.  FAIL processing means that
1309 ** the operation in progress stops and returns an error code.  But prior
1310 ** changes due to the same operation are not backed out and no rollback
1311 ** occurs.  IGNORE means that the particular row that caused the constraint
1312 ** error is not inserted or updated.  Processing continues and no error
1313 ** is returned.  REPLACE means that preexisting database rows that caused
1314 ** a UNIQUE constraint violation are removed so that the new insert or
1315 ** update can proceed.  Processing continues and no error is reported.
1316 **
1317 ** RESTRICT, SETNULL, and CASCADE actions apply only to foreign keys.
1318 ** RESTRICT is the same as ABORT for IMMEDIATE foreign keys and the
1319 ** same as ROLLBACK for DEFERRED keys.  SETNULL means that the foreign
1320 ** key is set to NULL.  CASCADE means that a DELETE or UPDATE of the
1321 ** referenced table row is propagated into the row that holds the
1322 ** foreign key.
1323 **
1324 ** The following symbolic values are used to record which type
1325 ** of action to take.
1326 */
1327 #define OE_None     0   /* There is no constraint to check */
1328 #define OE_Rollback 1   /* Fail the operation and rollback the transaction */
1329 #define OE_Abort    2   /* Back out changes but do no rollback transaction */
1330 #define OE_Fail     3   /* Stop the operation but leave all prior changes */
1331 #define OE_Ignore   4   /* Ignore the error. Do not do the INSERT or UPDATE */
1332 #define OE_Replace  5   /* Delete existing record, then do INSERT or UPDATE */
1333 
1334 #define OE_Restrict 6   /* OE_Abort for IMMEDIATE, OE_Rollback for DEFERRED */
1335 #define OE_SetNull  7   /* Set the foreign key value to NULL */
1336 #define OE_SetDflt  8   /* Set the foreign key value to its default */
1337 #define OE_Cascade  9   /* Cascade the changes */
1338 
1339 #define OE_Default  99  /* Do whatever the default action is */
1340 
1341 
1342 /*
1343 ** An instance of the following structure is passed as the first
1344 ** argument to sqlite3VdbeKeyCompare and is used to control the
1345 ** comparison of the two index keys.
1346 */
1347 struct KeyInfo {
1348   sqlite3 *db;        /* The database connection */
1349   u8 enc;             /* Text encoding - one of the TEXT_Utf* values */
1350   u16 nField;         /* Number of entries in aColl[] */
1351   u8 *aSortOrder;     /* If defined an aSortOrder[i] is true, sort DESC */
1352   CollSeq *aColl[1];  /* Collating sequence for each term of the key */
1353 };
1354 
1355 /*
1356 ** An instance of the following structure holds information about a
1357 ** single index record that has already been parsed out into individual
1358 ** values.
1359 **
1360 ** A record is an object that contains one or more fields of data.
1361 ** Records are used to store the content of a table row and to store
1362 ** the key of an index.  A blob encoding of a record is created by
1363 ** the OP_MakeRecord opcode of the VDBE and is disassembled by the
1364 ** OP_Column opcode.
1365 **
1366 ** This structure holds a record that has already been disassembled
1367 ** into its constituent fields.
1368 */
1369 struct UnpackedRecord {
1370   KeyInfo *pKeyInfo;  /* Collation and sort-order information */
1371   u16 nField;         /* Number of entries in apMem[] */
1372   u16 flags;          /* Boolean settings.  UNPACKED_... below */
1373   i64 rowid;          /* Used by UNPACKED_PREFIX_SEARCH */
1374   Mem *aMem;          /* Values */
1375 };
1376 
1377 /*
1378 ** Allowed values of UnpackedRecord.flags
1379 */
1380 #define UNPACKED_NEED_FREE     0x0001  /* Memory is from sqlite3Malloc() */
1381 #define UNPACKED_NEED_DESTROY  0x0002  /* apMem[]s should all be destroyed */
1382 #define UNPACKED_IGNORE_ROWID  0x0004  /* Ignore trailing rowid on key1 */
1383 #define UNPACKED_INCRKEY       0x0008  /* Make this key an epsilon larger */
1384 #define UNPACKED_PREFIX_MATCH  0x0010  /* A prefix match is considered OK */
1385 #define UNPACKED_PREFIX_SEARCH 0x0020  /* A prefix match is considered OK */
1386 
1387 /*
1388 ** Each SQL index is represented in memory by an
1389 ** instance of the following structure.
1390 **
1391 ** The columns of the table that are to be indexed are described
1392 ** by the aiColumn[] field of this structure.  For example, suppose
1393 ** we have the following table and index:
1394 **
1395 **     CREATE TABLE Ex1(c1 int, c2 int, c3 text);
1396 **     CREATE INDEX Ex2 ON Ex1(c3,c1);
1397 **
1398 ** In the Table structure describing Ex1, nCol==3 because there are
1399 ** three columns in the table.  In the Index structure describing
1400 ** Ex2, nColumn==2 since 2 of the 3 columns of Ex1 are indexed.
1401 ** The value of aiColumn is {2, 0}.  aiColumn[0]==2 because the
1402 ** first column to be indexed (c3) has an index of 2 in Ex1.aCol[].
1403 ** The second column to be indexed (c1) has an index of 0 in
1404 ** Ex1.aCol[], hence Ex2.aiColumn[1]==0.
1405 **
1406 ** The Index.onError field determines whether or not the indexed columns
1407 ** must be unique and what to do if they are not.  When Index.onError=OE_None,
1408 ** it means this is not a unique index.  Otherwise it is a unique index
1409 ** and the value of Index.onError indicate the which conflict resolution
1410 ** algorithm to employ whenever an attempt is made to insert a non-unique
1411 ** element.
1412 */
1413 struct Index {
1414   char *zName;     /* Name of this index */
1415   int nColumn;     /* Number of columns in the table used by this index */
1416   int *aiColumn;   /* Which columns are used by this index.  1st is 0 */
1417   unsigned *aiRowEst; /* Result of ANALYZE: Est. rows selected by each column */
1418   Table *pTable;   /* The SQL table being indexed */
1419   int tnum;        /* Page containing root of this index in database file */
1420   u8 onError;      /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
1421   u8 autoIndex;    /* True if is automatically created (ex: by UNIQUE) */
1422   char *zColAff;   /* String defining the affinity of each column */
1423   Index *pNext;    /* The next index associated with the same table */
1424   Schema *pSchema; /* Schema containing this index */
1425   u8 *aSortOrder;  /* Array of size Index.nColumn. True==DESC, False==ASC */
1426   char **azColl;   /* Array of collation sequence names for index */
1427   IndexSample *aSample;    /* Array of SQLITE_INDEX_SAMPLES samples */
1428 };
1429 
1430 /*
1431 ** Each sample stored in the sqlite_stat2 table is represented in memory
1432 ** using a structure of this type.
1433 */
1434 struct IndexSample {
1435   union {
1436     char *z;        /* Value if eType is SQLITE_TEXT or SQLITE_BLOB */
1437     double r;       /* Value if eType is SQLITE_FLOAT or SQLITE_INTEGER */
1438   } u;
1439   u8 eType;         /* SQLITE_NULL, SQLITE_INTEGER ... etc. */
1440   u8 nByte;         /* Size in byte of text or blob. */
1441 };
1442 
1443 /*
1444 ** Each token coming out of the lexer is an instance of
1445 ** this structure.  Tokens are also used as part of an expression.
1446 **
1447 ** Note if Token.z==0 then Token.dyn and Token.n are undefined and
1448 ** may contain random values.  Do not make any assumptions about Token.dyn
1449 ** and Token.n when Token.z==0.
1450 */
1451 struct Token {
1452   const char *z;     /* Text of the token.  Not NULL-terminated! */
1453   unsigned int n;    /* Number of characters in this token */
1454 };
1455 
1456 /*
1457 ** An instance of this structure contains information needed to generate
1458 ** code for a SELECT that contains aggregate functions.
1459 **
1460 ** If Expr.op==TK_AGG_COLUMN or TK_AGG_FUNCTION then Expr.pAggInfo is a
1461 ** pointer to this structure.  The Expr.iColumn field is the index in
1462 ** AggInfo.aCol[] or AggInfo.aFunc[] of information needed to generate
1463 ** code for that node.
1464 **
1465 ** AggInfo.pGroupBy and AggInfo.aFunc.pExpr point to fields within the
1466 ** original Select structure that describes the SELECT statement.  These
1467 ** fields do not need to be freed when deallocating the AggInfo structure.
1468 */
1469 struct AggInfo {
1470   u8 directMode;          /* Direct rendering mode means take data directly
1471                           ** from source tables rather than from accumulators */
1472   u8 useSortingIdx;       /* In direct mode, reference the sorting index rather
1473                           ** than the source table */
1474   int sortingIdx;         /* Cursor number of the sorting index */
1475   ExprList *pGroupBy;     /* The group by clause */
1476   int nSortingColumn;     /* Number of columns in the sorting index */
1477   struct AggInfo_col {    /* For each column used in source tables */
1478     Table *pTab;             /* Source table */
1479     int iTable;              /* Cursor number of the source table */
1480     int iColumn;             /* Column number within the source table */
1481     int iSorterColumn;       /* Column number in the sorting index */
1482     int iMem;                /* Memory location that acts as accumulator */
1483     Expr *pExpr;             /* The original expression */
1484   } *aCol;
1485   int nColumn;            /* Number of used entries in aCol[] */
1486   int nColumnAlloc;       /* Number of slots allocated for aCol[] */
1487   int nAccumulator;       /* Number of columns that show through to the output.
1488                           ** Additional columns are used only as parameters to
1489                           ** aggregate functions */
1490   struct AggInfo_func {   /* For each aggregate function */
1491     Expr *pExpr;             /* Expression encoding the function */
1492     FuncDef *pFunc;          /* The aggregate function implementation */
1493     int iMem;                /* Memory location that acts as accumulator */
1494     int iDistinct;           /* Ephemeral table used to enforce DISTINCT */
1495   } *aFunc;
1496   int nFunc;              /* Number of entries in aFunc[] */
1497   int nFuncAlloc;         /* Number of slots allocated for aFunc[] */
1498 };
1499 
1500 /*
1501 ** Each node of an expression in the parse tree is an instance
1502 ** of this structure.
1503 **
1504 ** Expr.op is the opcode. The integer parser token codes are reused
1505 ** as opcodes here. For example, the parser defines TK_GE to be an integer
1506 ** code representing the ">=" operator. This same integer code is reused
1507 ** to represent the greater-than-or-equal-to operator in the expression
1508 ** tree.
1509 **
1510 ** If the expression is an SQL literal (TK_INTEGER, TK_FLOAT, TK_BLOB,
1511 ** or TK_STRING), then Expr.token contains the text of the SQL literal. If
1512 ** the expression is a variable (TK_VARIABLE), then Expr.token contains the
1513 ** variable name. Finally, if the expression is an SQL function (TK_FUNCTION),
1514 ** then Expr.token contains the name of the function.
1515 **
1516 ** Expr.pRight and Expr.pLeft are the left and right subexpressions of a
1517 ** binary operator. Either or both may be NULL.
1518 **
1519 ** Expr.x.pList is a list of arguments if the expression is an SQL function,
1520 ** a CASE expression or an IN expression of the form "<lhs> IN (<y>, <z>...)".
1521 ** Expr.x.pSelect is used if the expression is a sub-select or an expression of
1522 ** the form "<lhs> IN (SELECT ...)". If the EP_xIsSelect bit is set in the
1523 ** Expr.flags mask, then Expr.x.pSelect is valid. Otherwise, Expr.x.pList is
1524 ** valid.
1525 **
1526 ** An expression of the form ID or ID.ID refers to a column in a table.
1527 ** For such expressions, Expr.op is set to TK_COLUMN and Expr.iTable is
1528 ** the integer cursor number of a VDBE cursor pointing to that table and
1529 ** Expr.iColumn is the column number for the specific column.  If the
1530 ** expression is used as a result in an aggregate SELECT, then the
1531 ** value is also stored in the Expr.iAgg column in the aggregate so that
1532 ** it can be accessed after all aggregates are computed.
1533 **
1534 ** If the expression is an unbound variable marker (a question mark
1535 ** character '?' in the original SQL) then the Expr.iTable holds the index
1536 ** number for that variable.
1537 **
1538 ** If the expression is a subquery then Expr.iColumn holds an integer
1539 ** register number containing the result of the subquery.  If the
1540 ** subquery gives a constant result, then iTable is -1.  If the subquery
1541 ** gives a different answer at different times during statement processing
1542 ** then iTable is the address of a subroutine that computes the subquery.
1543 **
1544 ** If the Expr is of type OP_Column, and the table it is selecting from
1545 ** is a disk table or the "old.*" pseudo-table, then pTab points to the
1546 ** corresponding table definition.
1547 **
1548 ** ALLOCATION NOTES:
1549 **
1550 ** Expr objects can use a lot of memory space in database schema.  To
1551 ** help reduce memory requirements, sometimes an Expr object will be
1552 ** truncated.  And to reduce the number of memory allocations, sometimes
1553 ** two or more Expr objects will be stored in a single memory allocation,
1554 ** together with Expr.zToken strings.
1555 **
1556 ** If the EP_Reduced and EP_TokenOnly flags are set when
1557 ** an Expr object is truncated.  When EP_Reduced is set, then all
1558 ** the child Expr objects in the Expr.pLeft and Expr.pRight subtrees
1559 ** are contained within the same memory allocation.  Note, however, that
1560 ** the subtrees in Expr.x.pList or Expr.x.pSelect are always separately
1561 ** allocated, regardless of whether or not EP_Reduced is set.
1562 */
1563 struct Expr {
1564   u8 op;                 /* Operation performed by this node */
1565   char affinity;         /* The affinity of the column or 0 if not a column */
1566   u16 flags;             /* Various flags.  EP_* See below */
1567   union {
1568     char *zToken;          /* Token value. Zero terminated and dequoted */
1569     int iValue;            /* Integer value if EP_IntValue */
1570   } u;
1571 
1572   /* If the EP_TokenOnly flag is set in the Expr.flags mask, then no
1573   ** space is allocated for the fields below this point. An attempt to
1574   ** access them will result in a segfault or malfunction.
1575   *********************************************************************/
1576 
1577   Expr *pLeft;           /* Left subnode */
1578   Expr *pRight;          /* Right subnode */
1579   union {
1580     ExprList *pList;     /* Function arguments or in "<expr> IN (<expr-list)" */
1581     Select *pSelect;     /* Used for sub-selects and "<expr> IN (<select>)" */
1582   } x;
1583   CollSeq *pColl;        /* The collation type of the column or 0 */
1584 
1585   /* If the EP_Reduced flag is set in the Expr.flags mask, then no
1586   ** space is allocated for the fields below this point. An attempt to
1587   ** access them will result in a segfault or malfunction.
1588   *********************************************************************/
1589 
1590   int iTable;            /* TK_COLUMN: cursor number of table holding column
1591                          ** TK_REGISTER: register number
1592                          ** TK_TRIGGER: 1 -> new, 0 -> old */
1593   i16 iColumn;           /* TK_COLUMN: column index.  -1 for rowid.
1594                          ** TK_VARIABLE: variable number (always >= 1). */
1595   i16 iAgg;              /* Which entry in pAggInfo->aCol[] or ->aFunc[] */
1596   i16 iRightJoinTable;   /* If EP_FromJoin, the right table of the join */
1597   u8 flags2;             /* Second set of flags.  EP2_... */
1598   u8 op2;                /* If a TK_REGISTER, the original value of Expr.op */
1599   AggInfo *pAggInfo;     /* Used by TK_AGG_COLUMN and TK_AGG_FUNCTION */
1600   Table *pTab;           /* Table for TK_COLUMN expressions. */
1601 #if SQLITE_MAX_EXPR_DEPTH>0
1602   int nHeight;           /* Height of the tree headed by this node */
1603 #endif
1604 };
1605 
1606 /*
1607 ** The following are the meanings of bits in the Expr.flags field.
1608 */
1609 #define EP_FromJoin   0x0001  /* Originated in ON or USING clause of a join */
1610 #define EP_Agg        0x0002  /* Contains one or more aggregate functions */
1611 #define EP_Resolved   0x0004  /* IDs have been resolved to COLUMNs */
1612 #define EP_Error      0x0008  /* Expression contains one or more errors */
1613 #define EP_Distinct   0x0010  /* Aggregate function with DISTINCT keyword */
1614 #define EP_VarSelect  0x0020  /* pSelect is correlated, not constant */
1615 #define EP_DblQuoted  0x0040  /* token.z was originally in "..." */
1616 #define EP_InfixFunc  0x0080  /* True for an infix function: LIKE, GLOB, etc */
1617 #define EP_ExpCollate 0x0100  /* Collating sequence specified explicitly */
1618 #define EP_AnyAff     0x0200  /* Can take a cached column of any affinity */
1619 #define EP_FixedDest  0x0400  /* Result needed in a specific register */
1620 #define EP_IntValue   0x0800  /* Integer value contained in u.iValue */
1621 #define EP_xIsSelect  0x1000  /* x.pSelect is valid (otherwise x.pList is) */
1622 
1623 #define EP_Reduced    0x2000  /* Expr struct is EXPR_REDUCEDSIZE bytes only */
1624 #define EP_TokenOnly  0x4000  /* Expr struct is EXPR_TOKENONLYSIZE bytes only */
1625 #define EP_Static     0x8000  /* Held in memory not obtained from malloc() */
1626 
1627 /*
1628 ** The following are the meanings of bits in the Expr.flags2 field.
1629 */
1630 #define EP2_MallocedToken  0x0001  /* Need to sqlite3DbFree() Expr.zToken */
1631 #define EP2_Irreducible    0x0002  /* Cannot EXPRDUP_REDUCE this Expr */
1632 
1633 /*
1634 ** The pseudo-routine sqlite3ExprSetIrreducible sets the EP2_Irreducible
1635 ** flag on an expression structure.  This flag is used for VV&A only.  The
1636 ** routine is implemented as a macro that only works when in debugging mode,
1637 ** so as not to burden production code.
1638 */
1639 #ifdef SQLITE_DEBUG
1640 # define ExprSetIrreducible(X)  (X)->flags2 |= EP2_Irreducible
1641 #else
1642 # define ExprSetIrreducible(X)
1643 #endif
1644 
1645 /*
1646 ** These macros can be used to test, set, or clear bits in the
1647 ** Expr.flags field.
1648 */
1649 #define ExprHasProperty(E,P)     (((E)->flags&(P))==(P))
1650 #define ExprHasAnyProperty(E,P)  (((E)->flags&(P))!=0)
1651 #define ExprSetProperty(E,P)     (E)->flags|=(P)
1652 #define ExprClearProperty(E,P)   (E)->flags&=~(P)
1653 
1654 /*
1655 ** Macros to determine the number of bytes required by a normal Expr
1656 ** struct, an Expr struct with the EP_Reduced flag set in Expr.flags
1657 ** and an Expr struct with the EP_TokenOnly flag set.
1658 */
1659 #define EXPR_FULLSIZE           sizeof(Expr)           /* Full size */
1660 #define EXPR_REDUCEDSIZE        offsetof(Expr,iTable)  /* Common features */
1661 #define EXPR_TOKENONLYSIZE      offsetof(Expr,pLeft)   /* Fewer features */
1662 
1663 /*
1664 ** Flags passed to the sqlite3ExprDup() function. See the header comment
1665 ** above sqlite3ExprDup() for details.
1666 */
1667 #define EXPRDUP_REDUCE         0x0001  /* Used reduced-size Expr nodes */
1668 
1669 /*
1670 ** A list of expressions.  Each expression may optionally have a
1671 ** name.  An expr/name combination can be used in several ways, such
1672 ** as the list of "expr AS ID" fields following a "SELECT" or in the
1673 ** list of "ID = expr" items in an UPDATE.  A list of expressions can
1674 ** also be used as the argument to a function, in which case the a.zName
1675 ** field is not used.
1676 */
1677 struct ExprList {
1678   int nExpr;             /* Number of expressions on the list */
1679   int nAlloc;            /* Number of entries allocated below */
1680   int iECursor;          /* VDBE Cursor associated with this ExprList */
1681   struct ExprList_item {
1682     Expr *pExpr;           /* The list of expressions */
1683     char *zName;           /* Token associated with this expression */
1684     char *zSpan;           /* Original text of the expression */
1685     u8 sortOrder;          /* 1 for DESC or 0 for ASC */
1686     u8 done;               /* A flag to indicate when processing is finished */
1687     u16 iCol;              /* For ORDER BY, column number in result set */
1688     u16 iAlias;            /* Index into Parse.aAlias[] for zName */
1689   } *a;                  /* One entry for each expression */
1690 };
1691 
1692 /*
1693 ** An instance of this structure is used by the parser to record both
1694 ** the parse tree for an expression and the span of input text for an
1695 ** expression.
1696 */
1697 struct ExprSpan {
1698   Expr *pExpr;          /* The expression parse tree */
1699   const char *zStart;   /* First character of input text */
1700   const char *zEnd;     /* One character past the end of input text */
1701 };
1702 
1703 /*
1704 ** An instance of this structure can hold a simple list of identifiers,
1705 ** such as the list "a,b,c" in the following statements:
1706 **
1707 **      INSERT INTO t(a,b,c) VALUES ...;
1708 **      CREATE INDEX idx ON t(a,b,c);
1709 **      CREATE TRIGGER trig BEFORE UPDATE ON t(a,b,c) ...;
1710 **
1711 ** The IdList.a.idx field is used when the IdList represents the list of
1712 ** column names after a table name in an INSERT statement.  In the statement
1713 **
1714 **     INSERT INTO t(a,b,c) ...
1715 **
1716 ** If "a" is the k-th column of table "t", then IdList.a[0].idx==k.
1717 */
1718 struct IdList {
1719   struct IdList_item {
1720     char *zName;      /* Name of the identifier */
1721     int idx;          /* Index in some Table.aCol[] of a column named zName */
1722   } *a;
1723   int nId;         /* Number of identifiers on the list */
1724   int nAlloc;      /* Number of entries allocated for a[] below */
1725 };
1726 
1727 /*
1728 ** The bitmask datatype defined below is used for various optimizations.
1729 **
1730 ** Changing this from a 64-bit to a 32-bit type limits the number of
1731 ** tables in a join to 32 instead of 64.  But it also reduces the size
1732 ** of the library by 738 bytes on ix86.
1733 */
1734 typedef u64 Bitmask;
1735 
1736 /*
1737 ** The number of bits in a Bitmask.  "BMS" means "BitMask Size".
1738 */
1739 #define BMS  ((int)(sizeof(Bitmask)*8))
1740 
1741 /*
1742 ** The following structure describes the FROM clause of a SELECT statement.
1743 ** Each table or subquery in the FROM clause is a separate element of
1744 ** the SrcList.a[] array.
1745 **
1746 ** With the addition of multiple database support, the following structure
1747 ** can also be used to describe a particular table such as the table that
1748 ** is modified by an INSERT, DELETE, or UPDATE statement.  In standard SQL,
1749 ** such a table must be a simple name: ID.  But in SQLite, the table can
1750 ** now be identified by a database name, a dot, then the table name: ID.ID.
1751 **
1752 ** The jointype starts out showing the join type between the current table
1753 ** and the next table on the list.  The parser builds the list this way.
1754 ** But sqlite3SrcListShiftJoinType() later shifts the jointypes so that each
1755 ** jointype expresses the join between the table and the previous table.
1756 */
1757 struct SrcList {
1758   i16 nSrc;        /* Number of tables or subqueries in the FROM clause */
1759   i16 nAlloc;      /* Number of entries allocated in a[] below */
1760   struct SrcList_item {
1761     char *zDatabase;  /* Name of database holding this table */
1762     char *zName;      /* Name of the table */
1763     char *zAlias;     /* The "B" part of a "A AS B" phrase.  zName is the "A" */
1764     Table *pTab;      /* An SQL table corresponding to zName */
1765     Select *pSelect;  /* A SELECT statement used in place of a table name */
1766     u8 isPopulated;   /* Temporary table associated with SELECT is populated */
1767     u8 jointype;      /* Type of join between this able and the previous */
1768     u8 notIndexed;    /* True if there is a NOT INDEXED clause */
1769     int iCursor;      /* The VDBE cursor number used to access this table */
1770     Expr *pOn;        /* The ON clause of a join */
1771     IdList *pUsing;   /* The USING clause of a join */
1772     Bitmask colUsed;  /* Bit N (1<<N) set if column N of pTab is used */
1773     char *zIndex;     /* Identifier from "INDEXED BY <zIndex>" clause */
1774     Index *pIndex;    /* Index structure corresponding to zIndex, if any */
1775   } a[1];             /* One entry for each identifier on the list */
1776 };
1777 
1778 /*
1779 ** Permitted values of the SrcList.a.jointype field
1780 */
1781 #define JT_INNER     0x0001    /* Any kind of inner or cross join */
1782 #define JT_CROSS     0x0002    /* Explicit use of the CROSS keyword */
1783 #define JT_NATURAL   0x0004    /* True for a "natural" join */
1784 #define JT_LEFT      0x0008    /* Left outer join */
1785 #define JT_RIGHT     0x0010    /* Right outer join */
1786 #define JT_OUTER     0x0020    /* The "OUTER" keyword is present */
1787 #define JT_ERROR     0x0040    /* unknown or unsupported join type */
1788 
1789 
1790 /*
1791 ** A WherePlan object holds information that describes a lookup
1792 ** strategy.
1793 **
1794 ** This object is intended to be opaque outside of the where.c module.
1795 ** It is included here only so that that compiler will know how big it
1796 ** is.  None of the fields in this object should be used outside of
1797 ** the where.c module.
1798 **
1799 ** Within the union, pIdx is only used when wsFlags&WHERE_INDEXED is true.
1800 ** pTerm is only used when wsFlags&WHERE_MULTI_OR is true.  And pVtabIdx
1801 ** is only used when wsFlags&WHERE_VIRTUALTABLE is true.  It is never the
1802 ** case that more than one of these conditions is true.
1803 */
1804 struct WherePlan {
1805   u32 wsFlags;                   /* WHERE_* flags that describe the strategy */
1806   u32 nEq;                       /* Number of == constraints */
1807   union {
1808     Index *pIdx;                   /* Index when WHERE_INDEXED is true */
1809     struct WhereTerm *pTerm;       /* WHERE clause term for OR-search */
1810     sqlite3_index_info *pVtabIdx;  /* Virtual table index to use */
1811   } u;
1812 };
1813 
1814 /*
1815 ** For each nested loop in a WHERE clause implementation, the WhereInfo
1816 ** structure contains a single instance of this structure.  This structure
1817 ** is intended to be private the the where.c module and should not be
1818 ** access or modified by other modules.
1819 **
1820 ** The pIdxInfo field is used to help pick the best index on a
1821 ** virtual table.  The pIdxInfo pointer contains indexing
1822 ** information for the i-th table in the FROM clause before reordering.
1823 ** All the pIdxInfo pointers are freed by whereInfoFree() in where.c.
1824 ** All other information in the i-th WhereLevel object for the i-th table
1825 ** after FROM clause ordering.
1826 */
1827 struct WhereLevel {
1828   WherePlan plan;       /* query plan for this element of the FROM clause */
1829   int iLeftJoin;        /* Memory cell used to implement LEFT OUTER JOIN */
1830   int iTabCur;          /* The VDBE cursor used to access the table */
1831   int iIdxCur;          /* The VDBE cursor used to access pIdx */
1832   int addrBrk;          /* Jump here to break out of the loop */
1833   int addrNxt;          /* Jump here to start the next IN combination */
1834   int addrCont;         /* Jump here to continue with the next loop cycle */
1835   int addrFirst;        /* First instruction of interior of the loop */
1836   u8 iFrom;             /* Which entry in the FROM clause */
1837   u8 op, p5;            /* Opcode and P5 of the opcode that ends the loop */
1838   int p1, p2;           /* Operands of the opcode used to ends the loop */
1839   union {               /* Information that depends on plan.wsFlags */
1840     struct {
1841       int nIn;              /* Number of entries in aInLoop[] */
1842       struct InLoop {
1843         int iCur;              /* The VDBE cursor used by this IN operator */
1844         int addrInTop;         /* Top of the IN loop */
1845       } *aInLoop;           /* Information about each nested IN operator */
1846     } in;                 /* Used when plan.wsFlags&WHERE_IN_ABLE */
1847   } u;
1848 
1849   /* The following field is really not part of the current level.  But
1850   ** we need a place to cache virtual table index information for each
1851   ** virtual table in the FROM clause and the WhereLevel structure is
1852   ** a convenient place since there is one WhereLevel for each FROM clause
1853   ** element.
1854   */
1855   sqlite3_index_info *pIdxInfo;  /* Index info for n-th source table */
1856 };
1857 
1858 /*
1859 ** Flags appropriate for the wctrlFlags parameter of sqlite3WhereBegin()
1860 ** and the WhereInfo.wctrlFlags member.
1861 */
1862 #define WHERE_ORDERBY_NORMAL   0x0000 /* No-op */
1863 #define WHERE_ORDERBY_MIN      0x0001 /* ORDER BY processing for min() func */
1864 #define WHERE_ORDERBY_MAX      0x0002 /* ORDER BY processing for max() func */
1865 #define WHERE_ONEPASS_DESIRED  0x0004 /* Want to do one-pass UPDATE/DELETE */
1866 #define WHERE_DUPLICATES_OK    0x0008 /* Ok to return a row more than once */
1867 #define WHERE_OMIT_OPEN        0x0010 /* Table cursor are already open */
1868 #define WHERE_OMIT_CLOSE       0x0020 /* Omit close of table & index cursors */
1869 #define WHERE_FORCE_TABLE      0x0040 /* Do not use an index-only search */
1870 
1871 /*
1872 ** The WHERE clause processing routine has two halves.  The
1873 ** first part does the start of the WHERE loop and the second
1874 ** half does the tail of the WHERE loop.  An instance of
1875 ** this structure is returned by the first half and passed
1876 ** into the second half to give some continuity.
1877 */
1878 struct WhereInfo {
1879   Parse *pParse;       /* Parsing and code generating context */
1880   u16 wctrlFlags;      /* Flags originally passed to sqlite3WhereBegin() */
1881   u8 okOnePass;        /* Ok to use one-pass algorithm for UPDATE or DELETE */
1882   SrcList *pTabList;             /* List of tables in the join */
1883   int iTop;                      /* The very beginning of the WHERE loop */
1884   int iContinue;                 /* Jump here to continue with next record */
1885   int iBreak;                    /* Jump here to break out of the loop */
1886   int nLevel;                    /* Number of nested loop */
1887   struct WhereClause *pWC;       /* Decomposition of the WHERE clause */
1888   WhereLevel a[1];               /* Information about each nest loop in WHERE */
1889 };
1890 
1891 /*
1892 ** A NameContext defines a context in which to resolve table and column
1893 ** names.  The context consists of a list of tables (the pSrcList) field and
1894 ** a list of named expression (pEList).  The named expression list may
1895 ** be NULL.  The pSrc corresponds to the FROM clause of a SELECT or
1896 ** to the table being operated on by INSERT, UPDATE, or DELETE.  The
1897 ** pEList corresponds to the result set of a SELECT and is NULL for
1898 ** other statements.
1899 **
1900 ** NameContexts can be nested.  When resolving names, the inner-most
1901 ** context is searched first.  If no match is found, the next outer
1902 ** context is checked.  If there is still no match, the next context
1903 ** is checked.  This process continues until either a match is found
1904 ** or all contexts are check.  When a match is found, the nRef member of
1905 ** the context containing the match is incremented.
1906 **
1907 ** Each subquery gets a new NameContext.  The pNext field points to the
1908 ** NameContext in the parent query.  Thus the process of scanning the
1909 ** NameContext list corresponds to searching through successively outer
1910 ** subqueries looking for a match.
1911 */
1912 struct NameContext {
1913   Parse *pParse;       /* The parser */
1914   SrcList *pSrcList;   /* One or more tables used to resolve names */
1915   ExprList *pEList;    /* Optional list of named expressions */
1916   int nRef;            /* Number of names resolved by this context */
1917   int nErr;            /* Number of errors encountered while resolving names */
1918   u8 allowAgg;         /* Aggregate functions allowed here */
1919   u8 hasAgg;           /* True if aggregates are seen */
1920   u8 isCheck;          /* True if resolving names in a CHECK constraint */
1921   int nDepth;          /* Depth of subquery recursion. 1 for no recursion */
1922   AggInfo *pAggInfo;   /* Information about aggregates at this level */
1923   NameContext *pNext;  /* Next outer name context.  NULL for outermost */
1924 };
1925 
1926 /*
1927 ** An instance of the following structure contains all information
1928 ** needed to generate code for a single SELECT statement.
1929 **
1930 ** nLimit is set to -1 if there is no LIMIT clause.  nOffset is set to 0.
1931 ** If there is a LIMIT clause, the parser sets nLimit to the value of the
1932 ** limit and nOffset to the value of the offset (or 0 if there is not
1933 ** offset).  But later on, nLimit and nOffset become the memory locations
1934 ** in the VDBE that record the limit and offset counters.
1935 **
1936 ** addrOpenEphm[] entries contain the address of OP_OpenEphemeral opcodes.
1937 ** These addresses must be stored so that we can go back and fill in
1938 ** the P4_KEYINFO and P2 parameters later.  Neither the KeyInfo nor
1939 ** the number of columns in P2 can be computed at the same time
1940 ** as the OP_OpenEphm instruction is coded because not
1941 ** enough information about the compound query is known at that point.
1942 ** The KeyInfo for addrOpenTran[0] and [1] contains collating sequences
1943 ** for the result set.  The KeyInfo for addrOpenTran[2] contains collating
1944 ** sequences for the ORDER BY clause.
1945 */
1946 struct Select {
1947   ExprList *pEList;      /* The fields of the result */
1948   u8 op;                 /* One of: TK_UNION TK_ALL TK_INTERSECT TK_EXCEPT */
1949   char affinity;         /* MakeRecord with this affinity for SRT_Set */
1950   u16 selFlags;          /* Various SF_* values */
1951   SrcList *pSrc;         /* The FROM clause */
1952   Expr *pWhere;          /* The WHERE clause */
1953   ExprList *pGroupBy;    /* The GROUP BY clause */
1954   Expr *pHaving;         /* The HAVING clause */
1955   ExprList *pOrderBy;    /* The ORDER BY clause */
1956   Select *pPrior;        /* Prior select in a compound select statement */
1957   Select *pNext;         /* Next select to the left in a compound */
1958   Select *pRightmost;    /* Right-most select in a compound select statement */
1959   Expr *pLimit;          /* LIMIT expression. NULL means not used. */
1960   Expr *pOffset;         /* OFFSET expression. NULL means not used. */
1961   int iLimit, iOffset;   /* Memory registers holding LIMIT & OFFSET counters */
1962   int addrOpenEphm[3];   /* OP_OpenEphem opcodes related to this select */
1963 };
1964 
1965 /*
1966 ** Allowed values for Select.selFlags.  The "SF" prefix stands for
1967 ** "Select Flag".
1968 */
1969 #define SF_Distinct        0x0001  /* Output should be DISTINCT */
1970 #define SF_Resolved        0x0002  /* Identifiers have been resolved */
1971 #define SF_Aggregate       0x0004  /* Contains aggregate functions */
1972 #define SF_UsesEphemeral   0x0008  /* Uses the OpenEphemeral opcode */
1973 #define SF_Expanded        0x0010  /* sqlite3SelectExpand() called on this */
1974 #define SF_HasTypeInfo     0x0020  /* FROM subqueries have Table metadata */
1975 
1976 
1977 /*
1978 ** The results of a select can be distributed in several ways.  The
1979 ** "SRT" prefix means "SELECT Result Type".
1980 */
1981 #define SRT_Union        1  /* Store result as keys in an index */
1982 #define SRT_Except       2  /* Remove result from a UNION index */
1983 #define SRT_Exists       3  /* Store 1 if the result is not empty */
1984 #define SRT_Discard      4  /* Do not save the results anywhere */
1985 
1986 /* The ORDER BY clause is ignored for all of the above */
1987 #define IgnorableOrderby(X) ((X->eDest)<=SRT_Discard)
1988 
1989 #define SRT_Output       5  /* Output each row of result */
1990 #define SRT_Mem          6  /* Store result in a memory cell */
1991 #define SRT_Set          7  /* Store results as keys in an index */
1992 #define SRT_Table        8  /* Store result as data with an automatic rowid */
1993 #define SRT_EphemTab     9  /* Create transient tab and store like SRT_Table */
1994 #define SRT_Coroutine   10  /* Generate a single row of result */
1995 
1996 /*
1997 ** A structure used to customize the behavior of sqlite3Select(). See
1998 ** comments above sqlite3Select() for details.
1999 */
2000 typedef struct SelectDest SelectDest;
2001 struct SelectDest {
2002   u8 eDest;         /* How to dispose of the results */
2003   u8 affinity;      /* Affinity used when eDest==SRT_Set */
2004   int iParm;        /* A parameter used by the eDest disposal method */
2005   int iMem;         /* Base register where results are written */
2006   int nMem;         /* Number of registers allocated */
2007 };
2008 
2009 /*
2010 ** During code generation of statements that do inserts into AUTOINCREMENT
2011 ** tables, the following information is attached to the Table.u.autoInc.p
2012 ** pointer of each autoincrement table to record some side information that
2013 ** the code generator needs.  We have to keep per-table autoincrement
2014 ** information in case inserts are down within triggers.  Triggers do not
2015 ** normally coordinate their activities, but we do need to coordinate the
2016 ** loading and saving of autoincrement information.
2017 */
2018 struct AutoincInfo {
2019   AutoincInfo *pNext;   /* Next info block in a list of them all */
2020   Table *pTab;          /* Table this info block refers to */
2021   int iDb;              /* Index in sqlite3.aDb[] of database holding pTab */
2022   int regCtr;           /* Memory register holding the rowid counter */
2023 };
2024 
2025 /*
2026 ** Size of the column cache
2027 */
2028 #ifndef SQLITE_N_COLCACHE
2029 # define SQLITE_N_COLCACHE 10
2030 #endif
2031 
2032 /*
2033 ** At least one instance of the following structure is created for each
2034 ** trigger that may be fired while parsing an INSERT, UPDATE or DELETE
2035 ** statement. All such objects are stored in the linked list headed at
2036 ** Parse.pTriggerPrg and deleted once statement compilation has been
2037 ** completed.
2038 **
2039 ** A Vdbe sub-program that implements the body and WHEN clause of trigger
2040 ** TriggerPrg.pTrigger, assuming a default ON CONFLICT clause of
2041 ** TriggerPrg.orconf, is stored in the TriggerPrg.pProgram variable.
2042 ** The Parse.pTriggerPrg list never contains two entries with the same
2043 ** values for both pTrigger and orconf.
2044 **
2045 ** The TriggerPrg.oldmask variable is set to a mask of old.* columns
2046 ** accessed (or set to 0 for triggers fired as a result of INSERT
2047 ** statements).
2048 */
2049 struct TriggerPrg {
2050   Trigger *pTrigger;      /* Trigger this program was coded from */
2051   int orconf;             /* Default ON CONFLICT policy */
2052   SubProgram *pProgram;   /* Program implementing pTrigger/orconf */
2053   u32 oldmask;            /* Mask of old.* columns accessed */
2054   TriggerPrg *pNext;      /* Next entry in Parse.pTriggerPrg list */
2055 };
2056 
2057 /*
2058 ** An SQL parser context.  A copy of this structure is passed through
2059 ** the parser and down into all the parser action routine in order to
2060 ** carry around information that is global to the entire parse.
2061 **
2062 ** The structure is divided into two parts.  When the parser and code
2063 ** generate call themselves recursively, the first part of the structure
2064 ** is constant but the second part is reset at the beginning and end of
2065 ** each recursion.
2066 **
2067 ** The nTableLock and aTableLock variables are only used if the shared-cache
2068 ** feature is enabled (if sqlite3Tsd()->useSharedData is true). They are
2069 ** used to store the set of table-locks required by the statement being
2070 ** compiled. Function sqlite3TableLock() is used to add entries to the
2071 ** list.
2072 */
2073 struct Parse {
2074   sqlite3 *db;         /* The main database structure */
2075   int rc;              /* Return code from execution */
2076   char *zErrMsg;       /* An error message */
2077   Vdbe *pVdbe;         /* An engine for executing database bytecode */
2078   u8 colNamesSet;      /* TRUE after OP_ColumnName has been issued to pVdbe */
2079   u8 nameClash;        /* A permanent table name clashes with temp table name */
2080   u8 checkSchema;      /* Causes schema cookie check after an error */
2081   u8 nested;           /* Number of nested calls to the parser/code generator */
2082   u8 parseError;       /* True after a parsing error.  Ticket #1794 */
2083   u8 nTempReg;         /* Number of temporary registers in aTempReg[] */
2084   u8 nTempInUse;       /* Number of aTempReg[] currently checked out */
2085   int aTempReg[8];     /* Holding area for temporary registers */
2086   int nRangeReg;       /* Size of the temporary register block */
2087   int iRangeReg;       /* First register in temporary register block */
2088   int nErr;            /* Number of errors seen */
2089   int nTab;            /* Number of previously allocated VDBE cursors */
2090   int nMem;            /* Number of memory cells used so far */
2091   int nSet;            /* Number of sets used so far */
2092   int ckBase;          /* Base register of data during check constraints */
2093   int iCacheLevel;     /* ColCache valid when aColCache[].iLevel<=iCacheLevel */
2094   int iCacheCnt;       /* Counter used to generate aColCache[].lru values */
2095   u8 nColCache;        /* Number of entries in the column cache */
2096   u8 iColCache;        /* Next entry of the cache to replace */
2097   struct yColCache {
2098     int iTable;           /* Table cursor number */
2099     int iColumn;          /* Table column number */
2100     u8 affChange;         /* True if this register has had an affinity change */
2101     u8 tempReg;           /* iReg is a temp register that needs to be freed */
2102     int iLevel;           /* Nesting level */
2103     int iReg;             /* Reg with value of this column. 0 means none. */
2104     int lru;              /* Least recently used entry has the smallest value */
2105   } aColCache[SQLITE_N_COLCACHE];  /* One for each column cache entry */
2106   u32 writeMask;       /* Start a write transaction on these databases */
2107   u32 cookieMask;      /* Bitmask of schema verified databases */
2108   u8 isMultiWrite;     /* True if statement may affect/insert multiple rows */
2109   u8 mayAbort;         /* True if statement may throw an ABORT exception */
2110   int cookieGoto;      /* Address of OP_Goto to cookie verifier subroutine */
2111   int cookieValue[SQLITE_MAX_ATTACHED+2];  /* Values of cookies to verify */
2112 #ifndef SQLITE_OMIT_SHARED_CACHE
2113   int nTableLock;        /* Number of locks in aTableLock */
2114   TableLock *aTableLock; /* Required table locks for shared-cache mode */
2115 #endif
2116   int regRowid;        /* Register holding rowid of CREATE TABLE entry */
2117   int regRoot;         /* Register holding root page number for new objects */
2118   AutoincInfo *pAinc;  /* Information about AUTOINCREMENT counters */
2119   int nMaxArg;         /* Max args passed to user function by sub-program */
2120 
2121   /* Information used while coding trigger programs. */
2122   Parse *pToplevel;    /* Parse structure for main program (or NULL) */
2123   Table *pTriggerTab;  /* Table triggers are being coded for */
2124   u32 oldmask;         /* Mask of old.* columns referenced */
2125   u8 eTriggerOp;       /* TK_UPDATE, TK_INSERT or TK_DELETE */
2126   u8 eOrconf;          /* Default ON CONFLICT policy for trigger steps */
2127   u8 disableTriggers;  /* True to disable triggers */
2128 
2129   /* Above is constant between recursions.  Below is reset before and after
2130   ** each recursion */
2131 
2132   int nVar;            /* Number of '?' variables seen in the SQL so far */
2133   int nVarExpr;        /* Number of used slots in apVarExpr[] */
2134   int nVarExprAlloc;   /* Number of allocated slots in apVarExpr[] */
2135   Expr **apVarExpr;    /* Pointers to :aaa and $aaaa wildcard expressions */
2136   Vdbe *pReprepare;    /* VM being reprepared (sqlite3Reprepare()) */
2137   int nAlias;          /* Number of aliased result set columns */
2138   int nAliasAlloc;     /* Number of allocated slots for aAlias[] */
2139   int *aAlias;         /* Register used to hold aliased result */
2140   u8 explain;          /* True if the EXPLAIN flag is found on the query */
2141   Token sNameToken;    /* Token with unqualified schema object name */
2142   Token sLastToken;    /* The last token parsed */
2143   const char *zTail;   /* All SQL text past the last semicolon parsed */
2144   Table *pNewTable;    /* A table being constructed by CREATE TABLE */
2145   Trigger *pNewTrigger;     /* Trigger under construct by a CREATE TRIGGER */
2146   const char *zAuthContext; /* The 6th parameter to db->xAuth callbacks */
2147 #ifndef SQLITE_OMIT_VIRTUALTABLE
2148   Token sArg;                /* Complete text of a module argument */
2149   u8 declareVtab;            /* True if inside sqlite3_declare_vtab() */
2150   int nVtabLock;             /* Number of virtual tables to lock */
2151   Table **apVtabLock;        /* Pointer to virtual tables needing locking */
2152 #endif
2153   int nHeight;            /* Expression tree height of current sub-select */
2154   Table *pZombieTab;      /* List of Table objects to delete after code gen */
2155   TriggerPrg *pTriggerPrg;    /* Linked list of coded triggers */
2156 };
2157 
2158 #ifdef SQLITE_OMIT_VIRTUALTABLE
2159   #define IN_DECLARE_VTAB 0
2160 #else
2161   #define IN_DECLARE_VTAB (pParse->declareVtab)
2162 #endif
2163 
2164 /*
2165 ** An instance of the following structure can be declared on a stack and used
2166 ** to save the Parse.zAuthContext value so that it can be restored later.
2167 */
2168 struct AuthContext {
2169   const char *zAuthContext;   /* Put saved Parse.zAuthContext here */
2170   Parse *pParse;              /* The Parse structure */
2171 };
2172 
2173 /*
2174 ** Bitfield flags for P5 value in OP_Insert and OP_Delete
2175 */
2176 #define OPFLAG_NCHANGE       0x01    /* Set to update db->nChange */
2177 #define OPFLAG_LASTROWID     0x02    /* Set to update db->lastRowid */
2178 #define OPFLAG_ISUPDATE      0x04    /* This OP_Insert is an sql UPDATE */
2179 #define OPFLAG_APPEND        0x08    /* This is likely to be an append */
2180 #define OPFLAG_USESEEKRESULT 0x10    /* Try to avoid a seek in BtreeInsert() */
2181 #define OPFLAG_CLEARCACHE    0x20    /* Clear pseudo-table cache in OP_Column */
2182 
2183 /*
2184  * Each trigger present in the database schema is stored as an instance of
2185  * struct Trigger.
2186  *
2187  * Pointers to instances of struct Trigger are stored in two ways.
2188  * 1. In the "trigHash" hash table (part of the sqlite3* that represents the
2189  *    database). This allows Trigger structures to be retrieved by name.
2190  * 2. All triggers associated with a single table form a linked list, using the
2191  *    pNext member of struct Trigger. A pointer to the first element of the
2192  *    linked list is stored as the "pTrigger" member of the associated
2193  *    struct Table.
2194  *
2195  * The "step_list" member points to the first element of a linked list
2196  * containing the SQL statements specified as the trigger program.
2197  */
2198 struct Trigger {
2199   char *zName;            /* The name of the trigger                        */
2200   char *table;            /* The table or view to which the trigger applies */
2201   u8 op;                  /* One of TK_DELETE, TK_UPDATE, TK_INSERT         */
2202   u8 tr_tm;               /* One of TRIGGER_BEFORE, TRIGGER_AFTER */
2203   Expr *pWhen;            /* The WHEN clause of the expression (may be NULL) */
2204   IdList *pColumns;       /* If this is an UPDATE OF <column-list> trigger,
2205                              the <column-list> is stored here */
2206   Schema *pSchema;        /* Schema containing the trigger */
2207   Schema *pTabSchema;     /* Schema containing the table */
2208   TriggerStep *step_list; /* Link list of trigger program steps             */
2209   Trigger *pNext;         /* Next trigger associated with the table */
2210 };
2211 
2212 /*
2213 ** A trigger is either a BEFORE or an AFTER trigger.  The following constants
2214 ** determine which.
2215 **
2216 ** If there are multiple triggers, you might of some BEFORE and some AFTER.
2217 ** In that cases, the constants below can be ORed together.
2218 */
2219 #define TRIGGER_BEFORE  1
2220 #define TRIGGER_AFTER   2
2221 
2222 /*
2223  * An instance of struct TriggerStep is used to store a single SQL statement
2224  * that is a part of a trigger-program.
2225  *
2226  * Instances of struct TriggerStep are stored in a singly linked list (linked
2227  * using the "pNext" member) referenced by the "step_list" member of the
2228  * associated struct Trigger instance. The first element of the linked list is
2229  * the first step of the trigger-program.
2230  *
2231  * The "op" member indicates whether this is a "DELETE", "INSERT", "UPDATE" or
2232  * "SELECT" statement. The meanings of the other members is determined by the
2233  * value of "op" as follows:
2234  *
2235  * (op == TK_INSERT)
2236  * orconf    -> stores the ON CONFLICT algorithm
2237  * pSelect   -> If this is an INSERT INTO ... SELECT ... statement, then
2238  *              this stores a pointer to the SELECT statement. Otherwise NULL.
2239  * target    -> A token holding the quoted name of the table to insert into.
2240  * pExprList -> If this is an INSERT INTO ... VALUES ... statement, then
2241  *              this stores values to be inserted. Otherwise NULL.
2242  * pIdList   -> If this is an INSERT INTO ... (<column-names>) VALUES ...
2243  *              statement, then this stores the column-names to be
2244  *              inserted into.
2245  *
2246  * (op == TK_DELETE)
2247  * target    -> A token holding the quoted name of the table to delete from.
2248  * pWhere    -> The WHERE clause of the DELETE statement if one is specified.
2249  *              Otherwise NULL.
2250  *
2251  * (op == TK_UPDATE)
2252  * target    -> A token holding the quoted name of the table to update rows of.
2253  * pWhere    -> The WHERE clause of the UPDATE statement if one is specified.
2254  *              Otherwise NULL.
2255  * pExprList -> A list of the columns to update and the expressions to update
2256  *              them to. See sqlite3Update() documentation of "pChanges"
2257  *              argument.
2258  *
2259  */
2260 struct TriggerStep {
2261   u8 op;               /* One of TK_DELETE, TK_UPDATE, TK_INSERT, TK_SELECT */
2262   u8 orconf;           /* OE_Rollback etc. */
2263   Trigger *pTrig;      /* The trigger that this step is a part of */
2264   Select *pSelect;     /* SELECT statment or RHS of INSERT INTO .. SELECT ... */
2265   Token target;        /* Target table for DELETE, UPDATE, INSERT */
2266   Expr *pWhere;        /* The WHERE clause for DELETE or UPDATE steps */
2267   ExprList *pExprList; /* SET clause for UPDATE.  VALUES clause for INSERT */
2268   IdList *pIdList;     /* Column names for INSERT */
2269   TriggerStep *pNext;  /* Next in the link-list */
2270   TriggerStep *pLast;  /* Last element in link-list. Valid for 1st elem only */
2271 };
2272 
2273 /*
2274 ** The following structure contains information used by the sqliteFix...
2275 ** routines as they walk the parse tree to make database references
2276 ** explicit.
2277 */
2278 typedef struct DbFixer DbFixer;
2279 struct DbFixer {
2280   Parse *pParse;      /* The parsing context.  Error messages written here */
2281   const char *zDb;    /* Make sure all objects are contained in this database */
2282   const char *zType;  /* Type of the container - used for error messages */
2283   const Token *pName; /* Name of the container - used for error messages */
2284 };
2285 
2286 /*
2287 ** An objected used to accumulate the text of a string where we
2288 ** do not necessarily know how big the string will be in the end.
2289 */
2290 struct StrAccum {
2291   sqlite3 *db;         /* Optional database for lookaside.  Can be NULL */
2292   char *zBase;         /* A base allocation.  Not from malloc. */
2293   char *zText;         /* The string collected so far */
2294   int  nChar;          /* Length of the string so far */
2295   int  nAlloc;         /* Amount of space allocated in zText */
2296   int  mxAlloc;        /* Maximum allowed string length */
2297   u8   mallocFailed;   /* Becomes true if any memory allocation fails */
2298   u8   useMalloc;      /* True if zText is enlargeable using realloc */
2299   u8   tooBig;         /* Becomes true if string size exceeds limits */
2300 };
2301 
2302 /*
2303 ** A pointer to this structure is used to communicate information
2304 ** from sqlite3Init and OP_ParseSchema into the sqlite3InitCallback.
2305 */
2306 typedef struct {
2307   sqlite3 *db;        /* The database being initialized */
2308   int iDb;            /* 0 for main database.  1 for TEMP, 2.. for ATTACHed */
2309   char **pzErrMsg;    /* Error message stored here */
2310   int rc;             /* Result code stored here */
2311 } InitData;
2312 
2313 /*
2314 ** Structure containing global configuration data for the SQLite library.
2315 **
2316 ** This structure also contains some state information.
2317 */
2318 struct Sqlite3Config {
2319   int bMemstat;                     /* True to enable memory status */
2320   int bCoreMutex;                   /* True to enable core mutexing */
2321   int bFullMutex;                   /* True to enable full mutexing */
2322   int mxStrlen;                     /* Maximum string length */
2323   int szLookaside;                  /* Default lookaside buffer size */
2324   int nLookaside;                   /* Default lookaside buffer count */
2325   sqlite3_mem_methods m;            /* Low-level memory allocation interface */
2326   sqlite3_mutex_methods mutex;      /* Low-level mutex interface */
2327   sqlite3_pcache_methods pcache;    /* Low-level page-cache interface */
2328   void *pHeap;                      /* Heap storage space */
2329   int nHeap;                        /* Size of pHeap[] */
2330   int mnReq, mxReq;                 /* Min and max heap requests sizes */
2331   void *pScratch;                   /* Scratch memory */
2332   int szScratch;                    /* Size of each scratch buffer */
2333   int nScratch;                     /* Number of scratch buffers */
2334   void *pPage;                      /* Page cache memory */
2335   int szPage;                       /* Size of each page in pPage[] */
2336   int nPage;                        /* Number of pages in pPage[] */
2337   int mxParserStack;                /* maximum depth of the parser stack */
2338   int sharedCacheEnabled;           /* true if shared-cache mode enabled */
2339   /* The above might be initialized to non-zero.  The following need to always
2340   ** initially be zero, however. */
2341   int isInit;                       /* True after initialization has finished */
2342   int inProgress;                   /* True while initialization in progress */
2343   int isMutexInit;                  /* True after mutexes are initialized */
2344   int isMallocInit;                 /* True after malloc is initialized */
2345   int isPCacheInit;                 /* True after malloc is initialized */
2346   sqlite3_mutex *pInitMutex;        /* Mutex used by sqlite3_initialize() */
2347   int nRefInitMutex;                /* Number of users of pInitMutex */
2348 };
2349 
2350 /*
2351 ** Context pointer passed down through the tree-walk.
2352 */
2353 struct Walker {
2354   int (*xExprCallback)(Walker*, Expr*);     /* Callback for expressions */
2355   int (*xSelectCallback)(Walker*,Select*);  /* Callback for SELECTs */
2356   Parse *pParse;                            /* Parser context.  */
2357   union {                                   /* Extra data for callback */
2358     NameContext *pNC;                          /* Naming context */
2359     int i;                                     /* Integer value */
2360   } u;
2361 };
2362 
2363 /* Forward declarations */
2364 int sqlite3WalkExpr(Walker*, Expr*);
2365 int sqlite3WalkExprList(Walker*, ExprList*);
2366 int sqlite3WalkSelect(Walker*, Select*);
2367 int sqlite3WalkSelectExpr(Walker*, Select*);
2368 int sqlite3WalkSelectFrom(Walker*, Select*);
2369 
2370 /*
2371 ** Return code from the parse-tree walking primitives and their
2372 ** callbacks.
2373 */
2374 #define WRC_Continue    0   /* Continue down into children */
2375 #define WRC_Prune       1   /* Omit children but continue walking siblings */
2376 #define WRC_Abort       2   /* Abandon the tree walk */
2377 
2378 /*
2379 ** Assuming zIn points to the first byte of a UTF-8 character,
2380 ** advance zIn to point to the first byte of the next UTF-8 character.
2381 */
2382 #define SQLITE_SKIP_UTF8(zIn) {                        \
2383   if( (*(zIn++))>=0xc0 ){                              \
2384     while( (*zIn & 0xc0)==0x80 ){ zIn++; }             \
2385   }                                                    \
2386 }
2387 
2388 /*
2389 ** The SQLITE_CORRUPT_BKPT macro can be either a constant (for production
2390 ** builds) or a function call (for debugging).  If it is a function call,
2391 ** it allows the operator to set a breakpoint at the spot where database
2392 ** corruption is first detected.
2393 */
2394 #ifdef SQLITE_DEBUG
2395   int sqlite3Corrupt(void);
2396 # define SQLITE_CORRUPT_BKPT sqlite3Corrupt()
2397 #else
2398 # define SQLITE_CORRUPT_BKPT SQLITE_CORRUPT
2399 #endif
2400 
2401 /*
2402 ** The ctype.h header is needed for non-ASCII systems.  It is also
2403 ** needed by FTS3 when FTS3 is included in the amalgamation.
2404 */
2405 #if !defined(SQLITE_ASCII) || \
2406     (defined(SQLITE_ENABLE_FTS3) && defined(SQLITE_AMALGAMATION))
2407 # include <ctype.h>
2408 #endif
2409 
2410 /*
2411 ** The following macros mimic the standard library functions toupper(),
2412 ** isspace(), isalnum(), isdigit() and isxdigit(), respectively. The
2413 ** sqlite versions only work for ASCII characters, regardless of locale.
2414 */
2415 #ifdef SQLITE_ASCII
2416 # define sqlite3Toupper(x)  ((x)&~(sqlite3CtypeMap[(unsigned char)(x)]&0x20))
2417 # define sqlite3Isspace(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x01)
2418 # define sqlite3Isalnum(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x06)
2419 # define sqlite3Isalpha(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x02)
2420 # define sqlite3Isdigit(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x04)
2421 # define sqlite3Isxdigit(x)  (sqlite3CtypeMap[(unsigned char)(x)]&0x08)
2422 # define sqlite3Tolower(x)   (sqlite3UpperToLower[(unsigned char)(x)])
2423 #else
2424 # define sqlite3Toupper(x)   toupper((unsigned char)(x))
2425 # define sqlite3Isspace(x)   isspace((unsigned char)(x))
2426 # define sqlite3Isalnum(x)   isalnum((unsigned char)(x))
2427 # define sqlite3Isalpha(x)   isalpha((unsigned char)(x))
2428 # define sqlite3Isdigit(x)   isdigit((unsigned char)(x))
2429 # define sqlite3Isxdigit(x)  isxdigit((unsigned char)(x))
2430 # define sqlite3Tolower(x)   tolower((unsigned char)(x))
2431 #endif
2432 
2433 /*
2434 ** Internal function prototypes
2435 */
2436 int sqlite3StrICmp(const char *, const char *);
2437 int sqlite3IsNumber(const char*, int*, u8);
2438 int sqlite3Strlen30(const char*);
2439 #define sqlite3StrNICmp sqlite3_strnicmp
2440 
2441 int sqlite3MallocInit(void);
2442 void sqlite3MallocEnd(void);
2443 void *sqlite3Malloc(int);
2444 void *sqlite3MallocZero(int);
2445 void *sqlite3DbMallocZero(sqlite3*, int);
2446 void *sqlite3DbMallocRaw(sqlite3*, int);
2447 char *sqlite3DbStrDup(sqlite3*,const char*);
2448 char *sqlite3DbStrNDup(sqlite3*,const char*, int);
2449 void *sqlite3Realloc(void*, int);
2450 void *sqlite3DbReallocOrFree(sqlite3 *, void *, int);
2451 void *sqlite3DbRealloc(sqlite3 *, void *, int);
2452 void sqlite3DbFree(sqlite3*, void*);
2453 int sqlite3MallocSize(void*);
2454 int sqlite3DbMallocSize(sqlite3*, void*);
2455 void *sqlite3ScratchMalloc(int);
2456 void sqlite3ScratchFree(void*);
2457 void *sqlite3PageMalloc(int);
2458 void sqlite3PageFree(void*);
2459 void sqlite3MemSetDefault(void);
2460 void sqlite3BenignMallocHooks(void (*)(void), void (*)(void));
2461 int sqlite3MemoryAlarm(void (*)(void*, sqlite3_int64, int), void*, sqlite3_int64);
2462 
2463 /*
2464 ** On systems with ample stack space and that support alloca(), make
2465 ** use of alloca() to obtain space for large automatic objects.  By default,
2466 ** obtain space from malloc().
2467 **
2468 ** The alloca() routine never returns NULL.  This will cause code paths
2469 ** that deal with sqlite3StackAlloc() failures to be unreachable.
2470 */
2471 #ifdef SQLITE_USE_ALLOCA
2472 # define sqlite3StackAllocRaw(D,N)   alloca(N)
2473 # define sqlite3StackAllocZero(D,N)  memset(alloca(N), 0, N)
2474 # define sqlite3StackFree(D,P)
2475 #else
2476 # define sqlite3StackAllocRaw(D,N)   sqlite3DbMallocRaw(D,N)
2477 # define sqlite3StackAllocZero(D,N)  sqlite3DbMallocZero(D,N)
2478 # define sqlite3StackFree(D,P)       sqlite3DbFree(D,P)
2479 #endif
2480 
2481 #ifdef SQLITE_ENABLE_MEMSYS3
2482 const sqlite3_mem_methods *sqlite3MemGetMemsys3(void);
2483 #endif
2484 #ifdef SQLITE_ENABLE_MEMSYS5
2485 const sqlite3_mem_methods *sqlite3MemGetMemsys5(void);
2486 #endif
2487 
2488 
2489 #ifndef SQLITE_MUTEX_OMIT
2490   sqlite3_mutex_methods *sqlite3DefaultMutex(void);
2491   sqlite3_mutex *sqlite3MutexAlloc(int);
2492   int sqlite3MutexInit(void);
2493   int sqlite3MutexEnd(void);
2494 #endif
2495 
2496 int sqlite3StatusValue(int);
2497 void sqlite3StatusAdd(int, int);
2498 void sqlite3StatusSet(int, int);
2499 
2500 int sqlite3IsNaN(double);
2501 
2502 void sqlite3VXPrintf(StrAccum*, int, const char*, va_list);
2503 char *sqlite3MPrintf(sqlite3*,const char*, ...);
2504 char *sqlite3VMPrintf(sqlite3*,const char*, va_list);
2505 char *sqlite3MAppendf(sqlite3*,char*,const char*,...);
2506 #if defined(SQLITE_TEST) || defined(SQLITE_DEBUG)
2507   void sqlite3DebugPrintf(const char*, ...);
2508 #endif
2509 #if defined(SQLITE_TEST)
2510   void *sqlite3TestTextToPtr(const char*);
2511 #endif
2512 void sqlite3SetString(char **, sqlite3*, const char*, ...);
2513 void sqlite3ErrorMsg(Parse*, const char*, ...);
2514 void sqlite3ErrorClear(Parse*);
2515 int sqlite3Dequote(char*);
2516 int sqlite3KeywordCode(const unsigned char*, int);
2517 int sqlite3RunParser(Parse*, const char*, char **);
2518 void sqlite3FinishCoding(Parse*);
2519 int sqlite3GetTempReg(Parse*);
2520 void sqlite3ReleaseTempReg(Parse*,int);
2521 int sqlite3GetTempRange(Parse*,int);
2522 void sqlite3ReleaseTempRange(Parse*,int,int);
2523 Expr *sqlite3ExprAlloc(sqlite3*,int,const Token*,int);
2524 Expr *sqlite3Expr(sqlite3*,int,const char*);
2525 void sqlite3ExprAttachSubtrees(sqlite3*,Expr*,Expr*,Expr*);
2526 Expr *sqlite3PExpr(Parse*, int, Expr*, Expr*, const Token*);
2527 Expr *sqlite3ExprAnd(sqlite3*,Expr*, Expr*);
2528 Expr *sqlite3ExprFunction(Parse*,ExprList*, Token*);
2529 void sqlite3ExprAssignVarNumber(Parse*, Expr*);
2530 void sqlite3ExprClear(sqlite3*, Expr*);
2531 void sqlite3ExprDelete(sqlite3*, Expr*);
2532 ExprList *sqlite3ExprListAppend(Parse*,ExprList*,Expr*);
2533 void sqlite3ExprListSetName(Parse*,ExprList*,Token*,int);
2534 void sqlite3ExprListSetSpan(Parse*,ExprList*,ExprSpan*);
2535 void sqlite3ExprListDelete(sqlite3*, ExprList*);
2536 int sqlite3Init(sqlite3*, char**);
2537 int sqlite3InitCallback(void*, int, char**, char**);
2538 void sqlite3Pragma(Parse*,Token*,Token*,Token*,int);
2539 void sqlite3ResetInternalSchema(sqlite3*, int);
2540 void sqlite3BeginParse(Parse*,int);
2541 void sqlite3CommitInternalChanges(sqlite3*);
2542 Table *sqlite3ResultSetOfSelect(Parse*,Select*);
2543 void sqlite3OpenMasterTable(Parse *, int);
2544 void sqlite3StartTable(Parse*,Token*,Token*,int,int,int,int);
2545 void sqlite3AddColumn(Parse*,Token*);
2546 void sqlite3AddNotNull(Parse*, int);
2547 void sqlite3AddPrimaryKey(Parse*, ExprList*, int, int, int);
2548 void sqlite3AddCheckConstraint(Parse*, Expr*);
2549 void sqlite3AddColumnType(Parse*,Token*);
2550 void sqlite3AddDefaultValue(Parse*,ExprSpan*);
2551 void sqlite3AddCollateType(Parse*, Token*);
2552 void sqlite3EndTable(Parse*,Token*,Token*,Select*);
2553 
2554 Bitvec *sqlite3BitvecCreate(u32);
2555 int sqlite3BitvecTest(Bitvec*, u32);
2556 int sqlite3BitvecSet(Bitvec*, u32);
2557 void sqlite3BitvecClear(Bitvec*, u32, void*);
2558 void sqlite3BitvecDestroy(Bitvec*);
2559 u32 sqlite3BitvecSize(Bitvec*);
2560 int sqlite3BitvecBuiltinTest(int,int*);
2561 
2562 RowSet *sqlite3RowSetInit(sqlite3*, void*, unsigned int);
2563 void sqlite3RowSetClear(RowSet*);
2564 void sqlite3RowSetInsert(RowSet*, i64);
2565 int sqlite3RowSetTest(RowSet*, u8 iBatch, i64);
2566 int sqlite3RowSetNext(RowSet*, i64*);
2567 
2568 void sqlite3CreateView(Parse*,Token*,Token*,Token*,Select*,int,int);
2569 
2570 #if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE)
2571   int sqlite3ViewGetColumnNames(Parse*,Table*);
2572 #else
2573 # define sqlite3ViewGetColumnNames(A,B) 0
2574 #endif
2575 
2576 void sqlite3DropTable(Parse*, SrcList*, int, int);
2577 void sqlite3DeleteTable(Table*);
2578 #ifndef SQLITE_OMIT_AUTOINCREMENT
2579   void sqlite3AutoincrementBegin(Parse *pParse);
2580   void sqlite3AutoincrementEnd(Parse *pParse);
2581 #else
2582 # define sqlite3AutoincrementBegin(X)
2583 # define sqlite3AutoincrementEnd(X)
2584 #endif
2585 void sqlite3Insert(Parse*, SrcList*, ExprList*, Select*, IdList*, int);
2586 void *sqlite3ArrayAllocate(sqlite3*,void*,int,int,int*,int*,int*);
2587 IdList *sqlite3IdListAppend(sqlite3*, IdList*, Token*);
2588 int sqlite3IdListIndex(IdList*,const char*);
2589 SrcList *sqlite3SrcListEnlarge(sqlite3*, SrcList*, int, int);
2590 SrcList *sqlite3SrcListAppend(sqlite3*, SrcList*, Token*, Token*);
2591 SrcList *sqlite3SrcListAppendFromTerm(Parse*, SrcList*, Token*, Token*,
2592                                       Token*, Select*, Expr*, IdList*);
2593 void sqlite3SrcListIndexedBy(Parse *, SrcList *, Token *);
2594 int sqlite3IndexedByLookup(Parse *, struct SrcList_item *);
2595 void sqlite3SrcListShiftJoinType(SrcList*);
2596 void sqlite3SrcListAssignCursors(Parse*, SrcList*);
2597 void sqlite3IdListDelete(sqlite3*, IdList*);
2598 void sqlite3SrcListDelete(sqlite3*, SrcList*);
2599 Index *sqlite3CreateIndex(Parse*,Token*,Token*,SrcList*,ExprList*,int,Token*,
2600                         Token*, int, int);
2601 void sqlite3DropIndex(Parse*, SrcList*, int);
2602 int sqlite3Select(Parse*, Select*, SelectDest*);
2603 Select *sqlite3SelectNew(Parse*,ExprList*,SrcList*,Expr*,ExprList*,
2604                          Expr*,ExprList*,int,Expr*,Expr*);
2605 void sqlite3SelectDelete(sqlite3*, Select*);
2606 Table *sqlite3SrcListLookup(Parse*, SrcList*);
2607 int sqlite3IsReadOnly(Parse*, Table*, int);
2608 void sqlite3OpenTable(Parse*, int iCur, int iDb, Table*, int);
2609 #if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY)
2610 Expr *sqlite3LimitWhere(Parse *, SrcList *, Expr *, ExprList *, Expr *, Expr *, char *);
2611 #endif
2612 void sqlite3DeleteFrom(Parse*, SrcList*, Expr*);
2613 void sqlite3Update(Parse*, SrcList*, ExprList*, Expr*, int);
2614 WhereInfo *sqlite3WhereBegin(Parse*, SrcList*, Expr*, ExprList**, u16);
2615 void sqlite3WhereEnd(WhereInfo*);
2616 int sqlite3ExprCodeGetColumn(Parse*, Table*, int, int, int, int);
2617 void sqlite3ExprCodeMove(Parse*, int, int, int);
2618 void sqlite3ExprCodeCopy(Parse*, int, int, int);
2619 void sqlite3ExprCacheStore(Parse*, int, int, int);
2620 void sqlite3ExprCachePush(Parse*);
2621 void sqlite3ExprCachePop(Parse*, int);
2622 void sqlite3ExprCacheRemove(Parse*, int);
2623 void sqlite3ExprCacheClear(Parse*);
2624 void sqlite3ExprCacheAffinityChange(Parse*, int, int);
2625 void sqlite3ExprHardCopy(Parse*,int,int);
2626 int sqlite3ExprCode(Parse*, Expr*, int);
2627 int sqlite3ExprCodeTemp(Parse*, Expr*, int*);
2628 int sqlite3ExprCodeTarget(Parse*, Expr*, int);
2629 int sqlite3ExprCodeAndCache(Parse*, Expr*, int);
2630 void sqlite3ExprCodeConstants(Parse*, Expr*);
2631 int sqlite3ExprCodeExprList(Parse*, ExprList*, int, int);
2632 void sqlite3ExprIfTrue(Parse*, Expr*, int, int);
2633 void sqlite3ExprIfFalse(Parse*, Expr*, int, int);
2634 Table *sqlite3FindTable(sqlite3*,const char*, const char*);
2635 Table *sqlite3LocateTable(Parse*,int isView,const char*, const char*);
2636 Index *sqlite3FindIndex(sqlite3*,const char*, const char*);
2637 void sqlite3UnlinkAndDeleteTable(sqlite3*,int,const char*);
2638 void sqlite3UnlinkAndDeleteIndex(sqlite3*,int,const char*);
2639 void sqlite3Vacuum(Parse*);
2640 int sqlite3RunVacuum(char**, sqlite3*);
2641 char *sqlite3NameFromToken(sqlite3*, Token*);
2642 int sqlite3ExprCompare(Expr*, Expr*);
2643 void sqlite3ExprAnalyzeAggregates(NameContext*, Expr*);
2644 void sqlite3ExprAnalyzeAggList(NameContext*,ExprList*);
2645 Vdbe *sqlite3GetVdbe(Parse*);
2646 Expr *sqlite3CreateIdExpr(Parse *, const char*);
2647 void sqlite3PrngSaveState(void);
2648 void sqlite3PrngRestoreState(void);
2649 void sqlite3PrngResetState(void);
2650 void sqlite3RollbackAll(sqlite3*);
2651 void sqlite3CodeVerifySchema(Parse*, int);
2652 void sqlite3BeginTransaction(Parse*, int);
2653 void sqlite3CommitTransaction(Parse*);
2654 void sqlite3RollbackTransaction(Parse*);
2655 void sqlite3Savepoint(Parse*, int, Token*);
2656 void sqlite3CloseSavepoints(sqlite3 *);
2657 int sqlite3ExprIsConstant(Expr*);
2658 int sqlite3ExprIsConstantNotJoin(Expr*);
2659 int sqlite3ExprIsConstantOrFunction(Expr*);
2660 int sqlite3ExprIsInteger(Expr*, int*);
2661 int sqlite3IsRowid(const char*);
2662 void sqlite3GenerateRowDelete(Parse*, Table*, int, int, int, Trigger *, int);
2663 void sqlite3GenerateRowIndexDelete(Parse*, Table*, int, int*);
2664 int sqlite3GenerateIndexKey(Parse*, Index*, int, int, int);
2665 void sqlite3GenerateConstraintChecks(Parse*,Table*,int,int,
2666                                      int*,int,int,int,int,int*);
2667 void sqlite3CompleteInsertion(Parse*, Table*, int, int, int*, int, int, int);
2668 int sqlite3OpenTableAndIndices(Parse*, Table*, int, int);
2669 void sqlite3BeginWriteOperation(Parse*, int, int);
2670 void sqlite3MultiWrite(Parse*);
2671 void sqlite3MayAbort(Parse*);
2672 void sqlite3HaltConstraint(Parse*, int, char*, int);
2673 Expr *sqlite3ExprDup(sqlite3*,Expr*,int);
2674 ExprList *sqlite3ExprListDup(sqlite3*,ExprList*,int);
2675 SrcList *sqlite3SrcListDup(sqlite3*,SrcList*,int);
2676 IdList *sqlite3IdListDup(sqlite3*,IdList*);
2677 Select *sqlite3SelectDup(sqlite3*,Select*,int);
2678 void sqlite3FuncDefInsert(FuncDefHash*, FuncDef*);
2679 FuncDef *sqlite3FindFunction(sqlite3*,const char*,int,int,u8,int);
2680 void sqlite3RegisterBuiltinFunctions(sqlite3*);
2681 void sqlite3RegisterDateTimeFunctions(void);
2682 void sqlite3RegisterGlobalFunctions(void);
2683 #ifdef SQLITE_DEBUG
2684   int sqlite3SafetyOn(sqlite3*);
2685   int sqlite3SafetyOff(sqlite3*);
2686 #else
2687 # define sqlite3SafetyOn(A) 0
2688 # define sqlite3SafetyOff(A) 0
2689 #endif
2690 int sqlite3SafetyCheckOk(sqlite3*);
2691 int sqlite3SafetyCheckSickOrOk(sqlite3*);
2692 void sqlite3ChangeCookie(Parse*, int);
2693 
2694 #if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
2695 void sqlite3MaterializeView(Parse*, Table*, Expr*, int);
2696 #endif
2697 
2698 #ifndef SQLITE_OMIT_TRIGGER
2699   void sqlite3BeginTrigger(Parse*, Token*,Token*,int,int,IdList*,SrcList*,
2700                            Expr*,int, int);
2701   void sqlite3FinishTrigger(Parse*, TriggerStep*, Token*);
2702   void sqlite3DropTrigger(Parse*, SrcList*, int);
2703   void sqlite3DropTriggerPtr(Parse*, Trigger*);
2704   Trigger *sqlite3TriggersExist(Parse *, Table*, int, ExprList*, int *pMask);
2705   Trigger *sqlite3TriggerList(Parse *, Table *);
2706   void sqlite3CodeRowTrigger(Parse*, Trigger *, int, ExprList*, int, Table *,
2707                             int, int, int);
2708   void sqlite3CodeRowTriggerDirect(Parse *, Trigger *, Table *, int, int, int);
2709   void sqliteViewTriggers(Parse*, Table*, Expr*, int, ExprList*);
2710   void sqlite3DeleteTriggerStep(sqlite3*, TriggerStep*);
2711   TriggerStep *sqlite3TriggerSelectStep(sqlite3*,Select*);
2712   TriggerStep *sqlite3TriggerInsertStep(sqlite3*,Token*, IdList*,
2713                                         ExprList*,Select*,u8);
2714   TriggerStep *sqlite3TriggerUpdateStep(sqlite3*,Token*,ExprList*, Expr*, u8);
2715   TriggerStep *sqlite3TriggerDeleteStep(sqlite3*,Token*, Expr*);
2716   void sqlite3DeleteTrigger(sqlite3*, Trigger*);
2717   void sqlite3UnlinkAndDeleteTrigger(sqlite3*,int,const char*);
2718   u32 sqlite3TriggerOldmask(Parse*,Trigger*,ExprList*,Table*,int);
2719 # define sqlite3ParseToplevel(p) ((p)->pToplevel ? (p)->pToplevel : (p))
2720 #else
2721 # define sqlite3TriggersExist(B,C,D,E,F) 0
2722 # define sqlite3DeleteTrigger(A,B)
2723 # define sqlite3DropTriggerPtr(A,B)
2724 # define sqlite3UnlinkAndDeleteTrigger(A,B,C)
2725 # define sqlite3CodeRowTrigger(A,B,C,D,E,F,G,H,I)
2726 # define sqlite3CodeRowTriggerDirect(A,B,C,D,E,F)
2727 # define sqlite3TriggerList(X, Y) 0
2728 # define sqlite3ParseToplevel(p) p
2729 # define sqlite3TriggerOldmask(A,B,C,D,E) 0
2730 #endif
2731 
2732 int sqlite3JoinType(Parse*, Token*, Token*, Token*);
2733 void sqlite3CreateForeignKey(Parse*, ExprList*, Token*, ExprList*, int);
2734 void sqlite3DeferForeignKey(Parse*, int);
2735 #ifndef SQLITE_OMIT_AUTHORIZATION
2736   void sqlite3AuthRead(Parse*,Expr*,Schema*,SrcList*);
2737   int sqlite3AuthCheck(Parse*,int, const char*, const char*, const char*);
2738   void sqlite3AuthContextPush(Parse*, AuthContext*, const char*);
2739   void sqlite3AuthContextPop(AuthContext*);
2740   int sqlite3AuthReadCol(Parse*, const char *, const char *, int);
2741 #else
2742 # define sqlite3AuthRead(a,b,c,d)
2743 # define sqlite3AuthCheck(a,b,c,d,e)    SQLITE_OK
2744 # define sqlite3AuthContextPush(a,b,c)
2745 # define sqlite3AuthContextPop(a)  ((void)(a))
2746 #endif
2747 void sqlite3Attach(Parse*, Expr*, Expr*, Expr*);
2748 void sqlite3Detach(Parse*, Expr*);
2749 int sqlite3BtreeFactory(const sqlite3 *db, const char *zFilename,
2750                        int omitJournal, int nCache, int flags, Btree **ppBtree);
2751 int sqlite3FixInit(DbFixer*, Parse*, int, const char*, const Token*);
2752 int sqlite3FixSrcList(DbFixer*, SrcList*);
2753 int sqlite3FixSelect(DbFixer*, Select*);
2754 int sqlite3FixExpr(DbFixer*, Expr*);
2755 int sqlite3FixExprList(DbFixer*, ExprList*);
2756 int sqlite3FixTriggerStep(DbFixer*, TriggerStep*);
2757 int sqlite3AtoF(const char *z, double*);
2758 int sqlite3GetInt32(const char *, int*);
2759 int sqlite3FitsIn64Bits(const char *, int);
2760 int sqlite3Utf16ByteLen(const void *pData, int nChar);
2761 int sqlite3Utf8CharLen(const char *pData, int nByte);
2762 int sqlite3Utf8Read(const u8*, const u8**);
2763 
2764 /*
2765 ** Routines to read and write variable-length integers.  These used to
2766 ** be defined locally, but now we use the varint routines in the util.c
2767 ** file.  Code should use the MACRO forms below, as the Varint32 versions
2768 ** are coded to assume the single byte case is already handled (which
2769 ** the MACRO form does).
2770 */
2771 int sqlite3PutVarint(unsigned char*, u64);
2772 int sqlite3PutVarint32(unsigned char*, u32);
2773 u8 sqlite3GetVarint(const unsigned char *, u64 *);
2774 u8 sqlite3GetVarint32(const unsigned char *, u32 *);
2775 int sqlite3VarintLen(u64 v);
2776 
2777 /*
2778 ** The header of a record consists of a sequence variable-length integers.
2779 ** These integers are almost always small and are encoded as a single byte.
2780 ** The following macros take advantage this fact to provide a fast encode
2781 ** and decode of the integers in a record header.  It is faster for the common
2782 ** case where the integer is a single byte.  It is a little slower when the
2783 ** integer is two or more bytes.  But overall it is faster.
2784 **
2785 ** The following expressions are equivalent:
2786 **
2787 **     x = sqlite3GetVarint32( A, &B );
2788 **     x = sqlite3PutVarint32( A, B );
2789 **
2790 **     x = getVarint32( A, B );
2791 **     x = putVarint32( A, B );
2792 **
2793 */
2794 #define getVarint32(A,B)  (u8)((*(A)<(u8)0x80) ? ((B) = (u32)*(A)),1 : sqlite3GetVarint32((A), (u32 *)&(B)))
2795 #define putVarint32(A,B)  (u8)(((u32)(B)<(u32)0x80) ? (*(A) = (unsigned char)(B)),1 : sqlite3PutVarint32((A), (B)))
2796 #define getVarint    sqlite3GetVarint
2797 #define putVarint    sqlite3PutVarint
2798 
2799 
2800 const char *sqlite3IndexAffinityStr(Vdbe *, Index *);
2801 void sqlite3TableAffinityStr(Vdbe *, Table *);
2802 char sqlite3CompareAffinity(Expr *pExpr, char aff2);
2803 int sqlite3IndexAffinityOk(Expr *pExpr, char idx_affinity);
2804 char sqlite3ExprAffinity(Expr *pExpr);
2805 int sqlite3Atoi64(const char*, i64*);
2806 void sqlite3Error(sqlite3*, int, const char*,...);
2807 void *sqlite3HexToBlob(sqlite3*, const char *z, int n);
2808 int sqlite3TwoPartName(Parse *, Token *, Token *, Token **);
2809 const char *sqlite3ErrStr(int);
2810 int sqlite3ReadSchema(Parse *pParse);
2811 CollSeq *sqlite3FindCollSeq(sqlite3*,u8 enc, const char*,int);
2812 CollSeq *sqlite3LocateCollSeq(Parse *pParse, const char*zName);
2813 CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr);
2814 Expr *sqlite3ExprSetColl(Parse *pParse, Expr *, Token *);
2815 int sqlite3CheckCollSeq(Parse *, CollSeq *);
2816 int sqlite3CheckObjectName(Parse *, const char *);
2817 void sqlite3VdbeSetChanges(sqlite3 *, int);
2818 
2819 const void *sqlite3ValueText(sqlite3_value*, u8);
2820 int sqlite3ValueBytes(sqlite3_value*, u8);
2821 void sqlite3ValueSetStr(sqlite3_value*, int, const void *,u8,
2822                         void(*)(void*));
2823 void sqlite3ValueFree(sqlite3_value*);
2824 sqlite3_value *sqlite3ValueNew(sqlite3 *);
2825 char *sqlite3Utf16to8(sqlite3 *, const void*, int);
2826 #ifdef SQLITE_ENABLE_STAT2
2827 char *sqlite3Utf8to16(sqlite3 *, u8, char *, int, int *);
2828 #endif
2829 int sqlite3ValueFromExpr(sqlite3 *, Expr *, u8, u8, sqlite3_value **);
2830 void sqlite3ValueApplyAffinity(sqlite3_value *, u8, u8);
2831 #ifndef SQLITE_AMALGAMATION
2832 extern const unsigned char sqlite3UpperToLower[];
2833 extern const unsigned char sqlite3CtypeMap[];
2834 extern SQLITE_WSD struct Sqlite3Config sqlite3Config;
2835 extern SQLITE_WSD FuncDefHash sqlite3GlobalFunctions;
2836 extern int sqlite3PendingByte;
2837 #endif
2838 void sqlite3RootPageMoved(Db*, int, int);
2839 void sqlite3Reindex(Parse*, Token*, Token*);
2840 void sqlite3AlterFunctions(sqlite3*);
2841 void sqlite3AlterRenameTable(Parse*, SrcList*, Token*);
2842 int sqlite3GetToken(const unsigned char *, int *);
2843 void sqlite3NestedParse(Parse*, const char*, ...);
2844 void sqlite3ExpirePreparedStatements(sqlite3*);
2845 void sqlite3CodeSubselect(Parse *, Expr *, int, int);
2846 void sqlite3SelectPrep(Parse*, Select*, NameContext*);
2847 int sqlite3ResolveExprNames(NameContext*, Expr*);
2848 void sqlite3ResolveSelectNames(Parse*, Select*, NameContext*);
2849 int sqlite3ResolveOrderGroupBy(Parse*, Select*, ExprList*, const char*);
2850 void sqlite3ColumnDefault(Vdbe *, Table *, int, int);
2851 void sqlite3AlterFinishAddColumn(Parse *, Token *);
2852 void sqlite3AlterBeginAddColumn(Parse *, SrcList *);
2853 CollSeq *sqlite3GetCollSeq(sqlite3*, u8, CollSeq *, const char*);
2854 char sqlite3AffinityType(const char*);
2855 void sqlite3Analyze(Parse*, Token*, Token*);
2856 int sqlite3InvokeBusyHandler(BusyHandler*);
2857 int sqlite3FindDb(sqlite3*, Token*);
2858 int sqlite3FindDbName(sqlite3 *, const char *);
2859 int sqlite3AnalysisLoad(sqlite3*,int iDB);
2860 void sqlite3DeleteIndexSamples(Index*);
2861 void sqlite3DefaultRowEst(Index*);
2862 void sqlite3RegisterLikeFunctions(sqlite3*, int);
2863 int sqlite3IsLikeFunction(sqlite3*,Expr*,int*,char*);
2864 void sqlite3MinimumFileFormat(Parse*, int, int);
2865 void sqlite3SchemaFree(void *);
2866 Schema *sqlite3SchemaGet(sqlite3 *, Btree *);
2867 int sqlite3SchemaToIndex(sqlite3 *db, Schema *);
2868 KeyInfo *sqlite3IndexKeyinfo(Parse *, Index *);
2869 int sqlite3CreateFunc(sqlite3 *, const char *, int, int, void *,
2870   void (*)(sqlite3_context*,int,sqlite3_value **),
2871   void (*)(sqlite3_context*,int,sqlite3_value **), void (*)(sqlite3_context*));
2872 int sqlite3ApiExit(sqlite3 *db, int);
2873 int sqlite3OpenTempDatabase(Parse *);
2874 
2875 void sqlite3StrAccumInit(StrAccum*, char*, int, int);
2876 void sqlite3StrAccumAppend(StrAccum*,const char*,int);
2877 char *sqlite3StrAccumFinish(StrAccum*);
2878 void sqlite3StrAccumReset(StrAccum*);
2879 void sqlite3SelectDestInit(SelectDest*,int,int);
2880 
2881 void sqlite3BackupRestart(sqlite3_backup *);
2882 void sqlite3BackupUpdate(sqlite3_backup *, Pgno, const u8 *);
2883 
2884 /*
2885 ** The interface to the LEMON-generated parser
2886 */
2887 void *sqlite3ParserAlloc(void*(*)(size_t));
2888 void sqlite3ParserFree(void*, void(*)(void*));
2889 void sqlite3Parser(void*, int, Token, Parse*);
2890 #ifdef YYTRACKMAXSTACKDEPTH
2891   int sqlite3ParserStackPeak(void*);
2892 #endif
2893 
2894 void sqlite3AutoLoadExtensions(sqlite3*);
2895 #ifndef SQLITE_OMIT_LOAD_EXTENSION
2896   void sqlite3CloseExtensions(sqlite3*);
2897 #else
2898 # define sqlite3CloseExtensions(X)
2899 #endif
2900 
2901 #ifndef SQLITE_OMIT_SHARED_CACHE
2902   void sqlite3TableLock(Parse *, int, int, u8, const char *);
2903 #else
2904   #define sqlite3TableLock(v,w,x,y,z)
2905 #endif
2906 
2907 #ifdef SQLITE_TEST
2908   int sqlite3Utf8To8(unsigned char*);
2909 #endif
2910 
2911 #ifdef SQLITE_OMIT_VIRTUALTABLE
2912 #  define sqlite3VtabClear(Y)
2913 #  define sqlite3VtabSync(X,Y) SQLITE_OK
2914 #  define sqlite3VtabRollback(X)
2915 #  define sqlite3VtabCommit(X)
2916 #  define sqlite3VtabInSync(db) 0
2917 #  define sqlite3VtabLock(X)
2918 #  define sqlite3VtabUnlock(X)
2919 #  define sqlite3VtabUnlockList(X)
2920 #else
2921    void sqlite3VtabClear(Table*);
2922    int sqlite3VtabSync(sqlite3 *db, char **);
2923    int sqlite3VtabRollback(sqlite3 *db);
2924    int sqlite3VtabCommit(sqlite3 *db);
2925    void sqlite3VtabLock(VTable *);
2926    void sqlite3VtabUnlock(VTable *);
2927    void sqlite3VtabUnlockList(sqlite3*);
2928 #  define sqlite3VtabInSync(db) ((db)->nVTrans>0 && (db)->aVTrans==0)
2929 #endif
2930 void sqlite3VtabMakeWritable(Parse*,Table*);
2931 void sqlite3VtabBeginParse(Parse*, Token*, Token*, Token*);
2932 void sqlite3VtabFinishParse(Parse*, Token*);
2933 void sqlite3VtabArgInit(Parse*);
2934 void sqlite3VtabArgExtend(Parse*, Token*);
2935 int sqlite3VtabCallCreate(sqlite3*, int, const char *, char **);
2936 int sqlite3VtabCallConnect(Parse*, Table*);
2937 int sqlite3VtabCallDestroy(sqlite3*, int, const char *);
2938 int sqlite3VtabBegin(sqlite3 *, VTable *);
2939 FuncDef *sqlite3VtabOverloadFunction(sqlite3 *,FuncDef*, int nArg, Expr*);
2940 void sqlite3InvalidFunction(sqlite3_context*,int,sqlite3_value**);
2941 int sqlite3TransferBindings(sqlite3_stmt *, sqlite3_stmt *);
2942 int sqlite3Reprepare(Vdbe*);
2943 void sqlite3ExprListCheckLength(Parse*, ExprList*, const char*);
2944 CollSeq *sqlite3BinaryCompareCollSeq(Parse *, Expr *, Expr *);
2945 int sqlite3TempInMemory(const sqlite3*);
2946 VTable *sqlite3GetVTable(sqlite3*, Table*);
2947 
2948 /* Declarations for functions in fkey.c. All of these are replaced by
2949 ** no-op macros if OMIT_FOREIGN_KEY is defined. In this case no foreign
2950 ** key functionality is available. If OMIT_TRIGGER is defined but
2951 ** OMIT_FOREIGN_KEY is not, only some of the functions are no-oped. In
2952 ** this case foreign keys are parsed, but no other functionality is
2953 ** provided (enforcement of FK constraints requires the triggers sub-system).
2954 */
2955 #if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)
2956   void sqlite3FkCheck(Parse*, Table*, int, int);
2957   void sqlite3FkDropTable(Parse*, SrcList *, Table*);
2958   void sqlite3FkActions(Parse*, Table*, ExprList*, int);
2959   int sqlite3FkRequired(Parse*, Table*, int*, int);
2960   u32 sqlite3FkOldmask(Parse*, Table*);
2961   FKey *sqlite3FkReferences(Table *);
2962 #else
2963   #define sqlite3FkActions(a,b,c,d)
2964   #define sqlite3FkCheck(a,b,c,d)
2965   #define sqlite3FkDropTable(a,b,c)
2966   #define sqlite3FkOldmask(a,b)      0
2967   #define sqlite3FkRequired(a,b,c,d) 0
2968 #endif
2969 #ifndef SQLITE_OMIT_FOREIGN_KEY
2970   void sqlite3FkDelete(Table*);
2971 #else
2972   #define sqlite3FkDelete(a)
2973 #endif
2974 
2975 
2976 /*
2977 ** Available fault injectors.  Should be numbered beginning with 0.
2978 */
2979 #define SQLITE_FAULTINJECTOR_MALLOC     0
2980 #define SQLITE_FAULTINJECTOR_COUNT      1
2981 
2982 /*
2983 ** The interface to the code in fault.c used for identifying "benign"
2984 ** malloc failures. This is only present if SQLITE_OMIT_BUILTIN_TEST
2985 ** is not defined.
2986 */
2987 #ifndef SQLITE_OMIT_BUILTIN_TEST
2988   void sqlite3BeginBenignMalloc(void);
2989   void sqlite3EndBenignMalloc(void);
2990 #else
2991   #define sqlite3BeginBenignMalloc()
2992   #define sqlite3EndBenignMalloc()
2993 #endif
2994 
2995 #define IN_INDEX_ROWID           1
2996 #define IN_INDEX_EPH             2
2997 #define IN_INDEX_INDEX           3
2998 int sqlite3FindInIndex(Parse *, Expr *, int*);
2999 
3000 #ifdef SQLITE_ENABLE_ATOMIC_WRITE
3001   int sqlite3JournalOpen(sqlite3_vfs *, const char *, sqlite3_file *, int, int);
3002   int sqlite3JournalSize(sqlite3_vfs *);
3003   int sqlite3JournalCreate(sqlite3_file *);
3004 #else
3005   #define sqlite3JournalSize(pVfs) ((pVfs)->szOsFile)
3006 #endif
3007 
3008 void sqlite3MemJournalOpen(sqlite3_file *);
3009 int sqlite3MemJournalSize(void);
3010 int sqlite3IsMemJournal(sqlite3_file *);
3011 
3012 #if SQLITE_MAX_EXPR_DEPTH>0
3013   void sqlite3ExprSetHeight(Parse *pParse, Expr *p);
3014   int sqlite3SelectExprHeight(Select *);
3015   int sqlite3ExprCheckHeight(Parse*, int);
3016 #else
3017   #define sqlite3ExprSetHeight(x,y)
3018   #define sqlite3SelectExprHeight(x) 0
3019   #define sqlite3ExprCheckHeight(x,y)
3020 #endif
3021 
3022 u32 sqlite3Get4byte(const u8*);
3023 void sqlite3Put4byte(u8*, u32);
3024 
3025 #ifdef SQLITE_ENABLE_UNLOCK_NOTIFY
3026   void sqlite3ConnectionBlocked(sqlite3 *, sqlite3 *);
3027   void sqlite3ConnectionUnlocked(sqlite3 *db);
3028   void sqlite3ConnectionClosed(sqlite3 *db);
3029 #else
3030   #define sqlite3ConnectionBlocked(x,y)
3031   #define sqlite3ConnectionUnlocked(x)
3032   #define sqlite3ConnectionClosed(x)
3033 #endif
3034 
3035 #ifdef SQLITE_DEBUG
3036   void sqlite3ParserTrace(FILE*, char *);
3037 #endif
3038 
3039 /*
3040 ** If the SQLITE_ENABLE IOTRACE exists then the global variable
3041 ** sqlite3IoTrace is a pointer to a printf-like routine used to
3042 ** print I/O tracing messages.
3043 */
3044 #ifdef SQLITE_ENABLE_IOTRACE
3045 # define IOTRACE(A)  if( sqlite3IoTrace ){ sqlite3IoTrace A; }
3046   void sqlite3VdbeIOTraceSql(Vdbe*);
3047 SQLITE_EXTERN void (*sqlite3IoTrace)(const char*,...);
3048 #else
3049 # define IOTRACE(A)
3050 # define sqlite3VdbeIOTraceSql(X)
3051 #endif
3052 
3053 #endif
3054