xref: /sqlite-3.40.0/src/sqliteInt.h (revision 42829635)
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 /*
80 ** The following macros are used to cast pointers to integers and
81 ** integers to pointers.  The way you do this varies from one compiler
82 ** to the next, so we have developed the following set of #if statements
83 ** to generate appropriate macros for a wide range of compilers.
84 **
85 ** The correct "ANSI" way to do this is to use the intptr_t type.
86 ** Unfortunately, that typedef is not available on all compilers, or
87 ** if it is available, it requires an #include of specific headers
88 ** that vary from one machine to the next.
89 **
90 ** Ticket #3860:  The llvm-gcc-4.2 compiler from Apple chokes on
91 ** the ((void*)&((char*)0)[X]) construct.  But MSVC chokes on ((void*)(X)).
92 ** So we have to define the macros in different ways depending on the
93 ** compiler.
94 */
95 #if defined(__PTRDIFF_TYPE__)  /* This case should work for GCC */
96 # define SQLITE_INT_TO_PTR(X)  ((void*)(__PTRDIFF_TYPE__)(X))
97 # define SQLITE_PTR_TO_INT(X)  ((int)(__PTRDIFF_TYPE__)(X))
98 #elif !defined(__GNUC__)       /* Works for compilers other than LLVM */
99 # define SQLITE_INT_TO_PTR(X)  ((void*)&((char*)0)[X])
100 # define SQLITE_PTR_TO_INT(X)  ((int)(((char*)X)-(char*)0))
101 #elif defined(HAVE_STDINT_H)   /* Use this case if we have ANSI headers */
102 # define SQLITE_INT_TO_PTR(X)  ((void*)(intptr_t)(X))
103 # define SQLITE_PTR_TO_INT(X)  ((int)(intptr_t)(X))
104 #else                          /* Generates a warning - but it always works */
105 # define SQLITE_INT_TO_PTR(X)  ((void*)(X))
106 # define SQLITE_PTR_TO_INT(X)  ((int)(X))
107 #endif
108 
109 /*
110 ** The SQLITE_THREADSAFE macro must be defined as 0, 1, or 2.
111 ** 0 means mutexes are permanently disable and the library is never
112 ** threadsafe.  1 means the library is serialized which is the highest
113 ** level of threadsafety.  2 means the libary is multithreaded - multiple
114 ** threads can use SQLite as long as no two threads try to use the same
115 ** database connection at the same time.
116 **
117 ** Older versions of SQLite used an optional THREADSAFE macro.
118 ** We support that for legacy.
119 */
120 #if !defined(SQLITE_THREADSAFE)
121 #if defined(THREADSAFE)
122 # define SQLITE_THREADSAFE THREADSAFE
123 #else
124 # define SQLITE_THREADSAFE 1 /* IMP: R-07272-22309 */
125 #endif
126 #endif
127 
128 /*
129 ** Powersafe overwrite is on by default.  But can be turned off using
130 ** the -DSQLITE_POWERSAFE_OVERWRITE=0 command-line option.
131 */
132 #ifndef SQLITE_POWERSAFE_OVERWRITE
133 # define SQLITE_POWERSAFE_OVERWRITE 1
134 #endif
135 
136 /*
137 ** The SQLITE_DEFAULT_MEMSTATUS macro must be defined as either 0 or 1.
138 ** It determines whether or not the features related to
139 ** SQLITE_CONFIG_MEMSTATUS are available by default or not. This value can
140 ** be overridden at runtime using the sqlite3_config() API.
141 */
142 #if !defined(SQLITE_DEFAULT_MEMSTATUS)
143 # define SQLITE_DEFAULT_MEMSTATUS 1
144 #endif
145 
146 /*
147 ** Exactly one of the following macros must be defined in order to
148 ** specify which memory allocation subsystem to use.
149 **
150 **     SQLITE_SYSTEM_MALLOC          // Use normal system malloc()
151 **     SQLITE_WIN32_MALLOC           // Use Win32 native heap API
152 **     SQLITE_MEMDEBUG               // Debugging version of system malloc()
153 **
154 ** On Windows, if the SQLITE_WIN32_MALLOC_VALIDATE macro is defined and the
155 ** assert() macro is enabled, each call into the Win32 native heap subsystem
156 ** will cause HeapValidate to be called.  If heap validation should fail, an
157 ** assertion will be triggered.
158 **
159 ** (Historical note:  There used to be several other options, but we've
160 ** pared it down to just these three.)
161 **
162 ** If none of the above are defined, then set SQLITE_SYSTEM_MALLOC as
163 ** the default.
164 */
165 #if defined(SQLITE_SYSTEM_MALLOC)+defined(SQLITE_WIN32_MALLOC)+defined(SQLITE_MEMDEBUG)>1
166 # error "At most one of the following compile-time configuration options\
167  is allows: SQLITE_SYSTEM_MALLOC, SQLITE_WIN32_MALLOC, SQLITE_MEMDEBUG"
168 #endif
169 #if defined(SQLITE_SYSTEM_MALLOC)+defined(SQLITE_WIN32_MALLOC)+defined(SQLITE_MEMDEBUG)==0
170 # define SQLITE_SYSTEM_MALLOC 1
171 #endif
172 
173 /*
174 ** If SQLITE_MALLOC_SOFT_LIMIT is not zero, then try to keep the
175 ** sizes of memory allocations below this value where possible.
176 */
177 #if !defined(SQLITE_MALLOC_SOFT_LIMIT)
178 # define SQLITE_MALLOC_SOFT_LIMIT 1024
179 #endif
180 
181 /*
182 ** We need to define _XOPEN_SOURCE as follows in order to enable
183 ** recursive mutexes on most Unix systems.  But Mac OS X is different.
184 ** The _XOPEN_SOURCE define causes problems for Mac OS X we are told,
185 ** so it is omitted there.  See ticket #2673.
186 **
187 ** Later we learn that _XOPEN_SOURCE is poorly or incorrectly
188 ** implemented on some systems.  So we avoid defining it at all
189 ** if it is already defined or if it is unneeded because we are
190 ** not doing a threadsafe build.  Ticket #2681.
191 **
192 ** See also ticket #2741.
193 */
194 #if !defined(_XOPEN_SOURCE) && !defined(__DARWIN__) && !defined(__APPLE__) && SQLITE_THREADSAFE
195 #  define _XOPEN_SOURCE 500  /* Needed to enable pthread recursive mutexes */
196 #endif
197 
198 /*
199 ** The TCL headers are only needed when compiling the TCL bindings.
200 */
201 #if defined(SQLITE_TCL) || defined(TCLSH)
202 # include <tcl.h>
203 #endif
204 
205 /*
206 ** Many people are failing to set -DNDEBUG=1 when compiling SQLite.
207 ** Setting NDEBUG makes the code smaller and run faster.  So the following
208 ** lines are added to automatically set NDEBUG unless the -DSQLITE_DEBUG=1
209 ** option is set.  Thus NDEBUG becomes an opt-in rather than an opt-out
210 ** feature.
211 */
212 #if !defined(NDEBUG) && !defined(SQLITE_DEBUG)
213 # define NDEBUG 1
214 #endif
215 
216 /*
217 ** The testcase() macro is used to aid in coverage testing.  When
218 ** doing coverage testing, the condition inside the argument to
219 ** testcase() must be evaluated both true and false in order to
220 ** get full branch coverage.  The testcase() macro is inserted
221 ** to help ensure adequate test coverage in places where simple
222 ** condition/decision coverage is inadequate.  For example, testcase()
223 ** can be used to make sure boundary values are tested.  For
224 ** bitmask tests, testcase() can be used to make sure each bit
225 ** is significant and used at least once.  On switch statements
226 ** where multiple cases go to the same block of code, testcase()
227 ** can insure that all cases are evaluated.
228 **
229 */
230 #ifdef SQLITE_COVERAGE_TEST
231   void sqlite3Coverage(int);
232 # define testcase(X)  if( X ){ sqlite3Coverage(__LINE__); }
233 #else
234 # define testcase(X)
235 #endif
236 
237 /*
238 ** The TESTONLY macro is used to enclose variable declarations or
239 ** other bits of code that are needed to support the arguments
240 ** within testcase() and assert() macros.
241 */
242 #if !defined(NDEBUG) || defined(SQLITE_COVERAGE_TEST)
243 # define TESTONLY(X)  X
244 #else
245 # define TESTONLY(X)
246 #endif
247 
248 /*
249 ** Sometimes we need a small amount of code such as a variable initialization
250 ** to setup for a later assert() statement.  We do not want this code to
251 ** appear when assert() is disabled.  The following macro is therefore
252 ** used to contain that setup code.  The "VVA" acronym stands for
253 ** "Verification, Validation, and Accreditation".  In other words, the
254 ** code within VVA_ONLY() will only run during verification processes.
255 */
256 #ifndef NDEBUG
257 # define VVA_ONLY(X)  X
258 #else
259 # define VVA_ONLY(X)
260 #endif
261 
262 /*
263 ** The ALWAYS and NEVER macros surround boolean expressions which
264 ** are intended to always be true or false, respectively.  Such
265 ** expressions could be omitted from the code completely.  But they
266 ** are included in a few cases in order to enhance the resilience
267 ** of SQLite to unexpected behavior - to make the code "self-healing"
268 ** or "ductile" rather than being "brittle" and crashing at the first
269 ** hint of unplanned behavior.
270 **
271 ** In other words, ALWAYS and NEVER are added for defensive code.
272 **
273 ** When doing coverage testing ALWAYS and NEVER are hard-coded to
274 ** be true and false so that the unreachable code then specify will
275 ** not be counted as untested code.
276 */
277 #if defined(SQLITE_COVERAGE_TEST)
278 # define ALWAYS(X)      (1)
279 # define NEVER(X)       (0)
280 #elif !defined(NDEBUG)
281 # define ALWAYS(X)      ((X)?1:(assert(0),0))
282 # define NEVER(X)       ((X)?(assert(0),1):0)
283 #else
284 # define ALWAYS(X)      (X)
285 # define NEVER(X)       (X)
286 #endif
287 
288 /*
289 ** Return true (non-zero) if the input is a integer that is too large
290 ** to fit in 32-bits.  This macro is used inside of various testcase()
291 ** macros to verify that we have tested SQLite for large-file support.
292 */
293 #define IS_BIG_INT(X)  (((X)&~(i64)0xffffffff)!=0)
294 
295 /*
296 ** The macro unlikely() is a hint that surrounds a boolean
297 ** expression that is usually false.  Macro likely() surrounds
298 ** a boolean expression that is usually true.  GCC is able to
299 ** use these hints to generate better code, sometimes.
300 */
301 #if defined(__GNUC__) && 0
302 # define likely(X)    __builtin_expect((X),1)
303 # define unlikely(X)  __builtin_expect((X),0)
304 #else
305 # define likely(X)    !!(X)
306 # define unlikely(X)  !!(X)
307 #endif
308 
309 #include "sqlite3.h"
310 #include "hash.h"
311 #include "parse.h"
312 #include <stdio.h>
313 #include <stdlib.h>
314 #include <string.h>
315 #include <assert.h>
316 #include <stddef.h>
317 
318 /*
319 ** If compiling for a processor that lacks floating point support,
320 ** substitute integer for floating-point
321 */
322 #ifdef SQLITE_OMIT_FLOATING_POINT
323 # define double sqlite_int64
324 # define float sqlite_int64
325 # define LONGDOUBLE_TYPE sqlite_int64
326 # ifndef SQLITE_BIG_DBL
327 #   define SQLITE_BIG_DBL (((sqlite3_int64)1)<<50)
328 # endif
329 # define SQLITE_OMIT_DATETIME_FUNCS 1
330 # define SQLITE_OMIT_TRACE 1
331 # undef SQLITE_MIXED_ENDIAN_64BIT_FLOAT
332 # undef SQLITE_HAVE_ISNAN
333 #endif
334 #ifndef SQLITE_BIG_DBL
335 # define SQLITE_BIG_DBL (1e99)
336 #endif
337 
338 /*
339 ** OMIT_TEMPDB is set to 1 if SQLITE_OMIT_TEMPDB is defined, or 0
340 ** afterward. Having this macro allows us to cause the C compiler
341 ** to omit code used by TEMP tables without messy #ifndef statements.
342 */
343 #ifdef SQLITE_OMIT_TEMPDB
344 #define OMIT_TEMPDB 1
345 #else
346 #define OMIT_TEMPDB 0
347 #endif
348 
349 /*
350 ** The "file format" number is an integer that is incremented whenever
351 ** the VDBE-level file format changes.  The following macros define the
352 ** the default file format for new databases and the maximum file format
353 ** that the library can read.
354 */
355 #define SQLITE_MAX_FILE_FORMAT 4
356 #ifndef SQLITE_DEFAULT_FILE_FORMAT
357 # define SQLITE_DEFAULT_FILE_FORMAT 4
358 #endif
359 
360 /*
361 ** Determine whether triggers are recursive by default.  This can be
362 ** changed at run-time using a pragma.
363 */
364 #ifndef SQLITE_DEFAULT_RECURSIVE_TRIGGERS
365 # define SQLITE_DEFAULT_RECURSIVE_TRIGGERS 0
366 #endif
367 
368 /*
369 ** Provide a default value for SQLITE_TEMP_STORE in case it is not specified
370 ** on the command-line
371 */
372 #ifndef SQLITE_TEMP_STORE
373 # define SQLITE_TEMP_STORE 1
374 #endif
375 
376 /*
377 ** GCC does not define the offsetof() macro so we'll have to do it
378 ** ourselves.
379 */
380 #ifndef offsetof
381 #define offsetof(STRUCTURE,FIELD) ((int)((char*)&((STRUCTURE*)0)->FIELD))
382 #endif
383 
384 /*
385 ** Check to see if this machine uses EBCDIC.  (Yes, believe it or
386 ** not, there are still machines out there that use EBCDIC.)
387 */
388 #if 'A' == '\301'
389 # define SQLITE_EBCDIC 1
390 #else
391 # define SQLITE_ASCII 1
392 #endif
393 
394 /*
395 ** Integers of known sizes.  These typedefs might change for architectures
396 ** where the sizes very.  Preprocessor macros are available so that the
397 ** types can be conveniently redefined at compile-type.  Like this:
398 **
399 **         cc '-DUINTPTR_TYPE=long long int' ...
400 */
401 #ifndef UINT32_TYPE
402 # ifdef HAVE_UINT32_T
403 #  define UINT32_TYPE uint32_t
404 # else
405 #  define UINT32_TYPE unsigned int
406 # endif
407 #endif
408 #ifndef UINT16_TYPE
409 # ifdef HAVE_UINT16_T
410 #  define UINT16_TYPE uint16_t
411 # else
412 #  define UINT16_TYPE unsigned short int
413 # endif
414 #endif
415 #ifndef INT16_TYPE
416 # ifdef HAVE_INT16_T
417 #  define INT16_TYPE int16_t
418 # else
419 #  define INT16_TYPE short int
420 # endif
421 #endif
422 #ifndef UINT8_TYPE
423 # ifdef HAVE_UINT8_T
424 #  define UINT8_TYPE uint8_t
425 # else
426 #  define UINT8_TYPE unsigned char
427 # endif
428 #endif
429 #ifndef INT8_TYPE
430 # ifdef HAVE_INT8_T
431 #  define INT8_TYPE int8_t
432 # else
433 #  define INT8_TYPE signed char
434 # endif
435 #endif
436 #ifndef LONGDOUBLE_TYPE
437 # define LONGDOUBLE_TYPE long double
438 #endif
439 typedef sqlite_int64 i64;          /* 8-byte signed integer */
440 typedef sqlite_uint64 u64;         /* 8-byte unsigned integer */
441 typedef UINT32_TYPE u32;           /* 4-byte unsigned integer */
442 typedef UINT16_TYPE u16;           /* 2-byte unsigned integer */
443 typedef INT16_TYPE i16;            /* 2-byte signed integer */
444 typedef UINT8_TYPE u8;             /* 1-byte unsigned integer */
445 typedef INT8_TYPE i8;              /* 1-byte signed integer */
446 
447 /*
448 ** SQLITE_MAX_U32 is a u64 constant that is the maximum u64 value
449 ** that can be stored in a u32 without loss of data.  The value
450 ** is 0x00000000ffffffff.  But because of quirks of some compilers, we
451 ** have to specify the value in the less intuitive manner shown:
452 */
453 #define SQLITE_MAX_U32  ((((u64)1)<<32)-1)
454 
455 /*
456 ** The datatype used to store estimates of the number of rows in a
457 ** table or index.  This is an unsigned integer type.  For 99.9% of
458 ** the world, a 32-bit integer is sufficient.  But a 64-bit integer
459 ** can be used at compile-time if desired.
460 */
461 #ifdef SQLITE_64BIT_STATS
462  typedef u64 tRowcnt;    /* 64-bit only if requested at compile-time */
463 #else
464  typedef u32 tRowcnt;    /* 32-bit is the default */
465 #endif
466 
467 /*
468 ** Macros to determine whether the machine is big or little endian,
469 ** evaluated at runtime.
470 */
471 #ifdef SQLITE_AMALGAMATION
472 const int sqlite3one = 1;
473 #else
474 extern const int sqlite3one;
475 #endif
476 #if defined(i386) || defined(__i386__) || defined(_M_IX86)\
477                              || defined(__x86_64) || defined(__x86_64__)
478 # define SQLITE_BIGENDIAN    0
479 # define SQLITE_LITTLEENDIAN 1
480 # define SQLITE_UTF16NATIVE  SQLITE_UTF16LE
481 #else
482 # define SQLITE_BIGENDIAN    (*(char *)(&sqlite3one)==0)
483 # define SQLITE_LITTLEENDIAN (*(char *)(&sqlite3one)==1)
484 # define SQLITE_UTF16NATIVE (SQLITE_BIGENDIAN?SQLITE_UTF16BE:SQLITE_UTF16LE)
485 #endif
486 
487 /*
488 ** Constants for the largest and smallest possible 64-bit signed integers.
489 ** These macros are designed to work correctly on both 32-bit and 64-bit
490 ** compilers.
491 */
492 #define LARGEST_INT64  (0xffffffff|(((i64)0x7fffffff)<<32))
493 #define SMALLEST_INT64 (((i64)-1) - LARGEST_INT64)
494 
495 /*
496 ** Round up a number to the next larger multiple of 8.  This is used
497 ** to force 8-byte alignment on 64-bit architectures.
498 */
499 #define ROUND8(x)     (((x)+7)&~7)
500 
501 /*
502 ** Round down to the nearest multiple of 8
503 */
504 #define ROUNDDOWN8(x) ((x)&~7)
505 
506 /*
507 ** Assert that the pointer X is aligned to an 8-byte boundary.  This
508 ** macro is used only within assert() to verify that the code gets
509 ** all alignment restrictions correct.
510 **
511 ** Except, if SQLITE_4_BYTE_ALIGNED_MALLOC is defined, then the
512 ** underlying malloc() implemention might return us 4-byte aligned
513 ** pointers.  In that case, only verify 4-byte alignment.
514 */
515 #ifdef SQLITE_4_BYTE_ALIGNED_MALLOC
516 # define EIGHT_BYTE_ALIGNMENT(X)   ((((char*)(X) - (char*)0)&3)==0)
517 #else
518 # define EIGHT_BYTE_ALIGNMENT(X)   ((((char*)(X) - (char*)0)&7)==0)
519 #endif
520 
521 
522 /*
523 ** An instance of the following structure is used to store the busy-handler
524 ** callback for a given sqlite handle.
525 **
526 ** The sqlite.busyHandler member of the sqlite struct contains the busy
527 ** callback for the database handle. Each pager opened via the sqlite
528 ** handle is passed a pointer to sqlite.busyHandler. The busy-handler
529 ** callback is currently invoked only from within pager.c.
530 */
531 typedef struct BusyHandler BusyHandler;
532 struct BusyHandler {
533   int (*xFunc)(void *,int);  /* The busy callback */
534   void *pArg;                /* First arg to busy callback */
535   int nBusy;                 /* Incremented with each busy call */
536 };
537 
538 /*
539 ** Name of the master database table.  The master database table
540 ** is a special table that holds the names and attributes of all
541 ** user tables and indices.
542 */
543 #define MASTER_NAME       "sqlite_master"
544 #define TEMP_MASTER_NAME  "sqlite_temp_master"
545 
546 /*
547 ** The root-page of the master database table.
548 */
549 #define MASTER_ROOT       1
550 
551 /*
552 ** The name of the schema table.
553 */
554 #define SCHEMA_TABLE(x)  ((!OMIT_TEMPDB)&&(x==1)?TEMP_MASTER_NAME:MASTER_NAME)
555 
556 /*
557 ** A convenience macro that returns the number of elements in
558 ** an array.
559 */
560 #define ArraySize(X)    ((int)(sizeof(X)/sizeof(X[0])))
561 
562 /*
563 ** The following value as a destructor means to use sqlite3DbFree().
564 ** The sqlite3DbFree() routine requires two parameters instead of the
565 ** one parameter that destructors normally want.  So we have to introduce
566 ** this magic value that the code knows to handle differently.  Any
567 ** pointer will work here as long as it is distinct from SQLITE_STATIC
568 ** and SQLITE_TRANSIENT.
569 */
570 #define SQLITE_DYNAMIC   ((sqlite3_destructor_type)sqlite3MallocSize)
571 
572 /*
573 ** When SQLITE_OMIT_WSD is defined, it means that the target platform does
574 ** not support Writable Static Data (WSD) such as global and static variables.
575 ** All variables must either be on the stack or dynamically allocated from
576 ** the heap.  When WSD is unsupported, the variable declarations scattered
577 ** throughout the SQLite code must become constants instead.  The SQLITE_WSD
578 ** macro is used for this purpose.  And instead of referencing the variable
579 ** directly, we use its constant as a key to lookup the run-time allocated
580 ** buffer that holds real variable.  The constant is also the initializer
581 ** for the run-time allocated buffer.
582 **
583 ** In the usual case where WSD is supported, the SQLITE_WSD and GLOBAL
584 ** macros become no-ops and have zero performance impact.
585 */
586 #ifdef SQLITE_OMIT_WSD
587   #define SQLITE_WSD const
588   #define GLOBAL(t,v) (*(t*)sqlite3_wsd_find((void*)&(v), sizeof(v)))
589   #define sqlite3GlobalConfig GLOBAL(struct Sqlite3Config, sqlite3Config)
590   int sqlite3_wsd_init(int N, int J);
591   void *sqlite3_wsd_find(void *K, int L);
592 #else
593   #define SQLITE_WSD
594   #define GLOBAL(t,v) v
595   #define sqlite3GlobalConfig sqlite3Config
596 #endif
597 
598 /*
599 ** The following macros are used to suppress compiler warnings and to
600 ** make it clear to human readers when a function parameter is deliberately
601 ** left unused within the body of a function. This usually happens when
602 ** a function is called via a function pointer. For example the
603 ** implementation of an SQL aggregate step callback may not use the
604 ** parameter indicating the number of arguments passed to the aggregate,
605 ** if it knows that this is enforced elsewhere.
606 **
607 ** When a function parameter is not used at all within the body of a function,
608 ** it is generally named "NotUsed" or "NotUsed2" to make things even clearer.
609 ** However, these macros may also be used to suppress warnings related to
610 ** parameters that may or may not be used depending on compilation options.
611 ** For example those parameters only used in assert() statements. In these
612 ** cases the parameters are named as per the usual conventions.
613 */
614 #define UNUSED_PARAMETER(x) (void)(x)
615 #define UNUSED_PARAMETER2(x,y) UNUSED_PARAMETER(x),UNUSED_PARAMETER(y)
616 
617 /*
618 ** Forward references to structures
619 */
620 typedef struct AggInfo AggInfo;
621 typedef struct AuthContext AuthContext;
622 typedef struct AutoincInfo AutoincInfo;
623 typedef struct Bitvec Bitvec;
624 typedef struct CollSeq CollSeq;
625 typedef struct Column Column;
626 typedef struct Db Db;
627 typedef struct Schema Schema;
628 typedef struct Expr Expr;
629 typedef struct ExprList ExprList;
630 typedef struct ExprSpan ExprSpan;
631 typedef struct FKey FKey;
632 typedef struct FuncDestructor FuncDestructor;
633 typedef struct FuncDef FuncDef;
634 typedef struct FuncDefHash FuncDefHash;
635 typedef struct IdList IdList;
636 typedef struct Index Index;
637 typedef struct IndexSample IndexSample;
638 typedef struct KeyClass KeyClass;
639 typedef struct KeyInfo KeyInfo;
640 typedef struct Lookaside Lookaside;
641 typedef struct LookasideSlot LookasideSlot;
642 typedef struct Module Module;
643 typedef struct NameContext NameContext;
644 typedef struct Parse Parse;
645 typedef struct RowSet RowSet;
646 typedef struct Savepoint Savepoint;
647 typedef struct Select Select;
648 typedef struct SrcList SrcList;
649 typedef struct StrAccum StrAccum;
650 typedef struct Table Table;
651 typedef struct TableLock TableLock;
652 typedef struct Token Token;
653 typedef struct Trigger Trigger;
654 typedef struct TriggerPrg TriggerPrg;
655 typedef struct TriggerStep TriggerStep;
656 typedef struct UnpackedRecord UnpackedRecord;
657 typedef struct VTable VTable;
658 typedef struct VtabCtx VtabCtx;
659 typedef struct Walker Walker;
660 typedef struct WherePlan WherePlan;
661 typedef struct WhereInfo WhereInfo;
662 typedef struct WhereLevel WhereLevel;
663 
664 /*
665 ** Defer sourcing vdbe.h and btree.h until after the "u8" and
666 ** "BusyHandler" typedefs. vdbe.h also requires a few of the opaque
667 ** pointer types (i.e. FuncDef) defined above.
668 */
669 #include "btree.h"
670 #include "vdbe.h"
671 #include "pager.h"
672 #include "pcache.h"
673 
674 #include "os.h"
675 #include "mutex.h"
676 
677 
678 /*
679 ** Each database file to be accessed by the system is an instance
680 ** of the following structure.  There are normally two of these structures
681 ** in the sqlite.aDb[] array.  aDb[0] is the main database file and
682 ** aDb[1] is the database file used to hold temporary tables.  Additional
683 ** databases may be attached.
684 */
685 struct Db {
686   char *zName;         /* Name of this database */
687   Btree *pBt;          /* The B*Tree structure for this database file */
688   u8 inTrans;          /* 0: not writable.  1: Transaction.  2: Checkpoint */
689   u8 safety_level;     /* How aggressive at syncing data to disk */
690   Schema *pSchema;     /* Pointer to database schema (possibly shared) */
691 };
692 
693 /*
694 ** An instance of the following structure stores a database schema.
695 **
696 ** Most Schema objects are associated with a Btree.  The exception is
697 ** the Schema for the TEMP databaes (sqlite3.aDb[1]) which is free-standing.
698 ** In shared cache mode, a single Schema object can be shared by multiple
699 ** Btrees that refer to the same underlying BtShared object.
700 **
701 ** Schema objects are automatically deallocated when the last Btree that
702 ** references them is destroyed.   The TEMP Schema is manually freed by
703 ** sqlite3_close().
704 *
705 ** A thread must be holding a mutex on the corresponding Btree in order
706 ** to access Schema content.  This implies that the thread must also be
707 ** holding a mutex on the sqlite3 connection pointer that owns the Btree.
708 ** For a TEMP Schema, only the connection mutex is required.
709 */
710 struct Schema {
711   int schema_cookie;   /* Database schema version number for this file */
712   int iGeneration;     /* Generation counter.  Incremented with each change */
713   Hash tblHash;        /* All tables indexed by name */
714   Hash idxHash;        /* All (named) indices indexed by name */
715   Hash trigHash;       /* All triggers indexed by name */
716   Hash fkeyHash;       /* All foreign keys by referenced table name */
717   Table *pSeqTab;      /* The sqlite_sequence table used by AUTOINCREMENT */
718   u8 file_format;      /* Schema format version for this file */
719   u8 enc;              /* Text encoding used by this database */
720   u16 flags;           /* Flags associated with this schema */
721   int cache_size;      /* Number of pages to use in the cache */
722 };
723 
724 /*
725 ** These macros can be used to test, set, or clear bits in the
726 ** Db.pSchema->flags field.
727 */
728 #define DbHasProperty(D,I,P)     (((D)->aDb[I].pSchema->flags&(P))==(P))
729 #define DbHasAnyProperty(D,I,P)  (((D)->aDb[I].pSchema->flags&(P))!=0)
730 #define DbSetProperty(D,I,P)     (D)->aDb[I].pSchema->flags|=(P)
731 #define DbClearProperty(D,I,P)   (D)->aDb[I].pSchema->flags&=~(P)
732 
733 /*
734 ** Allowed values for the DB.pSchema->flags field.
735 **
736 ** The DB_SchemaLoaded flag is set after the database schema has been
737 ** read into internal hash tables.
738 **
739 ** DB_UnresetViews means that one or more views have column names that
740 ** have been filled out.  If the schema changes, these column names might
741 ** changes and so the view will need to be reset.
742 */
743 #define DB_SchemaLoaded    0x0001  /* The schema has been loaded */
744 #define DB_UnresetViews    0x0002  /* Some views have defined column names */
745 #define DB_Empty           0x0004  /* The file is empty (length 0 bytes) */
746 
747 /*
748 ** The number of different kinds of things that can be limited
749 ** using the sqlite3_limit() interface.
750 */
751 #define SQLITE_N_LIMIT (SQLITE_LIMIT_TRIGGER_DEPTH+1)
752 
753 /*
754 ** Lookaside malloc is a set of fixed-size buffers that can be used
755 ** to satisfy small transient memory allocation requests for objects
756 ** associated with a particular database connection.  The use of
757 ** lookaside malloc provides a significant performance enhancement
758 ** (approx 10%) by avoiding numerous malloc/free requests while parsing
759 ** SQL statements.
760 **
761 ** The Lookaside structure holds configuration information about the
762 ** lookaside malloc subsystem.  Each available memory allocation in
763 ** the lookaside subsystem is stored on a linked list of LookasideSlot
764 ** objects.
765 **
766 ** Lookaside allocations are only allowed for objects that are associated
767 ** with a particular database connection.  Hence, schema information cannot
768 ** be stored in lookaside because in shared cache mode the schema information
769 ** is shared by multiple database connections.  Therefore, while parsing
770 ** schema information, the Lookaside.bEnabled flag is cleared so that
771 ** lookaside allocations are not used to construct the schema objects.
772 */
773 struct Lookaside {
774   u16 sz;                 /* Size of each buffer in bytes */
775   u8 bEnabled;            /* False to disable new lookaside allocations */
776   u8 bMalloced;           /* True if pStart obtained from sqlite3_malloc() */
777   int nOut;               /* Number of buffers currently checked out */
778   int mxOut;              /* Highwater mark for nOut */
779   int anStat[3];          /* 0: hits.  1: size misses.  2: full misses */
780   LookasideSlot *pFree;   /* List of available buffers */
781   void *pStart;           /* First byte of available memory space */
782   void *pEnd;             /* First byte past end of available space */
783 };
784 struct LookasideSlot {
785   LookasideSlot *pNext;    /* Next buffer in the list of free buffers */
786 };
787 
788 /*
789 ** A hash table for function definitions.
790 **
791 ** Hash each FuncDef structure into one of the FuncDefHash.a[] slots.
792 ** Collisions are on the FuncDef.pHash chain.
793 */
794 struct FuncDefHash {
795   FuncDef *a[23];       /* Hash table for functions */
796 };
797 
798 /*
799 ** Each database connection is an instance of the following structure.
800 **
801 ** The sqlite.lastRowid records the last insert rowid generated by an
802 ** insert statement.  Inserts on views do not affect its value.  Each
803 ** trigger has its own context, so that lastRowid can be updated inside
804 ** triggers as usual.  The previous value will be restored once the trigger
805 ** exits.  Upon entering a before or instead of trigger, lastRowid is no
806 ** longer (since after version 2.8.12) reset to -1.
807 **
808 ** The sqlite.nChange does not count changes within triggers and keeps no
809 ** context.  It is reset at start of sqlite3_exec.
810 ** The sqlite.lsChange represents the number of changes made by the last
811 ** insert, update, or delete statement.  It remains constant throughout the
812 ** length of a statement and is then updated by OP_SetCounts.  It keeps a
813 ** context stack just like lastRowid so that the count of changes
814 ** within a trigger is not seen outside the trigger.  Changes to views do not
815 ** affect the value of lsChange.
816 ** The sqlite.csChange keeps track of the number of current changes (since
817 ** the last statement) and is used to update sqlite_lsChange.
818 **
819 ** The member variables sqlite.errCode, sqlite.zErrMsg and sqlite.zErrMsg16
820 ** store the most recent error code and, if applicable, string. The
821 ** internal function sqlite3Error() is used to set these variables
822 ** consistently.
823 */
824 struct sqlite3 {
825   sqlite3_vfs *pVfs;            /* OS Interface */
826   int nDb;                      /* Number of backends currently in use */
827   Db *aDb;                      /* All backends */
828   int flags;                    /* Miscellaneous flags. See below */
829   unsigned int openFlags;       /* Flags passed to sqlite3_vfs.xOpen() */
830   int errCode;                  /* Most recent error code (SQLITE_*) */
831   int errMask;                  /* & result codes with this before returning */
832   u8 autoCommit;                /* The auto-commit flag. */
833   u8 temp_store;                /* 1: file 2: memory 0: default */
834   u8 mallocFailed;              /* True if we have seen a malloc failure */
835   u8 dfltLockMode;              /* Default locking-mode for attached dbs */
836   signed char nextAutovac;      /* Autovac setting after VACUUM if >=0 */
837   u8 suppressErr;               /* Do not issue error messages if true */
838   u8 vtabOnConflict;            /* Value to return for s3_vtab_on_conflict() */
839   int nextPagesize;             /* Pagesize after VACUUM if >0 */
840   int nTable;                   /* Number of tables in the database */
841   CollSeq *pDfltColl;           /* The default collating sequence (BINARY) */
842   i64 lastRowid;                /* ROWID of most recent insert (see above) */
843   u32 magic;                    /* Magic number for detect library misuse */
844   int nChange;                  /* Value returned by sqlite3_changes() */
845   int nTotalChange;             /* Value returned by sqlite3_total_changes() */
846   sqlite3_mutex *mutex;         /* Connection mutex */
847   int aLimit[SQLITE_N_LIMIT];   /* Limits */
848   struct sqlite3InitInfo {      /* Information used during initialization */
849     int iDb;                    /* When back is being initialized */
850     int newTnum;                /* Rootpage of table being initialized */
851     u8 busy;                    /* TRUE if currently initializing */
852     u8 orphanTrigger;           /* Last statement is orphaned TEMP trigger */
853   } init;
854   int nExtension;               /* Number of loaded extensions */
855   void **aExtension;            /* Array of shared library handles */
856   struct Vdbe *pVdbe;           /* List of active virtual machines */
857   int activeVdbeCnt;            /* Number of VDBEs currently executing */
858   int writeVdbeCnt;             /* Number of active VDBEs that are writing */
859   int vdbeExecCnt;              /* Number of nested calls to VdbeExec() */
860   void (*xTrace)(void*,const char*);        /* Trace function */
861   void *pTraceArg;                          /* Argument to the trace function */
862   void (*xProfile)(void*,const char*,u64);  /* Profiling function */
863   void *pProfileArg;                        /* Argument to profile function */
864   void *pCommitArg;                 /* Argument to xCommitCallback() */
865   int (*xCommitCallback)(void*);    /* Invoked at every commit. */
866   void *pRollbackArg;               /* Argument to xRollbackCallback() */
867   void (*xRollbackCallback)(void*); /* Invoked at every commit. */
868   void *pUpdateArg;
869   void (*xUpdateCallback)(void*,int, const char*,const char*,sqlite_int64);
870 #ifndef SQLITE_OMIT_WAL
871   int (*xWalCallback)(void *, sqlite3 *, const char *, int);
872   void *pWalArg;
873 #endif
874   void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*);
875   void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*);
876   void *pCollNeededArg;
877   sqlite3_value *pErr;          /* Most recent error message */
878   char *zErrMsg;                /* Most recent error message (UTF-8 encoded) */
879   char *zErrMsg16;              /* Most recent error message (UTF-16 encoded) */
880   union {
881     volatile int isInterrupted; /* True if sqlite3_interrupt has been called */
882     double notUsed1;            /* Spacer */
883   } u1;
884   Lookaside lookaside;          /* Lookaside malloc configuration */
885 #ifndef SQLITE_OMIT_AUTHORIZATION
886   int (*xAuth)(void*,int,const char*,const char*,const char*,const char*);
887                                 /* Access authorization function */
888   void *pAuthArg;               /* 1st argument to the access auth function */
889 #endif
890 #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
891   int (*xProgress)(void *);     /* The progress callback */
892   void *pProgressArg;           /* Argument to the progress callback */
893   int nProgressOps;             /* Number of opcodes for progress callback */
894 #endif
895 #ifndef SQLITE_OMIT_VIRTUALTABLE
896   Hash aModule;                 /* populated by sqlite3_create_module() */
897   VtabCtx *pVtabCtx;            /* Context for active vtab connect/create */
898   VTable **aVTrans;             /* Virtual tables with open transactions */
899   int nVTrans;                  /* Allocated size of aVTrans */
900   VTable *pDisconnect;    /* Disconnect these in next sqlite3_prepare() */
901 #endif
902   FuncDefHash aFunc;            /* Hash table of connection functions */
903   Hash aCollSeq;                /* All collating sequences */
904   BusyHandler busyHandler;      /* Busy callback */
905   int busyTimeout;              /* Busy handler timeout, in msec */
906   Db aDbStatic[2];              /* Static space for the 2 default backends */
907   Savepoint *pSavepoint;        /* List of active savepoints */
908   int nSavepoint;               /* Number of non-transaction savepoints */
909   int nStatement;               /* Number of nested statement-transactions  */
910   u8 isTransactionSavepoint;    /* True if the outermost savepoint is a TS */
911   i64 nDeferredCons;            /* Net deferred constraints this transaction. */
912   int *pnBytesFreed;            /* If not NULL, increment this in DbFree() */
913 
914 #ifdef SQLITE_ENABLE_UNLOCK_NOTIFY
915   /* The following variables are all protected by the STATIC_MASTER
916   ** mutex, not by sqlite3.mutex. They are used by code in notify.c.
917   **
918   ** When X.pUnlockConnection==Y, that means that X is waiting for Y to
919   ** unlock so that it can proceed.
920   **
921   ** When X.pBlockingConnection==Y, that means that something that X tried
922   ** tried to do recently failed with an SQLITE_LOCKED error due to locks
923   ** held by Y.
924   */
925   sqlite3 *pBlockingConnection; /* Connection that caused SQLITE_LOCKED */
926   sqlite3 *pUnlockConnection;           /* Connection to watch for unlock */
927   void *pUnlockArg;                     /* Argument to xUnlockNotify */
928   void (*xUnlockNotify)(void **, int);  /* Unlock notify callback */
929   sqlite3 *pNextBlocked;        /* Next in list of all blocked connections */
930 #endif
931 };
932 
933 /*
934 ** A macro to discover the encoding of a database.
935 */
936 #define ENC(db) ((db)->aDb[0].pSchema->enc)
937 
938 /*
939 ** Possible values for the sqlite3.flags.
940 */
941 #define SQLITE_VdbeTrace      0x00000100  /* True to trace VDBE execution */
942 #define SQLITE_InternChanges  0x00000200  /* Uncommitted Hash table changes */
943 #define SQLITE_FullColNames   0x00000400  /* Show full column names on SELECT */
944 #define SQLITE_ShortColNames  0x00000800  /* Show short columns names */
945 #define SQLITE_CountRows      0x00001000  /* Count rows changed by INSERT, */
946                                           /*   DELETE, or UPDATE and return */
947                                           /*   the count using a callback. */
948 #define SQLITE_NullCallback   0x00002000  /* Invoke the callback once if the */
949                                           /*   result set is empty */
950 #define SQLITE_SqlTrace       0x00004000  /* Debug print SQL as it executes */
951 #define SQLITE_VdbeListing    0x00008000  /* Debug listings of VDBE programs */
952 #define SQLITE_WriteSchema    0x00010000  /* OK to update SQLITE_MASTER */
953                          /*   0x00020000  Unused */
954 #define SQLITE_IgnoreChecks   0x00040000  /* Do not enforce check constraints */
955 #define SQLITE_ReadUncommitted 0x0080000  /* For shared-cache mode */
956 #define SQLITE_LegacyFileFmt  0x00100000  /* Create new databases in format 1 */
957 #define SQLITE_FullFSync      0x00200000  /* Use full fsync on the backend */
958 #define SQLITE_CkptFullFSync  0x00400000  /* Use full fsync for checkpoint */
959 #define SQLITE_RecoveryMode   0x00800000  /* Ignore schema errors */
960 #define SQLITE_ReverseOrder   0x01000000  /* Reverse unordered SELECTs */
961 #define SQLITE_RecTriggers    0x02000000  /* Enable recursive triggers */
962 #define SQLITE_ForeignKeys    0x04000000  /* Enforce foreign key constraints  */
963 #define SQLITE_AutoIndex      0x08000000  /* Enable automatic indexes */
964 #define SQLITE_PreferBuiltin  0x10000000  /* Preference to built-in funcs */
965 #define SQLITE_LoadExtension  0x20000000  /* Enable load_extension */
966 #define SQLITE_EnableTrigger  0x40000000  /* True to enable triggers */
967 
968 /*
969 ** Bits of the sqlite3.flags field that are used by the
970 ** sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS,...) interface.
971 ** These must be the low-order bits of the flags field.
972 */
973 #define SQLITE_QueryFlattener 0x01        /* Disable query flattening */
974 #define SQLITE_ColumnCache    0x02        /* Disable the column cache */
975 #define SQLITE_IndexSort      0x04        /* Disable indexes for sorting */
976 #define SQLITE_IndexSearch    0x08        /* Disable indexes for searching */
977 #define SQLITE_IndexCover     0x10        /* Disable index covering table */
978 #define SQLITE_GroupByOrder   0x20        /* Disable GROUPBY cover of ORDERBY */
979 #define SQLITE_FactorOutConst 0x40        /* Disable factoring out constants */
980 #define SQLITE_IdxRealAsInt   0x80        /* Store REAL as INT in indices */
981 #define SQLITE_DistinctOpt    0x80        /* DISTINCT using indexes */
982 #define SQLITE_OptMask        0xff        /* Mask of all disablable opts */
983 
984 /*
985 ** Possible values for the sqlite.magic field.
986 ** The numbers are obtained at random and have no special meaning, other
987 ** than being distinct from one another.
988 */
989 #define SQLITE_MAGIC_OPEN     0xa029a697  /* Database is open */
990 #define SQLITE_MAGIC_CLOSED   0x9f3c2d33  /* Database is closed */
991 #define SQLITE_MAGIC_SICK     0x4b771290  /* Error and awaiting close */
992 #define SQLITE_MAGIC_BUSY     0xf03b7906  /* Database currently in use */
993 #define SQLITE_MAGIC_ERROR    0xb5357930  /* An SQLITE_MISUSE error occurred */
994 
995 /*
996 ** Each SQL function is defined by an instance of the following
997 ** structure.  A pointer to this structure is stored in the sqlite.aFunc
998 ** hash table.  When multiple functions have the same name, the hash table
999 ** points to a linked list of these structures.
1000 */
1001 struct FuncDef {
1002   i16 nArg;            /* Number of arguments.  -1 means unlimited */
1003   u8 iPrefEnc;         /* Preferred text encoding (SQLITE_UTF8, 16LE, 16BE) */
1004   u8 flags;            /* Some combination of SQLITE_FUNC_* */
1005   void *pUserData;     /* User data parameter */
1006   FuncDef *pNext;      /* Next function with same name */
1007   void (*xFunc)(sqlite3_context*,int,sqlite3_value**); /* Regular function */
1008   void (*xStep)(sqlite3_context*,int,sqlite3_value**); /* Aggregate step */
1009   void (*xFinalize)(sqlite3_context*);                /* Aggregate finalizer */
1010   char *zName;         /* SQL name of the function. */
1011   FuncDef *pHash;      /* Next with a different name but the same hash */
1012   FuncDestructor *pDestructor;   /* Reference counted destructor function */
1013 };
1014 
1015 /*
1016 ** This structure encapsulates a user-function destructor callback (as
1017 ** configured using create_function_v2()) and a reference counter. When
1018 ** create_function_v2() is called to create a function with a destructor,
1019 ** a single object of this type is allocated. FuncDestructor.nRef is set to
1020 ** the number of FuncDef objects created (either 1 or 3, depending on whether
1021 ** or not the specified encoding is SQLITE_ANY). The FuncDef.pDestructor
1022 ** member of each of the new FuncDef objects is set to point to the allocated
1023 ** FuncDestructor.
1024 **
1025 ** Thereafter, when one of the FuncDef objects is deleted, the reference
1026 ** count on this object is decremented. When it reaches 0, the destructor
1027 ** is invoked and the FuncDestructor structure freed.
1028 */
1029 struct FuncDestructor {
1030   int nRef;
1031   void (*xDestroy)(void *);
1032   void *pUserData;
1033 };
1034 
1035 /*
1036 ** Possible values for FuncDef.flags
1037 */
1038 #define SQLITE_FUNC_LIKE     0x01 /* Candidate for the LIKE optimization */
1039 #define SQLITE_FUNC_CASE     0x02 /* Case-sensitive LIKE-type function */
1040 #define SQLITE_FUNC_EPHEM    0x04 /* Ephemeral.  Delete with VDBE */
1041 #define SQLITE_FUNC_NEEDCOLL 0x08 /* sqlite3GetFuncCollSeq() might be called */
1042 #define SQLITE_FUNC_PRIVATE  0x10 /* Allowed for internal use only */
1043 #define SQLITE_FUNC_COUNT    0x20 /* Built-in count(*) aggregate */
1044 #define SQLITE_FUNC_COALESCE 0x40 /* Built-in coalesce() or ifnull() function */
1045 
1046 /*
1047 ** The following three macros, FUNCTION(), LIKEFUNC() and AGGREGATE() are
1048 ** used to create the initializers for the FuncDef structures.
1049 **
1050 **   FUNCTION(zName, nArg, iArg, bNC, xFunc)
1051 **     Used to create a scalar function definition of a function zName
1052 **     implemented by C function xFunc that accepts nArg arguments. The
1053 **     value passed as iArg is cast to a (void*) and made available
1054 **     as the user-data (sqlite3_user_data()) for the function. If
1055 **     argument bNC is true, then the SQLITE_FUNC_NEEDCOLL flag is set.
1056 **
1057 **   AGGREGATE(zName, nArg, iArg, bNC, xStep, xFinal)
1058 **     Used to create an aggregate function definition implemented by
1059 **     the C functions xStep and xFinal. The first four parameters
1060 **     are interpreted in the same way as the first 4 parameters to
1061 **     FUNCTION().
1062 **
1063 **   LIKEFUNC(zName, nArg, pArg, flags)
1064 **     Used to create a scalar function definition of a function zName
1065 **     that accepts nArg arguments and is implemented by a call to C
1066 **     function likeFunc. Argument pArg is cast to a (void *) and made
1067 **     available as the function user-data (sqlite3_user_data()). The
1068 **     FuncDef.flags variable is set to the value passed as the flags
1069 **     parameter.
1070 */
1071 #define FUNCTION(zName, nArg, iArg, bNC, xFunc) \
1072   {nArg, SQLITE_UTF8, bNC*SQLITE_FUNC_NEEDCOLL, \
1073    SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, 0, #zName, 0, 0}
1074 #define STR_FUNCTION(zName, nArg, pArg, bNC, xFunc) \
1075   {nArg, SQLITE_UTF8, bNC*SQLITE_FUNC_NEEDCOLL, \
1076    pArg, 0, xFunc, 0, 0, #zName, 0, 0}
1077 #define LIKEFUNC(zName, nArg, arg, flags) \
1078   {nArg, SQLITE_UTF8, flags, (void *)arg, 0, likeFunc, 0, 0, #zName, 0, 0}
1079 #define AGGREGATE(zName, nArg, arg, nc, xStep, xFinal) \
1080   {nArg, SQLITE_UTF8, nc*SQLITE_FUNC_NEEDCOLL, \
1081    SQLITE_INT_TO_PTR(arg), 0, 0, xStep,xFinal,#zName,0,0}
1082 
1083 /*
1084 ** All current savepoints are stored in a linked list starting at
1085 ** sqlite3.pSavepoint. The first element in the list is the most recently
1086 ** opened savepoint. Savepoints are added to the list by the vdbe
1087 ** OP_Savepoint instruction.
1088 */
1089 struct Savepoint {
1090   char *zName;                        /* Savepoint name (nul-terminated) */
1091   i64 nDeferredCons;                  /* Number of deferred fk violations */
1092   Savepoint *pNext;                   /* Parent savepoint (if any) */
1093 };
1094 
1095 /*
1096 ** The following are used as the second parameter to sqlite3Savepoint(),
1097 ** and as the P1 argument to the OP_Savepoint instruction.
1098 */
1099 #define SAVEPOINT_BEGIN      0
1100 #define SAVEPOINT_RELEASE    1
1101 #define SAVEPOINT_ROLLBACK   2
1102 
1103 
1104 /*
1105 ** Each SQLite module (virtual table definition) is defined by an
1106 ** instance of the following structure, stored in the sqlite3.aModule
1107 ** hash table.
1108 */
1109 struct Module {
1110   const sqlite3_module *pModule;       /* Callback pointers */
1111   const char *zName;                   /* Name passed to create_module() */
1112   void *pAux;                          /* pAux passed to create_module() */
1113   void (*xDestroy)(void *);            /* Module destructor function */
1114 };
1115 
1116 /*
1117 ** information about each column of an SQL table is held in an instance
1118 ** of this structure.
1119 */
1120 struct Column {
1121   char *zName;     /* Name of this column */
1122   Expr *pDflt;     /* Default value of this column */
1123   char *zDflt;     /* Original text of the default value */
1124   char *zType;     /* Data type for this column */
1125   char *zColl;     /* Collating sequence.  If NULL, use the default */
1126   u8 notNull;      /* True if there is a NOT NULL constraint */
1127   u8 isPrimKey;    /* True if this column is part of the PRIMARY KEY */
1128   char affinity;   /* One of the SQLITE_AFF_... values */
1129 #ifndef SQLITE_OMIT_VIRTUALTABLE
1130   u8 isHidden;     /* True if this column is 'hidden' */
1131 #endif
1132 };
1133 
1134 /*
1135 ** A "Collating Sequence" is defined by an instance of the following
1136 ** structure. Conceptually, a collating sequence consists of a name and
1137 ** a comparison routine that defines the order of that sequence.
1138 **
1139 ** There may two separate implementations of the collation function, one
1140 ** that processes text in UTF-8 encoding (CollSeq.xCmp) and another that
1141 ** processes text encoded in UTF-16 (CollSeq.xCmp16), using the machine
1142 ** native byte order. When a collation sequence is invoked, SQLite selects
1143 ** the version that will require the least expensive encoding
1144 ** translations, if any.
1145 **
1146 ** The CollSeq.pUser member variable is an extra parameter that passed in
1147 ** as the first argument to the UTF-8 comparison function, xCmp.
1148 ** CollSeq.pUser16 is the equivalent for the UTF-16 comparison function,
1149 ** xCmp16.
1150 **
1151 ** If both CollSeq.xCmp and CollSeq.xCmp16 are NULL, it means that the
1152 ** collating sequence is undefined.  Indices built on an undefined
1153 ** collating sequence may not be read or written.
1154 */
1155 struct CollSeq {
1156   char *zName;          /* Name of the collating sequence, UTF-8 encoded */
1157   u8 enc;               /* Text encoding handled by xCmp() */
1158   void *pUser;          /* First argument to xCmp() */
1159   int (*xCmp)(void*,int, const void*, int, const void*);
1160   void (*xDel)(void*);  /* Destructor for pUser */
1161 };
1162 
1163 /*
1164 ** A sort order can be either ASC or DESC.
1165 */
1166 #define SQLITE_SO_ASC       0  /* Sort in ascending order */
1167 #define SQLITE_SO_DESC      1  /* Sort in ascending order */
1168 
1169 /*
1170 ** Column affinity types.
1171 **
1172 ** These used to have mnemonic name like 'i' for SQLITE_AFF_INTEGER and
1173 ** 't' for SQLITE_AFF_TEXT.  But we can save a little space and improve
1174 ** the speed a little by numbering the values consecutively.
1175 **
1176 ** But rather than start with 0 or 1, we begin with 'a'.  That way,
1177 ** when multiple affinity types are concatenated into a string and
1178 ** used as the P4 operand, they will be more readable.
1179 **
1180 ** Note also that the numeric types are grouped together so that testing
1181 ** for a numeric type is a single comparison.
1182 */
1183 #define SQLITE_AFF_TEXT     'a'
1184 #define SQLITE_AFF_NONE     'b'
1185 #define SQLITE_AFF_NUMERIC  'c'
1186 #define SQLITE_AFF_INTEGER  'd'
1187 #define SQLITE_AFF_REAL     'e'
1188 
1189 #define sqlite3IsNumericAffinity(X)  ((X)>=SQLITE_AFF_NUMERIC)
1190 
1191 /*
1192 ** The SQLITE_AFF_MASK values masks off the significant bits of an
1193 ** affinity value.
1194 */
1195 #define SQLITE_AFF_MASK     0x67
1196 
1197 /*
1198 ** Additional bit values that can be ORed with an affinity without
1199 ** changing the affinity.
1200 */
1201 #define SQLITE_JUMPIFNULL   0x08  /* jumps if either operand is NULL */
1202 #define SQLITE_STOREP2      0x10  /* Store result in reg[P2] rather than jump */
1203 #define SQLITE_NULLEQ       0x80  /* NULL=NULL */
1204 
1205 /*
1206 ** An object of this type is created for each virtual table present in
1207 ** the database schema.
1208 **
1209 ** If the database schema is shared, then there is one instance of this
1210 ** structure for each database connection (sqlite3*) that uses the shared
1211 ** schema. This is because each database connection requires its own unique
1212 ** instance of the sqlite3_vtab* handle used to access the virtual table
1213 ** implementation. sqlite3_vtab* handles can not be shared between
1214 ** database connections, even when the rest of the in-memory database
1215 ** schema is shared, as the implementation often stores the database
1216 ** connection handle passed to it via the xConnect() or xCreate() method
1217 ** during initialization internally. This database connection handle may
1218 ** then be used by the virtual table implementation to access real tables
1219 ** within the database. So that they appear as part of the callers
1220 ** transaction, these accesses need to be made via the same database
1221 ** connection as that used to execute SQL operations on the virtual table.
1222 **
1223 ** All VTable objects that correspond to a single table in a shared
1224 ** database schema are initially stored in a linked-list pointed to by
1225 ** the Table.pVTable member variable of the corresponding Table object.
1226 ** When an sqlite3_prepare() operation is required to access the virtual
1227 ** table, it searches the list for the VTable that corresponds to the
1228 ** database connection doing the preparing so as to use the correct
1229 ** sqlite3_vtab* handle in the compiled query.
1230 **
1231 ** When an in-memory Table object is deleted (for example when the
1232 ** schema is being reloaded for some reason), the VTable objects are not
1233 ** deleted and the sqlite3_vtab* handles are not xDisconnect()ed
1234 ** immediately. Instead, they are moved from the Table.pVTable list to
1235 ** another linked list headed by the sqlite3.pDisconnect member of the
1236 ** corresponding sqlite3 structure. They are then deleted/xDisconnected
1237 ** next time a statement is prepared using said sqlite3*. This is done
1238 ** to avoid deadlock issues involving multiple sqlite3.mutex mutexes.
1239 ** Refer to comments above function sqlite3VtabUnlockList() for an
1240 ** explanation as to why it is safe to add an entry to an sqlite3.pDisconnect
1241 ** list without holding the corresponding sqlite3.mutex mutex.
1242 **
1243 ** The memory for objects of this type is always allocated by
1244 ** sqlite3DbMalloc(), using the connection handle stored in VTable.db as
1245 ** the first argument.
1246 */
1247 struct VTable {
1248   sqlite3 *db;              /* Database connection associated with this table */
1249   Module *pMod;             /* Pointer to module implementation */
1250   sqlite3_vtab *pVtab;      /* Pointer to vtab instance */
1251   int nRef;                 /* Number of pointers to this structure */
1252   u8 bConstraint;           /* True if constraints are supported */
1253   int iSavepoint;           /* Depth of the SAVEPOINT stack */
1254   VTable *pNext;            /* Next in linked list (see above) */
1255 };
1256 
1257 /*
1258 ** Each SQL table is represented in memory by an instance of the
1259 ** following structure.
1260 **
1261 ** Table.zName is the name of the table.  The case of the original
1262 ** CREATE TABLE statement is stored, but case is not significant for
1263 ** comparisons.
1264 **
1265 ** Table.nCol is the number of columns in this table.  Table.aCol is a
1266 ** pointer to an array of Column structures, one for each column.
1267 **
1268 ** If the table has an INTEGER PRIMARY KEY, then Table.iPKey is the index of
1269 ** the column that is that key.   Otherwise Table.iPKey is negative.  Note
1270 ** that the datatype of the PRIMARY KEY must be INTEGER for this field to
1271 ** be set.  An INTEGER PRIMARY KEY is used as the rowid for each row of
1272 ** the table.  If a table has no INTEGER PRIMARY KEY, then a random rowid
1273 ** is generated for each row of the table.  TF_HasPrimaryKey is set if
1274 ** the table has any PRIMARY KEY, INTEGER or otherwise.
1275 **
1276 ** Table.tnum is the page number for the root BTree page of the table in the
1277 ** database file.  If Table.iDb is the index of the database table backend
1278 ** in sqlite.aDb[].  0 is for the main database and 1 is for the file that
1279 ** holds temporary tables and indices.  If TF_Ephemeral is set
1280 ** then the table is stored in a file that is automatically deleted
1281 ** when the VDBE cursor to the table is closed.  In this case Table.tnum
1282 ** refers VDBE cursor number that holds the table open, not to the root
1283 ** page number.  Transient tables are used to hold the results of a
1284 ** sub-query that appears instead of a real table name in the FROM clause
1285 ** of a SELECT statement.
1286 */
1287 struct Table {
1288   char *zName;         /* Name of the table or view */
1289   int iPKey;           /* If not negative, use aCol[iPKey] as the primary key */
1290   int nCol;            /* Number of columns in this table */
1291   Column *aCol;        /* Information about each column */
1292   Index *pIndex;       /* List of SQL indexes on this table. */
1293   int tnum;            /* Root BTree node for this table (see note above) */
1294   tRowcnt nRowEst;     /* Estimated rows in table - from sqlite_stat1 table */
1295   Select *pSelect;     /* NULL for tables.  Points to definition if a view. */
1296   u16 nRef;            /* Number of pointers to this Table */
1297   u8 tabFlags;         /* Mask of TF_* values */
1298   u8 keyConf;          /* What to do in case of uniqueness conflict on iPKey */
1299   FKey *pFKey;         /* Linked list of all foreign keys in this table */
1300   char *zColAff;       /* String defining the affinity of each column */
1301 #ifndef SQLITE_OMIT_CHECK
1302   Expr *pCheck;        /* The AND of all CHECK constraints */
1303 #endif
1304 #ifndef SQLITE_OMIT_ALTERTABLE
1305   int addColOffset;    /* Offset in CREATE TABLE stmt to add a new column */
1306 #endif
1307 #ifndef SQLITE_OMIT_VIRTUALTABLE
1308   VTable *pVTable;     /* List of VTable objects. */
1309   int nModuleArg;      /* Number of arguments to the module */
1310   char **azModuleArg;  /* Text of all module args. [0] is module name */
1311 #endif
1312   Trigger *pTrigger;   /* List of triggers stored in pSchema */
1313   Schema *pSchema;     /* Schema that contains this table */
1314   Table *pNextZombie;  /* Next on the Parse.pZombieTab list */
1315 };
1316 
1317 /*
1318 ** Allowed values for Tabe.tabFlags.
1319 */
1320 #define TF_Readonly        0x01    /* Read-only system table */
1321 #define TF_Ephemeral       0x02    /* An ephemeral table */
1322 #define TF_HasPrimaryKey   0x04    /* Table has a primary key */
1323 #define TF_Autoincrement   0x08    /* Integer primary key is autoincrement */
1324 #define TF_Virtual         0x10    /* Is a virtual table */
1325 #define TF_NeedMetadata    0x20    /* aCol[].zType and aCol[].pColl missing */
1326 
1327 
1328 
1329 /*
1330 ** Test to see whether or not a table is a virtual table.  This is
1331 ** done as a macro so that it will be optimized out when virtual
1332 ** table support is omitted from the build.
1333 */
1334 #ifndef SQLITE_OMIT_VIRTUALTABLE
1335 #  define IsVirtual(X)      (((X)->tabFlags & TF_Virtual)!=0)
1336 #  define IsHiddenColumn(X) ((X)->isHidden)
1337 #else
1338 #  define IsVirtual(X)      0
1339 #  define IsHiddenColumn(X) 0
1340 #endif
1341 
1342 /*
1343 ** Each foreign key constraint is an instance of the following structure.
1344 **
1345 ** A foreign key is associated with two tables.  The "from" table is
1346 ** the table that contains the REFERENCES clause that creates the foreign
1347 ** key.  The "to" table is the table that is named in the REFERENCES clause.
1348 ** Consider this example:
1349 **
1350 **     CREATE TABLE ex1(
1351 **       a INTEGER PRIMARY KEY,
1352 **       b INTEGER CONSTRAINT fk1 REFERENCES ex2(x)
1353 **     );
1354 **
1355 ** For foreign key "fk1", the from-table is "ex1" and the to-table is "ex2".
1356 **
1357 ** Each REFERENCES clause generates an instance of the following structure
1358 ** which is attached to the from-table.  The to-table need not exist when
1359 ** the from-table is created.  The existence of the to-table is not checked.
1360 */
1361 struct FKey {
1362   Table *pFrom;     /* Table containing the REFERENCES clause (aka: Child) */
1363   FKey *pNextFrom;  /* Next foreign key in pFrom */
1364   char *zTo;        /* Name of table that the key points to (aka: Parent) */
1365   FKey *pNextTo;    /* Next foreign key on table named zTo */
1366   FKey *pPrevTo;    /* Previous foreign key on table named zTo */
1367   int nCol;         /* Number of columns in this key */
1368   /* EV: R-30323-21917 */
1369   u8 isDeferred;    /* True if constraint checking is deferred till COMMIT */
1370   u8 aAction[2];          /* ON DELETE and ON UPDATE actions, respectively */
1371   Trigger *apTrigger[2];  /* Triggers for aAction[] actions */
1372   struct sColMap {  /* Mapping of columns in pFrom to columns in zTo */
1373     int iFrom;         /* Index of column in pFrom */
1374     char *zCol;        /* Name of column in zTo.  If 0 use PRIMARY KEY */
1375   } aCol[1];        /* One entry for each of nCol column s */
1376 };
1377 
1378 /*
1379 ** SQLite supports many different ways to resolve a constraint
1380 ** error.  ROLLBACK processing means that a constraint violation
1381 ** causes the operation in process to fail and for the current transaction
1382 ** to be rolled back.  ABORT processing means the operation in process
1383 ** fails and any prior changes from that one operation are backed out,
1384 ** but the transaction is not rolled back.  FAIL processing means that
1385 ** the operation in progress stops and returns an error code.  But prior
1386 ** changes due to the same operation are not backed out and no rollback
1387 ** occurs.  IGNORE means that the particular row that caused the constraint
1388 ** error is not inserted or updated.  Processing continues and no error
1389 ** is returned.  REPLACE means that preexisting database rows that caused
1390 ** a UNIQUE constraint violation are removed so that the new insert or
1391 ** update can proceed.  Processing continues and no error is reported.
1392 **
1393 ** RESTRICT, SETNULL, and CASCADE actions apply only to foreign keys.
1394 ** RESTRICT is the same as ABORT for IMMEDIATE foreign keys and the
1395 ** same as ROLLBACK for DEFERRED keys.  SETNULL means that the foreign
1396 ** key is set to NULL.  CASCADE means that a DELETE or UPDATE of the
1397 ** referenced table row is propagated into the row that holds the
1398 ** foreign key.
1399 **
1400 ** The following symbolic values are used to record which type
1401 ** of action to take.
1402 */
1403 #define OE_None     0   /* There is no constraint to check */
1404 #define OE_Rollback 1   /* Fail the operation and rollback the transaction */
1405 #define OE_Abort    2   /* Back out changes but do no rollback transaction */
1406 #define OE_Fail     3   /* Stop the operation but leave all prior changes */
1407 #define OE_Ignore   4   /* Ignore the error. Do not do the INSERT or UPDATE */
1408 #define OE_Replace  5   /* Delete existing record, then do INSERT or UPDATE */
1409 
1410 #define OE_Restrict 6   /* OE_Abort for IMMEDIATE, OE_Rollback for DEFERRED */
1411 #define OE_SetNull  7   /* Set the foreign key value to NULL */
1412 #define OE_SetDflt  8   /* Set the foreign key value to its default */
1413 #define OE_Cascade  9   /* Cascade the changes */
1414 
1415 #define OE_Default  99  /* Do whatever the default action is */
1416 
1417 
1418 /*
1419 ** An instance of the following structure is passed as the first
1420 ** argument to sqlite3VdbeKeyCompare and is used to control the
1421 ** comparison of the two index keys.
1422 */
1423 struct KeyInfo {
1424   sqlite3 *db;        /* The database connection */
1425   u8 enc;             /* Text encoding - one of the SQLITE_UTF* values */
1426   u16 nField;         /* Number of entries in aColl[] */
1427   u8 *aSortOrder;     /* Sort order for each column.  May be NULL */
1428   CollSeq *aColl[1];  /* Collating sequence for each term of the key */
1429 };
1430 
1431 /*
1432 ** An instance of the following structure holds information about a
1433 ** single index record that has already been parsed out into individual
1434 ** values.
1435 **
1436 ** A record is an object that contains one or more fields of data.
1437 ** Records are used to store the content of a table row and to store
1438 ** the key of an index.  A blob encoding of a record is created by
1439 ** the OP_MakeRecord opcode of the VDBE and is disassembled by the
1440 ** OP_Column opcode.
1441 **
1442 ** This structure holds a record that has already been disassembled
1443 ** into its constituent fields.
1444 */
1445 struct UnpackedRecord {
1446   KeyInfo *pKeyInfo;  /* Collation and sort-order information */
1447   u16 nField;         /* Number of entries in apMem[] */
1448   u8 flags;           /* Boolean settings.  UNPACKED_... below */
1449   i64 rowid;          /* Used by UNPACKED_PREFIX_SEARCH */
1450   Mem *aMem;          /* Values */
1451 };
1452 
1453 /*
1454 ** Allowed values of UnpackedRecord.flags
1455 */
1456 #define UNPACKED_INCRKEY       0x01  /* Make this key an epsilon larger */
1457 #define UNPACKED_PREFIX_MATCH  0x02  /* A prefix match is considered OK */
1458 #define UNPACKED_PREFIX_SEARCH 0x04  /* Ignore final (rowid) field */
1459 
1460 /*
1461 ** Each SQL index is represented in memory by an
1462 ** instance of the following structure.
1463 **
1464 ** The columns of the table that are to be indexed are described
1465 ** by the aiColumn[] field of this structure.  For example, suppose
1466 ** we have the following table and index:
1467 **
1468 **     CREATE TABLE Ex1(c1 int, c2 int, c3 text);
1469 **     CREATE INDEX Ex2 ON Ex1(c3,c1);
1470 **
1471 ** In the Table structure describing Ex1, nCol==3 because there are
1472 ** three columns in the table.  In the Index structure describing
1473 ** Ex2, nColumn==2 since 2 of the 3 columns of Ex1 are indexed.
1474 ** The value of aiColumn is {2, 0}.  aiColumn[0]==2 because the
1475 ** first column to be indexed (c3) has an index of 2 in Ex1.aCol[].
1476 ** The second column to be indexed (c1) has an index of 0 in
1477 ** Ex1.aCol[], hence Ex2.aiColumn[1]==0.
1478 **
1479 ** The Index.onError field determines whether or not the indexed columns
1480 ** must be unique and what to do if they are not.  When Index.onError=OE_None,
1481 ** it means this is not a unique index.  Otherwise it is a unique index
1482 ** and the value of Index.onError indicate the which conflict resolution
1483 ** algorithm to employ whenever an attempt is made to insert a non-unique
1484 ** element.
1485 */
1486 struct Index {
1487   char *zName;     /* Name of this index */
1488   int nColumn;     /* Number of columns in the table used by this index */
1489   int *aiColumn;   /* Which columns are used by this index.  1st is 0 */
1490   tRowcnt *aiRowEst; /* Result of ANALYZE: Est. rows selected by each column */
1491   Table *pTable;   /* The SQL table being indexed */
1492   int tnum;        /* Page containing root of this index in database file */
1493   u8 onError;      /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
1494   u8 autoIndex;    /* True if is automatically created (ex: by UNIQUE) */
1495   u8 bUnordered;   /* Use this index for == or IN queries only */
1496   char *zColAff;   /* String defining the affinity of each column */
1497   Index *pNext;    /* The next index associated with the same table */
1498   Schema *pSchema; /* Schema containing this index */
1499   u8 *aSortOrder;  /* Array of size Index.nColumn. True==DESC, False==ASC */
1500   char **azColl;   /* Array of collation sequence names for index */
1501 #ifdef SQLITE_ENABLE_STAT3
1502   int nSample;             /* Number of elements in aSample[] */
1503   tRowcnt avgEq;           /* Average nEq value for key values not in aSample */
1504   IndexSample *aSample;    /* Samples of the left-most key */
1505 #endif
1506 };
1507 
1508 /*
1509 ** Each sample stored in the sqlite_stat3 table is represented in memory
1510 ** using a structure of this type.  See documentation at the top of the
1511 ** analyze.c source file for additional information.
1512 */
1513 struct IndexSample {
1514   union {
1515     char *z;        /* Value if eType is SQLITE_TEXT or SQLITE_BLOB */
1516     double r;       /* Value if eType is SQLITE_FLOAT */
1517     i64 i;          /* Value if eType is SQLITE_INTEGER */
1518   } u;
1519   u8 eType;         /* SQLITE_NULL, SQLITE_INTEGER ... etc. */
1520   int nByte;        /* Size in byte of text or blob. */
1521   tRowcnt nEq;      /* Est. number of rows where the key equals this sample */
1522   tRowcnt nLt;      /* Est. number of rows where key is less than this sample */
1523   tRowcnt nDLt;     /* Est. number of distinct keys less than this sample */
1524 };
1525 
1526 /*
1527 ** Each token coming out of the lexer is an instance of
1528 ** this structure.  Tokens are also used as part of an expression.
1529 **
1530 ** Note if Token.z==0 then Token.dyn and Token.n are undefined and
1531 ** may contain random values.  Do not make any assumptions about Token.dyn
1532 ** and Token.n when Token.z==0.
1533 */
1534 struct Token {
1535   const char *z;     /* Text of the token.  Not NULL-terminated! */
1536   unsigned int n;    /* Number of characters in this token */
1537 };
1538 
1539 /*
1540 ** An instance of this structure contains information needed to generate
1541 ** code for a SELECT that contains aggregate functions.
1542 **
1543 ** If Expr.op==TK_AGG_COLUMN or TK_AGG_FUNCTION then Expr.pAggInfo is a
1544 ** pointer to this structure.  The Expr.iColumn field is the index in
1545 ** AggInfo.aCol[] or AggInfo.aFunc[] of information needed to generate
1546 ** code for that node.
1547 **
1548 ** AggInfo.pGroupBy and AggInfo.aFunc.pExpr point to fields within the
1549 ** original Select structure that describes the SELECT statement.  These
1550 ** fields do not need to be freed when deallocating the AggInfo structure.
1551 */
1552 struct AggInfo {
1553   u8 directMode;          /* Direct rendering mode means take data directly
1554                           ** from source tables rather than from accumulators */
1555   u8 useSortingIdx;       /* In direct mode, reference the sorting index rather
1556                           ** than the source table */
1557   int sortingIdx;         /* Cursor number of the sorting index */
1558   int sortingIdxPTab;     /* Cursor number of pseudo-table */
1559   ExprList *pGroupBy;     /* The group by clause */
1560   int nSortingColumn;     /* Number of columns in the sorting index */
1561   struct AggInfo_col {    /* For each column used in source tables */
1562     Table *pTab;             /* Source table */
1563     int iTable;              /* Cursor number of the source table */
1564     int iColumn;             /* Column number within the source table */
1565     int iSorterColumn;       /* Column number in the sorting index */
1566     int iMem;                /* Memory location that acts as accumulator */
1567     Expr *pExpr;             /* The original expression */
1568   } *aCol;
1569   int nColumn;            /* Number of used entries in aCol[] */
1570   int nColumnAlloc;       /* Number of slots allocated for aCol[] */
1571   int nAccumulator;       /* Number of columns that show through to the output.
1572                           ** Additional columns are used only as parameters to
1573                           ** aggregate functions */
1574   struct AggInfo_func {   /* For each aggregate function */
1575     Expr *pExpr;             /* Expression encoding the function */
1576     FuncDef *pFunc;          /* The aggregate function implementation */
1577     int iMem;                /* Memory location that acts as accumulator */
1578     int iDistinct;           /* Ephemeral table used to enforce DISTINCT */
1579   } *aFunc;
1580   int nFunc;              /* Number of entries in aFunc[] */
1581   int nFuncAlloc;         /* Number of slots allocated for aFunc[] */
1582 };
1583 
1584 /*
1585 ** The datatype ynVar is a signed integer, either 16-bit or 32-bit.
1586 ** Usually it is 16-bits.  But if SQLITE_MAX_VARIABLE_NUMBER is greater
1587 ** than 32767 we have to make it 32-bit.  16-bit is preferred because
1588 ** it uses less memory in the Expr object, which is a big memory user
1589 ** in systems with lots of prepared statements.  And few applications
1590 ** need more than about 10 or 20 variables.  But some extreme users want
1591 ** to have prepared statements with over 32767 variables, and for them
1592 ** the option is available (at compile-time).
1593 */
1594 #if SQLITE_MAX_VARIABLE_NUMBER<=32767
1595 typedef i16 ynVar;
1596 #else
1597 typedef int ynVar;
1598 #endif
1599 
1600 /*
1601 ** Each node of an expression in the parse tree is an instance
1602 ** of this structure.
1603 **
1604 ** Expr.op is the opcode. The integer parser token codes are reused
1605 ** as opcodes here. For example, the parser defines TK_GE to be an integer
1606 ** code representing the ">=" operator. This same integer code is reused
1607 ** to represent the greater-than-or-equal-to operator in the expression
1608 ** tree.
1609 **
1610 ** If the expression is an SQL literal (TK_INTEGER, TK_FLOAT, TK_BLOB,
1611 ** or TK_STRING), then Expr.token contains the text of the SQL literal. If
1612 ** the expression is a variable (TK_VARIABLE), then Expr.token contains the
1613 ** variable name. Finally, if the expression is an SQL function (TK_FUNCTION),
1614 ** then Expr.token contains the name of the function.
1615 **
1616 ** Expr.pRight and Expr.pLeft are the left and right subexpressions of a
1617 ** binary operator. Either or both may be NULL.
1618 **
1619 ** Expr.x.pList is a list of arguments if the expression is an SQL function,
1620 ** a CASE expression or an IN expression of the form "<lhs> IN (<y>, <z>...)".
1621 ** Expr.x.pSelect is used if the expression is a sub-select or an expression of
1622 ** the form "<lhs> IN (SELECT ...)". If the EP_xIsSelect bit is set in the
1623 ** Expr.flags mask, then Expr.x.pSelect is valid. Otherwise, Expr.x.pList is
1624 ** valid.
1625 **
1626 ** An expression of the form ID or ID.ID refers to a column in a table.
1627 ** For such expressions, Expr.op is set to TK_COLUMN and Expr.iTable is
1628 ** the integer cursor number of a VDBE cursor pointing to that table and
1629 ** Expr.iColumn is the column number for the specific column.  If the
1630 ** expression is used as a result in an aggregate SELECT, then the
1631 ** value is also stored in the Expr.iAgg column in the aggregate so that
1632 ** it can be accessed after all aggregates are computed.
1633 **
1634 ** If the expression is an unbound variable marker (a question mark
1635 ** character '?' in the original SQL) then the Expr.iTable holds the index
1636 ** number for that variable.
1637 **
1638 ** If the expression is a subquery then Expr.iColumn holds an integer
1639 ** register number containing the result of the subquery.  If the
1640 ** subquery gives a constant result, then iTable is -1.  If the subquery
1641 ** gives a different answer at different times during statement processing
1642 ** then iTable is the address of a subroutine that computes the subquery.
1643 **
1644 ** If the Expr is of type OP_Column, and the table it is selecting from
1645 ** is a disk table or the "old.*" pseudo-table, then pTab points to the
1646 ** corresponding table definition.
1647 **
1648 ** ALLOCATION NOTES:
1649 **
1650 ** Expr objects can use a lot of memory space in database schema.  To
1651 ** help reduce memory requirements, sometimes an Expr object will be
1652 ** truncated.  And to reduce the number of memory allocations, sometimes
1653 ** two or more Expr objects will be stored in a single memory allocation,
1654 ** together with Expr.zToken strings.
1655 **
1656 ** If the EP_Reduced and EP_TokenOnly flags are set when
1657 ** an Expr object is truncated.  When EP_Reduced is set, then all
1658 ** the child Expr objects in the Expr.pLeft and Expr.pRight subtrees
1659 ** are contained within the same memory allocation.  Note, however, that
1660 ** the subtrees in Expr.x.pList or Expr.x.pSelect are always separately
1661 ** allocated, regardless of whether or not EP_Reduced is set.
1662 */
1663 struct Expr {
1664   u8 op;                 /* Operation performed by this node */
1665   char affinity;         /* The affinity of the column or 0 if not a column */
1666   u16 flags;             /* Various flags.  EP_* See below */
1667   union {
1668     char *zToken;          /* Token value. Zero terminated and dequoted */
1669     int iValue;            /* Non-negative integer value if EP_IntValue */
1670   } u;
1671 
1672   /* If the EP_TokenOnly flag is set in the Expr.flags mask, then no
1673   ** space is allocated for the fields below this point. An attempt to
1674   ** access them will result in a segfault or malfunction.
1675   *********************************************************************/
1676 
1677   Expr *pLeft;           /* Left subnode */
1678   Expr *pRight;          /* Right subnode */
1679   union {
1680     ExprList *pList;     /* Function arguments or in "<expr> IN (<expr-list)" */
1681     Select *pSelect;     /* Used for sub-selects and "<expr> IN (<select>)" */
1682   } x;
1683   CollSeq *pColl;        /* The collation type of the column or 0 */
1684 
1685   /* If the EP_Reduced flag is set in the Expr.flags mask, then no
1686   ** space is allocated for the fields below this point. An attempt to
1687   ** access them will result in a segfault or malfunction.
1688   *********************************************************************/
1689 
1690   int iTable;            /* TK_COLUMN: cursor number of table holding column
1691                          ** TK_REGISTER: register number
1692                          ** TK_TRIGGER: 1 -> new, 0 -> old */
1693   ynVar iColumn;         /* TK_COLUMN: column index.  -1 for rowid.
1694                          ** TK_VARIABLE: variable number (always >= 1). */
1695   i16 iAgg;              /* Which entry in pAggInfo->aCol[] or ->aFunc[] */
1696   i16 iRightJoinTable;   /* If EP_FromJoin, the right table of the join */
1697   u8 flags2;             /* Second set of flags.  EP2_... */
1698   u8 op2;                /* If a TK_REGISTER, the original value of Expr.op */
1699   AggInfo *pAggInfo;     /* Used by TK_AGG_COLUMN and TK_AGG_FUNCTION */
1700   Table *pTab;           /* Table for TK_COLUMN expressions. */
1701 #if SQLITE_MAX_EXPR_DEPTH>0
1702   int nHeight;           /* Height of the tree headed by this node */
1703 #endif
1704 };
1705 
1706 /*
1707 ** The following are the meanings of bits in the Expr.flags field.
1708 */
1709 #define EP_FromJoin   0x0001  /* Originated in ON or USING clause of a join */
1710 #define EP_Agg        0x0002  /* Contains one or more aggregate functions */
1711 #define EP_Resolved   0x0004  /* IDs have been resolved to COLUMNs */
1712 #define EP_Error      0x0008  /* Expression contains one or more errors */
1713 #define EP_Distinct   0x0010  /* Aggregate function with DISTINCT keyword */
1714 #define EP_VarSelect  0x0020  /* pSelect is correlated, not constant */
1715 #define EP_DblQuoted  0x0040  /* token.z was originally in "..." */
1716 #define EP_InfixFunc  0x0080  /* True for an infix function: LIKE, GLOB, etc */
1717 #define EP_ExpCollate 0x0100  /* Collating sequence specified explicitly */
1718 #define EP_FixedDest  0x0200  /* Result needed in a specific register */
1719 #define EP_IntValue   0x0400  /* Integer value contained in u.iValue */
1720 #define EP_xIsSelect  0x0800  /* x.pSelect is valid (otherwise x.pList is) */
1721 #define EP_Hint       0x1000  /* Optimizer hint. Not required for correctness */
1722 #define EP_Reduced    0x2000  /* Expr struct is EXPR_REDUCEDSIZE bytes only */
1723 #define EP_TokenOnly  0x4000  /* Expr struct is EXPR_TOKENONLYSIZE bytes only */
1724 #define EP_Static     0x8000  /* Held in memory not obtained from malloc() */
1725 
1726 /*
1727 ** The following are the meanings of bits in the Expr.flags2 field.
1728 */
1729 #define EP2_MallocedToken  0x0001  /* Need to sqlite3DbFree() Expr.zToken */
1730 #define EP2_Irreducible    0x0002  /* Cannot EXPRDUP_REDUCE this Expr */
1731 
1732 /*
1733 ** The pseudo-routine sqlite3ExprSetIrreducible sets the EP2_Irreducible
1734 ** flag on an expression structure.  This flag is used for VV&A only.  The
1735 ** routine is implemented as a macro that only works when in debugging mode,
1736 ** so as not to burden production code.
1737 */
1738 #ifdef SQLITE_DEBUG
1739 # define ExprSetIrreducible(X)  (X)->flags2 |= EP2_Irreducible
1740 #else
1741 # define ExprSetIrreducible(X)
1742 #endif
1743 
1744 /*
1745 ** These macros can be used to test, set, or clear bits in the
1746 ** Expr.flags field.
1747 */
1748 #define ExprHasProperty(E,P)     (((E)->flags&(P))==(P))
1749 #define ExprHasAnyProperty(E,P)  (((E)->flags&(P))!=0)
1750 #define ExprSetProperty(E,P)     (E)->flags|=(P)
1751 #define ExprClearProperty(E,P)   (E)->flags&=~(P)
1752 
1753 /*
1754 ** Macros to determine the number of bytes required by a normal Expr
1755 ** struct, an Expr struct with the EP_Reduced flag set in Expr.flags
1756 ** and an Expr struct with the EP_TokenOnly flag set.
1757 */
1758 #define EXPR_FULLSIZE           sizeof(Expr)           /* Full size */
1759 #define EXPR_REDUCEDSIZE        offsetof(Expr,iTable)  /* Common features */
1760 #define EXPR_TOKENONLYSIZE      offsetof(Expr,pLeft)   /* Fewer features */
1761 
1762 /*
1763 ** Flags passed to the sqlite3ExprDup() function. See the header comment
1764 ** above sqlite3ExprDup() for details.
1765 */
1766 #define EXPRDUP_REDUCE         0x0001  /* Used reduced-size Expr nodes */
1767 
1768 /*
1769 ** A list of expressions.  Each expression may optionally have a
1770 ** name.  An expr/name combination can be used in several ways, such
1771 ** as the list of "expr AS ID" fields following a "SELECT" or in the
1772 ** list of "ID = expr" items in an UPDATE.  A list of expressions can
1773 ** also be used as the argument to a function, in which case the a.zName
1774 ** field is not used.
1775 */
1776 struct ExprList {
1777   int nExpr;             /* Number of expressions on the list */
1778   int nAlloc;            /* Number of entries allocated below */
1779   int iECursor;          /* VDBE Cursor associated with this ExprList */
1780   struct ExprList_item {
1781     Expr *pExpr;           /* The list of expressions */
1782     char *zName;           /* Token associated with this expression */
1783     char *zSpan;           /* Original text of the expression */
1784     u8 sortOrder;          /* 1 for DESC or 0 for ASC */
1785     u8 done;               /* A flag to indicate when processing is finished */
1786     u16 iOrderByCol;       /* For ORDER BY, column number in result set */
1787     u16 iAlias;            /* Index into Parse.aAlias[] for zName */
1788   } *a;                  /* One entry for each expression */
1789 };
1790 
1791 /*
1792 ** An instance of this structure is used by the parser to record both
1793 ** the parse tree for an expression and the span of input text for an
1794 ** expression.
1795 */
1796 struct ExprSpan {
1797   Expr *pExpr;          /* The expression parse tree */
1798   const char *zStart;   /* First character of input text */
1799   const char *zEnd;     /* One character past the end of input text */
1800 };
1801 
1802 /*
1803 ** An instance of this structure can hold a simple list of identifiers,
1804 ** such as the list "a,b,c" in the following statements:
1805 **
1806 **      INSERT INTO t(a,b,c) VALUES ...;
1807 **      CREATE INDEX idx ON t(a,b,c);
1808 **      CREATE TRIGGER trig BEFORE UPDATE ON t(a,b,c) ...;
1809 **
1810 ** The IdList.a.idx field is used when the IdList represents the list of
1811 ** column names after a table name in an INSERT statement.  In the statement
1812 **
1813 **     INSERT INTO t(a,b,c) ...
1814 **
1815 ** If "a" is the k-th column of table "t", then IdList.a[0].idx==k.
1816 */
1817 struct IdList {
1818   struct IdList_item {
1819     char *zName;      /* Name of the identifier */
1820     int idx;          /* Index in some Table.aCol[] of a column named zName */
1821   } *a;
1822   int nId;         /* Number of identifiers on the list */
1823   int nAlloc;      /* Number of entries allocated for a[] below */
1824 };
1825 
1826 /*
1827 ** The bitmask datatype defined below is used for various optimizations.
1828 **
1829 ** Changing this from a 64-bit to a 32-bit type limits the number of
1830 ** tables in a join to 32 instead of 64.  But it also reduces the size
1831 ** of the library by 738 bytes on ix86.
1832 */
1833 typedef u64 Bitmask;
1834 
1835 /*
1836 ** The number of bits in a Bitmask.  "BMS" means "BitMask Size".
1837 */
1838 #define BMS  ((int)(sizeof(Bitmask)*8))
1839 
1840 /*
1841 ** The following structure describes the FROM clause of a SELECT statement.
1842 ** Each table or subquery in the FROM clause is a separate element of
1843 ** the SrcList.a[] array.
1844 **
1845 ** With the addition of multiple database support, the following structure
1846 ** can also be used to describe a particular table such as the table that
1847 ** is modified by an INSERT, DELETE, or UPDATE statement.  In standard SQL,
1848 ** such a table must be a simple name: ID.  But in SQLite, the table can
1849 ** now be identified by a database name, a dot, then the table name: ID.ID.
1850 **
1851 ** The jointype starts out showing the join type between the current table
1852 ** and the next table on the list.  The parser builds the list this way.
1853 ** But sqlite3SrcListShiftJoinType() later shifts the jointypes so that each
1854 ** jointype expresses the join between the table and the previous table.
1855 **
1856 ** In the colUsed field, the high-order bit (bit 63) is set if the table
1857 ** contains more than 63 columns and the 64-th or later column is used.
1858 */
1859 struct SrcList {
1860   i16 nSrc;        /* Number of tables or subqueries in the FROM clause */
1861   i16 nAlloc;      /* Number of entries allocated in a[] below */
1862   struct SrcList_item {
1863     char *zDatabase;  /* Name of database holding this table */
1864     char *zName;      /* Name of the table */
1865     char *zAlias;     /* The "B" part of a "A AS B" phrase.  zName is the "A" */
1866     Table *pTab;      /* An SQL table corresponding to zName */
1867     Select *pSelect;  /* A SELECT statement used in place of a table name */
1868     int addrFillSub;  /* Address of subroutine to manifest a subquery */
1869     int regReturn;    /* Register holding return address of addrFillSub */
1870     u8 jointype;      /* Type of join between this able and the previous */
1871     u8 notIndexed;    /* True if there is a NOT INDEXED clause */
1872     u8 isCorrelated;  /* True if sub-query is correlated */
1873 #ifndef SQLITE_OMIT_EXPLAIN
1874     u8 iSelectId;     /* If pSelect!=0, the id of the sub-select in EQP */
1875 #endif
1876     int iCursor;      /* The VDBE cursor number used to access this table */
1877     Expr *pOn;        /* The ON clause of a join */
1878     IdList *pUsing;   /* The USING clause of a join */
1879     Bitmask colUsed;  /* Bit N (1<<N) set if column N of pTab is used */
1880     char *zIndex;     /* Identifier from "INDEXED BY <zIndex>" clause */
1881     Index *pIndex;    /* Index structure corresponding to zIndex, if any */
1882   } a[1];             /* One entry for each identifier on the list */
1883 };
1884 
1885 /*
1886 ** Permitted values of the SrcList.a.jointype field
1887 */
1888 #define JT_INNER     0x0001    /* Any kind of inner or cross join */
1889 #define JT_CROSS     0x0002    /* Explicit use of the CROSS keyword */
1890 #define JT_NATURAL   0x0004    /* True for a "natural" join */
1891 #define JT_LEFT      0x0008    /* Left outer join */
1892 #define JT_RIGHT     0x0010    /* Right outer join */
1893 #define JT_OUTER     0x0020    /* The "OUTER" keyword is present */
1894 #define JT_ERROR     0x0040    /* unknown or unsupported join type */
1895 
1896 
1897 /*
1898 ** A WherePlan object holds information that describes a lookup
1899 ** strategy.
1900 **
1901 ** This object is intended to be opaque outside of the where.c module.
1902 ** It is included here only so that that compiler will know how big it
1903 ** is.  None of the fields in this object should be used outside of
1904 ** the where.c module.
1905 **
1906 ** Within the union, pIdx is only used when wsFlags&WHERE_INDEXED is true.
1907 ** pTerm is only used when wsFlags&WHERE_MULTI_OR is true.  And pVtabIdx
1908 ** is only used when wsFlags&WHERE_VIRTUALTABLE is true.  It is never the
1909 ** case that more than one of these conditions is true.
1910 */
1911 struct WherePlan {
1912   u32 wsFlags;                   /* WHERE_* flags that describe the strategy */
1913   u32 nEq;                       /* Number of == constraints */
1914   double nRow;                   /* Estimated number of rows (for EQP) */
1915   union {
1916     Index *pIdx;                   /* Index when WHERE_INDEXED is true */
1917     struct WhereTerm *pTerm;       /* WHERE clause term for OR-search */
1918     sqlite3_index_info *pVtabIdx;  /* Virtual table index to use */
1919   } u;
1920 };
1921 
1922 /*
1923 ** For each nested loop in a WHERE clause implementation, the WhereInfo
1924 ** structure contains a single instance of this structure.  This structure
1925 ** is intended to be private the the where.c module and should not be
1926 ** access or modified by other modules.
1927 **
1928 ** The pIdxInfo field is used to help pick the best index on a
1929 ** virtual table.  The pIdxInfo pointer contains indexing
1930 ** information for the i-th table in the FROM clause before reordering.
1931 ** All the pIdxInfo pointers are freed by whereInfoFree() in where.c.
1932 ** All other information in the i-th WhereLevel object for the i-th table
1933 ** after FROM clause ordering.
1934 */
1935 struct WhereLevel {
1936   WherePlan plan;       /* query plan for this element of the FROM clause */
1937   int iLeftJoin;        /* Memory cell used to implement LEFT OUTER JOIN */
1938   int iTabCur;          /* The VDBE cursor used to access the table */
1939   int iIdxCur;          /* The VDBE cursor used to access pIdx */
1940   int addrBrk;          /* Jump here to break out of the loop */
1941   int addrNxt;          /* Jump here to start the next IN combination */
1942   int addrCont;         /* Jump here to continue with the next loop cycle */
1943   int addrFirst;        /* First instruction of interior of the loop */
1944   u8 iFrom;             /* Which entry in the FROM clause */
1945   u8 op, p5;            /* Opcode and P5 of the opcode that ends the loop */
1946   int p1, p2;           /* Operands of the opcode used to ends the loop */
1947   union {               /* Information that depends on plan.wsFlags */
1948     struct {
1949       int nIn;              /* Number of entries in aInLoop[] */
1950       struct InLoop {
1951         int iCur;              /* The VDBE cursor used by this IN operator */
1952         int addrInTop;         /* Top of the IN loop */
1953       } *aInLoop;           /* Information about each nested IN operator */
1954     } in;                 /* Used when plan.wsFlags&WHERE_IN_ABLE */
1955   } u;
1956 
1957   /* The following field is really not part of the current level.  But
1958   ** we need a place to cache virtual table index information for each
1959   ** virtual table in the FROM clause and the WhereLevel structure is
1960   ** a convenient place since there is one WhereLevel for each FROM clause
1961   ** element.
1962   */
1963   sqlite3_index_info *pIdxInfo;  /* Index info for n-th source table */
1964 };
1965 
1966 /*
1967 ** Flags appropriate for the wctrlFlags parameter of sqlite3WhereBegin()
1968 ** and the WhereInfo.wctrlFlags member.
1969 */
1970 #define WHERE_ORDERBY_NORMAL   0x0000 /* No-op */
1971 #define WHERE_ORDERBY_MIN      0x0001 /* ORDER BY processing for min() func */
1972 #define WHERE_ORDERBY_MAX      0x0002 /* ORDER BY processing for max() func */
1973 #define WHERE_ONEPASS_DESIRED  0x0004 /* Want to do one-pass UPDATE/DELETE */
1974 #define WHERE_DUPLICATES_OK    0x0008 /* Ok to return a row more than once */
1975 #define WHERE_OMIT_OPEN_CLOSE  0x0010 /* Table cursors are already open */
1976 #define WHERE_FORCE_TABLE      0x0020 /* Do not use an index-only search */
1977 #define WHERE_ONETABLE_ONLY    0x0040 /* Only code the 1st table in pTabList */
1978 #define WHERE_AND_ONLY         0x0080 /* Don't use indices for OR terms */
1979 
1980 /*
1981 ** The WHERE clause processing routine has two halves.  The
1982 ** first part does the start of the WHERE loop and the second
1983 ** half does the tail of the WHERE loop.  An instance of
1984 ** this structure is returned by the first half and passed
1985 ** into the second half to give some continuity.
1986 */
1987 struct WhereInfo {
1988   Parse *pParse;       /* Parsing and code generating context */
1989   u16 wctrlFlags;      /* Flags originally passed to sqlite3WhereBegin() */
1990   u8 okOnePass;        /* Ok to use one-pass algorithm for UPDATE or DELETE */
1991   u8 untestedTerms;    /* Not all WHERE terms resolved by outer loop */
1992   u8 eDistinct;
1993   SrcList *pTabList;             /* List of tables in the join */
1994   int iTop;                      /* The very beginning of the WHERE loop */
1995   int iContinue;                 /* Jump here to continue with next record */
1996   int iBreak;                    /* Jump here to break out of the loop */
1997   int nLevel;                    /* Number of nested loop */
1998   struct WhereClause *pWC;       /* Decomposition of the WHERE clause */
1999   double savedNQueryLoop;        /* pParse->nQueryLoop outside the WHERE loop */
2000   double nRowOut;                /* Estimated number of output rows */
2001   WhereLevel a[1];               /* Information about each nest loop in WHERE */
2002 };
2003 
2004 #define WHERE_DISTINCT_UNIQUE 1
2005 #define WHERE_DISTINCT_ORDERED 2
2006 
2007 /*
2008 ** A NameContext defines a context in which to resolve table and column
2009 ** names.  The context consists of a list of tables (the pSrcList) field and
2010 ** a list of named expression (pEList).  The named expression list may
2011 ** be NULL.  The pSrc corresponds to the FROM clause of a SELECT or
2012 ** to the table being operated on by INSERT, UPDATE, or DELETE.  The
2013 ** pEList corresponds to the result set of a SELECT and is NULL for
2014 ** other statements.
2015 **
2016 ** NameContexts can be nested.  When resolving names, the inner-most
2017 ** context is searched first.  If no match is found, the next outer
2018 ** context is checked.  If there is still no match, the next context
2019 ** is checked.  This process continues until either a match is found
2020 ** or all contexts are check.  When a match is found, the nRef member of
2021 ** the context containing the match is incremented.
2022 **
2023 ** Each subquery gets a new NameContext.  The pNext field points to the
2024 ** NameContext in the parent query.  Thus the process of scanning the
2025 ** NameContext list corresponds to searching through successively outer
2026 ** subqueries looking for a match.
2027 */
2028 struct NameContext {
2029   Parse *pParse;       /* The parser */
2030   SrcList *pSrcList;   /* One or more tables used to resolve names */
2031   ExprList *pEList;    /* Optional list of named expressions */
2032   int nRef;            /* Number of names resolved by this context */
2033   int nErr;            /* Number of errors encountered while resolving names */
2034   u8 allowAgg;         /* Aggregate functions allowed here */
2035   u8 hasAgg;           /* True if aggregates are seen */
2036   u8 isCheck;          /* True if resolving names in a CHECK constraint */
2037   int nDepth;          /* Depth of subquery recursion. 1 for no recursion */
2038   AggInfo *pAggInfo;   /* Information about aggregates at this level */
2039   NameContext *pNext;  /* Next outer name context.  NULL for outermost */
2040 };
2041 
2042 /*
2043 ** An instance of the following structure contains all information
2044 ** needed to generate code for a single SELECT statement.
2045 **
2046 ** nLimit is set to -1 if there is no LIMIT clause.  nOffset is set to 0.
2047 ** If there is a LIMIT clause, the parser sets nLimit to the value of the
2048 ** limit and nOffset to the value of the offset (or 0 if there is not
2049 ** offset).  But later on, nLimit and nOffset become the memory locations
2050 ** in the VDBE that record the limit and offset counters.
2051 **
2052 ** addrOpenEphm[] entries contain the address of OP_OpenEphemeral opcodes.
2053 ** These addresses must be stored so that we can go back and fill in
2054 ** the P4_KEYINFO and P2 parameters later.  Neither the KeyInfo nor
2055 ** the number of columns in P2 can be computed at the same time
2056 ** as the OP_OpenEphm instruction is coded because not
2057 ** enough information about the compound query is known at that point.
2058 ** The KeyInfo for addrOpenTran[0] and [1] contains collating sequences
2059 ** for the result set.  The KeyInfo for addrOpenTran[2] contains collating
2060 ** sequences for the ORDER BY clause.
2061 */
2062 struct Select {
2063   ExprList *pEList;      /* The fields of the result */
2064   u8 op;                 /* One of: TK_UNION TK_ALL TK_INTERSECT TK_EXCEPT */
2065   char affinity;         /* MakeRecord with this affinity for SRT_Set */
2066   u16 selFlags;          /* Various SF_* values */
2067   SrcList *pSrc;         /* The FROM clause */
2068   Expr *pWhere;          /* The WHERE clause */
2069   ExprList *pGroupBy;    /* The GROUP BY clause */
2070   Expr *pHaving;         /* The HAVING clause */
2071   ExprList *pOrderBy;    /* The ORDER BY clause */
2072   Select *pPrior;        /* Prior select in a compound select statement */
2073   Select *pNext;         /* Next select to the left in a compound */
2074   Select *pRightmost;    /* Right-most select in a compound select statement */
2075   Expr *pLimit;          /* LIMIT expression. NULL means not used. */
2076   Expr *pOffset;         /* OFFSET expression. NULL means not used. */
2077   int iLimit, iOffset;   /* Memory registers holding LIMIT & OFFSET counters */
2078   int addrOpenEphm[3];   /* OP_OpenEphem opcodes related to this select */
2079   double nSelectRow;     /* Estimated number of result rows */
2080 };
2081 
2082 /*
2083 ** Allowed values for Select.selFlags.  The "SF" prefix stands for
2084 ** "Select Flag".
2085 */
2086 #define SF_Distinct        0x01  /* Output should be DISTINCT */
2087 #define SF_Resolved        0x02  /* Identifiers have been resolved */
2088 #define SF_Aggregate       0x04  /* Contains aggregate functions */
2089 #define SF_UsesEphemeral   0x08  /* Uses the OpenEphemeral opcode */
2090 #define SF_Expanded        0x10  /* sqlite3SelectExpand() called on this */
2091 #define SF_HasTypeInfo     0x20  /* FROM subqueries have Table metadata */
2092 #define SF_UseSorter       0x40  /* Sort using a sorter */
2093 
2094 
2095 /*
2096 ** The results of a select can be distributed in several ways.  The
2097 ** "SRT" prefix means "SELECT Result Type".
2098 */
2099 #define SRT_Union        1  /* Store result as keys in an index */
2100 #define SRT_Except       2  /* Remove result from a UNION index */
2101 #define SRT_Exists       3  /* Store 1 if the result is not empty */
2102 #define SRT_Discard      4  /* Do not save the results anywhere */
2103 
2104 /* The ORDER BY clause is ignored for all of the above */
2105 #define IgnorableOrderby(X) ((X->eDest)<=SRT_Discard)
2106 
2107 #define SRT_Output       5  /* Output each row of result */
2108 #define SRT_Mem          6  /* Store result in a memory cell */
2109 #define SRT_Set          7  /* Store results as keys in an index */
2110 #define SRT_Table        8  /* Store result as data with an automatic rowid */
2111 #define SRT_EphemTab     9  /* Create transient tab and store like SRT_Table */
2112 #define SRT_Coroutine   10  /* Generate a single row of result */
2113 
2114 /*
2115 ** A structure used to customize the behavior of sqlite3Select(). See
2116 ** comments above sqlite3Select() for details.
2117 */
2118 typedef struct SelectDest SelectDest;
2119 struct SelectDest {
2120   u8 eDest;         /* How to dispose of the results */
2121   u8 affinity;      /* Affinity used when eDest==SRT_Set */
2122   int iParm;        /* A parameter used by the eDest disposal method */
2123   int iMem;         /* Base register where results are written */
2124   int nMem;         /* Number of registers allocated */
2125 };
2126 
2127 /*
2128 ** During code generation of statements that do inserts into AUTOINCREMENT
2129 ** tables, the following information is attached to the Table.u.autoInc.p
2130 ** pointer of each autoincrement table to record some side information that
2131 ** the code generator needs.  We have to keep per-table autoincrement
2132 ** information in case inserts are down within triggers.  Triggers do not
2133 ** normally coordinate their activities, but we do need to coordinate the
2134 ** loading and saving of autoincrement information.
2135 */
2136 struct AutoincInfo {
2137   AutoincInfo *pNext;   /* Next info block in a list of them all */
2138   Table *pTab;          /* Table this info block refers to */
2139   int iDb;              /* Index in sqlite3.aDb[] of database holding pTab */
2140   int regCtr;           /* Memory register holding the rowid counter */
2141 };
2142 
2143 /*
2144 ** Size of the column cache
2145 */
2146 #ifndef SQLITE_N_COLCACHE
2147 # define SQLITE_N_COLCACHE 10
2148 #endif
2149 
2150 /*
2151 ** At least one instance of the following structure is created for each
2152 ** trigger that may be fired while parsing an INSERT, UPDATE or DELETE
2153 ** statement. All such objects are stored in the linked list headed at
2154 ** Parse.pTriggerPrg and deleted once statement compilation has been
2155 ** completed.
2156 **
2157 ** A Vdbe sub-program that implements the body and WHEN clause of trigger
2158 ** TriggerPrg.pTrigger, assuming a default ON CONFLICT clause of
2159 ** TriggerPrg.orconf, is stored in the TriggerPrg.pProgram variable.
2160 ** The Parse.pTriggerPrg list never contains two entries with the same
2161 ** values for both pTrigger and orconf.
2162 **
2163 ** The TriggerPrg.aColmask[0] variable is set to a mask of old.* columns
2164 ** accessed (or set to 0 for triggers fired as a result of INSERT
2165 ** statements). Similarly, the TriggerPrg.aColmask[1] variable is set to
2166 ** a mask of new.* columns used by the program.
2167 */
2168 struct TriggerPrg {
2169   Trigger *pTrigger;      /* Trigger this program was coded from */
2170   int orconf;             /* Default ON CONFLICT policy */
2171   SubProgram *pProgram;   /* Program implementing pTrigger/orconf */
2172   u32 aColmask[2];        /* Masks of old.*, new.* columns accessed */
2173   TriggerPrg *pNext;      /* Next entry in Parse.pTriggerPrg list */
2174 };
2175 
2176 /*
2177 ** The yDbMask datatype for the bitmask of all attached databases.
2178 */
2179 #if SQLITE_MAX_ATTACHED>30
2180   typedef sqlite3_uint64 yDbMask;
2181 #else
2182   typedef unsigned int yDbMask;
2183 #endif
2184 
2185 /*
2186 ** An SQL parser context.  A copy of this structure is passed through
2187 ** the parser and down into all the parser action routine in order to
2188 ** carry around information that is global to the entire parse.
2189 **
2190 ** The structure is divided into two parts.  When the parser and code
2191 ** generate call themselves recursively, the first part of the structure
2192 ** is constant but the second part is reset at the beginning and end of
2193 ** each recursion.
2194 **
2195 ** The nTableLock and aTableLock variables are only used if the shared-cache
2196 ** feature is enabled (if sqlite3Tsd()->useSharedData is true). They are
2197 ** used to store the set of table-locks required by the statement being
2198 ** compiled. Function sqlite3TableLock() is used to add entries to the
2199 ** list.
2200 */
2201 struct Parse {
2202   sqlite3 *db;         /* The main database structure */
2203   int rc;              /* Return code from execution */
2204   char *zErrMsg;       /* An error message */
2205   Vdbe *pVdbe;         /* An engine for executing database bytecode */
2206   u8 colNamesSet;      /* TRUE after OP_ColumnName has been issued to pVdbe */
2207   u8 checkSchema;      /* Causes schema cookie check after an error */
2208   u8 nested;           /* Number of nested calls to the parser/code generator */
2209   u8 nTempReg;         /* Number of temporary registers in aTempReg[] */
2210   u8 nTempInUse;       /* Number of aTempReg[] currently checked out */
2211   int aTempReg[8];     /* Holding area for temporary registers */
2212   int nRangeReg;       /* Size of the temporary register block */
2213   int iRangeReg;       /* First register in temporary register block */
2214   int nErr;            /* Number of errors seen */
2215   int nTab;            /* Number of previously allocated VDBE cursors */
2216   int nMem;            /* Number of memory cells used so far */
2217   int nSet;            /* Number of sets used so far */
2218   int nOnce;           /* Number of OP_Once instructions so far */
2219   int ckBase;          /* Base register of data during check constraints */
2220   int iCacheLevel;     /* ColCache valid when aColCache[].iLevel<=iCacheLevel */
2221   int iCacheCnt;       /* Counter used to generate aColCache[].lru values */
2222   u8 nColCache;        /* Number of entries in aColCache[] */
2223   u8 iColCache;        /* Next entry in aColCache[] to replace */
2224   struct yColCache {
2225     int iTable;           /* Table cursor number */
2226     int iColumn;          /* Table column number */
2227     u8 tempReg;           /* iReg is a temp register that needs to be freed */
2228     int iLevel;           /* Nesting level */
2229     int iReg;             /* Reg with value of this column. 0 means none. */
2230     int lru;              /* Least recently used entry has the smallest value */
2231   } aColCache[SQLITE_N_COLCACHE];  /* One for each column cache entry */
2232   yDbMask writeMask;   /* Start a write transaction on these databases */
2233   yDbMask cookieMask;  /* Bitmask of schema verified databases */
2234   u8 isMultiWrite;     /* True if statement may affect/insert multiple rows */
2235   u8 mayAbort;         /* True if statement may throw an ABORT exception */
2236   int cookieGoto;      /* Address of OP_Goto to cookie verifier subroutine */
2237   int cookieValue[SQLITE_MAX_ATTACHED+2];  /* Values of cookies to verify */
2238 #ifndef SQLITE_OMIT_SHARED_CACHE
2239   int nTableLock;        /* Number of locks in aTableLock */
2240   TableLock *aTableLock; /* Required table locks for shared-cache mode */
2241 #endif
2242   int regRowid;        /* Register holding rowid of CREATE TABLE entry */
2243   int regRoot;         /* Register holding root page number for new objects */
2244   AutoincInfo *pAinc;  /* Information about AUTOINCREMENT counters */
2245   int nMaxArg;         /* Max args passed to user function by sub-program */
2246 
2247   /* Information used while coding trigger programs. */
2248   Parse *pToplevel;    /* Parse structure for main program (or NULL) */
2249   Table *pTriggerTab;  /* Table triggers are being coded for */
2250   u32 oldmask;         /* Mask of old.* columns referenced */
2251   u32 newmask;         /* Mask of new.* columns referenced */
2252   u8 eTriggerOp;       /* TK_UPDATE, TK_INSERT or TK_DELETE */
2253   u8 eOrconf;          /* Default ON CONFLICT policy for trigger steps */
2254   u8 disableTriggers;  /* True to disable triggers */
2255   double nQueryLoop;   /* Estimated number of iterations of a query */
2256 
2257   /* Above is constant between recursions.  Below is reset before and after
2258   ** each recursion */
2259 
2260   int nVar;            /* Number of '?' variables seen in the SQL so far */
2261   int nzVar;           /* Number of available slots in azVar[] */
2262   char **azVar;        /* Pointers to names of parameters */
2263   Vdbe *pReprepare;    /* VM being reprepared (sqlite3Reprepare()) */
2264   int nAlias;          /* Number of aliased result set columns */
2265   int *aAlias;         /* Register used to hold aliased result */
2266   u8 explain;          /* True if the EXPLAIN flag is found on the query */
2267   Token sNameToken;    /* Token with unqualified schema object name */
2268   Token sLastToken;    /* The last token parsed */
2269   const char *zTail;   /* All SQL text past the last semicolon parsed */
2270   Table *pNewTable;    /* A table being constructed by CREATE TABLE */
2271   Trigger *pNewTrigger;     /* Trigger under construct by a CREATE TRIGGER */
2272   const char *zAuthContext; /* The 6th parameter to db->xAuth callbacks */
2273 #ifndef SQLITE_OMIT_VIRTUALTABLE
2274   Token sArg;                /* Complete text of a module argument */
2275   u8 declareVtab;            /* True if inside sqlite3_declare_vtab() */
2276   int nVtabLock;             /* Number of virtual tables to lock */
2277   Table **apVtabLock;        /* Pointer to virtual tables needing locking */
2278 #endif
2279   int nHeight;            /* Expression tree height of current sub-select */
2280   Table *pZombieTab;      /* List of Table objects to delete after code gen */
2281   TriggerPrg *pTriggerPrg;    /* Linked list of coded triggers */
2282 
2283 #ifndef SQLITE_OMIT_EXPLAIN
2284   int iSelectId;
2285   int iNextSelectId;
2286 #endif
2287 };
2288 
2289 #ifdef SQLITE_OMIT_VIRTUALTABLE
2290   #define IN_DECLARE_VTAB 0
2291 #else
2292   #define IN_DECLARE_VTAB (pParse->declareVtab)
2293 #endif
2294 
2295 /*
2296 ** An instance of the following structure can be declared on a stack and used
2297 ** to save the Parse.zAuthContext value so that it can be restored later.
2298 */
2299 struct AuthContext {
2300   const char *zAuthContext;   /* Put saved Parse.zAuthContext here */
2301   Parse *pParse;              /* The Parse structure */
2302 };
2303 
2304 /*
2305 ** Bitfield flags for P5 value in OP_Insert and OP_Delete
2306 */
2307 #define OPFLAG_NCHANGE       0x01    /* Set to update db->nChange */
2308 #define OPFLAG_LASTROWID     0x02    /* Set to update db->lastRowid */
2309 #define OPFLAG_ISUPDATE      0x04    /* This OP_Insert is an sql UPDATE */
2310 #define OPFLAG_APPEND        0x08    /* This is likely to be an append */
2311 #define OPFLAG_USESEEKRESULT 0x10    /* Try to avoid a seek in BtreeInsert() */
2312 #define OPFLAG_CLEARCACHE    0x20    /* Clear pseudo-table cache in OP_Column */
2313 
2314 /*
2315  * Each trigger present in the database schema is stored as an instance of
2316  * struct Trigger.
2317  *
2318  * Pointers to instances of struct Trigger are stored in two ways.
2319  * 1. In the "trigHash" hash table (part of the sqlite3* that represents the
2320  *    database). This allows Trigger structures to be retrieved by name.
2321  * 2. All triggers associated with a single table form a linked list, using the
2322  *    pNext member of struct Trigger. A pointer to the first element of the
2323  *    linked list is stored as the "pTrigger" member of the associated
2324  *    struct Table.
2325  *
2326  * The "step_list" member points to the first element of a linked list
2327  * containing the SQL statements specified as the trigger program.
2328  */
2329 struct Trigger {
2330   char *zName;            /* The name of the trigger                        */
2331   char *table;            /* The table or view to which the trigger applies */
2332   u8 op;                  /* One of TK_DELETE, TK_UPDATE, TK_INSERT         */
2333   u8 tr_tm;               /* One of TRIGGER_BEFORE, TRIGGER_AFTER */
2334   Expr *pWhen;            /* The WHEN clause of the expression (may be NULL) */
2335   IdList *pColumns;       /* If this is an UPDATE OF <column-list> trigger,
2336                              the <column-list> is stored here */
2337   Schema *pSchema;        /* Schema containing the trigger */
2338   Schema *pTabSchema;     /* Schema containing the table */
2339   TriggerStep *step_list; /* Link list of trigger program steps             */
2340   Trigger *pNext;         /* Next trigger associated with the table */
2341 };
2342 
2343 /*
2344 ** A trigger is either a BEFORE or an AFTER trigger.  The following constants
2345 ** determine which.
2346 **
2347 ** If there are multiple triggers, you might of some BEFORE and some AFTER.
2348 ** In that cases, the constants below can be ORed together.
2349 */
2350 #define TRIGGER_BEFORE  1
2351 #define TRIGGER_AFTER   2
2352 
2353 /*
2354  * An instance of struct TriggerStep is used to store a single SQL statement
2355  * that is a part of a trigger-program.
2356  *
2357  * Instances of struct TriggerStep are stored in a singly linked list (linked
2358  * using the "pNext" member) referenced by the "step_list" member of the
2359  * associated struct Trigger instance. The first element of the linked list is
2360  * the first step of the trigger-program.
2361  *
2362  * The "op" member indicates whether this is a "DELETE", "INSERT", "UPDATE" or
2363  * "SELECT" statement. The meanings of the other members is determined by the
2364  * value of "op" as follows:
2365  *
2366  * (op == TK_INSERT)
2367  * orconf    -> stores the ON CONFLICT algorithm
2368  * pSelect   -> If this is an INSERT INTO ... SELECT ... statement, then
2369  *              this stores a pointer to the SELECT statement. Otherwise NULL.
2370  * target    -> A token holding the quoted name of the table to insert into.
2371  * pExprList -> If this is an INSERT INTO ... VALUES ... statement, then
2372  *              this stores values to be inserted. Otherwise NULL.
2373  * pIdList   -> If this is an INSERT INTO ... (<column-names>) VALUES ...
2374  *              statement, then this stores the column-names to be
2375  *              inserted into.
2376  *
2377  * (op == TK_DELETE)
2378  * target    -> A token holding the quoted name of the table to delete from.
2379  * pWhere    -> The WHERE clause of the DELETE statement if one is specified.
2380  *              Otherwise NULL.
2381  *
2382  * (op == TK_UPDATE)
2383  * target    -> A token holding the quoted name of the table to update rows of.
2384  * pWhere    -> The WHERE clause of the UPDATE statement if one is specified.
2385  *              Otherwise NULL.
2386  * pExprList -> A list of the columns to update and the expressions to update
2387  *              them to. See sqlite3Update() documentation of "pChanges"
2388  *              argument.
2389  *
2390  */
2391 struct TriggerStep {
2392   u8 op;               /* One of TK_DELETE, TK_UPDATE, TK_INSERT, TK_SELECT */
2393   u8 orconf;           /* OE_Rollback etc. */
2394   Trigger *pTrig;      /* The trigger that this step is a part of */
2395   Select *pSelect;     /* SELECT statment or RHS of INSERT INTO .. SELECT ... */
2396   Token target;        /* Target table for DELETE, UPDATE, INSERT */
2397   Expr *pWhere;        /* The WHERE clause for DELETE or UPDATE steps */
2398   ExprList *pExprList; /* SET clause for UPDATE.  VALUES clause for INSERT */
2399   IdList *pIdList;     /* Column names for INSERT */
2400   TriggerStep *pNext;  /* Next in the link-list */
2401   TriggerStep *pLast;  /* Last element in link-list. Valid for 1st elem only */
2402 };
2403 
2404 /*
2405 ** The following structure contains information used by the sqliteFix...
2406 ** routines as they walk the parse tree to make database references
2407 ** explicit.
2408 */
2409 typedef struct DbFixer DbFixer;
2410 struct DbFixer {
2411   Parse *pParse;      /* The parsing context.  Error messages written here */
2412   const char *zDb;    /* Make sure all objects are contained in this database */
2413   const char *zType;  /* Type of the container - used for error messages */
2414   const Token *pName; /* Name of the container - used for error messages */
2415 };
2416 
2417 /*
2418 ** An objected used to accumulate the text of a string where we
2419 ** do not necessarily know how big the string will be in the end.
2420 */
2421 struct StrAccum {
2422   sqlite3 *db;         /* Optional database for lookaside.  Can be NULL */
2423   char *zBase;         /* A base allocation.  Not from malloc. */
2424   char *zText;         /* The string collected so far */
2425   int  nChar;          /* Length of the string so far */
2426   int  nAlloc;         /* Amount of space allocated in zText */
2427   int  mxAlloc;        /* Maximum allowed string length */
2428   u8   mallocFailed;   /* Becomes true if any memory allocation fails */
2429   u8   useMalloc;      /* 0: none,  1: sqlite3DbMalloc,  2: sqlite3_malloc */
2430   u8   tooBig;         /* Becomes true if string size exceeds limits */
2431 };
2432 
2433 /*
2434 ** A pointer to this structure is used to communicate information
2435 ** from sqlite3Init and OP_ParseSchema into the sqlite3InitCallback.
2436 */
2437 typedef struct {
2438   sqlite3 *db;        /* The database being initialized */
2439   int iDb;            /* 0 for main database.  1 for TEMP, 2.. for ATTACHed */
2440   char **pzErrMsg;    /* Error message stored here */
2441   int rc;             /* Result code stored here */
2442 } InitData;
2443 
2444 /*
2445 ** Structure containing global configuration data for the SQLite library.
2446 **
2447 ** This structure also contains some state information.
2448 */
2449 struct Sqlite3Config {
2450   int bMemstat;                     /* True to enable memory status */
2451   int bCoreMutex;                   /* True to enable core mutexing */
2452   int bFullMutex;                   /* True to enable full mutexing */
2453   int bOpenUri;                     /* True to interpret filenames as URIs */
2454   int mxStrlen;                     /* Maximum string length */
2455   int szLookaside;                  /* Default lookaside buffer size */
2456   int nLookaside;                   /* Default lookaside buffer count */
2457   sqlite3_mem_methods m;            /* Low-level memory allocation interface */
2458   sqlite3_mutex_methods mutex;      /* Low-level mutex interface */
2459   sqlite3_pcache_methods2 pcache2;  /* Low-level page-cache interface */
2460   void *pHeap;                      /* Heap storage space */
2461   int nHeap;                        /* Size of pHeap[] */
2462   int mnReq, mxReq;                 /* Min and max heap requests sizes */
2463   void *pScratch;                   /* Scratch memory */
2464   int szScratch;                    /* Size of each scratch buffer */
2465   int nScratch;                     /* Number of scratch buffers */
2466   void *pPage;                      /* Page cache memory */
2467   int szPage;                       /* Size of each page in pPage[] */
2468   int nPage;                        /* Number of pages in pPage[] */
2469   int mxParserStack;                /* maximum depth of the parser stack */
2470   int sharedCacheEnabled;           /* true if shared-cache mode enabled */
2471   /* The above might be initialized to non-zero.  The following need to always
2472   ** initially be zero, however. */
2473   int isInit;                       /* True after initialization has finished */
2474   int inProgress;                   /* True while initialization in progress */
2475   int isMutexInit;                  /* True after mutexes are initialized */
2476   int isMallocInit;                 /* True after malloc is initialized */
2477   int isPCacheInit;                 /* True after malloc is initialized */
2478   sqlite3_mutex *pInitMutex;        /* Mutex used by sqlite3_initialize() */
2479   int nRefInitMutex;                /* Number of users of pInitMutex */
2480   void (*xLog)(void*,int,const char*); /* Function for logging */
2481   void *pLogArg;                       /* First argument to xLog() */
2482   int bLocaltimeFault;              /* True to fail localtime() calls */
2483 };
2484 
2485 /*
2486 ** Context pointer passed down through the tree-walk.
2487 */
2488 struct Walker {
2489   int (*xExprCallback)(Walker*, Expr*);     /* Callback for expressions */
2490   int (*xSelectCallback)(Walker*,Select*);  /* Callback for SELECTs */
2491   Parse *pParse;                            /* Parser context.  */
2492   union {                                   /* Extra data for callback */
2493     NameContext *pNC;                          /* Naming context */
2494     int i;                                     /* Integer value */
2495   } u;
2496 };
2497 
2498 /* Forward declarations */
2499 int sqlite3WalkExpr(Walker*, Expr*);
2500 int sqlite3WalkExprList(Walker*, ExprList*);
2501 int sqlite3WalkSelect(Walker*, Select*);
2502 int sqlite3WalkSelectExpr(Walker*, Select*);
2503 int sqlite3WalkSelectFrom(Walker*, Select*);
2504 
2505 /*
2506 ** Return code from the parse-tree walking primitives and their
2507 ** callbacks.
2508 */
2509 #define WRC_Continue    0   /* Continue down into children */
2510 #define WRC_Prune       1   /* Omit children but continue walking siblings */
2511 #define WRC_Abort       2   /* Abandon the tree walk */
2512 
2513 /*
2514 ** Assuming zIn points to the first byte of a UTF-8 character,
2515 ** advance zIn to point to the first byte of the next UTF-8 character.
2516 */
2517 #define SQLITE_SKIP_UTF8(zIn) {                        \
2518   if( (*(zIn++))>=0xc0 ){                              \
2519     while( (*zIn & 0xc0)==0x80 ){ zIn++; }             \
2520   }                                                    \
2521 }
2522 
2523 /*
2524 ** The SQLITE_*_BKPT macros are substitutes for the error codes with
2525 ** the same name but without the _BKPT suffix.  These macros invoke
2526 ** routines that report the line-number on which the error originated
2527 ** using sqlite3_log().  The routines also provide a convenient place
2528 ** to set a debugger breakpoint.
2529 */
2530 int sqlite3CorruptError(int);
2531 int sqlite3MisuseError(int);
2532 int sqlite3CantopenError(int);
2533 #define SQLITE_CORRUPT_BKPT sqlite3CorruptError(__LINE__)
2534 #define SQLITE_MISUSE_BKPT sqlite3MisuseError(__LINE__)
2535 #define SQLITE_CANTOPEN_BKPT sqlite3CantopenError(__LINE__)
2536 
2537 
2538 /*
2539 ** FTS4 is really an extension for FTS3.  It is enabled using the
2540 ** SQLITE_ENABLE_FTS3 macro.  But to avoid confusion we also all
2541 ** the SQLITE_ENABLE_FTS4 macro to serve as an alisse for SQLITE_ENABLE_FTS3.
2542 */
2543 #if defined(SQLITE_ENABLE_FTS4) && !defined(SQLITE_ENABLE_FTS3)
2544 # define SQLITE_ENABLE_FTS3
2545 #endif
2546 
2547 /*
2548 ** The ctype.h header is needed for non-ASCII systems.  It is also
2549 ** needed by FTS3 when FTS3 is included in the amalgamation.
2550 */
2551 #if !defined(SQLITE_ASCII) || \
2552     (defined(SQLITE_ENABLE_FTS3) && defined(SQLITE_AMALGAMATION))
2553 # include <ctype.h>
2554 #endif
2555 
2556 /*
2557 ** The following macros mimic the standard library functions toupper(),
2558 ** isspace(), isalnum(), isdigit() and isxdigit(), respectively. The
2559 ** sqlite versions only work for ASCII characters, regardless of locale.
2560 */
2561 #ifdef SQLITE_ASCII
2562 # define sqlite3Toupper(x)  ((x)&~(sqlite3CtypeMap[(unsigned char)(x)]&0x20))
2563 # define sqlite3Isspace(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x01)
2564 # define sqlite3Isalnum(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x06)
2565 # define sqlite3Isalpha(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x02)
2566 # define sqlite3Isdigit(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x04)
2567 # define sqlite3Isxdigit(x)  (sqlite3CtypeMap[(unsigned char)(x)]&0x08)
2568 # define sqlite3Tolower(x)   (sqlite3UpperToLower[(unsigned char)(x)])
2569 #else
2570 # define sqlite3Toupper(x)   toupper((unsigned char)(x))
2571 # define sqlite3Isspace(x)   isspace((unsigned char)(x))
2572 # define sqlite3Isalnum(x)   isalnum((unsigned char)(x))
2573 # define sqlite3Isalpha(x)   isalpha((unsigned char)(x))
2574 # define sqlite3Isdigit(x)   isdigit((unsigned char)(x))
2575 # define sqlite3Isxdigit(x)  isxdigit((unsigned char)(x))
2576 # define sqlite3Tolower(x)   tolower((unsigned char)(x))
2577 #endif
2578 
2579 /*
2580 ** Internal function prototypes
2581 */
2582 int sqlite3StrICmp(const char *, const char *);
2583 int sqlite3Strlen30(const char*);
2584 #define sqlite3StrNICmp sqlite3_strnicmp
2585 
2586 int sqlite3MallocInit(void);
2587 void sqlite3MallocEnd(void);
2588 void *sqlite3Malloc(int);
2589 void *sqlite3MallocZero(int);
2590 void *sqlite3DbMallocZero(sqlite3*, int);
2591 void *sqlite3DbMallocRaw(sqlite3*, int);
2592 char *sqlite3DbStrDup(sqlite3*,const char*);
2593 char *sqlite3DbStrNDup(sqlite3*,const char*, int);
2594 void *sqlite3Realloc(void*, int);
2595 void *sqlite3DbReallocOrFree(sqlite3 *, void *, int);
2596 void *sqlite3DbRealloc(sqlite3 *, void *, int);
2597 void sqlite3DbFree(sqlite3*, void*);
2598 int sqlite3MallocSize(void*);
2599 int sqlite3DbMallocSize(sqlite3*, void*);
2600 void *sqlite3ScratchMalloc(int);
2601 void sqlite3ScratchFree(void*);
2602 void *sqlite3PageMalloc(int);
2603 void sqlite3PageFree(void*);
2604 void sqlite3MemSetDefault(void);
2605 void sqlite3BenignMallocHooks(void (*)(void), void (*)(void));
2606 int sqlite3HeapNearlyFull(void);
2607 
2608 /*
2609 ** On systems with ample stack space and that support alloca(), make
2610 ** use of alloca() to obtain space for large automatic objects.  By default,
2611 ** obtain space from malloc().
2612 **
2613 ** The alloca() routine never returns NULL.  This will cause code paths
2614 ** that deal with sqlite3StackAlloc() failures to be unreachable.
2615 */
2616 #ifdef SQLITE_USE_ALLOCA
2617 # define sqlite3StackAllocRaw(D,N)   alloca(N)
2618 # define sqlite3StackAllocZero(D,N)  memset(alloca(N), 0, N)
2619 # define sqlite3StackFree(D,P)
2620 #else
2621 # define sqlite3StackAllocRaw(D,N)   sqlite3DbMallocRaw(D,N)
2622 # define sqlite3StackAllocZero(D,N)  sqlite3DbMallocZero(D,N)
2623 # define sqlite3StackFree(D,P)       sqlite3DbFree(D,P)
2624 #endif
2625 
2626 #ifdef SQLITE_ENABLE_MEMSYS3
2627 const sqlite3_mem_methods *sqlite3MemGetMemsys3(void);
2628 #endif
2629 #ifdef SQLITE_ENABLE_MEMSYS5
2630 const sqlite3_mem_methods *sqlite3MemGetMemsys5(void);
2631 #endif
2632 
2633 
2634 #ifndef SQLITE_MUTEX_OMIT
2635   sqlite3_mutex_methods const *sqlite3DefaultMutex(void);
2636   sqlite3_mutex_methods const *sqlite3NoopMutex(void);
2637   sqlite3_mutex *sqlite3MutexAlloc(int);
2638   int sqlite3MutexInit(void);
2639   int sqlite3MutexEnd(void);
2640 #endif
2641 
2642 int sqlite3StatusValue(int);
2643 void sqlite3StatusAdd(int, int);
2644 void sqlite3StatusSet(int, int);
2645 
2646 #ifndef SQLITE_OMIT_FLOATING_POINT
2647   int sqlite3IsNaN(double);
2648 #else
2649 # define sqlite3IsNaN(X)  0
2650 #endif
2651 
2652 void sqlite3VXPrintf(StrAccum*, int, const char*, va_list);
2653 #ifndef SQLITE_OMIT_TRACE
2654 void sqlite3XPrintf(StrAccum*, const char*, ...);
2655 #endif
2656 char *sqlite3MPrintf(sqlite3*,const char*, ...);
2657 char *sqlite3VMPrintf(sqlite3*,const char*, va_list);
2658 char *sqlite3MAppendf(sqlite3*,char*,const char*,...);
2659 #if defined(SQLITE_TEST) || defined(SQLITE_DEBUG)
2660   void sqlite3DebugPrintf(const char*, ...);
2661 #endif
2662 #if defined(SQLITE_TEST)
2663   void *sqlite3TestTextToPtr(const char*);
2664 #endif
2665 
2666 /* Output formatting for SQLITE_TESTCTRL_EXPLAIN */
2667 #if defined(SQLITE_ENABLE_TREE_EXPLAIN)
2668   void sqlite3ExplainBegin(Vdbe*);
2669   void sqlite3ExplainPrintf(Vdbe*, const char*, ...);
2670   void sqlite3ExplainNL(Vdbe*);
2671   void sqlite3ExplainPush(Vdbe*);
2672   void sqlite3ExplainPop(Vdbe*);
2673   void sqlite3ExplainFinish(Vdbe*);
2674   void sqlite3ExplainSelect(Vdbe*, Select*);
2675   void sqlite3ExplainExpr(Vdbe*, Expr*);
2676   void sqlite3ExplainExprList(Vdbe*, ExprList*);
2677   const char *sqlite3VdbeExplanation(Vdbe*);
2678 #else
2679 # define sqlite3ExplainBegin(X)
2680 # define sqlite3ExplainSelect(A,B)
2681 # define sqlite3ExplainExpr(A,B)
2682 # define sqlite3ExplainExprList(A,B)
2683 # define sqlite3ExplainFinish(X)
2684 # define sqlite3VdbeExplanation(X) 0
2685 #endif
2686 
2687 
2688 void sqlite3SetString(char **, sqlite3*, const char*, ...);
2689 void sqlite3ErrorMsg(Parse*, const char*, ...);
2690 int sqlite3Dequote(char*);
2691 int sqlite3KeywordCode(const unsigned char*, int);
2692 int sqlite3RunParser(Parse*, const char*, char **);
2693 void sqlite3FinishCoding(Parse*);
2694 int sqlite3GetTempReg(Parse*);
2695 void sqlite3ReleaseTempReg(Parse*,int);
2696 int sqlite3GetTempRange(Parse*,int);
2697 void sqlite3ReleaseTempRange(Parse*,int,int);
2698 void sqlite3ClearTempRegCache(Parse*);
2699 Expr *sqlite3ExprAlloc(sqlite3*,int,const Token*,int);
2700 Expr *sqlite3Expr(sqlite3*,int,const char*);
2701 void sqlite3ExprAttachSubtrees(sqlite3*,Expr*,Expr*,Expr*);
2702 Expr *sqlite3PExpr(Parse*, int, Expr*, Expr*, const Token*);
2703 Expr *sqlite3ExprAnd(sqlite3*,Expr*, Expr*);
2704 Expr *sqlite3ExprFunction(Parse*,ExprList*, Token*);
2705 void sqlite3ExprAssignVarNumber(Parse*, Expr*);
2706 void sqlite3ExprDelete(sqlite3*, Expr*);
2707 ExprList *sqlite3ExprListAppend(Parse*,ExprList*,Expr*);
2708 void sqlite3ExprListSetName(Parse*,ExprList*,Token*,int);
2709 void sqlite3ExprListSetSpan(Parse*,ExprList*,ExprSpan*);
2710 void sqlite3ExprListDelete(sqlite3*, ExprList*);
2711 int sqlite3Init(sqlite3*, char**);
2712 int sqlite3InitCallback(void*, int, char**, char**);
2713 void sqlite3Pragma(Parse*,Token*,Token*,Token*,int);
2714 void sqlite3ResetInternalSchema(sqlite3*, int);
2715 void sqlite3BeginParse(Parse*,int);
2716 void sqlite3CommitInternalChanges(sqlite3*);
2717 Table *sqlite3ResultSetOfSelect(Parse*,Select*);
2718 void sqlite3OpenMasterTable(Parse *, int);
2719 void sqlite3StartTable(Parse*,Token*,Token*,int,int,int,int);
2720 void sqlite3AddColumn(Parse*,Token*);
2721 void sqlite3AddNotNull(Parse*, int);
2722 void sqlite3AddPrimaryKey(Parse*, ExprList*, int, int, int);
2723 void sqlite3AddCheckConstraint(Parse*, Expr*);
2724 void sqlite3AddColumnType(Parse*,Token*);
2725 void sqlite3AddDefaultValue(Parse*,ExprSpan*);
2726 void sqlite3AddCollateType(Parse*, Token*);
2727 void sqlite3EndTable(Parse*,Token*,Token*,Select*);
2728 int sqlite3ParseUri(const char*,const char*,unsigned int*,
2729                     sqlite3_vfs**,char**,char **);
2730 int sqlite3CodeOnce(Parse *);
2731 
2732 Bitvec *sqlite3BitvecCreate(u32);
2733 int sqlite3BitvecTest(Bitvec*, u32);
2734 int sqlite3BitvecSet(Bitvec*, u32);
2735 void sqlite3BitvecClear(Bitvec*, u32, void*);
2736 void sqlite3BitvecDestroy(Bitvec*);
2737 u32 sqlite3BitvecSize(Bitvec*);
2738 int sqlite3BitvecBuiltinTest(int,int*);
2739 
2740 RowSet *sqlite3RowSetInit(sqlite3*, void*, unsigned int);
2741 void sqlite3RowSetClear(RowSet*);
2742 void sqlite3RowSetInsert(RowSet*, i64);
2743 int sqlite3RowSetTest(RowSet*, u8 iBatch, i64);
2744 int sqlite3RowSetNext(RowSet*, i64*);
2745 
2746 void sqlite3CreateView(Parse*,Token*,Token*,Token*,Select*,int,int);
2747 
2748 #if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE)
2749   int sqlite3ViewGetColumnNames(Parse*,Table*);
2750 #else
2751 # define sqlite3ViewGetColumnNames(A,B) 0
2752 #endif
2753 
2754 void sqlite3DropTable(Parse*, SrcList*, int, int);
2755 void sqlite3CodeDropTable(Parse*, Table*, int, int);
2756 void sqlite3DeleteTable(sqlite3*, Table*);
2757 #ifndef SQLITE_OMIT_AUTOINCREMENT
2758   void sqlite3AutoincrementBegin(Parse *pParse);
2759   void sqlite3AutoincrementEnd(Parse *pParse);
2760 #else
2761 # define sqlite3AutoincrementBegin(X)
2762 # define sqlite3AutoincrementEnd(X)
2763 #endif
2764 void sqlite3Insert(Parse*, SrcList*, ExprList*, Select*, IdList*, int);
2765 void *sqlite3ArrayAllocate(sqlite3*,void*,int,int,int*,int*,int*);
2766 IdList *sqlite3IdListAppend(sqlite3*, IdList*, Token*);
2767 int sqlite3IdListIndex(IdList*,const char*);
2768 SrcList *sqlite3SrcListEnlarge(sqlite3*, SrcList*, int, int);
2769 SrcList *sqlite3SrcListAppend(sqlite3*, SrcList*, Token*, Token*);
2770 SrcList *sqlite3SrcListAppendFromTerm(Parse*, SrcList*, Token*, Token*,
2771                                       Token*, Select*, Expr*, IdList*);
2772 void sqlite3SrcListIndexedBy(Parse *, SrcList *, Token *);
2773 int sqlite3IndexedByLookup(Parse *, struct SrcList_item *);
2774 void sqlite3SrcListShiftJoinType(SrcList*);
2775 void sqlite3SrcListAssignCursors(Parse*, SrcList*);
2776 void sqlite3IdListDelete(sqlite3*, IdList*);
2777 void sqlite3SrcListDelete(sqlite3*, SrcList*);
2778 Index *sqlite3CreateIndex(Parse*,Token*,Token*,SrcList*,ExprList*,int,Token*,
2779                         Token*, int, int);
2780 void sqlite3DropIndex(Parse*, SrcList*, int);
2781 int sqlite3Select(Parse*, Select*, SelectDest*);
2782 Select *sqlite3SelectNew(Parse*,ExprList*,SrcList*,Expr*,ExprList*,
2783                          Expr*,ExprList*,int,Expr*,Expr*);
2784 void sqlite3SelectDelete(sqlite3*, Select*);
2785 Table *sqlite3SrcListLookup(Parse*, SrcList*);
2786 int sqlite3IsReadOnly(Parse*, Table*, int);
2787 void sqlite3OpenTable(Parse*, int iCur, int iDb, Table*, int);
2788 #if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY)
2789 Expr *sqlite3LimitWhere(Parse *, SrcList *, Expr *, ExprList *, Expr *, Expr *, char *);
2790 #endif
2791 void sqlite3DeleteFrom(Parse*, SrcList*, Expr*);
2792 void sqlite3Update(Parse*, SrcList*, ExprList*, Expr*, int);
2793 WhereInfo *sqlite3WhereBegin(Parse*, SrcList*, Expr*, ExprList**,ExprList*,u16);
2794 void sqlite3WhereEnd(WhereInfo*);
2795 int sqlite3ExprCodeGetColumn(Parse*, Table*, int, int, int);
2796 void sqlite3ExprCodeGetColumnOfTable(Vdbe*, Table*, int, int, int);
2797 void sqlite3ExprCodeMove(Parse*, int, int, int);
2798 void sqlite3ExprCodeCopy(Parse*, int, int, int);
2799 void sqlite3ExprCacheStore(Parse*, int, int, int);
2800 void sqlite3ExprCachePush(Parse*);
2801 void sqlite3ExprCachePop(Parse*, int);
2802 void sqlite3ExprCacheRemove(Parse*, int, int);
2803 void sqlite3ExprCacheClear(Parse*);
2804 void sqlite3ExprCacheAffinityChange(Parse*, int, int);
2805 int sqlite3ExprCode(Parse*, Expr*, int);
2806 int sqlite3ExprCodeTemp(Parse*, Expr*, int*);
2807 int sqlite3ExprCodeTarget(Parse*, Expr*, int);
2808 int sqlite3ExprCodeAndCache(Parse*, Expr*, int);
2809 void sqlite3ExprCodeConstants(Parse*, Expr*);
2810 int sqlite3ExprCodeExprList(Parse*, ExprList*, int, int);
2811 void sqlite3ExprIfTrue(Parse*, Expr*, int, int);
2812 void sqlite3ExprIfFalse(Parse*, Expr*, int, int);
2813 Table *sqlite3FindTable(sqlite3*,const char*, const char*);
2814 Table *sqlite3LocateTable(Parse*,int isView,const char*, const char*);
2815 Index *sqlite3FindIndex(sqlite3*,const char*, const char*);
2816 void sqlite3UnlinkAndDeleteTable(sqlite3*,int,const char*);
2817 void sqlite3UnlinkAndDeleteIndex(sqlite3*,int,const char*);
2818 void sqlite3Vacuum(Parse*);
2819 int sqlite3RunVacuum(char**, sqlite3*);
2820 char *sqlite3NameFromToken(sqlite3*, Token*);
2821 int sqlite3ExprCompare(Expr*, Expr*);
2822 int sqlite3ExprListCompare(ExprList*, ExprList*);
2823 void sqlite3ExprAnalyzeAggregates(NameContext*, Expr*);
2824 void sqlite3ExprAnalyzeAggList(NameContext*,ExprList*);
2825 Vdbe *sqlite3GetVdbe(Parse*);
2826 void sqlite3PrngSaveState(void);
2827 void sqlite3PrngRestoreState(void);
2828 void sqlite3PrngResetState(void);
2829 void sqlite3RollbackAll(sqlite3*);
2830 void sqlite3CodeVerifySchema(Parse*, int);
2831 void sqlite3CodeVerifyNamedSchema(Parse*, const char *zDb);
2832 void sqlite3BeginTransaction(Parse*, int);
2833 void sqlite3CommitTransaction(Parse*);
2834 void sqlite3RollbackTransaction(Parse*);
2835 void sqlite3Savepoint(Parse*, int, Token*);
2836 void sqlite3CloseSavepoints(sqlite3 *);
2837 int sqlite3ExprIsConstant(Expr*);
2838 int sqlite3ExprIsConstantNotJoin(Expr*);
2839 int sqlite3ExprIsConstantOrFunction(Expr*);
2840 int sqlite3ExprIsInteger(Expr*, int*);
2841 int sqlite3ExprCanBeNull(const Expr*);
2842 void sqlite3ExprCodeIsNullJump(Vdbe*, const Expr*, int, int);
2843 int sqlite3ExprNeedsNoAffinityChange(const Expr*, char);
2844 int sqlite3IsRowid(const char*);
2845 void sqlite3GenerateRowDelete(Parse*, Table*, int, int, int, Trigger *, int);
2846 void sqlite3GenerateRowIndexDelete(Parse*, Table*, int, int*);
2847 int sqlite3GenerateIndexKey(Parse*, Index*, int, int, int);
2848 void sqlite3GenerateConstraintChecks(Parse*,Table*,int,int,
2849                                      int*,int,int,int,int,int*);
2850 void sqlite3CompleteInsertion(Parse*, Table*, int, int, int*, int, int, int);
2851 int sqlite3OpenTableAndIndices(Parse*, Table*, int, int);
2852 void sqlite3BeginWriteOperation(Parse*, int, int);
2853 void sqlite3MultiWrite(Parse*);
2854 void sqlite3MayAbort(Parse*);
2855 void sqlite3HaltConstraint(Parse*, int, char*, int);
2856 Expr *sqlite3ExprDup(sqlite3*,Expr*,int);
2857 ExprList *sqlite3ExprListDup(sqlite3*,ExprList*,int);
2858 SrcList *sqlite3SrcListDup(sqlite3*,SrcList*,int);
2859 IdList *sqlite3IdListDup(sqlite3*,IdList*);
2860 Select *sqlite3SelectDup(sqlite3*,Select*,int);
2861 void sqlite3FuncDefInsert(FuncDefHash*, FuncDef*);
2862 FuncDef *sqlite3FindFunction(sqlite3*,const char*,int,int,u8,int);
2863 void sqlite3RegisterBuiltinFunctions(sqlite3*);
2864 void sqlite3RegisterDateTimeFunctions(void);
2865 void sqlite3RegisterGlobalFunctions(void);
2866 int sqlite3SafetyCheckOk(sqlite3*);
2867 int sqlite3SafetyCheckSickOrOk(sqlite3*);
2868 void sqlite3ChangeCookie(Parse*, int);
2869 
2870 #if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
2871 void sqlite3MaterializeView(Parse*, Table*, Expr*, int);
2872 #endif
2873 
2874 #ifndef SQLITE_OMIT_TRIGGER
2875   void sqlite3BeginTrigger(Parse*, Token*,Token*,int,int,IdList*,SrcList*,
2876                            Expr*,int, int);
2877   void sqlite3FinishTrigger(Parse*, TriggerStep*, Token*);
2878   void sqlite3DropTrigger(Parse*, SrcList*, int);
2879   void sqlite3DropTriggerPtr(Parse*, Trigger*);
2880   Trigger *sqlite3TriggersExist(Parse *, Table*, int, ExprList*, int *pMask);
2881   Trigger *sqlite3TriggerList(Parse *, Table *);
2882   void sqlite3CodeRowTrigger(Parse*, Trigger *, int, ExprList*, int, Table *,
2883                             int, int, int);
2884   void sqlite3CodeRowTriggerDirect(Parse *, Trigger *, Table *, int, int, int);
2885   void sqliteViewTriggers(Parse*, Table*, Expr*, int, ExprList*);
2886   void sqlite3DeleteTriggerStep(sqlite3*, TriggerStep*);
2887   TriggerStep *sqlite3TriggerSelectStep(sqlite3*,Select*);
2888   TriggerStep *sqlite3TriggerInsertStep(sqlite3*,Token*, IdList*,
2889                                         ExprList*,Select*,u8);
2890   TriggerStep *sqlite3TriggerUpdateStep(sqlite3*,Token*,ExprList*, Expr*, u8);
2891   TriggerStep *sqlite3TriggerDeleteStep(sqlite3*,Token*, Expr*);
2892   void sqlite3DeleteTrigger(sqlite3*, Trigger*);
2893   void sqlite3UnlinkAndDeleteTrigger(sqlite3*,int,const char*);
2894   u32 sqlite3TriggerColmask(Parse*,Trigger*,ExprList*,int,int,Table*,int);
2895 # define sqlite3ParseToplevel(p) ((p)->pToplevel ? (p)->pToplevel : (p))
2896 #else
2897 # define sqlite3TriggersExist(B,C,D,E,F) 0
2898 # define sqlite3DeleteTrigger(A,B)
2899 # define sqlite3DropTriggerPtr(A,B)
2900 # define sqlite3UnlinkAndDeleteTrigger(A,B,C)
2901 # define sqlite3CodeRowTrigger(A,B,C,D,E,F,G,H,I)
2902 # define sqlite3CodeRowTriggerDirect(A,B,C,D,E,F)
2903 # define sqlite3TriggerList(X, Y) 0
2904 # define sqlite3ParseToplevel(p) p
2905 # define sqlite3TriggerColmask(A,B,C,D,E,F,G) 0
2906 #endif
2907 
2908 int sqlite3JoinType(Parse*, Token*, Token*, Token*);
2909 void sqlite3CreateForeignKey(Parse*, ExprList*, Token*, ExprList*, int);
2910 void sqlite3DeferForeignKey(Parse*, int);
2911 #ifndef SQLITE_OMIT_AUTHORIZATION
2912   void sqlite3AuthRead(Parse*,Expr*,Schema*,SrcList*);
2913   int sqlite3AuthCheck(Parse*,int, const char*, const char*, const char*);
2914   void sqlite3AuthContextPush(Parse*, AuthContext*, const char*);
2915   void sqlite3AuthContextPop(AuthContext*);
2916   int sqlite3AuthReadCol(Parse*, const char *, const char *, int);
2917 #else
2918 # define sqlite3AuthRead(a,b,c,d)
2919 # define sqlite3AuthCheck(a,b,c,d,e)    SQLITE_OK
2920 # define sqlite3AuthContextPush(a,b,c)
2921 # define sqlite3AuthContextPop(a)  ((void)(a))
2922 #endif
2923 void sqlite3Attach(Parse*, Expr*, Expr*, Expr*);
2924 void sqlite3Detach(Parse*, Expr*);
2925 int sqlite3FixInit(DbFixer*, Parse*, int, const char*, const Token*);
2926 int sqlite3FixSrcList(DbFixer*, SrcList*);
2927 int sqlite3FixSelect(DbFixer*, Select*);
2928 int sqlite3FixExpr(DbFixer*, Expr*);
2929 int sqlite3FixExprList(DbFixer*, ExprList*);
2930 int sqlite3FixTriggerStep(DbFixer*, TriggerStep*);
2931 int sqlite3AtoF(const char *z, double*, int, u8);
2932 int sqlite3GetInt32(const char *, int*);
2933 int sqlite3Atoi(const char*);
2934 int sqlite3Utf16ByteLen(const void *pData, int nChar);
2935 int sqlite3Utf8CharLen(const char *pData, int nByte);
2936 u32 sqlite3Utf8Read(const u8*, const u8**);
2937 
2938 /*
2939 ** Routines to read and write variable-length integers.  These used to
2940 ** be defined locally, but now we use the varint routines in the util.c
2941 ** file.  Code should use the MACRO forms below, as the Varint32 versions
2942 ** are coded to assume the single byte case is already handled (which
2943 ** the MACRO form does).
2944 */
2945 int sqlite3PutVarint(unsigned char*, u64);
2946 int sqlite3PutVarint32(unsigned char*, u32);
2947 u8 sqlite3GetVarint(const unsigned char *, u64 *);
2948 u8 sqlite3GetVarint32(const unsigned char *, u32 *);
2949 int sqlite3VarintLen(u64 v);
2950 
2951 /*
2952 ** The header of a record consists of a sequence variable-length integers.
2953 ** These integers are almost always small and are encoded as a single byte.
2954 ** The following macros take advantage this fact to provide a fast encode
2955 ** and decode of the integers in a record header.  It is faster for the common
2956 ** case where the integer is a single byte.  It is a little slower when the
2957 ** integer is two or more bytes.  But overall it is faster.
2958 **
2959 ** The following expressions are equivalent:
2960 **
2961 **     x = sqlite3GetVarint32( A, &B );
2962 **     x = sqlite3PutVarint32( A, B );
2963 **
2964 **     x = getVarint32( A, B );
2965 **     x = putVarint32( A, B );
2966 **
2967 */
2968 #define getVarint32(A,B)  (u8)((*(A)<(u8)0x80) ? ((B) = (u32)*(A)),1 : sqlite3GetVarint32((A), (u32 *)&(B)))
2969 #define putVarint32(A,B)  (u8)(((u32)(B)<(u32)0x80) ? (*(A) = (unsigned char)(B)),1 : sqlite3PutVarint32((A), (B)))
2970 #define getVarint    sqlite3GetVarint
2971 #define putVarint    sqlite3PutVarint
2972 
2973 
2974 const char *sqlite3IndexAffinityStr(Vdbe *, Index *);
2975 void sqlite3TableAffinityStr(Vdbe *, Table *);
2976 char sqlite3CompareAffinity(Expr *pExpr, char aff2);
2977 int sqlite3IndexAffinityOk(Expr *pExpr, char idx_affinity);
2978 char sqlite3ExprAffinity(Expr *pExpr);
2979 int sqlite3Atoi64(const char*, i64*, int, u8);
2980 void sqlite3Error(sqlite3*, int, const char*,...);
2981 void *sqlite3HexToBlob(sqlite3*, const char *z, int n);
2982 u8 sqlite3HexToInt(int h);
2983 int sqlite3TwoPartName(Parse *, Token *, Token *, Token **);
2984 const char *sqlite3ErrStr(int);
2985 int sqlite3ReadSchema(Parse *pParse);
2986 CollSeq *sqlite3FindCollSeq(sqlite3*,u8 enc, const char*,int);
2987 CollSeq *sqlite3LocateCollSeq(Parse *pParse, const char*zName);
2988 CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr);
2989 Expr *sqlite3ExprSetColl(Expr*, CollSeq*);
2990 Expr *sqlite3ExprSetCollByToken(Parse *pParse, Expr*, Token*);
2991 int sqlite3CheckCollSeq(Parse *, CollSeq *);
2992 int sqlite3CheckObjectName(Parse *, const char *);
2993 void sqlite3VdbeSetChanges(sqlite3 *, int);
2994 int sqlite3AddInt64(i64*,i64);
2995 int sqlite3SubInt64(i64*,i64);
2996 int sqlite3MulInt64(i64*,i64);
2997 int sqlite3AbsInt32(int);
2998 #ifdef SQLITE_ENABLE_8_3_NAMES
2999 void sqlite3FileSuffix3(const char*, char*);
3000 #else
3001 # define sqlite3FileSuffix3(X,Y)
3002 #endif
3003 u8 sqlite3GetBoolean(const char *z);
3004 
3005 const void *sqlite3ValueText(sqlite3_value*, u8);
3006 int sqlite3ValueBytes(sqlite3_value*, u8);
3007 void sqlite3ValueSetStr(sqlite3_value*, int, const void *,u8,
3008                         void(*)(void*));
3009 void sqlite3ValueFree(sqlite3_value*);
3010 sqlite3_value *sqlite3ValueNew(sqlite3 *);
3011 char *sqlite3Utf16to8(sqlite3 *, const void*, int, u8);
3012 #ifdef SQLITE_ENABLE_STAT3
3013 char *sqlite3Utf8to16(sqlite3 *, u8, char *, int, int *);
3014 #endif
3015 int sqlite3ValueFromExpr(sqlite3 *, Expr *, u8, u8, sqlite3_value **);
3016 void sqlite3ValueApplyAffinity(sqlite3_value *, u8, u8);
3017 #ifndef SQLITE_AMALGAMATION
3018 extern const unsigned char sqlite3OpcodeProperty[];
3019 extern const unsigned char sqlite3UpperToLower[];
3020 extern const unsigned char sqlite3CtypeMap[];
3021 extern const Token sqlite3IntTokens[];
3022 extern SQLITE_WSD struct Sqlite3Config sqlite3Config;
3023 extern SQLITE_WSD FuncDefHash sqlite3GlobalFunctions;
3024 #ifndef SQLITE_OMIT_WSD
3025 extern int sqlite3PendingByte;
3026 #endif
3027 #endif
3028 void sqlite3RootPageMoved(sqlite3*, int, int, int);
3029 void sqlite3Reindex(Parse*, Token*, Token*);
3030 void sqlite3AlterFunctions(void);
3031 void sqlite3AlterRenameTable(Parse*, SrcList*, Token*);
3032 int sqlite3GetToken(const unsigned char *, int *);
3033 void sqlite3NestedParse(Parse*, const char*, ...);
3034 void sqlite3ExpirePreparedStatements(sqlite3*);
3035 int sqlite3CodeSubselect(Parse *, Expr *, int, int);
3036 void sqlite3SelectPrep(Parse*, Select*, NameContext*);
3037 int sqlite3ResolveExprNames(NameContext*, Expr*);
3038 void sqlite3ResolveSelectNames(Parse*, Select*, NameContext*);
3039 int sqlite3ResolveOrderGroupBy(Parse*, Select*, ExprList*, const char*);
3040 void sqlite3ColumnDefault(Vdbe *, Table *, int, int);
3041 void sqlite3AlterFinishAddColumn(Parse *, Token *);
3042 void sqlite3AlterBeginAddColumn(Parse *, SrcList *);
3043 CollSeq *sqlite3GetCollSeq(sqlite3*, u8, CollSeq *, const char*);
3044 char sqlite3AffinityType(const char*);
3045 void sqlite3Analyze(Parse*, Token*, Token*);
3046 int sqlite3InvokeBusyHandler(BusyHandler*);
3047 int sqlite3FindDb(sqlite3*, Token*);
3048 int sqlite3FindDbName(sqlite3 *, const char *);
3049 int sqlite3AnalysisLoad(sqlite3*,int iDB);
3050 void sqlite3DeleteIndexSamples(sqlite3*,Index*);
3051 void sqlite3DefaultRowEst(Index*);
3052 void sqlite3RegisterLikeFunctions(sqlite3*, int);
3053 int sqlite3IsLikeFunction(sqlite3*,Expr*,int*,char*);
3054 void sqlite3MinimumFileFormat(Parse*, int, int);
3055 void sqlite3SchemaClear(void *);
3056 Schema *sqlite3SchemaGet(sqlite3 *, Btree *);
3057 int sqlite3SchemaToIndex(sqlite3 *db, Schema *);
3058 KeyInfo *sqlite3IndexKeyinfo(Parse *, Index *);
3059 int sqlite3CreateFunc(sqlite3 *, const char *, int, int, void *,
3060   void (*)(sqlite3_context*,int,sqlite3_value **),
3061   void (*)(sqlite3_context*,int,sqlite3_value **), void (*)(sqlite3_context*),
3062   FuncDestructor *pDestructor
3063 );
3064 int sqlite3ApiExit(sqlite3 *db, int);
3065 int sqlite3OpenTempDatabase(Parse *);
3066 
3067 void sqlite3StrAccumInit(StrAccum*, char*, int, int);
3068 void sqlite3StrAccumAppend(StrAccum*,const char*,int);
3069 void sqlite3AppendSpace(StrAccum*,int);
3070 char *sqlite3StrAccumFinish(StrAccum*);
3071 void sqlite3StrAccumReset(StrAccum*);
3072 void sqlite3SelectDestInit(SelectDest*,int,int);
3073 Expr *sqlite3CreateColumnExpr(sqlite3 *, SrcList *, int, int);
3074 
3075 void sqlite3BackupRestart(sqlite3_backup *);
3076 void sqlite3BackupUpdate(sqlite3_backup *, Pgno, const u8 *);
3077 
3078 /*
3079 ** The interface to the LEMON-generated parser
3080 */
3081 void *sqlite3ParserAlloc(void*(*)(size_t));
3082 void sqlite3ParserFree(void*, void(*)(void*));
3083 void sqlite3Parser(void*, int, Token, Parse*);
3084 #ifdef YYTRACKMAXSTACKDEPTH
3085   int sqlite3ParserStackPeak(void*);
3086 #endif
3087 
3088 void sqlite3AutoLoadExtensions(sqlite3*);
3089 #ifndef SQLITE_OMIT_LOAD_EXTENSION
3090   void sqlite3CloseExtensions(sqlite3*);
3091 #else
3092 # define sqlite3CloseExtensions(X)
3093 #endif
3094 
3095 #ifndef SQLITE_OMIT_SHARED_CACHE
3096   void sqlite3TableLock(Parse *, int, int, u8, const char *);
3097 #else
3098   #define sqlite3TableLock(v,w,x,y,z)
3099 #endif
3100 
3101 #ifdef SQLITE_TEST
3102   int sqlite3Utf8To8(unsigned char*);
3103 #endif
3104 
3105 #ifdef SQLITE_OMIT_VIRTUALTABLE
3106 #  define sqlite3VtabClear(Y)
3107 #  define sqlite3VtabSync(X,Y) SQLITE_OK
3108 #  define sqlite3VtabRollback(X)
3109 #  define sqlite3VtabCommit(X)
3110 #  define sqlite3VtabInSync(db) 0
3111 #  define sqlite3VtabLock(X)
3112 #  define sqlite3VtabUnlock(X)
3113 #  define sqlite3VtabUnlockList(X)
3114 #  define sqlite3VtabSavepoint(X, Y, Z) SQLITE_OK
3115 #  define sqlite3GetVTable(X,Y)  ((VTable*)0)
3116 #else
3117    void sqlite3VtabClear(sqlite3 *db, Table*);
3118    int sqlite3VtabSync(sqlite3 *db, char **);
3119    int sqlite3VtabRollback(sqlite3 *db);
3120    int sqlite3VtabCommit(sqlite3 *db);
3121    void sqlite3VtabLock(VTable *);
3122    void sqlite3VtabUnlock(VTable *);
3123    void sqlite3VtabUnlockList(sqlite3*);
3124    int sqlite3VtabSavepoint(sqlite3 *, int, int);
3125    VTable *sqlite3GetVTable(sqlite3*, Table*);
3126 #  define sqlite3VtabInSync(db) ((db)->nVTrans>0 && (db)->aVTrans==0)
3127 #endif
3128 void sqlite3VtabMakeWritable(Parse*,Table*);
3129 void sqlite3VtabBeginParse(Parse*, Token*, Token*, Token*);
3130 void sqlite3VtabFinishParse(Parse*, Token*);
3131 void sqlite3VtabArgInit(Parse*);
3132 void sqlite3VtabArgExtend(Parse*, Token*);
3133 int sqlite3VtabCallCreate(sqlite3*, int, const char *, char **);
3134 int sqlite3VtabCallConnect(Parse*, Table*);
3135 int sqlite3VtabCallDestroy(sqlite3*, int, const char *);
3136 int sqlite3VtabBegin(sqlite3 *, VTable *);
3137 FuncDef *sqlite3VtabOverloadFunction(sqlite3 *,FuncDef*, int nArg, Expr*);
3138 void sqlite3InvalidFunction(sqlite3_context*,int,sqlite3_value**);
3139 int sqlite3VdbeParameterIndex(Vdbe*, const char*, int);
3140 int sqlite3TransferBindings(sqlite3_stmt *, sqlite3_stmt *);
3141 int sqlite3Reprepare(Vdbe*);
3142 void sqlite3ExprListCheckLength(Parse*, ExprList*, const char*);
3143 CollSeq *sqlite3BinaryCompareCollSeq(Parse *, Expr *, Expr *);
3144 int sqlite3TempInMemory(const sqlite3*);
3145 const char *sqlite3JournalModename(int);
3146 int sqlite3Checkpoint(sqlite3*, int, int, int*, int*);
3147 int sqlite3WalDefaultHook(void*,sqlite3*,const char*,int);
3148 
3149 /* Declarations for functions in fkey.c. All of these are replaced by
3150 ** no-op macros if OMIT_FOREIGN_KEY is defined. In this case no foreign
3151 ** key functionality is available. If OMIT_TRIGGER is defined but
3152 ** OMIT_FOREIGN_KEY is not, only some of the functions are no-oped. In
3153 ** this case foreign keys are parsed, but no other functionality is
3154 ** provided (enforcement of FK constraints requires the triggers sub-system).
3155 */
3156 #if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)
3157   void sqlite3FkCheck(Parse*, Table*, int, int);
3158   void sqlite3FkDropTable(Parse*, SrcList *, Table*);
3159   void sqlite3FkActions(Parse*, Table*, ExprList*, int);
3160   int sqlite3FkRequired(Parse*, Table*, int*, int);
3161   u32 sqlite3FkOldmask(Parse*, Table*);
3162   FKey *sqlite3FkReferences(Table *);
3163 #else
3164   #define sqlite3FkActions(a,b,c,d)
3165   #define sqlite3FkCheck(a,b,c,d)
3166   #define sqlite3FkDropTable(a,b,c)
3167   #define sqlite3FkOldmask(a,b)      0
3168   #define sqlite3FkRequired(a,b,c,d) 0
3169 #endif
3170 #ifndef SQLITE_OMIT_FOREIGN_KEY
3171   void sqlite3FkDelete(sqlite3 *, Table*);
3172 #else
3173   #define sqlite3FkDelete(a,b)
3174 #endif
3175 
3176 
3177 /*
3178 ** Available fault injectors.  Should be numbered beginning with 0.
3179 */
3180 #define SQLITE_FAULTINJECTOR_MALLOC     0
3181 #define SQLITE_FAULTINJECTOR_COUNT      1
3182 
3183 /*
3184 ** The interface to the code in fault.c used for identifying "benign"
3185 ** malloc failures. This is only present if SQLITE_OMIT_BUILTIN_TEST
3186 ** is not defined.
3187 */
3188 #ifndef SQLITE_OMIT_BUILTIN_TEST
3189   void sqlite3BeginBenignMalloc(void);
3190   void sqlite3EndBenignMalloc(void);
3191 #else
3192   #define sqlite3BeginBenignMalloc()
3193   #define sqlite3EndBenignMalloc()
3194 #endif
3195 
3196 #define IN_INDEX_ROWID           1
3197 #define IN_INDEX_EPH             2
3198 #define IN_INDEX_INDEX           3
3199 int sqlite3FindInIndex(Parse *, Expr *, int*);
3200 
3201 #ifdef SQLITE_ENABLE_ATOMIC_WRITE
3202   int sqlite3JournalOpen(sqlite3_vfs *, const char *, sqlite3_file *, int, int);
3203   int sqlite3JournalSize(sqlite3_vfs *);
3204   int sqlite3JournalCreate(sqlite3_file *);
3205 #else
3206   #define sqlite3JournalSize(pVfs) ((pVfs)->szOsFile)
3207 #endif
3208 
3209 void sqlite3MemJournalOpen(sqlite3_file *);
3210 int sqlite3MemJournalSize(void);
3211 int sqlite3IsMemJournal(sqlite3_file *);
3212 
3213 #if SQLITE_MAX_EXPR_DEPTH>0
3214   void sqlite3ExprSetHeight(Parse *pParse, Expr *p);
3215   int sqlite3SelectExprHeight(Select *);
3216   int sqlite3ExprCheckHeight(Parse*, int);
3217 #else
3218   #define sqlite3ExprSetHeight(x,y)
3219   #define sqlite3SelectExprHeight(x) 0
3220   #define sqlite3ExprCheckHeight(x,y)
3221 #endif
3222 
3223 u32 sqlite3Get4byte(const u8*);
3224 void sqlite3Put4byte(u8*, u32);
3225 
3226 #ifdef SQLITE_ENABLE_UNLOCK_NOTIFY
3227   void sqlite3ConnectionBlocked(sqlite3 *, sqlite3 *);
3228   void sqlite3ConnectionUnlocked(sqlite3 *db);
3229   void sqlite3ConnectionClosed(sqlite3 *db);
3230 #else
3231   #define sqlite3ConnectionBlocked(x,y)
3232   #define sqlite3ConnectionUnlocked(x)
3233   #define sqlite3ConnectionClosed(x)
3234 #endif
3235 
3236 #ifdef SQLITE_DEBUG
3237   void sqlite3ParserTrace(FILE*, char *);
3238 #endif
3239 
3240 /*
3241 ** If the SQLITE_ENABLE IOTRACE exists then the global variable
3242 ** sqlite3IoTrace is a pointer to a printf-like routine used to
3243 ** print I/O tracing messages.
3244 */
3245 #ifdef SQLITE_ENABLE_IOTRACE
3246 # define IOTRACE(A)  if( sqlite3IoTrace ){ sqlite3IoTrace A; }
3247   void sqlite3VdbeIOTraceSql(Vdbe*);
3248 SQLITE_EXTERN void (*sqlite3IoTrace)(const char*,...);
3249 #else
3250 # define IOTRACE(A)
3251 # define sqlite3VdbeIOTraceSql(X)
3252 #endif
3253 
3254 /*
3255 ** These routines are available for the mem2.c debugging memory allocator
3256 ** only.  They are used to verify that different "types" of memory
3257 ** allocations are properly tracked by the system.
3258 **
3259 ** sqlite3MemdebugSetType() sets the "type" of an allocation to one of
3260 ** the MEMTYPE_* macros defined below.  The type must be a bitmask with
3261 ** a single bit set.
3262 **
3263 ** sqlite3MemdebugHasType() returns true if any of the bits in its second
3264 ** argument match the type set by the previous sqlite3MemdebugSetType().
3265 ** sqlite3MemdebugHasType() is intended for use inside assert() statements.
3266 **
3267 ** sqlite3MemdebugNoType() returns true if none of the bits in its second
3268 ** argument match the type set by the previous sqlite3MemdebugSetType().
3269 **
3270 ** Perhaps the most important point is the difference between MEMTYPE_HEAP
3271 ** and MEMTYPE_LOOKASIDE.  If an allocation is MEMTYPE_LOOKASIDE, that means
3272 ** it might have been allocated by lookaside, except the allocation was
3273 ** too large or lookaside was already full.  It is important to verify
3274 ** that allocations that might have been satisfied by lookaside are not
3275 ** passed back to non-lookaside free() routines.  Asserts such as the
3276 ** example above are placed on the non-lookaside free() routines to verify
3277 ** this constraint.
3278 **
3279 ** All of this is no-op for a production build.  It only comes into
3280 ** play when the SQLITE_MEMDEBUG compile-time option is used.
3281 */
3282 #ifdef SQLITE_MEMDEBUG
3283   void sqlite3MemdebugSetType(void*,u8);
3284   int sqlite3MemdebugHasType(void*,u8);
3285   int sqlite3MemdebugNoType(void*,u8);
3286 #else
3287 # define sqlite3MemdebugSetType(X,Y)  /* no-op */
3288 # define sqlite3MemdebugHasType(X,Y)  1
3289 # define sqlite3MemdebugNoType(X,Y)   1
3290 #endif
3291 #define MEMTYPE_HEAP       0x01  /* General heap allocations */
3292 #define MEMTYPE_LOOKASIDE  0x02  /* Might have been lookaside memory */
3293 #define MEMTYPE_SCRATCH    0x04  /* Scratch allocations */
3294 #define MEMTYPE_PCACHE     0x08  /* Page cache allocations */
3295 #define MEMTYPE_DB         0x10  /* Uses sqlite3DbMalloc, not sqlite_malloc */
3296 
3297 #endif /* _SQLITEINT_H_ */
3298