xref: /sqlite-3.40.0/src/sqliteInt.h (revision 754d3adf)
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 ** NDEBUG and SQLITE_DEBUG are opposites.  It should always be true that
207 ** defined(NDEBUG)==!defined(SQLITE_DEBUG).  If this is not currently true,
208 ** make it true by defining or undefining NDEBUG.
209 **
210 ** Setting NDEBUG makes the code smaller and run faster by disabling the
211 ** number assert() statements in the code.  So we want the default action
212 ** to be for NDEBUG to be set and NDEBUG to be undefined only if SQLITE_DEBUG
213 ** is set.  Thus NDEBUG becomes an opt-in rather than an opt-out
214 ** feature.
215 */
216 #if !defined(NDEBUG) && !defined(SQLITE_DEBUG)
217 # define NDEBUG 1
218 #endif
219 #if defined(NDEBUG) && defined(SQLITE_DEBUG)
220 # undef NDEBUG
221 #endif
222 
223 /*
224 ** The testcase() macro is used to aid in coverage testing.  When
225 ** doing coverage testing, the condition inside the argument to
226 ** testcase() must be evaluated both true and false in order to
227 ** get full branch coverage.  The testcase() macro is inserted
228 ** to help ensure adequate test coverage in places where simple
229 ** condition/decision coverage is inadequate.  For example, testcase()
230 ** can be used to make sure boundary values are tested.  For
231 ** bitmask tests, testcase() can be used to make sure each bit
232 ** is significant and used at least once.  On switch statements
233 ** where multiple cases go to the same block of code, testcase()
234 ** can insure that all cases are evaluated.
235 **
236 */
237 #ifdef SQLITE_COVERAGE_TEST
238   void sqlite3Coverage(int);
239 # define testcase(X)  if( X ){ sqlite3Coverage(__LINE__); }
240 #else
241 # define testcase(X)
242 #endif
243 
244 /*
245 ** The TESTONLY macro is used to enclose variable declarations or
246 ** other bits of code that are needed to support the arguments
247 ** within testcase() and assert() macros.
248 */
249 #if !defined(NDEBUG) || defined(SQLITE_COVERAGE_TEST)
250 # define TESTONLY(X)  X
251 #else
252 # define TESTONLY(X)
253 #endif
254 
255 /*
256 ** Sometimes we need a small amount of code such as a variable initialization
257 ** to setup for a later assert() statement.  We do not want this code to
258 ** appear when assert() is disabled.  The following macro is therefore
259 ** used to contain that setup code.  The "VVA" acronym stands for
260 ** "Verification, Validation, and Accreditation".  In other words, the
261 ** code within VVA_ONLY() will only run during verification processes.
262 */
263 #ifndef NDEBUG
264 # define VVA_ONLY(X)  X
265 #else
266 # define VVA_ONLY(X)
267 #endif
268 
269 /*
270 ** The ALWAYS and NEVER macros surround boolean expressions which
271 ** are intended to always be true or false, respectively.  Such
272 ** expressions could be omitted from the code completely.  But they
273 ** are included in a few cases in order to enhance the resilience
274 ** of SQLite to unexpected behavior - to make the code "self-healing"
275 ** or "ductile" rather than being "brittle" and crashing at the first
276 ** hint of unplanned behavior.
277 **
278 ** In other words, ALWAYS and NEVER are added for defensive code.
279 **
280 ** When doing coverage testing ALWAYS and NEVER are hard-coded to
281 ** be true and false so that the unreachable code then specify will
282 ** not be counted as untested code.
283 */
284 #if defined(SQLITE_COVERAGE_TEST)
285 # define ALWAYS(X)      (1)
286 # define NEVER(X)       (0)
287 #elif !defined(NDEBUG)
288 # define ALWAYS(X)      ((X)?1:(assert(0),0))
289 # define NEVER(X)       ((X)?(assert(0),1):0)
290 #else
291 # define ALWAYS(X)      (X)
292 # define NEVER(X)       (X)
293 #endif
294 
295 /*
296 ** Return true (non-zero) if the input is a integer that is too large
297 ** to fit in 32-bits.  This macro is used inside of various testcase()
298 ** macros to verify that we have tested SQLite for large-file support.
299 */
300 #define IS_BIG_INT(X)  (((X)&~(i64)0xffffffff)!=0)
301 
302 /*
303 ** The macro unlikely() is a hint that surrounds a boolean
304 ** expression that is usually false.  Macro likely() surrounds
305 ** a boolean expression that is usually true.  GCC is able to
306 ** use these hints to generate better code, sometimes.
307 */
308 #if defined(__GNUC__) && 0
309 # define likely(X)    __builtin_expect((X),1)
310 # define unlikely(X)  __builtin_expect((X),0)
311 #else
312 # define likely(X)    !!(X)
313 # define unlikely(X)  !!(X)
314 #endif
315 
316 #include "sqlite3.h"
317 #include "hash.h"
318 #include "parse.h"
319 #include <stdio.h>
320 #include <stdlib.h>
321 #include <string.h>
322 #include <assert.h>
323 #include <stddef.h>
324 
325 /*
326 ** If compiling for a processor that lacks floating point support,
327 ** substitute integer for floating-point
328 */
329 #ifdef SQLITE_OMIT_FLOATING_POINT
330 # define double sqlite_int64
331 # define float sqlite_int64
332 # define LONGDOUBLE_TYPE sqlite_int64
333 # ifndef SQLITE_BIG_DBL
334 #   define SQLITE_BIG_DBL (((sqlite3_int64)1)<<50)
335 # endif
336 # define SQLITE_OMIT_DATETIME_FUNCS 1
337 # define SQLITE_OMIT_TRACE 1
338 # undef SQLITE_MIXED_ENDIAN_64BIT_FLOAT
339 # undef SQLITE_HAVE_ISNAN
340 #endif
341 #ifndef SQLITE_BIG_DBL
342 # define SQLITE_BIG_DBL (1e99)
343 #endif
344 
345 /*
346 ** OMIT_TEMPDB is set to 1 if SQLITE_OMIT_TEMPDB is defined, or 0
347 ** afterward. Having this macro allows us to cause the C compiler
348 ** to omit code used by TEMP tables without messy #ifndef statements.
349 */
350 #ifdef SQLITE_OMIT_TEMPDB
351 #define OMIT_TEMPDB 1
352 #else
353 #define OMIT_TEMPDB 0
354 #endif
355 
356 /*
357 ** The "file format" number is an integer that is incremented whenever
358 ** the VDBE-level file format changes.  The following macros define the
359 ** the default file format for new databases and the maximum file format
360 ** that the library can read.
361 */
362 #define SQLITE_MAX_FILE_FORMAT 4
363 #ifndef SQLITE_DEFAULT_FILE_FORMAT
364 # define SQLITE_DEFAULT_FILE_FORMAT 4
365 #endif
366 
367 /*
368 ** Determine whether triggers are recursive by default.  This can be
369 ** changed at run-time using a pragma.
370 */
371 #ifndef SQLITE_DEFAULT_RECURSIVE_TRIGGERS
372 # define SQLITE_DEFAULT_RECURSIVE_TRIGGERS 0
373 #endif
374 
375 /*
376 ** Provide a default value for SQLITE_TEMP_STORE in case it is not specified
377 ** on the command-line
378 */
379 #ifndef SQLITE_TEMP_STORE
380 # define SQLITE_TEMP_STORE 1
381 #endif
382 
383 /*
384 ** GCC does not define the offsetof() macro so we'll have to do it
385 ** ourselves.
386 */
387 #ifndef offsetof
388 #define offsetof(STRUCTURE,FIELD) ((int)((char*)&((STRUCTURE*)0)->FIELD))
389 #endif
390 
391 /*
392 ** Check to see if this machine uses EBCDIC.  (Yes, believe it or
393 ** not, there are still machines out there that use EBCDIC.)
394 */
395 #if 'A' == '\301'
396 # define SQLITE_EBCDIC 1
397 #else
398 # define SQLITE_ASCII 1
399 #endif
400 
401 /*
402 ** Integers of known sizes.  These typedefs might change for architectures
403 ** where the sizes very.  Preprocessor macros are available so that the
404 ** types can be conveniently redefined at compile-type.  Like this:
405 **
406 **         cc '-DUINTPTR_TYPE=long long int' ...
407 */
408 #ifndef UINT32_TYPE
409 # ifdef HAVE_UINT32_T
410 #  define UINT32_TYPE uint32_t
411 # else
412 #  define UINT32_TYPE unsigned int
413 # endif
414 #endif
415 #ifndef UINT16_TYPE
416 # ifdef HAVE_UINT16_T
417 #  define UINT16_TYPE uint16_t
418 # else
419 #  define UINT16_TYPE unsigned short int
420 # endif
421 #endif
422 #ifndef INT16_TYPE
423 # ifdef HAVE_INT16_T
424 #  define INT16_TYPE int16_t
425 # else
426 #  define INT16_TYPE short int
427 # endif
428 #endif
429 #ifndef UINT8_TYPE
430 # ifdef HAVE_UINT8_T
431 #  define UINT8_TYPE uint8_t
432 # else
433 #  define UINT8_TYPE unsigned char
434 # endif
435 #endif
436 #ifndef INT8_TYPE
437 # ifdef HAVE_INT8_T
438 #  define INT8_TYPE int8_t
439 # else
440 #  define INT8_TYPE signed char
441 # endif
442 #endif
443 #ifndef LONGDOUBLE_TYPE
444 # define LONGDOUBLE_TYPE long double
445 #endif
446 typedef sqlite_int64 i64;          /* 8-byte signed integer */
447 typedef sqlite_uint64 u64;         /* 8-byte unsigned integer */
448 typedef UINT32_TYPE u32;           /* 4-byte unsigned integer */
449 typedef UINT16_TYPE u16;           /* 2-byte unsigned integer */
450 typedef INT16_TYPE i16;            /* 2-byte signed integer */
451 typedef UINT8_TYPE u8;             /* 1-byte unsigned integer */
452 typedef INT8_TYPE i8;              /* 1-byte signed integer */
453 
454 /*
455 ** SQLITE_MAX_U32 is a u64 constant that is the maximum u64 value
456 ** that can be stored in a u32 without loss of data.  The value
457 ** is 0x00000000ffffffff.  But because of quirks of some compilers, we
458 ** have to specify the value in the less intuitive manner shown:
459 */
460 #define SQLITE_MAX_U32  ((((u64)1)<<32)-1)
461 
462 /*
463 ** The datatype used to store estimates of the number of rows in a
464 ** table or index.  This is an unsigned integer type.  For 99.9% of
465 ** the world, a 32-bit integer is sufficient.  But a 64-bit integer
466 ** can be used at compile-time if desired.
467 */
468 #ifdef SQLITE_64BIT_STATS
469  typedef u64 tRowcnt;    /* 64-bit only if requested at compile-time */
470 #else
471  typedef u32 tRowcnt;    /* 32-bit is the default */
472 #endif
473 
474 /*
475 ** Macros to determine whether the machine is big or little endian,
476 ** evaluated at runtime.
477 */
478 #ifdef SQLITE_AMALGAMATION
479 const int sqlite3one = 1;
480 #else
481 extern const int sqlite3one;
482 #endif
483 #if defined(i386) || defined(__i386__) || defined(_M_IX86)\
484                              || defined(__x86_64) || defined(__x86_64__)
485 # define SQLITE_BIGENDIAN    0
486 # define SQLITE_LITTLEENDIAN 1
487 # define SQLITE_UTF16NATIVE  SQLITE_UTF16LE
488 #else
489 # define SQLITE_BIGENDIAN    (*(char *)(&sqlite3one)==0)
490 # define SQLITE_LITTLEENDIAN (*(char *)(&sqlite3one)==1)
491 # define SQLITE_UTF16NATIVE (SQLITE_BIGENDIAN?SQLITE_UTF16BE:SQLITE_UTF16LE)
492 #endif
493 
494 /*
495 ** Constants for the largest and smallest possible 64-bit signed integers.
496 ** These macros are designed to work correctly on both 32-bit and 64-bit
497 ** compilers.
498 */
499 #define LARGEST_INT64  (0xffffffff|(((i64)0x7fffffff)<<32))
500 #define SMALLEST_INT64 (((i64)-1) - LARGEST_INT64)
501 
502 /*
503 ** Round up a number to the next larger multiple of 8.  This is used
504 ** to force 8-byte alignment on 64-bit architectures.
505 */
506 #define ROUND8(x)     (((x)+7)&~7)
507 
508 /*
509 ** Round down to the nearest multiple of 8
510 */
511 #define ROUNDDOWN8(x) ((x)&~7)
512 
513 /*
514 ** Assert that the pointer X is aligned to an 8-byte boundary.  This
515 ** macro is used only within assert() to verify that the code gets
516 ** all alignment restrictions correct.
517 **
518 ** Except, if SQLITE_4_BYTE_ALIGNED_MALLOC is defined, then the
519 ** underlying malloc() implemention might return us 4-byte aligned
520 ** pointers.  In that case, only verify 4-byte alignment.
521 */
522 #ifdef SQLITE_4_BYTE_ALIGNED_MALLOC
523 # define EIGHT_BYTE_ALIGNMENT(X)   ((((char*)(X) - (char*)0)&3)==0)
524 #else
525 # define EIGHT_BYTE_ALIGNMENT(X)   ((((char*)(X) - (char*)0)&7)==0)
526 #endif
527 
528 
529 /*
530 ** An instance of the following structure is used to store the busy-handler
531 ** callback for a given sqlite handle.
532 **
533 ** The sqlite.busyHandler member of the sqlite struct contains the busy
534 ** callback for the database handle. Each pager opened via the sqlite
535 ** handle is passed a pointer to sqlite.busyHandler. The busy-handler
536 ** callback is currently invoked only from within pager.c.
537 */
538 typedef struct BusyHandler BusyHandler;
539 struct BusyHandler {
540   int (*xFunc)(void *,int);  /* The busy callback */
541   void *pArg;                /* First arg to busy callback */
542   int nBusy;                 /* Incremented with each busy call */
543 };
544 
545 /*
546 ** Name of the master database table.  The master database table
547 ** is a special table that holds the names and attributes of all
548 ** user tables and indices.
549 */
550 #define MASTER_NAME       "sqlite_master"
551 #define TEMP_MASTER_NAME  "sqlite_temp_master"
552 
553 /*
554 ** The root-page of the master database table.
555 */
556 #define MASTER_ROOT       1
557 
558 /*
559 ** The name of the schema table.
560 */
561 #define SCHEMA_TABLE(x)  ((!OMIT_TEMPDB)&&(x==1)?TEMP_MASTER_NAME:MASTER_NAME)
562 
563 /*
564 ** A convenience macro that returns the number of elements in
565 ** an array.
566 */
567 #define ArraySize(X)    ((int)(sizeof(X)/sizeof(X[0])))
568 
569 /*
570 ** The following value as a destructor means to use sqlite3DbFree().
571 ** The sqlite3DbFree() routine requires two parameters instead of the
572 ** one parameter that destructors normally want.  So we have to introduce
573 ** this magic value that the code knows to handle differently.  Any
574 ** pointer will work here as long as it is distinct from SQLITE_STATIC
575 ** and SQLITE_TRANSIENT.
576 */
577 #define SQLITE_DYNAMIC   ((sqlite3_destructor_type)sqlite3MallocSize)
578 
579 /*
580 ** When SQLITE_OMIT_WSD is defined, it means that the target platform does
581 ** not support Writable Static Data (WSD) such as global and static variables.
582 ** All variables must either be on the stack or dynamically allocated from
583 ** the heap.  When WSD is unsupported, the variable declarations scattered
584 ** throughout the SQLite code must become constants instead.  The SQLITE_WSD
585 ** macro is used for this purpose.  And instead of referencing the variable
586 ** directly, we use its constant as a key to lookup the run-time allocated
587 ** buffer that holds real variable.  The constant is also the initializer
588 ** for the run-time allocated buffer.
589 **
590 ** In the usual case where WSD is supported, the SQLITE_WSD and GLOBAL
591 ** macros become no-ops and have zero performance impact.
592 */
593 #ifdef SQLITE_OMIT_WSD
594   #define SQLITE_WSD const
595   #define GLOBAL(t,v) (*(t*)sqlite3_wsd_find((void*)&(v), sizeof(v)))
596   #define sqlite3GlobalConfig GLOBAL(struct Sqlite3Config, sqlite3Config)
597   int sqlite3_wsd_init(int N, int J);
598   void *sqlite3_wsd_find(void *K, int L);
599 #else
600   #define SQLITE_WSD
601   #define GLOBAL(t,v) v
602   #define sqlite3GlobalConfig sqlite3Config
603 #endif
604 
605 /*
606 ** The following macros are used to suppress compiler warnings and to
607 ** make it clear to human readers when a function parameter is deliberately
608 ** left unused within the body of a function. This usually happens when
609 ** a function is called via a function pointer. For example the
610 ** implementation of an SQL aggregate step callback may not use the
611 ** parameter indicating the number of arguments passed to the aggregate,
612 ** if it knows that this is enforced elsewhere.
613 **
614 ** When a function parameter is not used at all within the body of a function,
615 ** it is generally named "NotUsed" or "NotUsed2" to make things even clearer.
616 ** However, these macros may also be used to suppress warnings related to
617 ** parameters that may or may not be used depending on compilation options.
618 ** For example those parameters only used in assert() statements. In these
619 ** cases the parameters are named as per the usual conventions.
620 */
621 #define UNUSED_PARAMETER(x) (void)(x)
622 #define UNUSED_PARAMETER2(x,y) UNUSED_PARAMETER(x),UNUSED_PARAMETER(y)
623 
624 /*
625 ** Forward references to structures
626 */
627 typedef struct AggInfo AggInfo;
628 typedef struct AuthContext AuthContext;
629 typedef struct AutoincInfo AutoincInfo;
630 typedef struct Bitvec Bitvec;
631 typedef struct CollSeq CollSeq;
632 typedef struct Column Column;
633 typedef struct Db Db;
634 typedef struct Schema Schema;
635 typedef struct Expr Expr;
636 typedef struct ExprList ExprList;
637 typedef struct ExprSpan ExprSpan;
638 typedef struct FKey FKey;
639 typedef struct FuncDestructor FuncDestructor;
640 typedef struct FuncDef FuncDef;
641 typedef struct FuncDefHash FuncDefHash;
642 typedef struct IdList IdList;
643 typedef struct Index Index;
644 typedef struct IndexSample IndexSample;
645 typedef struct KeyClass KeyClass;
646 typedef struct KeyInfo KeyInfo;
647 typedef struct Lookaside Lookaside;
648 typedef struct LookasideSlot LookasideSlot;
649 typedef struct Module Module;
650 typedef struct NameContext NameContext;
651 typedef struct Parse Parse;
652 typedef struct RowSet RowSet;
653 typedef struct Savepoint Savepoint;
654 typedef struct Select Select;
655 typedef struct SrcList SrcList;
656 typedef struct StrAccum StrAccum;
657 typedef struct Table Table;
658 typedef struct TableLock TableLock;
659 typedef struct Token Token;
660 typedef struct Trigger Trigger;
661 typedef struct TriggerPrg TriggerPrg;
662 typedef struct TriggerStep TriggerStep;
663 typedef struct UnpackedRecord UnpackedRecord;
664 typedef struct VTable VTable;
665 typedef struct VtabCtx VtabCtx;
666 typedef struct Walker Walker;
667 typedef struct WherePlan WherePlan;
668 typedef struct WhereInfo WhereInfo;
669 typedef struct WhereLevel WhereLevel;
670 
671 /*
672 ** Defer sourcing vdbe.h and btree.h until after the "u8" and
673 ** "BusyHandler" typedefs. vdbe.h also requires a few of the opaque
674 ** pointer types (i.e. FuncDef) defined above.
675 */
676 #include "btree.h"
677 #include "vdbe.h"
678 #include "pager.h"
679 #include "pcache.h"
680 
681 #include "os.h"
682 #include "mutex.h"
683 
684 
685 /*
686 ** Each database file to be accessed by the system is an instance
687 ** of the following structure.  There are normally two of these structures
688 ** in the sqlite.aDb[] array.  aDb[0] is the main database file and
689 ** aDb[1] is the database file used to hold temporary tables.  Additional
690 ** databases may be attached.
691 */
692 struct Db {
693   char *zName;         /* Name of this database */
694   Btree *pBt;          /* The B*Tree structure for this database file */
695   u8 inTrans;          /* 0: not writable.  1: Transaction.  2: Checkpoint */
696   u8 safety_level;     /* How aggressive at syncing data to disk */
697   Schema *pSchema;     /* Pointer to database schema (possibly shared) */
698 };
699 
700 /*
701 ** An instance of the following structure stores a database schema.
702 **
703 ** Most Schema objects are associated with a Btree.  The exception is
704 ** the Schema for the TEMP databaes (sqlite3.aDb[1]) which is free-standing.
705 ** In shared cache mode, a single Schema object can be shared by multiple
706 ** Btrees that refer to the same underlying BtShared object.
707 **
708 ** Schema objects are automatically deallocated when the last Btree that
709 ** references them is destroyed.   The TEMP Schema is manually freed by
710 ** sqlite3_close().
711 *
712 ** A thread must be holding a mutex on the corresponding Btree in order
713 ** to access Schema content.  This implies that the thread must also be
714 ** holding a mutex on the sqlite3 connection pointer that owns the Btree.
715 ** For a TEMP Schema, only the connection mutex is required.
716 */
717 struct Schema {
718   int schema_cookie;   /* Database schema version number for this file */
719   int iGeneration;     /* Generation counter.  Incremented with each change */
720   Hash tblHash;        /* All tables indexed by name */
721   Hash idxHash;        /* All (named) indices indexed by name */
722   Hash trigHash;       /* All triggers indexed by name */
723   Hash fkeyHash;       /* All foreign keys by referenced table name */
724   Table *pSeqTab;      /* The sqlite_sequence table used by AUTOINCREMENT */
725   u8 file_format;      /* Schema format version for this file */
726   u8 enc;              /* Text encoding used by this database */
727   u16 flags;           /* Flags associated with this schema */
728   int cache_size;      /* Number of pages to use in the cache */
729 };
730 
731 /*
732 ** These macros can be used to test, set, or clear bits in the
733 ** Db.pSchema->flags field.
734 */
735 #define DbHasProperty(D,I,P)     (((D)->aDb[I].pSchema->flags&(P))==(P))
736 #define DbHasAnyProperty(D,I,P)  (((D)->aDb[I].pSchema->flags&(P))!=0)
737 #define DbSetProperty(D,I,P)     (D)->aDb[I].pSchema->flags|=(P)
738 #define DbClearProperty(D,I,P)   (D)->aDb[I].pSchema->flags&=~(P)
739 
740 /*
741 ** Allowed values for the DB.pSchema->flags field.
742 **
743 ** The DB_SchemaLoaded flag is set after the database schema has been
744 ** read into internal hash tables.
745 **
746 ** DB_UnresetViews means that one or more views have column names that
747 ** have been filled out.  If the schema changes, these column names might
748 ** changes and so the view will need to be reset.
749 */
750 #define DB_SchemaLoaded    0x0001  /* The schema has been loaded */
751 #define DB_UnresetViews    0x0002  /* Some views have defined column names */
752 #define DB_Empty           0x0004  /* The file is empty (length 0 bytes) */
753 
754 /*
755 ** The number of different kinds of things that can be limited
756 ** using the sqlite3_limit() interface.
757 */
758 #define SQLITE_N_LIMIT (SQLITE_LIMIT_TRIGGER_DEPTH+1)
759 
760 /*
761 ** Lookaside malloc is a set of fixed-size buffers that can be used
762 ** to satisfy small transient memory allocation requests for objects
763 ** associated with a particular database connection.  The use of
764 ** lookaside malloc provides a significant performance enhancement
765 ** (approx 10%) by avoiding numerous malloc/free requests while parsing
766 ** SQL statements.
767 **
768 ** The Lookaside structure holds configuration information about the
769 ** lookaside malloc subsystem.  Each available memory allocation in
770 ** the lookaside subsystem is stored on a linked list of LookasideSlot
771 ** objects.
772 **
773 ** Lookaside allocations are only allowed for objects that are associated
774 ** with a particular database connection.  Hence, schema information cannot
775 ** be stored in lookaside because in shared cache mode the schema information
776 ** is shared by multiple database connections.  Therefore, while parsing
777 ** schema information, the Lookaside.bEnabled flag is cleared so that
778 ** lookaside allocations are not used to construct the schema objects.
779 */
780 struct Lookaside {
781   u16 sz;                 /* Size of each buffer in bytes */
782   u8 bEnabled;            /* False to disable new lookaside allocations */
783   u8 bMalloced;           /* True if pStart obtained from sqlite3_malloc() */
784   int nOut;               /* Number of buffers currently checked out */
785   int mxOut;              /* Highwater mark for nOut */
786   int anStat[3];          /* 0: hits.  1: size misses.  2: full misses */
787   LookasideSlot *pFree;   /* List of available buffers */
788   void *pStart;           /* First byte of available memory space */
789   void *pEnd;             /* First byte past end of available space */
790 };
791 struct LookasideSlot {
792   LookasideSlot *pNext;    /* Next buffer in the list of free buffers */
793 };
794 
795 /*
796 ** A hash table for function definitions.
797 **
798 ** Hash each FuncDef structure into one of the FuncDefHash.a[] slots.
799 ** Collisions are on the FuncDef.pHash chain.
800 */
801 struct FuncDefHash {
802   FuncDef *a[23];       /* Hash table for functions */
803 };
804 
805 /*
806 ** Each database connection is an instance of the following structure.
807 */
808 struct sqlite3 {
809   sqlite3_vfs *pVfs;            /* OS Interface */
810   struct Vdbe *pVdbe;           /* List of active virtual machines */
811   CollSeq *pDfltColl;           /* The default collating sequence (BINARY) */
812   sqlite3_mutex *mutex;         /* Connection mutex */
813   Db *aDb;                      /* All backends */
814   int nDb;                      /* Number of backends currently in use */
815   int flags;                    /* Miscellaneous flags. See below */
816   i64 lastRowid;                /* ROWID of most recent insert (see above) */
817   unsigned int openFlags;       /* Flags passed to sqlite3_vfs.xOpen() */
818   int errCode;                  /* Most recent error code (SQLITE_*) */
819   int errMask;                  /* & result codes with this before returning */
820   u8 autoCommit;                /* The auto-commit flag. */
821   u8 temp_store;                /* 1: file 2: memory 0: default */
822   u8 mallocFailed;              /* True if we have seen a malloc failure */
823   u8 dfltLockMode;              /* Default locking-mode for attached dbs */
824   signed char nextAutovac;      /* Autovac setting after VACUUM if >=0 */
825   u8 suppressErr;               /* Do not issue error messages if true */
826   u8 vtabOnConflict;            /* Value to return for s3_vtab_on_conflict() */
827   u8 isTransactionSavepoint;    /* True if the outermost savepoint is a TS */
828   int nextPagesize;             /* Pagesize after VACUUM if >0 */
829   u32 magic;                    /* Magic number for detect library misuse */
830   int nChange;                  /* Value returned by sqlite3_changes() */
831   int nTotalChange;             /* Value returned by sqlite3_total_changes() */
832   int aLimit[SQLITE_N_LIMIT];   /* Limits */
833   struct sqlite3InitInfo {      /* Information used during initialization */
834     int newTnum;                /* Rootpage of table being initialized */
835     u8 iDb;                     /* Which db file is being initialized */
836     u8 busy;                    /* TRUE if currently initializing */
837     u8 orphanTrigger;           /* Last statement is orphaned TEMP trigger */
838   } init;
839   int activeVdbeCnt;            /* Number of VDBEs currently executing */
840   int writeVdbeCnt;             /* Number of active VDBEs that are writing */
841   int vdbeExecCnt;              /* Number of nested calls to VdbeExec() */
842   int nExtension;               /* Number of loaded extensions */
843   void **aExtension;            /* Array of shared library handles */
844   void (*xTrace)(void*,const char*);        /* Trace function */
845   void *pTraceArg;                          /* Argument to the trace function */
846   void (*xProfile)(void*,const char*,u64);  /* Profiling function */
847   void *pProfileArg;                        /* Argument to profile function */
848   void *pCommitArg;                 /* Argument to xCommitCallback() */
849   int (*xCommitCallback)(void*);    /* Invoked at every commit. */
850   void *pRollbackArg;               /* Argument to xRollbackCallback() */
851   void (*xRollbackCallback)(void*); /* Invoked at every commit. */
852   void *pUpdateArg;
853   void (*xUpdateCallback)(void*,int, const char*,const char*,sqlite_int64);
854 #ifndef SQLITE_OMIT_WAL
855   int (*xWalCallback)(void *, sqlite3 *, const char *, int);
856   void *pWalArg;
857 #endif
858   void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*);
859   void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*);
860   void *pCollNeededArg;
861   sqlite3_value *pErr;          /* Most recent error message */
862   char *zErrMsg;                /* Most recent error message (UTF-8 encoded) */
863   char *zErrMsg16;              /* Most recent error message (UTF-16 encoded) */
864   union {
865     volatile int isInterrupted; /* True if sqlite3_interrupt has been called */
866     double notUsed1;            /* Spacer */
867   } u1;
868   Lookaside lookaside;          /* Lookaside malloc configuration */
869 #ifndef SQLITE_OMIT_AUTHORIZATION
870   int (*xAuth)(void*,int,const char*,const char*,const char*,const char*);
871                                 /* Access authorization function */
872   void *pAuthArg;               /* 1st argument to the access auth function */
873 #endif
874 #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
875   int (*xProgress)(void *);     /* The progress callback */
876   void *pProgressArg;           /* Argument to the progress callback */
877   int nProgressOps;             /* Number of opcodes for progress callback */
878 #endif
879 #ifndef SQLITE_OMIT_VIRTUALTABLE
880   int nVTrans;                  /* Allocated size of aVTrans */
881   Hash aModule;                 /* populated by sqlite3_create_module() */
882   VtabCtx *pVtabCtx;            /* Context for active vtab connect/create */
883   VTable **aVTrans;             /* Virtual tables with open transactions */
884   VTable *pDisconnect;    /* Disconnect these in next sqlite3_prepare() */
885 #endif
886   FuncDefHash aFunc;            /* Hash table of connection functions */
887   Hash aCollSeq;                /* All collating sequences */
888   BusyHandler busyHandler;      /* Busy callback */
889   Db aDbStatic[2];              /* Static space for the 2 default backends */
890   Savepoint *pSavepoint;        /* List of active savepoints */
891   int busyTimeout;              /* Busy handler timeout, in msec */
892   int nSavepoint;               /* Number of non-transaction savepoints */
893   int nStatement;               /* Number of nested statement-transactions  */
894   i64 nDeferredCons;            /* Net deferred constraints this transaction. */
895   int *pnBytesFreed;            /* If not NULL, increment this in DbFree() */
896 
897 #ifdef SQLITE_ENABLE_UNLOCK_NOTIFY
898   /* The following variables are all protected by the STATIC_MASTER
899   ** mutex, not by sqlite3.mutex. They are used by code in notify.c.
900   **
901   ** When X.pUnlockConnection==Y, that means that X is waiting for Y to
902   ** unlock so that it can proceed.
903   **
904   ** When X.pBlockingConnection==Y, that means that something that X tried
905   ** tried to do recently failed with an SQLITE_LOCKED error due to locks
906   ** held by Y.
907   */
908   sqlite3 *pBlockingConnection; /* Connection that caused SQLITE_LOCKED */
909   sqlite3 *pUnlockConnection;           /* Connection to watch for unlock */
910   void *pUnlockArg;                     /* Argument to xUnlockNotify */
911   void (*xUnlockNotify)(void **, int);  /* Unlock notify callback */
912   sqlite3 *pNextBlocked;        /* Next in list of all blocked connections */
913 #endif
914 };
915 
916 /*
917 ** A macro to discover the encoding of a database.
918 */
919 #define ENC(db) ((db)->aDb[0].pSchema->enc)
920 
921 /*
922 ** Possible values for the sqlite3.flags.
923 */
924 #define SQLITE_VdbeTrace      0x00000100  /* True to trace VDBE execution */
925 #define SQLITE_InternChanges  0x00000200  /* Uncommitted Hash table changes */
926 #define SQLITE_FullColNames   0x00000400  /* Show full column names on SELECT */
927 #define SQLITE_ShortColNames  0x00000800  /* Show short columns names */
928 #define SQLITE_CountRows      0x00001000  /* Count rows changed by INSERT, */
929                                           /*   DELETE, or UPDATE and return */
930                                           /*   the count using a callback. */
931 #define SQLITE_NullCallback   0x00002000  /* Invoke the callback once if the */
932                                           /*   result set is empty */
933 #define SQLITE_SqlTrace       0x00004000  /* Debug print SQL as it executes */
934 #define SQLITE_VdbeListing    0x00008000  /* Debug listings of VDBE programs */
935 #define SQLITE_WriteSchema    0x00010000  /* OK to update SQLITE_MASTER */
936                          /*   0x00020000  Unused */
937 #define SQLITE_IgnoreChecks   0x00040000  /* Do not enforce check constraints */
938 #define SQLITE_ReadUncommitted 0x0080000  /* For shared-cache mode */
939 #define SQLITE_LegacyFileFmt  0x00100000  /* Create new databases in format 1 */
940 #define SQLITE_FullFSync      0x00200000  /* Use full fsync on the backend */
941 #define SQLITE_CkptFullFSync  0x00400000  /* Use full fsync for checkpoint */
942 #define SQLITE_RecoveryMode   0x00800000  /* Ignore schema errors */
943 #define SQLITE_ReverseOrder   0x01000000  /* Reverse unordered SELECTs */
944 #define SQLITE_RecTriggers    0x02000000  /* Enable recursive triggers */
945 #define SQLITE_ForeignKeys    0x04000000  /* Enforce foreign key constraints  */
946 #define SQLITE_AutoIndex      0x08000000  /* Enable automatic indexes */
947 #define SQLITE_PreferBuiltin  0x10000000  /* Preference to built-in funcs */
948 #define SQLITE_LoadExtension  0x20000000  /* Enable load_extension */
949 #define SQLITE_EnableTrigger  0x40000000  /* True to enable triggers */
950 
951 /*
952 ** Bits of the sqlite3.flags field that are used by the
953 ** sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS,...) interface.
954 ** These must be the low-order bits of the flags field.
955 */
956 #define SQLITE_QueryFlattener 0x01        /* Disable query flattening */
957 #define SQLITE_ColumnCache    0x02        /* Disable the column cache */
958 #define SQLITE_IndexSort      0x04        /* Disable indexes for sorting */
959 #define SQLITE_IndexSearch    0x08        /* Disable indexes for searching */
960 #define SQLITE_IndexCover     0x10        /* Disable index covering table */
961 #define SQLITE_GroupByOrder   0x20        /* Disable GROUPBY cover of ORDERBY */
962 #define SQLITE_FactorOutConst 0x40        /* Disable factoring out constants */
963 #define SQLITE_IdxRealAsInt   0x80        /* Store REAL as INT in indices */
964 #define SQLITE_DistinctOpt    0x80        /* DISTINCT using indexes */
965 #define SQLITE_OptMask        0xff        /* Mask of all disablable opts */
966 
967 /*
968 ** Possible values for the sqlite.magic field.
969 ** The numbers are obtained at random and have no special meaning, other
970 ** than being distinct from one another.
971 */
972 #define SQLITE_MAGIC_OPEN     0xa029a697  /* Database is open */
973 #define SQLITE_MAGIC_CLOSED   0x9f3c2d33  /* Database is closed */
974 #define SQLITE_MAGIC_SICK     0x4b771290  /* Error and awaiting close */
975 #define SQLITE_MAGIC_BUSY     0xf03b7906  /* Database currently in use */
976 #define SQLITE_MAGIC_ERROR    0xb5357930  /* An SQLITE_MISUSE error occurred */
977 
978 /*
979 ** Each SQL function is defined by an instance of the following
980 ** structure.  A pointer to this structure is stored in the sqlite.aFunc
981 ** hash table.  When multiple functions have the same name, the hash table
982 ** points to a linked list of these structures.
983 */
984 struct FuncDef {
985   i16 nArg;            /* Number of arguments.  -1 means unlimited */
986   u8 iPrefEnc;         /* Preferred text encoding (SQLITE_UTF8, 16LE, 16BE) */
987   u8 flags;            /* Some combination of SQLITE_FUNC_* */
988   void *pUserData;     /* User data parameter */
989   FuncDef *pNext;      /* Next function with same name */
990   void (*xFunc)(sqlite3_context*,int,sqlite3_value**); /* Regular function */
991   void (*xStep)(sqlite3_context*,int,sqlite3_value**); /* Aggregate step */
992   void (*xFinalize)(sqlite3_context*);                /* Aggregate finalizer */
993   char *zName;         /* SQL name of the function. */
994   FuncDef *pHash;      /* Next with a different name but the same hash */
995   FuncDestructor *pDestructor;   /* Reference counted destructor function */
996 };
997 
998 /*
999 ** This structure encapsulates a user-function destructor callback (as
1000 ** configured using create_function_v2()) and a reference counter. When
1001 ** create_function_v2() is called to create a function with a destructor,
1002 ** a single object of this type is allocated. FuncDestructor.nRef is set to
1003 ** the number of FuncDef objects created (either 1 or 3, depending on whether
1004 ** or not the specified encoding is SQLITE_ANY). The FuncDef.pDestructor
1005 ** member of each of the new FuncDef objects is set to point to the allocated
1006 ** FuncDestructor.
1007 **
1008 ** Thereafter, when one of the FuncDef objects is deleted, the reference
1009 ** count on this object is decremented. When it reaches 0, the destructor
1010 ** is invoked and the FuncDestructor structure freed.
1011 */
1012 struct FuncDestructor {
1013   int nRef;
1014   void (*xDestroy)(void *);
1015   void *pUserData;
1016 };
1017 
1018 /*
1019 ** Possible values for FuncDef.flags.  Note that the _LENGTH and _TYPEOF
1020 ** values must correspond to OPFLAG_LENGTHARG and OPFLAG_TYPEOFARG.  There
1021 ** are assert() statements in the code to verify this.
1022 */
1023 #define SQLITE_FUNC_LIKE     0x01 /* Candidate for the LIKE optimization */
1024 #define SQLITE_FUNC_CASE     0x02 /* Case-sensitive LIKE-type function */
1025 #define SQLITE_FUNC_EPHEM    0x04 /* Ephemeral.  Delete with VDBE */
1026 #define SQLITE_FUNC_NEEDCOLL 0x08 /* sqlite3GetFuncCollSeq() might be called */
1027 #define SQLITE_FUNC_COUNT    0x10 /* Built-in count(*) aggregate */
1028 #define SQLITE_FUNC_COALESCE 0x20 /* Built-in coalesce() or ifnull() function */
1029 #define SQLITE_FUNC_LENGTH   0x40 /* Built-in length() function */
1030 #define SQLITE_FUNC_TYPEOF   0x80 /* Built-in typeof() function */
1031 
1032 /*
1033 ** The following three macros, FUNCTION(), LIKEFUNC() and AGGREGATE() are
1034 ** used to create the initializers for the FuncDef structures.
1035 **
1036 **   FUNCTION(zName, nArg, iArg, bNC, xFunc)
1037 **     Used to create a scalar function definition of a function zName
1038 **     implemented by C function xFunc that accepts nArg arguments. The
1039 **     value passed as iArg is cast to a (void*) and made available
1040 **     as the user-data (sqlite3_user_data()) for the function. If
1041 **     argument bNC is true, then the SQLITE_FUNC_NEEDCOLL flag is set.
1042 **
1043 **   AGGREGATE(zName, nArg, iArg, bNC, xStep, xFinal)
1044 **     Used to create an aggregate function definition implemented by
1045 **     the C functions xStep and xFinal. The first four parameters
1046 **     are interpreted in the same way as the first 4 parameters to
1047 **     FUNCTION().
1048 **
1049 **   LIKEFUNC(zName, nArg, pArg, flags)
1050 **     Used to create a scalar function definition of a function zName
1051 **     that accepts nArg arguments and is implemented by a call to C
1052 **     function likeFunc. Argument pArg is cast to a (void *) and made
1053 **     available as the function user-data (sqlite3_user_data()). The
1054 **     FuncDef.flags variable is set to the value passed as the flags
1055 **     parameter.
1056 */
1057 #define FUNCTION(zName, nArg, iArg, bNC, xFunc) \
1058   {nArg, SQLITE_UTF8, (bNC*SQLITE_FUNC_NEEDCOLL), \
1059    SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, 0, #zName, 0, 0}
1060 #define FUNCTION2(zName, nArg, iArg, bNC, xFunc, extraFlags) \
1061   {nArg, SQLITE_UTF8, (bNC*SQLITE_FUNC_NEEDCOLL)|extraFlags, \
1062    SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, 0, #zName, 0, 0}
1063 #define STR_FUNCTION(zName, nArg, pArg, bNC, xFunc) \
1064   {nArg, SQLITE_UTF8, bNC*SQLITE_FUNC_NEEDCOLL, \
1065    pArg, 0, xFunc, 0, 0, #zName, 0, 0}
1066 #define LIKEFUNC(zName, nArg, arg, flags) \
1067   {nArg, SQLITE_UTF8, flags, (void *)arg, 0, likeFunc, 0, 0, #zName, 0, 0}
1068 #define AGGREGATE(zName, nArg, arg, nc, xStep, xFinal) \
1069   {nArg, SQLITE_UTF8, nc*SQLITE_FUNC_NEEDCOLL, \
1070    SQLITE_INT_TO_PTR(arg), 0, 0, xStep,xFinal,#zName,0,0}
1071 
1072 /*
1073 ** All current savepoints are stored in a linked list starting at
1074 ** sqlite3.pSavepoint. The first element in the list is the most recently
1075 ** opened savepoint. Savepoints are added to the list by the vdbe
1076 ** OP_Savepoint instruction.
1077 */
1078 struct Savepoint {
1079   char *zName;                        /* Savepoint name (nul-terminated) */
1080   i64 nDeferredCons;                  /* Number of deferred fk violations */
1081   Savepoint *pNext;                   /* Parent savepoint (if any) */
1082 };
1083 
1084 /*
1085 ** The following are used as the second parameter to sqlite3Savepoint(),
1086 ** and as the P1 argument to the OP_Savepoint instruction.
1087 */
1088 #define SAVEPOINT_BEGIN      0
1089 #define SAVEPOINT_RELEASE    1
1090 #define SAVEPOINT_ROLLBACK   2
1091 
1092 
1093 /*
1094 ** Each SQLite module (virtual table definition) is defined by an
1095 ** instance of the following structure, stored in the sqlite3.aModule
1096 ** hash table.
1097 */
1098 struct Module {
1099   const sqlite3_module *pModule;       /* Callback pointers */
1100   const char *zName;                   /* Name passed to create_module() */
1101   void *pAux;                          /* pAux passed to create_module() */
1102   void (*xDestroy)(void *);            /* Module destructor function */
1103 };
1104 
1105 /*
1106 ** information about each column of an SQL table is held in an instance
1107 ** of this structure.
1108 */
1109 struct Column {
1110   char *zName;     /* Name of this column */
1111   Expr *pDflt;     /* Default value of this column */
1112   char *zDflt;     /* Original text of the default value */
1113   char *zType;     /* Data type for this column */
1114   char *zColl;     /* Collating sequence.  If NULL, use the default */
1115   u8 notNull;      /* True if there is a NOT NULL constraint */
1116   u8 isPrimKey;    /* True if this column is part of the PRIMARY KEY */
1117   char affinity;   /* One of the SQLITE_AFF_... values */
1118 #ifndef SQLITE_OMIT_VIRTUALTABLE
1119   u8 isHidden;     /* True if this column is 'hidden' */
1120 #endif
1121 };
1122 
1123 /*
1124 ** A "Collating Sequence" is defined by an instance of the following
1125 ** structure. Conceptually, a collating sequence consists of a name and
1126 ** a comparison routine that defines the order of that sequence.
1127 **
1128 ** There may two separate implementations of the collation function, one
1129 ** that processes text in UTF-8 encoding (CollSeq.xCmp) and another that
1130 ** processes text encoded in UTF-16 (CollSeq.xCmp16), using the machine
1131 ** native byte order. When a collation sequence is invoked, SQLite selects
1132 ** the version that will require the least expensive encoding
1133 ** translations, if any.
1134 **
1135 ** The CollSeq.pUser member variable is an extra parameter that passed in
1136 ** as the first argument to the UTF-8 comparison function, xCmp.
1137 ** CollSeq.pUser16 is the equivalent for the UTF-16 comparison function,
1138 ** xCmp16.
1139 **
1140 ** If both CollSeq.xCmp and CollSeq.xCmp16 are NULL, it means that the
1141 ** collating sequence is undefined.  Indices built on an undefined
1142 ** collating sequence may not be read or written.
1143 */
1144 struct CollSeq {
1145   char *zName;          /* Name of the collating sequence, UTF-8 encoded */
1146   u8 enc;               /* Text encoding handled by xCmp() */
1147   void *pUser;          /* First argument to xCmp() */
1148   int (*xCmp)(void*,int, const void*, int, const void*);
1149   void (*xDel)(void*);  /* Destructor for pUser */
1150 };
1151 
1152 /*
1153 ** A sort order can be either ASC or DESC.
1154 */
1155 #define SQLITE_SO_ASC       0  /* Sort in ascending order */
1156 #define SQLITE_SO_DESC      1  /* Sort in ascending order */
1157 
1158 /*
1159 ** Column affinity types.
1160 **
1161 ** These used to have mnemonic name like 'i' for SQLITE_AFF_INTEGER and
1162 ** 't' for SQLITE_AFF_TEXT.  But we can save a little space and improve
1163 ** the speed a little by numbering the values consecutively.
1164 **
1165 ** But rather than start with 0 or 1, we begin with 'a'.  That way,
1166 ** when multiple affinity types are concatenated into a string and
1167 ** used as the P4 operand, they will be more readable.
1168 **
1169 ** Note also that the numeric types are grouped together so that testing
1170 ** for a numeric type is a single comparison.
1171 */
1172 #define SQLITE_AFF_TEXT     'a'
1173 #define SQLITE_AFF_NONE     'b'
1174 #define SQLITE_AFF_NUMERIC  'c'
1175 #define SQLITE_AFF_INTEGER  'd'
1176 #define SQLITE_AFF_REAL     'e'
1177 
1178 #define sqlite3IsNumericAffinity(X)  ((X)>=SQLITE_AFF_NUMERIC)
1179 
1180 /*
1181 ** The SQLITE_AFF_MASK values masks off the significant bits of an
1182 ** affinity value.
1183 */
1184 #define SQLITE_AFF_MASK     0x67
1185 
1186 /*
1187 ** Additional bit values that can be ORed with an affinity without
1188 ** changing the affinity.
1189 */
1190 #define SQLITE_JUMPIFNULL   0x08  /* jumps if either operand is NULL */
1191 #define SQLITE_STOREP2      0x10  /* Store result in reg[P2] rather than jump */
1192 #define SQLITE_NULLEQ       0x80  /* NULL=NULL */
1193 
1194 /*
1195 ** An object of this type is created for each virtual table present in
1196 ** the database schema.
1197 **
1198 ** If the database schema is shared, then there is one instance of this
1199 ** structure for each database connection (sqlite3*) that uses the shared
1200 ** schema. This is because each database connection requires its own unique
1201 ** instance of the sqlite3_vtab* handle used to access the virtual table
1202 ** implementation. sqlite3_vtab* handles can not be shared between
1203 ** database connections, even when the rest of the in-memory database
1204 ** schema is shared, as the implementation often stores the database
1205 ** connection handle passed to it via the xConnect() or xCreate() method
1206 ** during initialization internally. This database connection handle may
1207 ** then be used by the virtual table implementation to access real tables
1208 ** within the database. So that they appear as part of the callers
1209 ** transaction, these accesses need to be made via the same database
1210 ** connection as that used to execute SQL operations on the virtual table.
1211 **
1212 ** All VTable objects that correspond to a single table in a shared
1213 ** database schema are initially stored in a linked-list pointed to by
1214 ** the Table.pVTable member variable of the corresponding Table object.
1215 ** When an sqlite3_prepare() operation is required to access the virtual
1216 ** table, it searches the list for the VTable that corresponds to the
1217 ** database connection doing the preparing so as to use the correct
1218 ** sqlite3_vtab* handle in the compiled query.
1219 **
1220 ** When an in-memory Table object is deleted (for example when the
1221 ** schema is being reloaded for some reason), the VTable objects are not
1222 ** deleted and the sqlite3_vtab* handles are not xDisconnect()ed
1223 ** immediately. Instead, they are moved from the Table.pVTable list to
1224 ** another linked list headed by the sqlite3.pDisconnect member of the
1225 ** corresponding sqlite3 structure. They are then deleted/xDisconnected
1226 ** next time a statement is prepared using said sqlite3*. This is done
1227 ** to avoid deadlock issues involving multiple sqlite3.mutex mutexes.
1228 ** Refer to comments above function sqlite3VtabUnlockList() for an
1229 ** explanation as to why it is safe to add an entry to an sqlite3.pDisconnect
1230 ** list without holding the corresponding sqlite3.mutex mutex.
1231 **
1232 ** The memory for objects of this type is always allocated by
1233 ** sqlite3DbMalloc(), using the connection handle stored in VTable.db as
1234 ** the first argument.
1235 */
1236 struct VTable {
1237   sqlite3 *db;              /* Database connection associated with this table */
1238   Module *pMod;             /* Pointer to module implementation */
1239   sqlite3_vtab *pVtab;      /* Pointer to vtab instance */
1240   int nRef;                 /* Number of pointers to this structure */
1241   u8 bConstraint;           /* True if constraints are supported */
1242   int iSavepoint;           /* Depth of the SAVEPOINT stack */
1243   VTable *pNext;            /* Next in linked list (see above) */
1244 };
1245 
1246 /*
1247 ** Each SQL table is represented in memory by an instance of the
1248 ** following structure.
1249 **
1250 ** Table.zName is the name of the table.  The case of the original
1251 ** CREATE TABLE statement is stored, but case is not significant for
1252 ** comparisons.
1253 **
1254 ** Table.nCol is the number of columns in this table.  Table.aCol is a
1255 ** pointer to an array of Column structures, one for each column.
1256 **
1257 ** If the table has an INTEGER PRIMARY KEY, then Table.iPKey is the index of
1258 ** the column that is that key.   Otherwise Table.iPKey is negative.  Note
1259 ** that the datatype of the PRIMARY KEY must be INTEGER for this field to
1260 ** be set.  An INTEGER PRIMARY KEY is used as the rowid for each row of
1261 ** the table.  If a table has no INTEGER PRIMARY KEY, then a random rowid
1262 ** is generated for each row of the table.  TF_HasPrimaryKey is set if
1263 ** the table has any PRIMARY KEY, INTEGER or otherwise.
1264 **
1265 ** Table.tnum is the page number for the root BTree page of the table in the
1266 ** database file.  If Table.iDb is the index of the database table backend
1267 ** in sqlite.aDb[].  0 is for the main database and 1 is for the file that
1268 ** holds temporary tables and indices.  If TF_Ephemeral is set
1269 ** then the table is stored in a file that is automatically deleted
1270 ** when the VDBE cursor to the table is closed.  In this case Table.tnum
1271 ** refers VDBE cursor number that holds the table open, not to the root
1272 ** page number.  Transient tables are used to hold the results of a
1273 ** sub-query that appears instead of a real table name in the FROM clause
1274 ** of a SELECT statement.
1275 */
1276 struct Table {
1277   char *zName;         /* Name of the table or view */
1278   int iPKey;           /* If not negative, use aCol[iPKey] as the primary key */
1279   int nCol;            /* Number of columns in this table */
1280   Column *aCol;        /* Information about each column */
1281   Index *pIndex;       /* List of SQL indexes on this table. */
1282   int tnum;            /* Root BTree node for this table (see note above) */
1283   tRowcnt nRowEst;     /* Estimated rows in table - from sqlite_stat1 table */
1284   Select *pSelect;     /* NULL for tables.  Points to definition if a view. */
1285   u16 nRef;            /* Number of pointers to this Table */
1286   u8 tabFlags;         /* Mask of TF_* values */
1287   u8 keyConf;          /* What to do in case of uniqueness conflict on iPKey */
1288   FKey *pFKey;         /* Linked list of all foreign keys in this table */
1289   char *zColAff;       /* String defining the affinity of each column */
1290 #ifndef SQLITE_OMIT_CHECK
1291   ExprList *pCheck;    /* All CHECK constraints */
1292 #endif
1293 #ifndef SQLITE_OMIT_ALTERTABLE
1294   int addColOffset;    /* Offset in CREATE TABLE stmt to add a new column */
1295 #endif
1296 #ifndef SQLITE_OMIT_VIRTUALTABLE
1297   VTable *pVTable;     /* List of VTable objects. */
1298   int nModuleArg;      /* Number of arguments to the module */
1299   char **azModuleArg;  /* Text of all module args. [0] is module name */
1300 #endif
1301   Trigger *pTrigger;   /* List of triggers stored in pSchema */
1302   Schema *pSchema;     /* Schema that contains this table */
1303   Table *pNextZombie;  /* Next on the Parse.pZombieTab list */
1304 };
1305 
1306 /*
1307 ** Allowed values for Tabe.tabFlags.
1308 */
1309 #define TF_Readonly        0x01    /* Read-only system table */
1310 #define TF_Ephemeral       0x02    /* An ephemeral table */
1311 #define TF_HasPrimaryKey   0x04    /* Table has a primary key */
1312 #define TF_Autoincrement   0x08    /* Integer primary key is autoincrement */
1313 #define TF_Virtual         0x10    /* Is a virtual table */
1314 
1315 
1316 /*
1317 ** Test to see whether or not a table is a virtual table.  This is
1318 ** done as a macro so that it will be optimized out when virtual
1319 ** table support is omitted from the build.
1320 */
1321 #ifndef SQLITE_OMIT_VIRTUALTABLE
1322 #  define IsVirtual(X)      (((X)->tabFlags & TF_Virtual)!=0)
1323 #  define IsHiddenColumn(X) ((X)->isHidden)
1324 #else
1325 #  define IsVirtual(X)      0
1326 #  define IsHiddenColumn(X) 0
1327 #endif
1328 
1329 /*
1330 ** Each foreign key constraint is an instance of the following structure.
1331 **
1332 ** A foreign key is associated with two tables.  The "from" table is
1333 ** the table that contains the REFERENCES clause that creates the foreign
1334 ** key.  The "to" table is the table that is named in the REFERENCES clause.
1335 ** Consider this example:
1336 **
1337 **     CREATE TABLE ex1(
1338 **       a INTEGER PRIMARY KEY,
1339 **       b INTEGER CONSTRAINT fk1 REFERENCES ex2(x)
1340 **     );
1341 **
1342 ** For foreign key "fk1", the from-table is "ex1" and the to-table is "ex2".
1343 **
1344 ** Each REFERENCES clause generates an instance of the following structure
1345 ** which is attached to the from-table.  The to-table need not exist when
1346 ** the from-table is created.  The existence of the to-table is not checked.
1347 */
1348 struct FKey {
1349   Table *pFrom;     /* Table containing the REFERENCES clause (aka: Child) */
1350   FKey *pNextFrom;  /* Next foreign key in pFrom */
1351   char *zTo;        /* Name of table that the key points to (aka: Parent) */
1352   FKey *pNextTo;    /* Next foreign key on table named zTo */
1353   FKey *pPrevTo;    /* Previous foreign key on table named zTo */
1354   int nCol;         /* Number of columns in this key */
1355   /* EV: R-30323-21917 */
1356   u8 isDeferred;    /* True if constraint checking is deferred till COMMIT */
1357   u8 aAction[2];          /* ON DELETE and ON UPDATE actions, respectively */
1358   Trigger *apTrigger[2];  /* Triggers for aAction[] actions */
1359   struct sColMap {  /* Mapping of columns in pFrom to columns in zTo */
1360     int iFrom;         /* Index of column in pFrom */
1361     char *zCol;        /* Name of column in zTo.  If 0 use PRIMARY KEY */
1362   } aCol[1];        /* One entry for each of nCol column s */
1363 };
1364 
1365 /*
1366 ** SQLite supports many different ways to resolve a constraint
1367 ** error.  ROLLBACK processing means that a constraint violation
1368 ** causes the operation in process to fail and for the current transaction
1369 ** to be rolled back.  ABORT processing means the operation in process
1370 ** fails and any prior changes from that one operation are backed out,
1371 ** but the transaction is not rolled back.  FAIL processing means that
1372 ** the operation in progress stops and returns an error code.  But prior
1373 ** changes due to the same operation are not backed out and no rollback
1374 ** occurs.  IGNORE means that the particular row that caused the constraint
1375 ** error is not inserted or updated.  Processing continues and no error
1376 ** is returned.  REPLACE means that preexisting database rows that caused
1377 ** a UNIQUE constraint violation are removed so that the new insert or
1378 ** update can proceed.  Processing continues and no error is reported.
1379 **
1380 ** RESTRICT, SETNULL, and CASCADE actions apply only to foreign keys.
1381 ** RESTRICT is the same as ABORT for IMMEDIATE foreign keys and the
1382 ** same as ROLLBACK for DEFERRED keys.  SETNULL means that the foreign
1383 ** key is set to NULL.  CASCADE means that a DELETE or UPDATE of the
1384 ** referenced table row is propagated into the row that holds the
1385 ** foreign key.
1386 **
1387 ** The following symbolic values are used to record which type
1388 ** of action to take.
1389 */
1390 #define OE_None     0   /* There is no constraint to check */
1391 #define OE_Rollback 1   /* Fail the operation and rollback the transaction */
1392 #define OE_Abort    2   /* Back out changes but do no rollback transaction */
1393 #define OE_Fail     3   /* Stop the operation but leave all prior changes */
1394 #define OE_Ignore   4   /* Ignore the error. Do not do the INSERT or UPDATE */
1395 #define OE_Replace  5   /* Delete existing record, then do INSERT or UPDATE */
1396 
1397 #define OE_Restrict 6   /* OE_Abort for IMMEDIATE, OE_Rollback for DEFERRED */
1398 #define OE_SetNull  7   /* Set the foreign key value to NULL */
1399 #define OE_SetDflt  8   /* Set the foreign key value to its default */
1400 #define OE_Cascade  9   /* Cascade the changes */
1401 
1402 #define OE_Default  99  /* Do whatever the default action is */
1403 
1404 
1405 /*
1406 ** An instance of the following structure is passed as the first
1407 ** argument to sqlite3VdbeKeyCompare and is used to control the
1408 ** comparison of the two index keys.
1409 */
1410 struct KeyInfo {
1411   sqlite3 *db;        /* The database connection */
1412   u8 enc;             /* Text encoding - one of the SQLITE_UTF* values */
1413   u16 nField;         /* Number of entries in aColl[] */
1414   u8 *aSortOrder;     /* Sort order for each column.  May be NULL */
1415   CollSeq *aColl[1];  /* Collating sequence for each term of the key */
1416 };
1417 
1418 /*
1419 ** An instance of the following structure holds information about a
1420 ** single index record that has already been parsed out into individual
1421 ** values.
1422 **
1423 ** A record is an object that contains one or more fields of data.
1424 ** Records are used to store the content of a table row and to store
1425 ** the key of an index.  A blob encoding of a record is created by
1426 ** the OP_MakeRecord opcode of the VDBE and is disassembled by the
1427 ** OP_Column opcode.
1428 **
1429 ** This structure holds a record that has already been disassembled
1430 ** into its constituent fields.
1431 */
1432 struct UnpackedRecord {
1433   KeyInfo *pKeyInfo;  /* Collation and sort-order information */
1434   u16 nField;         /* Number of entries in apMem[] */
1435   u8 flags;           /* Boolean settings.  UNPACKED_... below */
1436   i64 rowid;          /* Used by UNPACKED_PREFIX_SEARCH */
1437   Mem *aMem;          /* Values */
1438 };
1439 
1440 /*
1441 ** Allowed values of UnpackedRecord.flags
1442 */
1443 #define UNPACKED_INCRKEY       0x01  /* Make this key an epsilon larger */
1444 #define UNPACKED_PREFIX_MATCH  0x02  /* A prefix match is considered OK */
1445 #define UNPACKED_PREFIX_SEARCH 0x04  /* Ignore final (rowid) field */
1446 
1447 /*
1448 ** Each SQL index is represented in memory by an
1449 ** instance of the following structure.
1450 **
1451 ** The columns of the table that are to be indexed are described
1452 ** by the aiColumn[] field of this structure.  For example, suppose
1453 ** we have the following table and index:
1454 **
1455 **     CREATE TABLE Ex1(c1 int, c2 int, c3 text);
1456 **     CREATE INDEX Ex2 ON Ex1(c3,c1);
1457 **
1458 ** In the Table structure describing Ex1, nCol==3 because there are
1459 ** three columns in the table.  In the Index structure describing
1460 ** Ex2, nColumn==2 since 2 of the 3 columns of Ex1 are indexed.
1461 ** The value of aiColumn is {2, 0}.  aiColumn[0]==2 because the
1462 ** first column to be indexed (c3) has an index of 2 in Ex1.aCol[].
1463 ** The second column to be indexed (c1) has an index of 0 in
1464 ** Ex1.aCol[], hence Ex2.aiColumn[1]==0.
1465 **
1466 ** The Index.onError field determines whether or not the indexed columns
1467 ** must be unique and what to do if they are not.  When Index.onError=OE_None,
1468 ** it means this is not a unique index.  Otherwise it is a unique index
1469 ** and the value of Index.onError indicate the which conflict resolution
1470 ** algorithm to employ whenever an attempt is made to insert a non-unique
1471 ** element.
1472 */
1473 struct Index {
1474   char *zName;     /* Name of this index */
1475   int *aiColumn;   /* Which columns are used by this index.  1st is 0 */
1476   tRowcnt *aiRowEst; /* Result of ANALYZE: Est. rows selected by each column */
1477   Table *pTable;   /* The SQL table being indexed */
1478   char *zColAff;   /* String defining the affinity of each column */
1479   Index *pNext;    /* The next index associated with the same table */
1480   Schema *pSchema; /* Schema containing this index */
1481   u8 *aSortOrder;  /* Array of size Index.nColumn. True==DESC, False==ASC */
1482   char **azColl;   /* Array of collation sequence names for index */
1483   int nColumn;     /* Number of columns in the table used by this index */
1484   int tnum;        /* Page containing root of this index in database file */
1485   u8 onError;      /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
1486   u8 autoIndex;    /* True if is automatically created (ex: by UNIQUE) */
1487   u8 bUnordered;   /* Use this index for == or IN queries only */
1488 #ifdef SQLITE_ENABLE_STAT3
1489   int nSample;             /* Number of elements in aSample[] */
1490   tRowcnt avgEq;           /* Average nEq value for key values not in aSample */
1491   IndexSample *aSample;    /* Samples of the left-most key */
1492 #endif
1493 };
1494 
1495 /*
1496 ** Each sample stored in the sqlite_stat3 table is represented in memory
1497 ** using a structure of this type.  See documentation at the top of the
1498 ** analyze.c source file for additional information.
1499 */
1500 struct IndexSample {
1501   union {
1502     char *z;        /* Value if eType is SQLITE_TEXT or SQLITE_BLOB */
1503     double r;       /* Value if eType is SQLITE_FLOAT */
1504     i64 i;          /* Value if eType is SQLITE_INTEGER */
1505   } u;
1506   u8 eType;         /* SQLITE_NULL, SQLITE_INTEGER ... etc. */
1507   int nByte;        /* Size in byte of text or blob. */
1508   tRowcnt nEq;      /* Est. number of rows where the key equals this sample */
1509   tRowcnt nLt;      /* Est. number of rows where key is less than this sample */
1510   tRowcnt nDLt;     /* Est. number of distinct keys less than this sample */
1511 };
1512 
1513 /*
1514 ** Each token coming out of the lexer is an instance of
1515 ** this structure.  Tokens are also used as part of an expression.
1516 **
1517 ** Note if Token.z==0 then Token.dyn and Token.n are undefined and
1518 ** may contain random values.  Do not make any assumptions about Token.dyn
1519 ** and Token.n when Token.z==0.
1520 */
1521 struct Token {
1522   const char *z;     /* Text of the token.  Not NULL-terminated! */
1523   unsigned int n;    /* Number of characters in this token */
1524 };
1525 
1526 /*
1527 ** An instance of this structure contains information needed to generate
1528 ** code for a SELECT that contains aggregate functions.
1529 **
1530 ** If Expr.op==TK_AGG_COLUMN or TK_AGG_FUNCTION then Expr.pAggInfo is a
1531 ** pointer to this structure.  The Expr.iColumn field is the index in
1532 ** AggInfo.aCol[] or AggInfo.aFunc[] of information needed to generate
1533 ** code for that node.
1534 **
1535 ** AggInfo.pGroupBy and AggInfo.aFunc.pExpr point to fields within the
1536 ** original Select structure that describes the SELECT statement.  These
1537 ** fields do not need to be freed when deallocating the AggInfo structure.
1538 */
1539 struct AggInfo {
1540   u8 directMode;          /* Direct rendering mode means take data directly
1541                           ** from source tables rather than from accumulators */
1542   u8 useSortingIdx;       /* In direct mode, reference the sorting index rather
1543                           ** than the source table */
1544   int sortingIdx;         /* Cursor number of the sorting index */
1545   int sortingIdxPTab;     /* Cursor number of pseudo-table */
1546   int nSortingColumn;     /* Number of columns in the sorting index */
1547   ExprList *pGroupBy;     /* The group by clause */
1548   struct AggInfo_col {    /* For each column used in source tables */
1549     Table *pTab;             /* Source table */
1550     int iTable;              /* Cursor number of the source table */
1551     int iColumn;             /* Column number within the source table */
1552     int iSorterColumn;       /* Column number in the sorting index */
1553     int iMem;                /* Memory location that acts as accumulator */
1554     Expr *pExpr;             /* The original expression */
1555   } *aCol;
1556   int nColumn;            /* Number of used entries in aCol[] */
1557   int nAccumulator;       /* Number of columns that show through to the output.
1558                           ** Additional columns are used only as parameters to
1559                           ** aggregate functions */
1560   struct AggInfo_func {   /* For each aggregate function */
1561     Expr *pExpr;             /* Expression encoding the function */
1562     FuncDef *pFunc;          /* The aggregate function implementation */
1563     int iMem;                /* Memory location that acts as accumulator */
1564     int iDistinct;           /* Ephemeral table used to enforce DISTINCT */
1565   } *aFunc;
1566   int nFunc;              /* Number of entries in aFunc[] */
1567 };
1568 
1569 /*
1570 ** The datatype ynVar is a signed integer, either 16-bit or 32-bit.
1571 ** Usually it is 16-bits.  But if SQLITE_MAX_VARIABLE_NUMBER is greater
1572 ** than 32767 we have to make it 32-bit.  16-bit is preferred because
1573 ** it uses less memory in the Expr object, which is a big memory user
1574 ** in systems with lots of prepared statements.  And few applications
1575 ** need more than about 10 or 20 variables.  But some extreme users want
1576 ** to have prepared statements with over 32767 variables, and for them
1577 ** the option is available (at compile-time).
1578 */
1579 #if SQLITE_MAX_VARIABLE_NUMBER<=32767
1580 typedef i16 ynVar;
1581 #else
1582 typedef int ynVar;
1583 #endif
1584 
1585 /*
1586 ** Each node of an expression in the parse tree is an instance
1587 ** of this structure.
1588 **
1589 ** Expr.op is the opcode. The integer parser token codes are reused
1590 ** as opcodes here. For example, the parser defines TK_GE to be an integer
1591 ** code representing the ">=" operator. This same integer code is reused
1592 ** to represent the greater-than-or-equal-to operator in the expression
1593 ** tree.
1594 **
1595 ** If the expression is an SQL literal (TK_INTEGER, TK_FLOAT, TK_BLOB,
1596 ** or TK_STRING), then Expr.token contains the text of the SQL literal. If
1597 ** the expression is a variable (TK_VARIABLE), then Expr.token contains the
1598 ** variable name. Finally, if the expression is an SQL function (TK_FUNCTION),
1599 ** then Expr.token contains the name of the function.
1600 **
1601 ** Expr.pRight and Expr.pLeft are the left and right subexpressions of a
1602 ** binary operator. Either or both may be NULL.
1603 **
1604 ** Expr.x.pList is a list of arguments if the expression is an SQL function,
1605 ** a CASE expression or an IN expression of the form "<lhs> IN (<y>, <z>...)".
1606 ** Expr.x.pSelect is used if the expression is a sub-select or an expression of
1607 ** the form "<lhs> IN (SELECT ...)". If the EP_xIsSelect bit is set in the
1608 ** Expr.flags mask, then Expr.x.pSelect is valid. Otherwise, Expr.x.pList is
1609 ** valid.
1610 **
1611 ** An expression of the form ID or ID.ID refers to a column in a table.
1612 ** For such expressions, Expr.op is set to TK_COLUMN and Expr.iTable is
1613 ** the integer cursor number of a VDBE cursor pointing to that table and
1614 ** Expr.iColumn is the column number for the specific column.  If the
1615 ** expression is used as a result in an aggregate SELECT, then the
1616 ** value is also stored in the Expr.iAgg column in the aggregate so that
1617 ** it can be accessed after all aggregates are computed.
1618 **
1619 ** If the expression is an unbound variable marker (a question mark
1620 ** character '?' in the original SQL) then the Expr.iTable holds the index
1621 ** number for that variable.
1622 **
1623 ** If the expression is a subquery then Expr.iColumn holds an integer
1624 ** register number containing the result of the subquery.  If the
1625 ** subquery gives a constant result, then iTable is -1.  If the subquery
1626 ** gives a different answer at different times during statement processing
1627 ** then iTable is the address of a subroutine that computes the subquery.
1628 **
1629 ** If the Expr is of type OP_Column, and the table it is selecting from
1630 ** is a disk table or the "old.*" pseudo-table, then pTab points to the
1631 ** corresponding table definition.
1632 **
1633 ** ALLOCATION NOTES:
1634 **
1635 ** Expr objects can use a lot of memory space in database schema.  To
1636 ** help reduce memory requirements, sometimes an Expr object will be
1637 ** truncated.  And to reduce the number of memory allocations, sometimes
1638 ** two or more Expr objects will be stored in a single memory allocation,
1639 ** together with Expr.zToken strings.
1640 **
1641 ** If the EP_Reduced and EP_TokenOnly flags are set when
1642 ** an Expr object is truncated.  When EP_Reduced is set, then all
1643 ** the child Expr objects in the Expr.pLeft and Expr.pRight subtrees
1644 ** are contained within the same memory allocation.  Note, however, that
1645 ** the subtrees in Expr.x.pList or Expr.x.pSelect are always separately
1646 ** allocated, regardless of whether or not EP_Reduced is set.
1647 */
1648 struct Expr {
1649   u8 op;                 /* Operation performed by this node */
1650   char affinity;         /* The affinity of the column or 0 if not a column */
1651   u16 flags;             /* Various flags.  EP_* See below */
1652   union {
1653     char *zToken;          /* Token value. Zero terminated and dequoted */
1654     int iValue;            /* Non-negative integer value if EP_IntValue */
1655   } u;
1656 
1657   /* If the EP_TokenOnly flag is set in the Expr.flags mask, then no
1658   ** space is allocated for the fields below this point. An attempt to
1659   ** access them will result in a segfault or malfunction.
1660   *********************************************************************/
1661 
1662   Expr *pLeft;           /* Left subnode */
1663   Expr *pRight;          /* Right subnode */
1664   union {
1665     ExprList *pList;     /* Function arguments or in "<expr> IN (<expr-list)" */
1666     Select *pSelect;     /* Used for sub-selects and "<expr> IN (<select>)" */
1667   } x;
1668   CollSeq *pColl;        /* The collation type of the column or 0 */
1669 
1670   /* If the EP_Reduced flag is set in the Expr.flags mask, then no
1671   ** space is allocated for the fields below this point. An attempt to
1672   ** access them will result in a segfault or malfunction.
1673   *********************************************************************/
1674 
1675   int iTable;            /* TK_COLUMN: cursor number of table holding column
1676                          ** TK_REGISTER: register number
1677                          ** TK_TRIGGER: 1 -> new, 0 -> old */
1678   ynVar iColumn;         /* TK_COLUMN: column index.  -1 for rowid.
1679                          ** TK_VARIABLE: variable number (always >= 1). */
1680   i16 iAgg;              /* Which entry in pAggInfo->aCol[] or ->aFunc[] */
1681   i16 iRightJoinTable;   /* If EP_FromJoin, the right table of the join */
1682   u8 flags2;             /* Second set of flags.  EP2_... */
1683   u8 op2;                /* If a TK_REGISTER, the original value of Expr.op */
1684                          /* If TK_COLUMN, the value of p5 for OP_Column */
1685   AggInfo *pAggInfo;     /* Used by TK_AGG_COLUMN and TK_AGG_FUNCTION */
1686   Table *pTab;           /* Table for TK_COLUMN expressions. */
1687 #if SQLITE_MAX_EXPR_DEPTH>0
1688   int nHeight;           /* Height of the tree headed by this node */
1689 #endif
1690 };
1691 
1692 /*
1693 ** The following are the meanings of bits in the Expr.flags field.
1694 */
1695 #define EP_FromJoin   0x0001  /* Originated in ON or USING clause of a join */
1696 #define EP_Agg        0x0002  /* Contains one or more aggregate functions */
1697 #define EP_Resolved   0x0004  /* IDs have been resolved to COLUMNs */
1698 #define EP_Error      0x0008  /* Expression contains one or more errors */
1699 #define EP_Distinct   0x0010  /* Aggregate function with DISTINCT keyword */
1700 #define EP_VarSelect  0x0020  /* pSelect is correlated, not constant */
1701 #define EP_DblQuoted  0x0040  /* token.z was originally in "..." */
1702 #define EP_InfixFunc  0x0080  /* True for an infix function: LIKE, GLOB, etc */
1703 #define EP_ExpCollate 0x0100  /* Collating sequence specified explicitly */
1704 #define EP_FixedDest  0x0200  /* Result needed in a specific register */
1705 #define EP_IntValue   0x0400  /* Integer value contained in u.iValue */
1706 #define EP_xIsSelect  0x0800  /* x.pSelect is valid (otherwise x.pList is) */
1707 #define EP_Hint       0x1000  /* Not used */
1708 #define EP_Reduced    0x2000  /* Expr struct is EXPR_REDUCEDSIZE bytes only */
1709 #define EP_TokenOnly  0x4000  /* Expr struct is EXPR_TOKENONLYSIZE bytes only */
1710 #define EP_Static     0x8000  /* Held in memory not obtained from malloc() */
1711 
1712 /*
1713 ** The following are the meanings of bits in the Expr.flags2 field.
1714 */
1715 #define EP2_MallocedToken  0x0001  /* Need to sqlite3DbFree() Expr.zToken */
1716 #define EP2_Irreducible    0x0002  /* Cannot EXPRDUP_REDUCE this Expr */
1717 
1718 /*
1719 ** The pseudo-routine sqlite3ExprSetIrreducible sets the EP2_Irreducible
1720 ** flag on an expression structure.  This flag is used for VV&A only.  The
1721 ** routine is implemented as a macro that only works when in debugging mode,
1722 ** so as not to burden production code.
1723 */
1724 #ifdef SQLITE_DEBUG
1725 # define ExprSetIrreducible(X)  (X)->flags2 |= EP2_Irreducible
1726 #else
1727 # define ExprSetIrreducible(X)
1728 #endif
1729 
1730 /*
1731 ** These macros can be used to test, set, or clear bits in the
1732 ** Expr.flags field.
1733 */
1734 #define ExprHasProperty(E,P)     (((E)->flags&(P))==(P))
1735 #define ExprHasAnyProperty(E,P)  (((E)->flags&(P))!=0)
1736 #define ExprSetProperty(E,P)     (E)->flags|=(P)
1737 #define ExprClearProperty(E,P)   (E)->flags&=~(P)
1738 
1739 /*
1740 ** Macros to determine the number of bytes required by a normal Expr
1741 ** struct, an Expr struct with the EP_Reduced flag set in Expr.flags
1742 ** and an Expr struct with the EP_TokenOnly flag set.
1743 */
1744 #define EXPR_FULLSIZE           sizeof(Expr)           /* Full size */
1745 #define EXPR_REDUCEDSIZE        offsetof(Expr,iTable)  /* Common features */
1746 #define EXPR_TOKENONLYSIZE      offsetof(Expr,pLeft)   /* Fewer features */
1747 
1748 /*
1749 ** Flags passed to the sqlite3ExprDup() function. See the header comment
1750 ** above sqlite3ExprDup() for details.
1751 */
1752 #define EXPRDUP_REDUCE         0x0001  /* Used reduced-size Expr nodes */
1753 
1754 /*
1755 ** A list of expressions.  Each expression may optionally have a
1756 ** name.  An expr/name combination can be used in several ways, such
1757 ** as the list of "expr AS ID" fields following a "SELECT" or in the
1758 ** list of "ID = expr" items in an UPDATE.  A list of expressions can
1759 ** also be used as the argument to a function, in which case the a.zName
1760 ** field is not used.
1761 */
1762 struct ExprList {
1763   int nExpr;             /* Number of expressions on the list */
1764   int iECursor;          /* VDBE Cursor associated with this ExprList */
1765   struct ExprList_item { /* For each expression in the list */
1766     Expr *pExpr;           /* The list of expressions */
1767     char *zName;           /* Token associated with this expression */
1768     char *zSpan;           /* Original text of the expression */
1769     u8 sortOrder;          /* 1 for DESC or 0 for ASC */
1770     u8 done;               /* A flag to indicate when processing is finished */
1771     u16 iOrderByCol;       /* For ORDER BY, column number in result set */
1772     u16 iAlias;            /* Index into Parse.aAlias[] for zName */
1773   } *a;                  /* Alloc a power of two greater or equal to nExpr */
1774 };
1775 
1776 /*
1777 ** An instance of this structure is used by the parser to record both
1778 ** the parse tree for an expression and the span of input text for an
1779 ** expression.
1780 */
1781 struct ExprSpan {
1782   Expr *pExpr;          /* The expression parse tree */
1783   const char *zStart;   /* First character of input text */
1784   const char *zEnd;     /* One character past the end of input text */
1785 };
1786 
1787 /*
1788 ** An instance of this structure can hold a simple list of identifiers,
1789 ** such as the list "a,b,c" in the following statements:
1790 **
1791 **      INSERT INTO t(a,b,c) VALUES ...;
1792 **      CREATE INDEX idx ON t(a,b,c);
1793 **      CREATE TRIGGER trig BEFORE UPDATE ON t(a,b,c) ...;
1794 **
1795 ** The IdList.a.idx field is used when the IdList represents the list of
1796 ** column names after a table name in an INSERT statement.  In the statement
1797 **
1798 **     INSERT INTO t(a,b,c) ...
1799 **
1800 ** If "a" is the k-th column of table "t", then IdList.a[0].idx==k.
1801 */
1802 struct IdList {
1803   struct IdList_item {
1804     char *zName;      /* Name of the identifier */
1805     int idx;          /* Index in some Table.aCol[] of a column named zName */
1806   } *a;
1807   int nId;         /* Number of identifiers on the list */
1808 };
1809 
1810 /*
1811 ** The bitmask datatype defined below is used for various optimizations.
1812 **
1813 ** Changing this from a 64-bit to a 32-bit type limits the number of
1814 ** tables in a join to 32 instead of 64.  But it also reduces the size
1815 ** of the library by 738 bytes on ix86.
1816 */
1817 typedef u64 Bitmask;
1818 
1819 /*
1820 ** The number of bits in a Bitmask.  "BMS" means "BitMask Size".
1821 */
1822 #define BMS  ((int)(sizeof(Bitmask)*8))
1823 
1824 /*
1825 ** The following structure describes the FROM clause of a SELECT statement.
1826 ** Each table or subquery in the FROM clause is a separate element of
1827 ** the SrcList.a[] array.
1828 **
1829 ** With the addition of multiple database support, the following structure
1830 ** can also be used to describe a particular table such as the table that
1831 ** is modified by an INSERT, DELETE, or UPDATE statement.  In standard SQL,
1832 ** such a table must be a simple name: ID.  But in SQLite, the table can
1833 ** now be identified by a database name, a dot, then the table name: ID.ID.
1834 **
1835 ** The jointype starts out showing the join type between the current table
1836 ** and the next table on the list.  The parser builds the list this way.
1837 ** But sqlite3SrcListShiftJoinType() later shifts the jointypes so that each
1838 ** jointype expresses the join between the table and the previous table.
1839 **
1840 ** In the colUsed field, the high-order bit (bit 63) is set if the table
1841 ** contains more than 63 columns and the 64-th or later column is used.
1842 */
1843 struct SrcList {
1844   i16 nSrc;        /* Number of tables or subqueries in the FROM clause */
1845   i16 nAlloc;      /* Number of entries allocated in a[] below */
1846   struct SrcList_item {
1847     char *zDatabase;  /* Name of database holding this table */
1848     char *zName;      /* Name of the table */
1849     char *zAlias;     /* The "B" part of a "A AS B" phrase.  zName is the "A" */
1850     Table *pTab;      /* An SQL table corresponding to zName */
1851     Select *pSelect;  /* A SELECT statement used in place of a table name */
1852     int addrFillSub;  /* Address of subroutine to manifest a subquery */
1853     int regReturn;    /* Register holding return address of addrFillSub */
1854     u8 jointype;      /* Type of join between this able and the previous */
1855     u8 notIndexed;    /* True if there is a NOT INDEXED clause */
1856     u8 isCorrelated;  /* True if sub-query is correlated */
1857 #ifndef SQLITE_OMIT_EXPLAIN
1858     u8 iSelectId;     /* If pSelect!=0, the id of the sub-select in EQP */
1859 #endif
1860     int iCursor;      /* The VDBE cursor number used to access this table */
1861     Expr *pOn;        /* The ON clause of a join */
1862     IdList *pUsing;   /* The USING clause of a join */
1863     Bitmask colUsed;  /* Bit N (1<<N) set if column N of pTab is used */
1864     char *zIndex;     /* Identifier from "INDEXED BY <zIndex>" clause */
1865     Index *pIndex;    /* Index structure corresponding to zIndex, if any */
1866   } a[1];             /* One entry for each identifier on the list */
1867 };
1868 
1869 /*
1870 ** Permitted values of the SrcList.a.jointype field
1871 */
1872 #define JT_INNER     0x0001    /* Any kind of inner or cross join */
1873 #define JT_CROSS     0x0002    /* Explicit use of the CROSS keyword */
1874 #define JT_NATURAL   0x0004    /* True for a "natural" join */
1875 #define JT_LEFT      0x0008    /* Left outer join */
1876 #define JT_RIGHT     0x0010    /* Right outer join */
1877 #define JT_OUTER     0x0020    /* The "OUTER" keyword is present */
1878 #define JT_ERROR     0x0040    /* unknown or unsupported join type */
1879 
1880 
1881 /*
1882 ** A WherePlan object holds information that describes a lookup
1883 ** strategy.
1884 **
1885 ** This object is intended to be opaque outside of the where.c module.
1886 ** It is included here only so that that compiler will know how big it
1887 ** is.  None of the fields in this object should be used outside of
1888 ** the where.c module.
1889 **
1890 ** Within the union, pIdx is only used when wsFlags&WHERE_INDEXED is true.
1891 ** pTerm is only used when wsFlags&WHERE_MULTI_OR is true.  And pVtabIdx
1892 ** is only used when wsFlags&WHERE_VIRTUALTABLE is true.  It is never the
1893 ** case that more than one of these conditions is true.
1894 */
1895 struct WherePlan {
1896   u32 wsFlags;                   /* WHERE_* flags that describe the strategy */
1897   u32 nEq;                       /* Number of == constraints */
1898   double nRow;                   /* Estimated number of rows (for EQP) */
1899   union {
1900     Index *pIdx;                   /* Index when WHERE_INDEXED is true */
1901     struct WhereTerm *pTerm;       /* WHERE clause term for OR-search */
1902     sqlite3_index_info *pVtabIdx;  /* Virtual table index to use */
1903   } u;
1904 };
1905 
1906 /*
1907 ** For each nested loop in a WHERE clause implementation, the WhereInfo
1908 ** structure contains a single instance of this structure.  This structure
1909 ** is intended to be private the the where.c module and should not be
1910 ** access or modified by other modules.
1911 **
1912 ** The pIdxInfo field is used to help pick the best index on a
1913 ** virtual table.  The pIdxInfo pointer contains indexing
1914 ** information for the i-th table in the FROM clause before reordering.
1915 ** All the pIdxInfo pointers are freed by whereInfoFree() in where.c.
1916 ** All other information in the i-th WhereLevel object for the i-th table
1917 ** after FROM clause ordering.
1918 */
1919 struct WhereLevel {
1920   WherePlan plan;       /* query plan for this element of the FROM clause */
1921   int iLeftJoin;        /* Memory cell used to implement LEFT OUTER JOIN */
1922   int iTabCur;          /* The VDBE cursor used to access the table */
1923   int iIdxCur;          /* The VDBE cursor used to access pIdx */
1924   int addrBrk;          /* Jump here to break out of the loop */
1925   int addrNxt;          /* Jump here to start the next IN combination */
1926   int addrCont;         /* Jump here to continue with the next loop cycle */
1927   int addrFirst;        /* First instruction of interior of the loop */
1928   u8 iFrom;             /* Which entry in the FROM clause */
1929   u8 op, p5;            /* Opcode and P5 of the opcode that ends the loop */
1930   int p1, p2;           /* Operands of the opcode used to ends the loop */
1931   union {               /* Information that depends on plan.wsFlags */
1932     struct {
1933       int nIn;              /* Number of entries in aInLoop[] */
1934       struct InLoop {
1935         int iCur;              /* The VDBE cursor used by this IN operator */
1936         int addrInTop;         /* Top of the IN loop */
1937       } *aInLoop;           /* Information about each nested IN operator */
1938     } in;                 /* Used when plan.wsFlags&WHERE_IN_ABLE */
1939   } u;
1940 
1941   /* The following field is really not part of the current level.  But
1942   ** we need a place to cache virtual table index information for each
1943   ** virtual table in the FROM clause and the WhereLevel structure is
1944   ** a convenient place since there is one WhereLevel for each FROM clause
1945   ** element.
1946   */
1947   sqlite3_index_info *pIdxInfo;  /* Index info for n-th source table */
1948 };
1949 
1950 /*
1951 ** Flags appropriate for the wctrlFlags parameter of sqlite3WhereBegin()
1952 ** and the WhereInfo.wctrlFlags member.
1953 */
1954 #define WHERE_ORDERBY_NORMAL   0x0000 /* No-op */
1955 #define WHERE_ORDERBY_MIN      0x0001 /* ORDER BY processing for min() func */
1956 #define WHERE_ORDERBY_MAX      0x0002 /* ORDER BY processing for max() func */
1957 #define WHERE_ONEPASS_DESIRED  0x0004 /* Want to do one-pass UPDATE/DELETE */
1958 #define WHERE_DUPLICATES_OK    0x0008 /* Ok to return a row more than once */
1959 #define WHERE_OMIT_OPEN_CLOSE  0x0010 /* Table cursors are already open */
1960 #define WHERE_FORCE_TABLE      0x0020 /* Do not use an index-only search */
1961 #define WHERE_ONETABLE_ONLY    0x0040 /* Only code the 1st table in pTabList */
1962 #define WHERE_AND_ONLY         0x0080 /* Don't use indices for OR terms */
1963 
1964 /*
1965 ** The WHERE clause processing routine has two halves.  The
1966 ** first part does the start of the WHERE loop and the second
1967 ** half does the tail of the WHERE loop.  An instance of
1968 ** this structure is returned by the first half and passed
1969 ** into the second half to give some continuity.
1970 */
1971 struct WhereInfo {
1972   Parse *pParse;       /* Parsing and code generating context */
1973   u16 wctrlFlags;      /* Flags originally passed to sqlite3WhereBegin() */
1974   u8 okOnePass;        /* Ok to use one-pass algorithm for UPDATE or DELETE */
1975   u8 untestedTerms;    /* Not all WHERE terms resolved by outer loop */
1976   u8 eDistinct;
1977   SrcList *pTabList;             /* List of tables in the join */
1978   int iTop;                      /* The very beginning of the WHERE loop */
1979   int iContinue;                 /* Jump here to continue with next record */
1980   int iBreak;                    /* Jump here to break out of the loop */
1981   int nLevel;                    /* Number of nested loop */
1982   struct WhereClause *pWC;       /* Decomposition of the WHERE clause */
1983   double savedNQueryLoop;        /* pParse->nQueryLoop outside the WHERE loop */
1984   double nRowOut;                /* Estimated number of output rows */
1985   WhereLevel a[1];               /* Information about each nest loop in WHERE */
1986 };
1987 
1988 #define WHERE_DISTINCT_UNIQUE 1
1989 #define WHERE_DISTINCT_ORDERED 2
1990 
1991 /*
1992 ** A NameContext defines a context in which to resolve table and column
1993 ** names.  The context consists of a list of tables (the pSrcList) field and
1994 ** a list of named expression (pEList).  The named expression list may
1995 ** be NULL.  The pSrc corresponds to the FROM clause of a SELECT or
1996 ** to the table being operated on by INSERT, UPDATE, or DELETE.  The
1997 ** pEList corresponds to the result set of a SELECT and is NULL for
1998 ** other statements.
1999 **
2000 ** NameContexts can be nested.  When resolving names, the inner-most
2001 ** context is searched first.  If no match is found, the next outer
2002 ** context is checked.  If there is still no match, the next context
2003 ** is checked.  This process continues until either a match is found
2004 ** or all contexts are check.  When a match is found, the nRef member of
2005 ** the context containing the match is incremented.
2006 **
2007 ** Each subquery gets a new NameContext.  The pNext field points to the
2008 ** NameContext in the parent query.  Thus the process of scanning the
2009 ** NameContext list corresponds to searching through successively outer
2010 ** subqueries looking for a match.
2011 */
2012 struct NameContext {
2013   Parse *pParse;       /* The parser */
2014   SrcList *pSrcList;   /* One or more tables used to resolve names */
2015   ExprList *pEList;    /* Optional list of named expressions */
2016   AggInfo *pAggInfo;   /* Information about aggregates at this level */
2017   NameContext *pNext;  /* Next outer name context.  NULL for outermost */
2018   int nRef;            /* Number of names resolved by this context */
2019   int nErr;            /* Number of errors encountered while resolving names */
2020   u8 ncFlags;          /* Zero or more NC_* flags defined below */
2021 };
2022 
2023 /*
2024 ** Allowed values for the NameContext, ncFlags field.
2025 */
2026 #define NC_AllowAgg  0x01    /* Aggregate functions are allowed here */
2027 #define NC_HasAgg    0x02    /* One or more aggregate functions seen */
2028 #define NC_IsCheck   0x04    /* True if resolving names in a CHECK constraint */
2029 #define NC_InAggFunc 0x08    /* True if analyzing arguments to an agg func */
2030 
2031 /*
2032 ** An instance of the following structure contains all information
2033 ** needed to generate code for a single SELECT statement.
2034 **
2035 ** nLimit is set to -1 if there is no LIMIT clause.  nOffset is set to 0.
2036 ** If there is a LIMIT clause, the parser sets nLimit to the value of the
2037 ** limit and nOffset to the value of the offset (or 0 if there is not
2038 ** offset).  But later on, nLimit and nOffset become the memory locations
2039 ** in the VDBE that record the limit and offset counters.
2040 **
2041 ** addrOpenEphm[] entries contain the address of OP_OpenEphemeral opcodes.
2042 ** These addresses must be stored so that we can go back and fill in
2043 ** the P4_KEYINFO and P2 parameters later.  Neither the KeyInfo nor
2044 ** the number of columns in P2 can be computed at the same time
2045 ** as the OP_OpenEphm instruction is coded because not
2046 ** enough information about the compound query is known at that point.
2047 ** The KeyInfo for addrOpenTran[0] and [1] contains collating sequences
2048 ** for the result set.  The KeyInfo for addrOpenTran[2] contains collating
2049 ** sequences for the ORDER BY clause.
2050 */
2051 struct Select {
2052   ExprList *pEList;      /* The fields of the result */
2053   u8 op;                 /* One of: TK_UNION TK_ALL TK_INTERSECT TK_EXCEPT */
2054   char affinity;         /* MakeRecord with this affinity for SRT_Set */
2055   u16 selFlags;          /* Various SF_* values */
2056   int iLimit, iOffset;   /* Memory registers holding LIMIT & OFFSET counters */
2057   int addrOpenEphm[3];   /* OP_OpenEphem opcodes related to this select */
2058   double nSelectRow;     /* Estimated number of result rows */
2059   SrcList *pSrc;         /* The FROM clause */
2060   Expr *pWhere;          /* The WHERE clause */
2061   ExprList *pGroupBy;    /* The GROUP BY clause */
2062   Expr *pHaving;         /* The HAVING clause */
2063   ExprList *pOrderBy;    /* The ORDER BY clause */
2064   Select *pPrior;        /* Prior select in a compound select statement */
2065   Select *pNext;         /* Next select to the left in a compound */
2066   Select *pRightmost;    /* Right-most select in a compound select statement */
2067   Expr *pLimit;          /* LIMIT expression. NULL means not used. */
2068   Expr *pOffset;         /* OFFSET expression. NULL means not used. */
2069 };
2070 
2071 /*
2072 ** Allowed values for Select.selFlags.  The "SF" prefix stands for
2073 ** "Select Flag".
2074 */
2075 #define SF_Distinct        0x01  /* Output should be DISTINCT */
2076 #define SF_Resolved        0x02  /* Identifiers have been resolved */
2077 #define SF_Aggregate       0x04  /* Contains aggregate functions */
2078 #define SF_UsesEphemeral   0x08  /* Uses the OpenEphemeral opcode */
2079 #define SF_Expanded        0x10  /* sqlite3SelectExpand() called on this */
2080 #define SF_HasTypeInfo     0x20  /* FROM subqueries have Table metadata */
2081 #define SF_UseSorter       0x40  /* Sort using a sorter */
2082 #define SF_Values          0x80  /* Synthesized from VALUES clause */
2083 
2084 
2085 /*
2086 ** The results of a select can be distributed in several ways.  The
2087 ** "SRT" prefix means "SELECT Result Type".
2088 */
2089 #define SRT_Union        1  /* Store result as keys in an index */
2090 #define SRT_Except       2  /* Remove result from a UNION index */
2091 #define SRT_Exists       3  /* Store 1 if the result is not empty */
2092 #define SRT_Discard      4  /* Do not save the results anywhere */
2093 
2094 /* The ORDER BY clause is ignored for all of the above */
2095 #define IgnorableOrderby(X) ((X->eDest)<=SRT_Discard)
2096 
2097 #define SRT_Output       5  /* Output each row of result */
2098 #define SRT_Mem          6  /* Store result in a memory cell */
2099 #define SRT_Set          7  /* Store results as keys in an index */
2100 #define SRT_Table        8  /* Store result as data with an automatic rowid */
2101 #define SRT_EphemTab     9  /* Create transient tab and store like SRT_Table */
2102 #define SRT_Coroutine   10  /* Generate a single row of result */
2103 
2104 /*
2105 ** A structure used to customize the behavior of sqlite3Select(). See
2106 ** comments above sqlite3Select() for details.
2107 */
2108 typedef struct SelectDest SelectDest;
2109 struct SelectDest {
2110   u8 eDest;         /* How to dispose of the results */
2111   u8 affinity;      /* Affinity used when eDest==SRT_Set */
2112   int iParm;        /* A parameter used by the eDest disposal method */
2113   int iMem;         /* Base register where results are written */
2114   int nMem;         /* Number of registers allocated */
2115 };
2116 
2117 /*
2118 ** During code generation of statements that do inserts into AUTOINCREMENT
2119 ** tables, the following information is attached to the Table.u.autoInc.p
2120 ** pointer of each autoincrement table to record some side information that
2121 ** the code generator needs.  We have to keep per-table autoincrement
2122 ** information in case inserts are down within triggers.  Triggers do not
2123 ** normally coordinate their activities, but we do need to coordinate the
2124 ** loading and saving of autoincrement information.
2125 */
2126 struct AutoincInfo {
2127   AutoincInfo *pNext;   /* Next info block in a list of them all */
2128   Table *pTab;          /* Table this info block refers to */
2129   int iDb;              /* Index in sqlite3.aDb[] of database holding pTab */
2130   int regCtr;           /* Memory register holding the rowid counter */
2131 };
2132 
2133 /*
2134 ** Size of the column cache
2135 */
2136 #ifndef SQLITE_N_COLCACHE
2137 # define SQLITE_N_COLCACHE 10
2138 #endif
2139 
2140 /*
2141 ** At least one instance of the following structure is created for each
2142 ** trigger that may be fired while parsing an INSERT, UPDATE or DELETE
2143 ** statement. All such objects are stored in the linked list headed at
2144 ** Parse.pTriggerPrg and deleted once statement compilation has been
2145 ** completed.
2146 **
2147 ** A Vdbe sub-program that implements the body and WHEN clause of trigger
2148 ** TriggerPrg.pTrigger, assuming a default ON CONFLICT clause of
2149 ** TriggerPrg.orconf, is stored in the TriggerPrg.pProgram variable.
2150 ** The Parse.pTriggerPrg list never contains two entries with the same
2151 ** values for both pTrigger and orconf.
2152 **
2153 ** The TriggerPrg.aColmask[0] variable is set to a mask of old.* columns
2154 ** accessed (or set to 0 for triggers fired as a result of INSERT
2155 ** statements). Similarly, the TriggerPrg.aColmask[1] variable is set to
2156 ** a mask of new.* columns used by the program.
2157 */
2158 struct TriggerPrg {
2159   Trigger *pTrigger;      /* Trigger this program was coded from */
2160   TriggerPrg *pNext;      /* Next entry in Parse.pTriggerPrg list */
2161   SubProgram *pProgram;   /* Program implementing pTrigger/orconf */
2162   int orconf;             /* Default ON CONFLICT policy */
2163   u32 aColmask[2];        /* Masks of old.*, new.* columns accessed */
2164 };
2165 
2166 /*
2167 ** The yDbMask datatype for the bitmask of all attached databases.
2168 */
2169 #if SQLITE_MAX_ATTACHED>30
2170   typedef sqlite3_uint64 yDbMask;
2171 #else
2172   typedef unsigned int yDbMask;
2173 #endif
2174 
2175 /*
2176 ** An SQL parser context.  A copy of this structure is passed through
2177 ** the parser and down into all the parser action routine in order to
2178 ** carry around information that is global to the entire parse.
2179 **
2180 ** The structure is divided into two parts.  When the parser and code
2181 ** generate call themselves recursively, the first part of the structure
2182 ** is constant but the second part is reset at the beginning and end of
2183 ** each recursion.
2184 **
2185 ** The nTableLock and aTableLock variables are only used if the shared-cache
2186 ** feature is enabled (if sqlite3Tsd()->useSharedData is true). They are
2187 ** used to store the set of table-locks required by the statement being
2188 ** compiled. Function sqlite3TableLock() is used to add entries to the
2189 ** list.
2190 */
2191 struct Parse {
2192   sqlite3 *db;         /* The main database structure */
2193   char *zErrMsg;       /* An error message */
2194   Vdbe *pVdbe;         /* An engine for executing database bytecode */
2195   int rc;              /* Return code from execution */
2196   u8 colNamesSet;      /* TRUE after OP_ColumnName has been issued to pVdbe */
2197   u8 checkSchema;      /* Causes schema cookie check after an error */
2198   u8 nested;           /* Number of nested calls to the parser/code generator */
2199   u8 nTempReg;         /* Number of temporary registers in aTempReg[] */
2200   u8 nTempInUse;       /* Number of aTempReg[] currently checked out */
2201   u8 nColCache;        /* Number of entries in aColCache[] */
2202   u8 iColCache;        /* Next entry in aColCache[] to replace */
2203   u8 isMultiWrite;     /* True if statement may modify/insert multiple rows */
2204   u8 mayAbort;         /* True if statement may throw an ABORT exception */
2205   int aTempReg[8];     /* Holding area for temporary registers */
2206   int nRangeReg;       /* Size of the temporary register block */
2207   int iRangeReg;       /* First register in temporary register block */
2208   int nErr;            /* Number of errors seen */
2209   int nTab;            /* Number of previously allocated VDBE cursors */
2210   int nMem;            /* Number of memory cells used so far */
2211   int nSet;            /* Number of sets used so far */
2212   int nOnce;           /* Number of OP_Once instructions so far */
2213   int ckBase;          /* Base register of data during check constraints */
2214   int iCacheLevel;     /* ColCache valid when aColCache[].iLevel<=iCacheLevel */
2215   int iCacheCnt;       /* Counter used to generate aColCache[].lru values */
2216   struct yColCache {
2217     int iTable;           /* Table cursor number */
2218     int iColumn;          /* Table column number */
2219     u8 tempReg;           /* iReg is a temp register that needs to be freed */
2220     int iLevel;           /* Nesting level */
2221     int iReg;             /* Reg with value of this column. 0 means none. */
2222     int lru;              /* Least recently used entry has the smallest value */
2223   } aColCache[SQLITE_N_COLCACHE];  /* One for each column cache entry */
2224   yDbMask writeMask;   /* Start a write transaction on these databases */
2225   yDbMask cookieMask;  /* Bitmask of schema verified databases */
2226   int cookieGoto;      /* Address of OP_Goto to cookie verifier subroutine */
2227   int cookieValue[SQLITE_MAX_ATTACHED+2];  /* Values of cookies to verify */
2228   int regRowid;        /* Register holding rowid of CREATE TABLE entry */
2229   int regRoot;         /* Register holding root page number for new objects */
2230   int nMaxArg;         /* Max args passed to user function by sub-program */
2231   Token constraintName;/* Name of the constraint currently being parsed */
2232 #ifndef SQLITE_OMIT_SHARED_CACHE
2233   int nTableLock;        /* Number of locks in aTableLock */
2234   TableLock *aTableLock; /* Required table locks for shared-cache mode */
2235 #endif
2236   AutoincInfo *pAinc;  /* Information about AUTOINCREMENT counters */
2237 
2238   /* Information used while coding trigger programs. */
2239   Parse *pToplevel;    /* Parse structure for main program (or NULL) */
2240   Table *pTriggerTab;  /* Table triggers are being coded for */
2241   double nQueryLoop;   /* Estimated number of iterations of a query */
2242   u32 oldmask;         /* Mask of old.* columns referenced */
2243   u32 newmask;         /* Mask of new.* columns referenced */
2244   u8 eTriggerOp;       /* TK_UPDATE, TK_INSERT or TK_DELETE */
2245   u8 eOrconf;          /* Default ON CONFLICT policy for trigger steps */
2246   u8 disableTriggers;  /* True to disable triggers */
2247 
2248   /* Above is constant between recursions.  Below is reset before and after
2249   ** each recursion */
2250 
2251   int nVar;                 /* Number of '?' variables seen in the SQL so far */
2252   int nzVar;                /* Number of available slots in azVar[] */
2253   u8 explain;               /* True if the EXPLAIN flag is found on the query */
2254 #ifndef SQLITE_OMIT_VIRTUALTABLE
2255   u8 declareVtab;           /* True if inside sqlite3_declare_vtab() */
2256   int nVtabLock;            /* Number of virtual tables to lock */
2257 #endif
2258   int nAlias;               /* Number of aliased result set columns */
2259   int nHeight;              /* Expression tree height of current sub-select */
2260 #ifndef SQLITE_OMIT_EXPLAIN
2261   int iSelectId;            /* ID of current select for EXPLAIN output */
2262   int iNextSelectId;        /* Next available select ID for EXPLAIN output */
2263 #endif
2264   char **azVar;             /* Pointers to names of parameters */
2265   Vdbe *pReprepare;         /* VM being reprepared (sqlite3Reprepare()) */
2266   int *aAlias;              /* Register used to hold aliased result */
2267   const char *zTail;        /* All SQL text past the last semicolon parsed */
2268   Table *pNewTable;         /* A table being constructed by CREATE TABLE */
2269   Trigger *pNewTrigger;     /* Trigger under construct by a CREATE TRIGGER */
2270   const char *zAuthContext; /* The 6th parameter to db->xAuth callbacks */
2271   Token sNameToken;         /* Token with unqualified schema object name */
2272   Token sLastToken;         /* The last token parsed */
2273 #ifndef SQLITE_OMIT_VIRTUALTABLE
2274   Token sArg;               /* Complete text of a module argument */
2275   Table **apVtabLock;       /* Pointer to virtual tables needing locking */
2276 #endif
2277   Table *pZombieTab;        /* List of Table objects to delete after code gen */
2278   TriggerPrg *pTriggerPrg;  /* Linked list of coded triggers */
2279 };
2280 
2281 /*
2282 ** Return true if currently inside an sqlite3_declare_vtab() call.
2283 */
2284 #ifdef SQLITE_OMIT_VIRTUALTABLE
2285   #define IN_DECLARE_VTAB 0
2286 #else
2287   #define IN_DECLARE_VTAB (pParse->declareVtab)
2288 #endif
2289 
2290 /*
2291 ** An instance of the following structure can be declared on a stack and used
2292 ** to save the Parse.zAuthContext value so that it can be restored later.
2293 */
2294 struct AuthContext {
2295   const char *zAuthContext;   /* Put saved Parse.zAuthContext here */
2296   Parse *pParse;              /* The Parse structure */
2297 };
2298 
2299 /*
2300 ** Bitfield flags for P5 value in various opcodes.
2301 */
2302 #define OPFLAG_NCHANGE       0x01    /* Set to update db->nChange */
2303 #define OPFLAG_LASTROWID     0x02    /* Set to update db->lastRowid */
2304 #define OPFLAG_ISUPDATE      0x04    /* This OP_Insert is an sql UPDATE */
2305 #define OPFLAG_APPEND        0x08    /* This is likely to be an append */
2306 #define OPFLAG_USESEEKRESULT 0x10    /* Try to avoid a seek in BtreeInsert() */
2307 #define OPFLAG_CLEARCACHE    0x20    /* Clear pseudo-table cache in OP_Column */
2308 #define OPFLAG_LENGTHARG     0x40    /* OP_Column only used for length() */
2309 #define OPFLAG_TYPEOFARG     0x80    /* OP_Column only used for typeof() */
2310 
2311 /*
2312  * Each trigger present in the database schema is stored as an instance of
2313  * struct Trigger.
2314  *
2315  * Pointers to instances of struct Trigger are stored in two ways.
2316  * 1. In the "trigHash" hash table (part of the sqlite3* that represents the
2317  *    database). This allows Trigger structures to be retrieved by name.
2318  * 2. All triggers associated with a single table form a linked list, using the
2319  *    pNext member of struct Trigger. A pointer to the first element of the
2320  *    linked list is stored as the "pTrigger" member of the associated
2321  *    struct Table.
2322  *
2323  * The "step_list" member points to the first element of a linked list
2324  * containing the SQL statements specified as the trigger program.
2325  */
2326 struct Trigger {
2327   char *zName;            /* The name of the trigger                        */
2328   char *table;            /* The table or view to which the trigger applies */
2329   u8 op;                  /* One of TK_DELETE, TK_UPDATE, TK_INSERT         */
2330   u8 tr_tm;               /* One of TRIGGER_BEFORE, TRIGGER_AFTER */
2331   Expr *pWhen;            /* The WHEN clause of the expression (may be NULL) */
2332   IdList *pColumns;       /* If this is an UPDATE OF <column-list> trigger,
2333                              the <column-list> is stored here */
2334   Schema *pSchema;        /* Schema containing the trigger */
2335   Schema *pTabSchema;     /* Schema containing the table */
2336   TriggerStep *step_list; /* Link list of trigger program steps             */
2337   Trigger *pNext;         /* Next trigger associated with the table */
2338 };
2339 
2340 /*
2341 ** A trigger is either a BEFORE or an AFTER trigger.  The following constants
2342 ** determine which.
2343 **
2344 ** If there are multiple triggers, you might of some BEFORE and some AFTER.
2345 ** In that cases, the constants below can be ORed together.
2346 */
2347 #define TRIGGER_BEFORE  1
2348 #define TRIGGER_AFTER   2
2349 
2350 /*
2351  * An instance of struct TriggerStep is used to store a single SQL statement
2352  * that is a part of a trigger-program.
2353  *
2354  * Instances of struct TriggerStep are stored in a singly linked list (linked
2355  * using the "pNext" member) referenced by the "step_list" member of the
2356  * associated struct Trigger instance. The first element of the linked list is
2357  * the first step of the trigger-program.
2358  *
2359  * The "op" member indicates whether this is a "DELETE", "INSERT", "UPDATE" or
2360  * "SELECT" statement. The meanings of the other members is determined by the
2361  * value of "op" as follows:
2362  *
2363  * (op == TK_INSERT)
2364  * orconf    -> stores the ON CONFLICT algorithm
2365  * pSelect   -> If this is an INSERT INTO ... SELECT ... statement, then
2366  *              this stores a pointer to the SELECT statement. Otherwise NULL.
2367  * target    -> A token holding the quoted name of the table to insert into.
2368  * pExprList -> If this is an INSERT INTO ... VALUES ... statement, then
2369  *              this stores values to be inserted. Otherwise NULL.
2370  * pIdList   -> If this is an INSERT INTO ... (<column-names>) VALUES ...
2371  *              statement, then this stores the column-names to be
2372  *              inserted into.
2373  *
2374  * (op == TK_DELETE)
2375  * target    -> A token holding the quoted name of the table to delete from.
2376  * pWhere    -> The WHERE clause of the DELETE statement if one is specified.
2377  *              Otherwise NULL.
2378  *
2379  * (op == TK_UPDATE)
2380  * target    -> A token holding the quoted name of the table to update rows of.
2381  * pWhere    -> The WHERE clause of the UPDATE statement if one is specified.
2382  *              Otherwise NULL.
2383  * pExprList -> A list of the columns to update and the expressions to update
2384  *              them to. See sqlite3Update() documentation of "pChanges"
2385  *              argument.
2386  *
2387  */
2388 struct TriggerStep {
2389   u8 op;               /* One of TK_DELETE, TK_UPDATE, TK_INSERT, TK_SELECT */
2390   u8 orconf;           /* OE_Rollback etc. */
2391   Trigger *pTrig;      /* The trigger that this step is a part of */
2392   Select *pSelect;     /* SELECT statment or RHS of INSERT INTO .. SELECT ... */
2393   Token target;        /* Target table for DELETE, UPDATE, INSERT */
2394   Expr *pWhere;        /* The WHERE clause for DELETE or UPDATE steps */
2395   ExprList *pExprList; /* SET clause for UPDATE.  VALUES clause for INSERT */
2396   IdList *pIdList;     /* Column names for INSERT */
2397   TriggerStep *pNext;  /* Next in the link-list */
2398   TriggerStep *pLast;  /* Last element in link-list. Valid for 1st elem only */
2399 };
2400 
2401 /*
2402 ** The following structure contains information used by the sqliteFix...
2403 ** routines as they walk the parse tree to make database references
2404 ** explicit.
2405 */
2406 typedef struct DbFixer DbFixer;
2407 struct DbFixer {
2408   Parse *pParse;      /* The parsing context.  Error messages written here */
2409   const char *zDb;    /* Make sure all objects are contained in this database */
2410   const char *zType;  /* Type of the container - used for error messages */
2411   const Token *pName; /* Name of the container - used for error messages */
2412 };
2413 
2414 /*
2415 ** An objected used to accumulate the text of a string where we
2416 ** do not necessarily know how big the string will be in the end.
2417 */
2418 struct StrAccum {
2419   sqlite3 *db;         /* Optional database for lookaside.  Can be NULL */
2420   char *zBase;         /* A base allocation.  Not from malloc. */
2421   char *zText;         /* The string collected so far */
2422   int  nChar;          /* Length of the string so far */
2423   int  nAlloc;         /* Amount of space allocated in zText */
2424   int  mxAlloc;        /* Maximum allowed string length */
2425   u8   mallocFailed;   /* Becomes true if any memory allocation fails */
2426   u8   useMalloc;      /* 0: none,  1: sqlite3DbMalloc,  2: sqlite3_malloc */
2427   u8   tooBig;         /* Becomes true if string size exceeds limits */
2428 };
2429 
2430 /*
2431 ** A pointer to this structure is used to communicate information
2432 ** from sqlite3Init and OP_ParseSchema into the sqlite3InitCallback.
2433 */
2434 typedef struct {
2435   sqlite3 *db;        /* The database being initialized */
2436   char **pzErrMsg;    /* Error message stored here */
2437   int iDb;            /* 0 for main database.  1 for TEMP, 2.. for ATTACHed */
2438   int rc;             /* Result code stored here */
2439 } InitData;
2440 
2441 /*
2442 ** Structure containing global configuration data for the SQLite library.
2443 **
2444 ** This structure also contains some state information.
2445 */
2446 struct Sqlite3Config {
2447   int bMemstat;                     /* True to enable memory status */
2448   int bCoreMutex;                   /* True to enable core mutexing */
2449   int bFullMutex;                   /* True to enable full mutexing */
2450   int bOpenUri;                     /* True to interpret filenames as URIs */
2451   int mxStrlen;                     /* Maximum string length */
2452   int szLookaside;                  /* Default lookaside buffer size */
2453   int nLookaside;                   /* Default lookaside buffer count */
2454   sqlite3_mem_methods m;            /* Low-level memory allocation interface */
2455   sqlite3_mutex_methods mutex;      /* Low-level mutex interface */
2456   sqlite3_pcache_methods2 pcache2;  /* Low-level page-cache interface */
2457   void *pHeap;                      /* Heap storage space */
2458   int nHeap;                        /* Size of pHeap[] */
2459   int mnReq, mxReq;                 /* Min and max heap requests sizes */
2460   void *pScratch;                   /* Scratch memory */
2461   int szScratch;                    /* Size of each scratch buffer */
2462   int nScratch;                     /* Number of scratch buffers */
2463   void *pPage;                      /* Page cache memory */
2464   int szPage;                       /* Size of each page in pPage[] */
2465   int nPage;                        /* Number of pages in pPage[] */
2466   int mxParserStack;                /* maximum depth of the parser stack */
2467   int sharedCacheEnabled;           /* true if shared-cache mode enabled */
2468   /* The above might be initialized to non-zero.  The following need to always
2469   ** initially be zero, however. */
2470   int isInit;                       /* True after initialization has finished */
2471   int inProgress;                   /* True while initialization in progress */
2472   int isMutexInit;                  /* True after mutexes are initialized */
2473   int isMallocInit;                 /* True after malloc is initialized */
2474   int isPCacheInit;                 /* True after malloc is initialized */
2475   sqlite3_mutex *pInitMutex;        /* Mutex used by sqlite3_initialize() */
2476   int nRefInitMutex;                /* Number of users of pInitMutex */
2477   void (*xLog)(void*,int,const char*); /* Function for logging */
2478   void *pLogArg;                       /* First argument to xLog() */
2479   int bLocaltimeFault;              /* True to fail localtime() calls */
2480 };
2481 
2482 /*
2483 ** Context pointer passed down through the tree-walk.
2484 */
2485 struct Walker {
2486   int (*xExprCallback)(Walker*, Expr*);     /* Callback for expressions */
2487   int (*xSelectCallback)(Walker*,Select*);  /* Callback for SELECTs */
2488   Parse *pParse;                            /* Parser context.  */
2489   union {                                   /* Extra data for callback */
2490     NameContext *pNC;                          /* Naming context */
2491     int i;                                     /* Integer value */
2492     SrcList *pSrcList;                         /* FROM clause */
2493   } u;
2494 };
2495 
2496 /* Forward declarations */
2497 int sqlite3WalkExpr(Walker*, Expr*);
2498 int sqlite3WalkExprList(Walker*, ExprList*);
2499 int sqlite3WalkSelect(Walker*, Select*);
2500 int sqlite3WalkSelectExpr(Walker*, Select*);
2501 int sqlite3WalkSelectFrom(Walker*, Select*);
2502 
2503 /*
2504 ** Return code from the parse-tree walking primitives and their
2505 ** callbacks.
2506 */
2507 #define WRC_Continue    0   /* Continue down into children */
2508 #define WRC_Prune       1   /* Omit children but continue walking siblings */
2509 #define WRC_Abort       2   /* Abandon the tree walk */
2510 
2511 /*
2512 ** Assuming zIn points to the first byte of a UTF-8 character,
2513 ** advance zIn to point to the first byte of the next UTF-8 character.
2514 */
2515 #define SQLITE_SKIP_UTF8(zIn) {                        \
2516   if( (*(zIn++))>=0xc0 ){                              \
2517     while( (*zIn & 0xc0)==0x80 ){ zIn++; }             \
2518   }                                                    \
2519 }
2520 
2521 /*
2522 ** The SQLITE_*_BKPT macros are substitutes for the error codes with
2523 ** the same name but without the _BKPT suffix.  These macros invoke
2524 ** routines that report the line-number on which the error originated
2525 ** using sqlite3_log().  The routines also provide a convenient place
2526 ** to set a debugger breakpoint.
2527 */
2528 int sqlite3CorruptError(int);
2529 int sqlite3MisuseError(int);
2530 int sqlite3CantopenError(int);
2531 #define SQLITE_CORRUPT_BKPT sqlite3CorruptError(__LINE__)
2532 #define SQLITE_MISUSE_BKPT sqlite3MisuseError(__LINE__)
2533 #define SQLITE_CANTOPEN_BKPT sqlite3CantopenError(__LINE__)
2534 
2535 
2536 /*
2537 ** FTS4 is really an extension for FTS3.  It is enabled using the
2538 ** SQLITE_ENABLE_FTS3 macro.  But to avoid confusion we also all
2539 ** the SQLITE_ENABLE_FTS4 macro to serve as an alisse for SQLITE_ENABLE_FTS3.
2540 */
2541 #if defined(SQLITE_ENABLE_FTS4) && !defined(SQLITE_ENABLE_FTS3)
2542 # define SQLITE_ENABLE_FTS3
2543 #endif
2544 
2545 /*
2546 ** The ctype.h header is needed for non-ASCII systems.  It is also
2547 ** needed by FTS3 when FTS3 is included in the amalgamation.
2548 */
2549 #if !defined(SQLITE_ASCII) || \
2550     (defined(SQLITE_ENABLE_FTS3) && defined(SQLITE_AMALGAMATION))
2551 # include <ctype.h>
2552 #endif
2553 
2554 /*
2555 ** The following macros mimic the standard library functions toupper(),
2556 ** isspace(), isalnum(), isdigit() and isxdigit(), respectively. The
2557 ** sqlite versions only work for ASCII characters, regardless of locale.
2558 */
2559 #ifdef SQLITE_ASCII
2560 # define sqlite3Toupper(x)  ((x)&~(sqlite3CtypeMap[(unsigned char)(x)]&0x20))
2561 # define sqlite3Isspace(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x01)
2562 # define sqlite3Isalnum(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x06)
2563 # define sqlite3Isalpha(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x02)
2564 # define sqlite3Isdigit(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x04)
2565 # define sqlite3Isxdigit(x)  (sqlite3CtypeMap[(unsigned char)(x)]&0x08)
2566 # define sqlite3Tolower(x)   (sqlite3UpperToLower[(unsigned char)(x)])
2567 #else
2568 # define sqlite3Toupper(x)   toupper((unsigned char)(x))
2569 # define sqlite3Isspace(x)   isspace((unsigned char)(x))
2570 # define sqlite3Isalnum(x)   isalnum((unsigned char)(x))
2571 # define sqlite3Isalpha(x)   isalpha((unsigned char)(x))
2572 # define sqlite3Isdigit(x)   isdigit((unsigned char)(x))
2573 # define sqlite3Isxdigit(x)  isxdigit((unsigned char)(x))
2574 # define sqlite3Tolower(x)   tolower((unsigned char)(x))
2575 #endif
2576 
2577 /*
2578 ** Internal function prototypes
2579 */
2580 #define sqlite3StrICmp sqlite3_stricmp
2581 int sqlite3Strlen30(const char*);
2582 #define sqlite3StrNICmp sqlite3_strnicmp
2583 
2584 int sqlite3MallocInit(void);
2585 void sqlite3MallocEnd(void);
2586 void *sqlite3Malloc(int);
2587 void *sqlite3MallocZero(int);
2588 void *sqlite3DbMallocZero(sqlite3*, int);
2589 void *sqlite3DbMallocRaw(sqlite3*, int);
2590 char *sqlite3DbStrDup(sqlite3*,const char*);
2591 char *sqlite3DbStrNDup(sqlite3*,const char*, int);
2592 void *sqlite3Realloc(void*, int);
2593 void *sqlite3DbReallocOrFree(sqlite3 *, void *, int);
2594 void *sqlite3DbRealloc(sqlite3 *, void *, int);
2595 void sqlite3DbFree(sqlite3*, void*);
2596 int sqlite3MallocSize(void*);
2597 int sqlite3DbMallocSize(sqlite3*, void*);
2598 void *sqlite3ScratchMalloc(int);
2599 void sqlite3ScratchFree(void*);
2600 void *sqlite3PageMalloc(int);
2601 void sqlite3PageFree(void*);
2602 void sqlite3MemSetDefault(void);
2603 void sqlite3BenignMallocHooks(void (*)(void), void (*)(void));
2604 int sqlite3HeapNearlyFull(void);
2605 
2606 /*
2607 ** On systems with ample stack space and that support alloca(), make
2608 ** use of alloca() to obtain space for large automatic objects.  By default,
2609 ** obtain space from malloc().
2610 **
2611 ** The alloca() routine never returns NULL.  This will cause code paths
2612 ** that deal with sqlite3StackAlloc() failures to be unreachable.
2613 */
2614 #ifdef SQLITE_USE_ALLOCA
2615 # define sqlite3StackAllocRaw(D,N)   alloca(N)
2616 # define sqlite3StackAllocZero(D,N)  memset(alloca(N), 0, N)
2617 # define sqlite3StackFree(D,P)
2618 #else
2619 # define sqlite3StackAllocRaw(D,N)   sqlite3DbMallocRaw(D,N)
2620 # define sqlite3StackAllocZero(D,N)  sqlite3DbMallocZero(D,N)
2621 # define sqlite3StackFree(D,P)       sqlite3DbFree(D,P)
2622 #endif
2623 
2624 #ifdef SQLITE_ENABLE_MEMSYS3
2625 const sqlite3_mem_methods *sqlite3MemGetMemsys3(void);
2626 #endif
2627 #ifdef SQLITE_ENABLE_MEMSYS5
2628 const sqlite3_mem_methods *sqlite3MemGetMemsys5(void);
2629 #endif
2630 
2631 
2632 #ifndef SQLITE_MUTEX_OMIT
2633   sqlite3_mutex_methods const *sqlite3DefaultMutex(void);
2634   sqlite3_mutex_methods const *sqlite3NoopMutex(void);
2635   sqlite3_mutex *sqlite3MutexAlloc(int);
2636   int sqlite3MutexInit(void);
2637   int sqlite3MutexEnd(void);
2638 #endif
2639 
2640 int sqlite3StatusValue(int);
2641 void sqlite3StatusAdd(int, int);
2642 void sqlite3StatusSet(int, int);
2643 
2644 #ifndef SQLITE_OMIT_FLOATING_POINT
2645   int sqlite3IsNaN(double);
2646 #else
2647 # define sqlite3IsNaN(X)  0
2648 #endif
2649 
2650 void sqlite3VXPrintf(StrAccum*, int, const char*, va_list);
2651 #ifndef SQLITE_OMIT_TRACE
2652 void sqlite3XPrintf(StrAccum*, const char*, ...);
2653 #endif
2654 char *sqlite3MPrintf(sqlite3*,const char*, ...);
2655 char *sqlite3VMPrintf(sqlite3*,const char*, va_list);
2656 char *sqlite3MAppendf(sqlite3*,char*,const char*,...);
2657 #if defined(SQLITE_TEST) || defined(SQLITE_DEBUG)
2658   void sqlite3DebugPrintf(const char*, ...);
2659 #endif
2660 #if defined(SQLITE_TEST)
2661   void *sqlite3TestTextToPtr(const char*);
2662 #endif
2663 
2664 /* Output formatting for SQLITE_TESTCTRL_EXPLAIN */
2665 #if defined(SQLITE_ENABLE_TREE_EXPLAIN)
2666   void sqlite3ExplainBegin(Vdbe*);
2667   void sqlite3ExplainPrintf(Vdbe*, const char*, ...);
2668   void sqlite3ExplainNL(Vdbe*);
2669   void sqlite3ExplainPush(Vdbe*);
2670   void sqlite3ExplainPop(Vdbe*);
2671   void sqlite3ExplainFinish(Vdbe*);
2672   void sqlite3ExplainSelect(Vdbe*, Select*);
2673   void sqlite3ExplainExpr(Vdbe*, Expr*);
2674   void sqlite3ExplainExprList(Vdbe*, ExprList*);
2675   const char *sqlite3VdbeExplanation(Vdbe*);
2676 #else
2677 # define sqlite3ExplainBegin(X)
2678 # define sqlite3ExplainSelect(A,B)
2679 # define sqlite3ExplainExpr(A,B)
2680 # define sqlite3ExplainExprList(A,B)
2681 # define sqlite3ExplainFinish(X)
2682 # define sqlite3VdbeExplanation(X) 0
2683 #endif
2684 
2685 
2686 void sqlite3SetString(char **, sqlite3*, const char*, ...);
2687 void sqlite3ErrorMsg(Parse*, const char*, ...);
2688 int sqlite3Dequote(char*);
2689 int sqlite3KeywordCode(const unsigned char*, int);
2690 int sqlite3RunParser(Parse*, const char*, char **);
2691 void sqlite3FinishCoding(Parse*);
2692 int sqlite3GetTempReg(Parse*);
2693 void sqlite3ReleaseTempReg(Parse*,int);
2694 int sqlite3GetTempRange(Parse*,int);
2695 void sqlite3ReleaseTempRange(Parse*,int,int);
2696 void sqlite3ClearTempRegCache(Parse*);
2697 Expr *sqlite3ExprAlloc(sqlite3*,int,const Token*,int);
2698 Expr *sqlite3Expr(sqlite3*,int,const char*);
2699 void sqlite3ExprAttachSubtrees(sqlite3*,Expr*,Expr*,Expr*);
2700 Expr *sqlite3PExpr(Parse*, int, Expr*, Expr*, const Token*);
2701 Expr *sqlite3ExprAnd(sqlite3*,Expr*, Expr*);
2702 Expr *sqlite3ExprFunction(Parse*,ExprList*, Token*);
2703 void sqlite3ExprAssignVarNumber(Parse*, Expr*);
2704 void sqlite3ExprDelete(sqlite3*, Expr*);
2705 ExprList *sqlite3ExprListAppend(Parse*,ExprList*,Expr*);
2706 void sqlite3ExprListSetName(Parse*,ExprList*,Token*,int);
2707 void sqlite3ExprListSetSpan(Parse*,ExprList*,ExprSpan*);
2708 void sqlite3ExprListDelete(sqlite3*, ExprList*);
2709 int sqlite3Init(sqlite3*, char**);
2710 int sqlite3InitCallback(void*, int, char**, char**);
2711 void sqlite3Pragma(Parse*,Token*,Token*,Token*,int);
2712 void sqlite3ResetAllSchemasOfConnection(sqlite3*);
2713 void sqlite3ResetOneSchema(sqlite3*,int);
2714 void sqlite3CollapseDatabaseArray(sqlite3*);
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 Btree *sqlite3DbNameToBtree(sqlite3*,const char*);
2731 int sqlite3CodeOnce(Parse *);
2732 
2733 Bitvec *sqlite3BitvecCreate(u32);
2734 int sqlite3BitvecTest(Bitvec*, u32);
2735 int sqlite3BitvecSet(Bitvec*, u32);
2736 void sqlite3BitvecClear(Bitvec*, u32, void*);
2737 void sqlite3BitvecDestroy(Bitvec*);
2738 u32 sqlite3BitvecSize(Bitvec*);
2739 int sqlite3BitvecBuiltinTest(int,int*);
2740 
2741 RowSet *sqlite3RowSetInit(sqlite3*, void*, unsigned int);
2742 void sqlite3RowSetClear(RowSet*);
2743 void sqlite3RowSetInsert(RowSet*, i64);
2744 int sqlite3RowSetTest(RowSet*, u8 iBatch, i64);
2745 int sqlite3RowSetNext(RowSet*, i64*);
2746 
2747 void sqlite3CreateView(Parse*,Token*,Token*,Token*,Select*,int,int);
2748 
2749 #if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE)
2750   int sqlite3ViewGetColumnNames(Parse*,Table*);
2751 #else
2752 # define sqlite3ViewGetColumnNames(A,B) 0
2753 #endif
2754 
2755 void sqlite3DropTable(Parse*, SrcList*, int, int);
2756 void sqlite3CodeDropTable(Parse*, Table*, int, int);
2757 void sqlite3DeleteTable(sqlite3*, Table*);
2758 #ifndef SQLITE_OMIT_AUTOINCREMENT
2759   void sqlite3AutoincrementBegin(Parse *pParse);
2760   void sqlite3AutoincrementEnd(Parse *pParse);
2761 #else
2762 # define sqlite3AutoincrementBegin(X)
2763 # define sqlite3AutoincrementEnd(X)
2764 #endif
2765 void sqlite3Insert(Parse*, SrcList*, ExprList*, Select*, IdList*, int);
2766 void *sqlite3ArrayAllocate(sqlite3*,void*,int,int*,int*);
2767 IdList *sqlite3IdListAppend(sqlite3*, IdList*, Token*);
2768 int sqlite3IdListIndex(IdList*,const char*);
2769 SrcList *sqlite3SrcListEnlarge(sqlite3*, SrcList*, int, int);
2770 SrcList *sqlite3SrcListAppend(sqlite3*, SrcList*, Token*, Token*);
2771 SrcList *sqlite3SrcListAppendFromTerm(Parse*, SrcList*, Token*, Token*,
2772                                       Token*, Select*, Expr*, IdList*);
2773 void sqlite3SrcListIndexedBy(Parse *, SrcList *, Token *);
2774 int sqlite3IndexedByLookup(Parse *, struct SrcList_item *);
2775 void sqlite3SrcListShiftJoinType(SrcList*);
2776 void sqlite3SrcListAssignCursors(Parse*, SrcList*);
2777 void sqlite3IdListDelete(sqlite3*, IdList*);
2778 void sqlite3SrcListDelete(sqlite3*, SrcList*);
2779 Index *sqlite3CreateIndex(Parse*,Token*,Token*,SrcList*,ExprList*,int,Token*,
2780                         Token*, int, int);
2781 void sqlite3DropIndex(Parse*, SrcList*, int);
2782 int sqlite3Select(Parse*, Select*, SelectDest*);
2783 Select *sqlite3SelectNew(Parse*,ExprList*,SrcList*,Expr*,ExprList*,
2784                          Expr*,ExprList*,int,Expr*,Expr*);
2785 void sqlite3SelectDelete(sqlite3*, Select*);
2786 Table *sqlite3SrcListLookup(Parse*, SrcList*);
2787 int sqlite3IsReadOnly(Parse*, Table*, int);
2788 void sqlite3OpenTable(Parse*, int iCur, int iDb, Table*, int);
2789 #if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY)
2790 Expr *sqlite3LimitWhere(Parse *, SrcList *, Expr *, ExprList *, Expr *, Expr *, char *);
2791 #endif
2792 void sqlite3DeleteFrom(Parse*, SrcList*, Expr*);
2793 void sqlite3Update(Parse*, SrcList*, ExprList*, Expr*, int);
2794 WhereInfo *sqlite3WhereBegin(Parse*, SrcList*, Expr*, ExprList**,ExprList*,u16);
2795 void sqlite3WhereEnd(WhereInfo*);
2796 int sqlite3ExprCodeGetColumn(Parse*, Table*, int, int, int, u8);
2797 void sqlite3ExprCodeGetColumnOfTable(Vdbe*, Table*, int, int, int);
2798 void sqlite3ExprCodeMove(Parse*, int, int, int);
2799 void sqlite3ExprCodeCopy(Parse*, int, int, int);
2800 void sqlite3ExprCacheStore(Parse*, int, int, int);
2801 void sqlite3ExprCachePush(Parse*);
2802 void sqlite3ExprCachePop(Parse*, int);
2803 void sqlite3ExprCacheRemove(Parse*, int, int);
2804 void sqlite3ExprCacheClear(Parse*);
2805 void sqlite3ExprCacheAffinityChange(Parse*, int, int);
2806 int sqlite3ExprCode(Parse*, Expr*, int);
2807 int sqlite3ExprCodeTemp(Parse*, Expr*, int*);
2808 int sqlite3ExprCodeTarget(Parse*, Expr*, int);
2809 int sqlite3ExprCodeAndCache(Parse*, Expr*, int);
2810 void sqlite3ExprCodeConstants(Parse*, Expr*);
2811 int sqlite3ExprCodeExprList(Parse*, ExprList*, int, int);
2812 void sqlite3ExprIfTrue(Parse*, Expr*, int, int);
2813 void sqlite3ExprIfFalse(Parse*, Expr*, int, int);
2814 Table *sqlite3FindTable(sqlite3*,const char*, const char*);
2815 Table *sqlite3LocateTable(Parse*,int isView,const char*, const char*);
2816 Index *sqlite3FindIndex(sqlite3*,const char*, const char*);
2817 void sqlite3UnlinkAndDeleteTable(sqlite3*,int,const char*);
2818 void sqlite3UnlinkAndDeleteIndex(sqlite3*,int,const char*);
2819 void sqlite3Vacuum(Parse*);
2820 int sqlite3RunVacuum(char**, sqlite3*);
2821 char *sqlite3NameFromToken(sqlite3*, Token*);
2822 int sqlite3ExprCompare(Expr*, Expr*);
2823 int sqlite3ExprListCompare(ExprList*, ExprList*);
2824 void sqlite3ExprAnalyzeAggregates(NameContext*, Expr*);
2825 void sqlite3ExprAnalyzeAggList(NameContext*,ExprList*);
2826 Vdbe *sqlite3GetVdbe(Parse*);
2827 void sqlite3PrngSaveState(void);
2828 void sqlite3PrngRestoreState(void);
2829 void sqlite3PrngResetState(void);
2830 void sqlite3RollbackAll(sqlite3*,int);
2831 void sqlite3CodeVerifySchema(Parse*, int);
2832 void sqlite3CodeVerifyNamedSchema(Parse*, const char *zDb);
2833 void sqlite3BeginTransaction(Parse*, int);
2834 void sqlite3CommitTransaction(Parse*);
2835 void sqlite3RollbackTransaction(Parse*);
2836 void sqlite3Savepoint(Parse*, int, Token*);
2837 void sqlite3CloseSavepoints(sqlite3 *);
2838 int sqlite3ExprIsConstant(Expr*);
2839 int sqlite3ExprIsConstantNotJoin(Expr*);
2840 int sqlite3ExprIsConstantOrFunction(Expr*);
2841 int sqlite3ExprIsInteger(Expr*, int*);
2842 int sqlite3ExprCanBeNull(const Expr*);
2843 void sqlite3ExprCodeIsNullJump(Vdbe*, const Expr*, int, int);
2844 int sqlite3ExprNeedsNoAffinityChange(const Expr*, char);
2845 int sqlite3IsRowid(const char*);
2846 void sqlite3GenerateRowDelete(Parse*, Table*, int, int, int, Trigger *, int);
2847 void sqlite3GenerateRowIndexDelete(Parse*, Table*, int, int*);
2848 int sqlite3GenerateIndexKey(Parse*, Index*, int, int, int);
2849 void sqlite3GenerateConstraintChecks(Parse*,Table*,int,int,
2850                                      int*,int,int,int,int,int*);
2851 void sqlite3CompleteInsertion(Parse*, Table*, int, int, int*, int, int, int);
2852 int sqlite3OpenTableAndIndices(Parse*, Table*, int, int);
2853 void sqlite3BeginWriteOperation(Parse*, int, int);
2854 void sqlite3MultiWrite(Parse*);
2855 void sqlite3MayAbort(Parse*);
2856 void sqlite3HaltConstraint(Parse*, int, char*, int);
2857 Expr *sqlite3ExprDup(sqlite3*,Expr*,int);
2858 ExprList *sqlite3ExprListDup(sqlite3*,ExprList*,int);
2859 SrcList *sqlite3SrcListDup(sqlite3*,SrcList*,int);
2860 IdList *sqlite3IdListDup(sqlite3*,IdList*);
2861 Select *sqlite3SelectDup(sqlite3*,Select*,int);
2862 void sqlite3FuncDefInsert(FuncDefHash*, FuncDef*);
2863 FuncDef *sqlite3FindFunction(sqlite3*,const char*,int,int,u8,u8);
2864 void sqlite3RegisterBuiltinFunctions(sqlite3*);
2865 void sqlite3RegisterDateTimeFunctions(void);
2866 void sqlite3RegisterGlobalFunctions(void);
2867 int sqlite3SafetyCheckOk(sqlite3*);
2868 int sqlite3SafetyCheckSickOrOk(sqlite3*);
2869 void sqlite3ChangeCookie(Parse*, int);
2870 
2871 #if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
2872 void sqlite3MaterializeView(Parse*, Table*, Expr*, int);
2873 #endif
2874 
2875 #ifndef SQLITE_OMIT_TRIGGER
2876   void sqlite3BeginTrigger(Parse*, Token*,Token*,int,int,IdList*,SrcList*,
2877                            Expr*,int, int);
2878   void sqlite3FinishTrigger(Parse*, TriggerStep*, Token*);
2879   void sqlite3DropTrigger(Parse*, SrcList*, int);
2880   void sqlite3DropTriggerPtr(Parse*, Trigger*);
2881   Trigger *sqlite3TriggersExist(Parse *, Table*, int, ExprList*, int *pMask);
2882   Trigger *sqlite3TriggerList(Parse *, Table *);
2883   void sqlite3CodeRowTrigger(Parse*, Trigger *, int, ExprList*, int, Table *,
2884                             int, int, int);
2885   void sqlite3CodeRowTriggerDirect(Parse *, Trigger *, Table *, int, int, int);
2886   void sqliteViewTriggers(Parse*, Table*, Expr*, int, ExprList*);
2887   void sqlite3DeleteTriggerStep(sqlite3*, TriggerStep*);
2888   TriggerStep *sqlite3TriggerSelectStep(sqlite3*,Select*);
2889   TriggerStep *sqlite3TriggerInsertStep(sqlite3*,Token*, IdList*,
2890                                         ExprList*,Select*,u8);
2891   TriggerStep *sqlite3TriggerUpdateStep(sqlite3*,Token*,ExprList*, Expr*, u8);
2892   TriggerStep *sqlite3TriggerDeleteStep(sqlite3*,Token*, Expr*);
2893   void sqlite3DeleteTrigger(sqlite3*, Trigger*);
2894   void sqlite3UnlinkAndDeleteTrigger(sqlite3*,int,const char*);
2895   u32 sqlite3TriggerColmask(Parse*,Trigger*,ExprList*,int,int,Table*,int);
2896 # define sqlite3ParseToplevel(p) ((p)->pToplevel ? (p)->pToplevel : (p))
2897 #else
2898 # define sqlite3TriggersExist(B,C,D,E,F) 0
2899 # define sqlite3DeleteTrigger(A,B)
2900 # define sqlite3DropTriggerPtr(A,B)
2901 # define sqlite3UnlinkAndDeleteTrigger(A,B,C)
2902 # define sqlite3CodeRowTrigger(A,B,C,D,E,F,G,H,I)
2903 # define sqlite3CodeRowTriggerDirect(A,B,C,D,E,F)
2904 # define sqlite3TriggerList(X, Y) 0
2905 # define sqlite3ParseToplevel(p) p
2906 # define sqlite3TriggerColmask(A,B,C,D,E,F,G) 0
2907 #endif
2908 
2909 int sqlite3JoinType(Parse*, Token*, Token*, Token*);
2910 void sqlite3CreateForeignKey(Parse*, ExprList*, Token*, ExprList*, int);
2911 void sqlite3DeferForeignKey(Parse*, int);
2912 #ifndef SQLITE_OMIT_AUTHORIZATION
2913   void sqlite3AuthRead(Parse*,Expr*,Schema*,SrcList*);
2914   int sqlite3AuthCheck(Parse*,int, const char*, const char*, const char*);
2915   void sqlite3AuthContextPush(Parse*, AuthContext*, const char*);
2916   void sqlite3AuthContextPop(AuthContext*);
2917   int sqlite3AuthReadCol(Parse*, const char *, const char *, int);
2918 #else
2919 # define sqlite3AuthRead(a,b,c,d)
2920 # define sqlite3AuthCheck(a,b,c,d,e)    SQLITE_OK
2921 # define sqlite3AuthContextPush(a,b,c)
2922 # define sqlite3AuthContextPop(a)  ((void)(a))
2923 #endif
2924 void sqlite3Attach(Parse*, Expr*, Expr*, Expr*);
2925 void sqlite3Detach(Parse*, Expr*);
2926 int sqlite3FixInit(DbFixer*, Parse*, int, const char*, const Token*);
2927 int sqlite3FixSrcList(DbFixer*, SrcList*);
2928 int sqlite3FixSelect(DbFixer*, Select*);
2929 int sqlite3FixExpr(DbFixer*, Expr*);
2930 int sqlite3FixExprList(DbFixer*, ExprList*);
2931 int sqlite3FixTriggerStep(DbFixer*, TriggerStep*);
2932 int sqlite3AtoF(const char *z, double*, int, u8);
2933 int sqlite3GetInt32(const char *, int*);
2934 int sqlite3Atoi(const char*);
2935 int sqlite3Utf16ByteLen(const void *pData, int nChar);
2936 int sqlite3Utf8CharLen(const char *pData, int nByte);
2937 u32 sqlite3Utf8Read(const u8*, const u8**);
2938 
2939 /*
2940 ** Routines to read and write variable-length integers.  These used to
2941 ** be defined locally, but now we use the varint routines in the util.c
2942 ** file.  Code should use the MACRO forms below, as the Varint32 versions
2943 ** are coded to assume the single byte case is already handled (which
2944 ** the MACRO form does).
2945 */
2946 int sqlite3PutVarint(unsigned char*, u64);
2947 int sqlite3PutVarint32(unsigned char*, u32);
2948 u8 sqlite3GetVarint(const unsigned char *, u64 *);
2949 u8 sqlite3GetVarint32(const unsigned char *, u32 *);
2950 int sqlite3VarintLen(u64 v);
2951 
2952 /*
2953 ** The header of a record consists of a sequence variable-length integers.
2954 ** These integers are almost always small and are encoded as a single byte.
2955 ** The following macros take advantage this fact to provide a fast encode
2956 ** and decode of the integers in a record header.  It is faster for the common
2957 ** case where the integer is a single byte.  It is a little slower when the
2958 ** integer is two or more bytes.  But overall it is faster.
2959 **
2960 ** The following expressions are equivalent:
2961 **
2962 **     x = sqlite3GetVarint32( A, &B );
2963 **     x = sqlite3PutVarint32( A, B );
2964 **
2965 **     x = getVarint32( A, B );
2966 **     x = putVarint32( A, B );
2967 **
2968 */
2969 #define getVarint32(A,B)  (u8)((*(A)<(u8)0x80) ? ((B) = (u32)*(A)),1 : sqlite3GetVarint32((A), (u32 *)&(B)))
2970 #define putVarint32(A,B)  (u8)(((u32)(B)<(u32)0x80) ? (*(A) = (unsigned char)(B)),1 : sqlite3PutVarint32((A), (B)))
2971 #define getVarint    sqlite3GetVarint
2972 #define putVarint    sqlite3PutVarint
2973 
2974 
2975 const char *sqlite3IndexAffinityStr(Vdbe *, Index *);
2976 void sqlite3TableAffinityStr(Vdbe *, Table *);
2977 char sqlite3CompareAffinity(Expr *pExpr, char aff2);
2978 int sqlite3IndexAffinityOk(Expr *pExpr, char idx_affinity);
2979 char sqlite3ExprAffinity(Expr *pExpr);
2980 int sqlite3Atoi64(const char*, i64*, int, u8);
2981 void sqlite3Error(sqlite3*, int, const char*,...);
2982 void *sqlite3HexToBlob(sqlite3*, const char *z, int n);
2983 u8 sqlite3HexToInt(int h);
2984 int sqlite3TwoPartName(Parse *, Token *, Token *, Token **);
2985 const char *sqlite3ErrStr(int);
2986 int sqlite3ReadSchema(Parse *pParse);
2987 CollSeq *sqlite3FindCollSeq(sqlite3*,u8 enc, const char*,int);
2988 CollSeq *sqlite3LocateCollSeq(Parse *pParse, const char*zName);
2989 CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr);
2990 Expr *sqlite3ExprSetColl(Expr*, CollSeq*);
2991 Expr *sqlite3ExprSetCollByToken(Parse *pParse, Expr*, Token*);
2992 int sqlite3CheckCollSeq(Parse *, CollSeq *);
2993 int sqlite3CheckObjectName(Parse *, const char *);
2994 void sqlite3VdbeSetChanges(sqlite3 *, int);
2995 int sqlite3AddInt64(i64*,i64);
2996 int sqlite3SubInt64(i64*,i64);
2997 int sqlite3MulInt64(i64*,i64);
2998 int sqlite3AbsInt32(int);
2999 #ifdef SQLITE_ENABLE_8_3_NAMES
3000 void sqlite3FileSuffix3(const char*, char*);
3001 #else
3002 # define sqlite3FileSuffix3(X,Y)
3003 #endif
3004 u8 sqlite3GetBoolean(const char *z,int);
3005 
3006 const void *sqlite3ValueText(sqlite3_value*, u8);
3007 int sqlite3ValueBytes(sqlite3_value*, u8);
3008 void sqlite3ValueSetStr(sqlite3_value*, int, const void *,u8,
3009                         void(*)(void*));
3010 void sqlite3ValueFree(sqlite3_value*);
3011 sqlite3_value *sqlite3ValueNew(sqlite3 *);
3012 char *sqlite3Utf16to8(sqlite3 *, const void*, int, u8);
3013 #ifdef SQLITE_ENABLE_STAT3
3014 char *sqlite3Utf8to16(sqlite3 *, u8, char *, int, int *);
3015 #endif
3016 int sqlite3ValueFromExpr(sqlite3 *, Expr *, u8, u8, sqlite3_value **);
3017 void sqlite3ValueApplyAffinity(sqlite3_value *, u8, u8);
3018 #ifndef SQLITE_AMALGAMATION
3019 extern const unsigned char sqlite3OpcodeProperty[];
3020 extern const unsigned char sqlite3UpperToLower[];
3021 extern const unsigned char sqlite3CtypeMap[];
3022 extern const Token sqlite3IntTokens[];
3023 extern SQLITE_WSD struct Sqlite3Config sqlite3Config;
3024 extern SQLITE_WSD FuncDefHash sqlite3GlobalFunctions;
3025 #ifndef SQLITE_OMIT_WSD
3026 extern int sqlite3PendingByte;
3027 #endif
3028 #endif
3029 void sqlite3RootPageMoved(sqlite3*, int, int, int);
3030 void sqlite3Reindex(Parse*, Token*, Token*);
3031 void sqlite3AlterFunctions(void);
3032 void sqlite3AlterRenameTable(Parse*, SrcList*, Token*);
3033 int sqlite3GetToken(const unsigned char *, int *);
3034 void sqlite3NestedParse(Parse*, const char*, ...);
3035 void sqlite3ExpirePreparedStatements(sqlite3*);
3036 int sqlite3CodeSubselect(Parse *, Expr *, int, int);
3037 void sqlite3SelectPrep(Parse*, Select*, NameContext*);
3038 int sqlite3ResolveExprNames(NameContext*, Expr*);
3039 void sqlite3ResolveSelectNames(Parse*, Select*, NameContext*);
3040 int sqlite3ResolveOrderGroupBy(Parse*, Select*, ExprList*, const char*);
3041 void sqlite3ColumnDefault(Vdbe *, Table *, int, int);
3042 void sqlite3AlterFinishAddColumn(Parse *, Token *);
3043 void sqlite3AlterBeginAddColumn(Parse *, SrcList *);
3044 CollSeq *sqlite3GetCollSeq(sqlite3*, u8, CollSeq *, const char*);
3045 char sqlite3AffinityType(const char*);
3046 void sqlite3Analyze(Parse*, Token*, Token*);
3047 int sqlite3InvokeBusyHandler(BusyHandler*);
3048 int sqlite3FindDb(sqlite3*, Token*);
3049 int sqlite3FindDbName(sqlite3 *, const char *);
3050 int sqlite3AnalysisLoad(sqlite3*,int iDB);
3051 void sqlite3DeleteIndexSamples(sqlite3*,Index*);
3052 void sqlite3DefaultRowEst(Index*);
3053 void sqlite3RegisterLikeFunctions(sqlite3*, int);
3054 int sqlite3IsLikeFunction(sqlite3*,Expr*,int*,char*);
3055 void sqlite3MinimumFileFormat(Parse*, int, int);
3056 void sqlite3SchemaClear(void *);
3057 Schema *sqlite3SchemaGet(sqlite3 *, Btree *);
3058 int sqlite3SchemaToIndex(sqlite3 *db, Schema *);
3059 KeyInfo *sqlite3IndexKeyinfo(Parse *, Index *);
3060 int sqlite3CreateFunc(sqlite3 *, const char *, int, int, void *,
3061   void (*)(sqlite3_context*,int,sqlite3_value **),
3062   void (*)(sqlite3_context*,int,sqlite3_value **), void (*)(sqlite3_context*),
3063   FuncDestructor *pDestructor
3064 );
3065 int sqlite3ApiExit(sqlite3 *db, int);
3066 int sqlite3OpenTempDatabase(Parse *);
3067 
3068 void sqlite3StrAccumInit(StrAccum*, char*, int, int);
3069 void sqlite3StrAccumAppend(StrAccum*,const char*,int);
3070 void sqlite3AppendSpace(StrAccum*,int);
3071 char *sqlite3StrAccumFinish(StrAccum*);
3072 void sqlite3StrAccumReset(StrAccum*);
3073 void sqlite3SelectDestInit(SelectDest*,int,int);
3074 Expr *sqlite3CreateColumnExpr(sqlite3 *, SrcList *, int, int);
3075 
3076 void sqlite3BackupRestart(sqlite3_backup *);
3077 void sqlite3BackupUpdate(sqlite3_backup *, Pgno, const u8 *);
3078 
3079 /*
3080 ** The interface to the LEMON-generated parser
3081 */
3082 void *sqlite3ParserAlloc(void*(*)(size_t));
3083 void sqlite3ParserFree(void*, void(*)(void*));
3084 void sqlite3Parser(void*, int, Token, Parse*);
3085 #ifdef YYTRACKMAXSTACKDEPTH
3086   int sqlite3ParserStackPeak(void*);
3087 #endif
3088 
3089 void sqlite3AutoLoadExtensions(sqlite3*);
3090 #ifndef SQLITE_OMIT_LOAD_EXTENSION
3091   void sqlite3CloseExtensions(sqlite3*);
3092 #else
3093 # define sqlite3CloseExtensions(X)
3094 #endif
3095 
3096 #ifndef SQLITE_OMIT_SHARED_CACHE
3097   void sqlite3TableLock(Parse *, int, int, u8, const char *);
3098 #else
3099   #define sqlite3TableLock(v,w,x,y,z)
3100 #endif
3101 
3102 #ifdef SQLITE_TEST
3103   int sqlite3Utf8To8(unsigned char*);
3104 #endif
3105 
3106 #ifdef SQLITE_OMIT_VIRTUALTABLE
3107 #  define sqlite3VtabClear(Y)
3108 #  define sqlite3VtabSync(X,Y) SQLITE_OK
3109 #  define sqlite3VtabRollback(X)
3110 #  define sqlite3VtabCommit(X)
3111 #  define sqlite3VtabInSync(db) 0
3112 #  define sqlite3VtabLock(X)
3113 #  define sqlite3VtabUnlock(X)
3114 #  define sqlite3VtabUnlockList(X)
3115 #  define sqlite3VtabSavepoint(X, Y, Z) SQLITE_OK
3116 #  define sqlite3GetVTable(X,Y)  ((VTable*)0)
3117 #else
3118    void sqlite3VtabClear(sqlite3 *db, Table*);
3119    void sqlite3VtabDisconnect(sqlite3 *db, Table *p);
3120    int sqlite3VtabSync(sqlite3 *db, char **);
3121    int sqlite3VtabRollback(sqlite3 *db);
3122    int sqlite3VtabCommit(sqlite3 *db);
3123    void sqlite3VtabLock(VTable *);
3124    void sqlite3VtabUnlock(VTable *);
3125    void sqlite3VtabUnlockList(sqlite3*);
3126    int sqlite3VtabSavepoint(sqlite3 *, int, int);
3127    VTable *sqlite3GetVTable(sqlite3*, Table*);
3128 #  define sqlite3VtabInSync(db) ((db)->nVTrans>0 && (db)->aVTrans==0)
3129 #endif
3130 void sqlite3VtabMakeWritable(Parse*,Table*);
3131 void sqlite3VtabBeginParse(Parse*, Token*, Token*, Token*, int);
3132 void sqlite3VtabFinishParse(Parse*, Token*);
3133 void sqlite3VtabArgInit(Parse*);
3134 void sqlite3VtabArgExtend(Parse*, Token*);
3135 int sqlite3VtabCallCreate(sqlite3*, int, const char *, char **);
3136 int sqlite3VtabCallConnect(Parse*, Table*);
3137 int sqlite3VtabCallDestroy(sqlite3*, int, const char *);
3138 int sqlite3VtabBegin(sqlite3 *, VTable *);
3139 FuncDef *sqlite3VtabOverloadFunction(sqlite3 *,FuncDef*, int nArg, Expr*);
3140 void sqlite3InvalidFunction(sqlite3_context*,int,sqlite3_value**);
3141 int sqlite3VdbeParameterIndex(Vdbe*, const char*, int);
3142 int sqlite3TransferBindings(sqlite3_stmt *, sqlite3_stmt *);
3143 int sqlite3Reprepare(Vdbe*);
3144 void sqlite3ExprListCheckLength(Parse*, ExprList*, const char*);
3145 CollSeq *sqlite3BinaryCompareCollSeq(Parse *, Expr *, Expr *);
3146 int sqlite3TempInMemory(const sqlite3*);
3147 const char *sqlite3JournalModename(int);
3148 int sqlite3Checkpoint(sqlite3*, int, int, int*, int*);
3149 int sqlite3WalDefaultHook(void*,sqlite3*,const char*,int);
3150 
3151 /* Declarations for functions in fkey.c. All of these are replaced by
3152 ** no-op macros if OMIT_FOREIGN_KEY is defined. In this case no foreign
3153 ** key functionality is available. If OMIT_TRIGGER is defined but
3154 ** OMIT_FOREIGN_KEY is not, only some of the functions are no-oped. In
3155 ** this case foreign keys are parsed, but no other functionality is
3156 ** provided (enforcement of FK constraints requires the triggers sub-system).
3157 */
3158 #if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)
3159   void sqlite3FkCheck(Parse*, Table*, int, int);
3160   void sqlite3FkDropTable(Parse*, SrcList *, Table*);
3161   void sqlite3FkActions(Parse*, Table*, ExprList*, int);
3162   int sqlite3FkRequired(Parse*, Table*, int*, int);
3163   u32 sqlite3FkOldmask(Parse*, Table*);
3164   FKey *sqlite3FkReferences(Table *);
3165 #else
3166   #define sqlite3FkActions(a,b,c,d)
3167   #define sqlite3FkCheck(a,b,c,d)
3168   #define sqlite3FkDropTable(a,b,c)
3169   #define sqlite3FkOldmask(a,b)      0
3170   #define sqlite3FkRequired(a,b,c,d) 0
3171 #endif
3172 #ifndef SQLITE_OMIT_FOREIGN_KEY
3173   void sqlite3FkDelete(sqlite3 *, Table*);
3174 #else
3175   #define sqlite3FkDelete(a,b)
3176 #endif
3177 
3178 
3179 /*
3180 ** Available fault injectors.  Should be numbered beginning with 0.
3181 */
3182 #define SQLITE_FAULTINJECTOR_MALLOC     0
3183 #define SQLITE_FAULTINJECTOR_COUNT      1
3184 
3185 /*
3186 ** The interface to the code in fault.c used for identifying "benign"
3187 ** malloc failures. This is only present if SQLITE_OMIT_BUILTIN_TEST
3188 ** is not defined.
3189 */
3190 #ifndef SQLITE_OMIT_BUILTIN_TEST
3191   void sqlite3BeginBenignMalloc(void);
3192   void sqlite3EndBenignMalloc(void);
3193 #else
3194   #define sqlite3BeginBenignMalloc()
3195   #define sqlite3EndBenignMalloc()
3196 #endif
3197 
3198 #define IN_INDEX_ROWID           1
3199 #define IN_INDEX_EPH             2
3200 #define IN_INDEX_INDEX           3
3201 int sqlite3FindInIndex(Parse *, Expr *, int*);
3202 
3203 #ifdef SQLITE_ENABLE_ATOMIC_WRITE
3204   int sqlite3JournalOpen(sqlite3_vfs *, const char *, sqlite3_file *, int, int);
3205   int sqlite3JournalSize(sqlite3_vfs *);
3206   int sqlite3JournalCreate(sqlite3_file *);
3207 #else
3208   #define sqlite3JournalSize(pVfs) ((pVfs)->szOsFile)
3209 #endif
3210 
3211 void sqlite3MemJournalOpen(sqlite3_file *);
3212 int sqlite3MemJournalSize(void);
3213 int sqlite3IsMemJournal(sqlite3_file *);
3214 
3215 #if SQLITE_MAX_EXPR_DEPTH>0
3216   void sqlite3ExprSetHeight(Parse *pParse, Expr *p);
3217   int sqlite3SelectExprHeight(Select *);
3218   int sqlite3ExprCheckHeight(Parse*, int);
3219 #else
3220   #define sqlite3ExprSetHeight(x,y)
3221   #define sqlite3SelectExprHeight(x) 0
3222   #define sqlite3ExprCheckHeight(x,y)
3223 #endif
3224 
3225 u32 sqlite3Get4byte(const u8*);
3226 void sqlite3Put4byte(u8*, u32);
3227 
3228 #ifdef SQLITE_ENABLE_UNLOCK_NOTIFY
3229   void sqlite3ConnectionBlocked(sqlite3 *, sqlite3 *);
3230   void sqlite3ConnectionUnlocked(sqlite3 *db);
3231   void sqlite3ConnectionClosed(sqlite3 *db);
3232 #else
3233   #define sqlite3ConnectionBlocked(x,y)
3234   #define sqlite3ConnectionUnlocked(x)
3235   #define sqlite3ConnectionClosed(x)
3236 #endif
3237 
3238 #ifdef SQLITE_DEBUG
3239   void sqlite3ParserTrace(FILE*, char *);
3240 #endif
3241 
3242 /*
3243 ** If the SQLITE_ENABLE IOTRACE exists then the global variable
3244 ** sqlite3IoTrace is a pointer to a printf-like routine used to
3245 ** print I/O tracing messages.
3246 */
3247 #ifdef SQLITE_ENABLE_IOTRACE
3248 # define IOTRACE(A)  if( sqlite3IoTrace ){ sqlite3IoTrace A; }
3249   void sqlite3VdbeIOTraceSql(Vdbe*);
3250 SQLITE_EXTERN void (*sqlite3IoTrace)(const char*,...);
3251 #else
3252 # define IOTRACE(A)
3253 # define sqlite3VdbeIOTraceSql(X)
3254 #endif
3255 
3256 /*
3257 ** These routines are available for the mem2.c debugging memory allocator
3258 ** only.  They are used to verify that different "types" of memory
3259 ** allocations are properly tracked by the system.
3260 **
3261 ** sqlite3MemdebugSetType() sets the "type" of an allocation to one of
3262 ** the MEMTYPE_* macros defined below.  The type must be a bitmask with
3263 ** a single bit set.
3264 **
3265 ** sqlite3MemdebugHasType() returns true if any of the bits in its second
3266 ** argument match the type set by the previous sqlite3MemdebugSetType().
3267 ** sqlite3MemdebugHasType() is intended for use inside assert() statements.
3268 **
3269 ** sqlite3MemdebugNoType() returns true if none of the bits in its second
3270 ** argument match the type set by the previous sqlite3MemdebugSetType().
3271 **
3272 ** Perhaps the most important point is the difference between MEMTYPE_HEAP
3273 ** and MEMTYPE_LOOKASIDE.  If an allocation is MEMTYPE_LOOKASIDE, that means
3274 ** it might have been allocated by lookaside, except the allocation was
3275 ** too large or lookaside was already full.  It is important to verify
3276 ** that allocations that might have been satisfied by lookaside are not
3277 ** passed back to non-lookaside free() routines.  Asserts such as the
3278 ** example above are placed on the non-lookaside free() routines to verify
3279 ** this constraint.
3280 **
3281 ** All of this is no-op for a production build.  It only comes into
3282 ** play when the SQLITE_MEMDEBUG compile-time option is used.
3283 */
3284 #ifdef SQLITE_MEMDEBUG
3285   void sqlite3MemdebugSetType(void*,u8);
3286   int sqlite3MemdebugHasType(void*,u8);
3287   int sqlite3MemdebugNoType(void*,u8);
3288 #else
3289 # define sqlite3MemdebugSetType(X,Y)  /* no-op */
3290 # define sqlite3MemdebugHasType(X,Y)  1
3291 # define sqlite3MemdebugNoType(X,Y)   1
3292 #endif
3293 #define MEMTYPE_HEAP       0x01  /* General heap allocations */
3294 #define MEMTYPE_LOOKASIDE  0x02  /* Might have been lookaside memory */
3295 #define MEMTYPE_SCRATCH    0x04  /* Scratch allocations */
3296 #define MEMTYPE_PCACHE     0x08  /* Page cache allocations */
3297 #define MEMTYPE_DB         0x10  /* Uses sqlite3DbMalloc, not sqlite_malloc */
3298 
3299 #endif /* _SQLITEINT_H_ */
3300