xref: /sqlite-3.40.0/src/sqliteInt.h (revision cd423525)
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 ** Include the header file used to customize the compiler options for MSVC.
20 ** This should be done first so that it can successfully prevent spurious
21 ** compiler warnings due to subsequent content in this file and other files
22 ** that are included by this file.
23 */
24 #include "msvc.h"
25 
26 /*
27 ** Special setup for VxWorks
28 */
29 #include "vxworks.h"
30 
31 /*
32 ** These #defines should enable >2GB file support on POSIX if the
33 ** underlying operating system supports it.  If the OS lacks
34 ** large file support, or if the OS is windows, these should be no-ops.
35 **
36 ** Ticket #2739:  The _LARGEFILE_SOURCE macro must appear before any
37 ** system #includes.  Hence, this block of code must be the very first
38 ** code in all source files.
39 **
40 ** Large file support can be disabled using the -DSQLITE_DISABLE_LFS switch
41 ** on the compiler command line.  This is necessary if you are compiling
42 ** on a recent machine (ex: Red Hat 7.2) but you want your code to work
43 ** on an older machine (ex: Red Hat 6.0).  If you compile on Red Hat 7.2
44 ** without this option, LFS is enable.  But LFS does not exist in the kernel
45 ** in Red Hat 6.0, so the code won't work.  Hence, for maximum binary
46 ** portability you should omit LFS.
47 **
48 ** The previous paragraph was written in 2005.  (This paragraph is written
49 ** on 2008-11-28.) These days, all Linux kernels support large files, so
50 ** you should probably leave LFS enabled.  But some embedded platforms might
51 ** lack LFS in which case the SQLITE_DISABLE_LFS macro might still be useful.
52 **
53 ** Similar is true for Mac OS X.  LFS is only supported on Mac OS X 9 and later.
54 */
55 #ifndef SQLITE_DISABLE_LFS
56 # define _LARGE_FILE       1
57 # ifndef _FILE_OFFSET_BITS
58 #   define _FILE_OFFSET_BITS 64
59 # endif
60 # define _LARGEFILE_SOURCE 1
61 #endif
62 
63 /* What version of GCC is being used.  0 means GCC is not being used */
64 #ifdef __GNUC__
65 # define GCC_VERSION (__GNUC__*1000000+__GNUC_MINOR__*1000+__GNUC_PATCHLEVEL__)
66 #else
67 # define GCC_VERSION 0
68 #endif
69 
70 /* Needed for various definitions... */
71 #if defined(__GNUC__) && !defined(_GNU_SOURCE)
72 # define _GNU_SOURCE
73 #endif
74 
75 #if defined(__OpenBSD__) && !defined(_BSD_SOURCE)
76 # define _BSD_SOURCE
77 #endif
78 
79 /*
80 ** For MinGW, check to see if we can include the header file containing its
81 ** version information, among other things.  Normally, this internal MinGW
82 ** header file would [only] be included automatically by other MinGW header
83 ** files; however, the contained version information is now required by this
84 ** header file to work around binary compatibility issues (see below) and
85 ** this is the only known way to reliably obtain it.  This entire #if block
86 ** would be completely unnecessary if there was any other way of detecting
87 ** MinGW via their preprocessor (e.g. if they customized their GCC to define
88 ** some MinGW-specific macros).  When compiling for MinGW, either the
89 ** _HAVE_MINGW_H or _HAVE__MINGW_H (note the extra underscore) macro must be
90 ** defined; otherwise, detection of conditions specific to MinGW will be
91 ** disabled.
92 */
93 #if defined(_HAVE_MINGW_H)
94 # include "mingw.h"
95 #elif defined(_HAVE__MINGW_H)
96 # include "_mingw.h"
97 #endif
98 
99 /*
100 ** For MinGW version 4.x (and higher), check to see if the _USE_32BIT_TIME_T
101 ** define is required to maintain binary compatibility with the MSVC runtime
102 ** library in use (e.g. for Windows XP).
103 */
104 #if !defined(_USE_32BIT_TIME_T) && !defined(_USE_64BIT_TIME_T) && \
105     defined(_WIN32) && !defined(_WIN64) && \
106     defined(__MINGW_MAJOR_VERSION) && __MINGW_MAJOR_VERSION >= 4 && \
107     defined(__MSVCRT__)
108 # define _USE_32BIT_TIME_T
109 #endif
110 
111 /* The public SQLite interface.  The _FILE_OFFSET_BITS macro must appear
112 ** first in QNX.  Also, the _USE_32BIT_TIME_T macro must appear first for
113 ** MinGW.
114 */
115 #include "sqlite3.h"
116 
117 /*
118 ** Include the configuration header output by 'configure' if we're using the
119 ** autoconf-based build
120 */
121 #ifdef _HAVE_SQLITE_CONFIG_H
122 #include "config.h"
123 #endif
124 
125 #include "sqliteLimit.h"
126 
127 /* Disable nuisance warnings on Borland compilers */
128 #if defined(__BORLANDC__)
129 #pragma warn -rch /* unreachable code */
130 #pragma warn -ccc /* Condition is always true or false */
131 #pragma warn -aus /* Assigned value is never used */
132 #pragma warn -csu /* Comparing signed and unsigned */
133 #pragma warn -spa /* Suspicious pointer arithmetic */
134 #endif
135 
136 /*
137 ** Include standard header files as necessary
138 */
139 #ifdef HAVE_STDINT_H
140 #include <stdint.h>
141 #endif
142 #ifdef HAVE_INTTYPES_H
143 #include <inttypes.h>
144 #endif
145 
146 /*
147 ** The following macros are used to cast pointers to integers and
148 ** integers to pointers.  The way you do this varies from one compiler
149 ** to the next, so we have developed the following set of #if statements
150 ** to generate appropriate macros for a wide range of compilers.
151 **
152 ** The correct "ANSI" way to do this is to use the intptr_t type.
153 ** Unfortunately, that typedef is not available on all compilers, or
154 ** if it is available, it requires an #include of specific headers
155 ** that vary from one machine to the next.
156 **
157 ** Ticket #3860:  The llvm-gcc-4.2 compiler from Apple chokes on
158 ** the ((void*)&((char*)0)[X]) construct.  But MSVC chokes on ((void*)(X)).
159 ** So we have to define the macros in different ways depending on the
160 ** compiler.
161 */
162 #if defined(__PTRDIFF_TYPE__)  /* This case should work for GCC */
163 # define SQLITE_INT_TO_PTR(X)  ((void*)(__PTRDIFF_TYPE__)(X))
164 # define SQLITE_PTR_TO_INT(X)  ((int)(__PTRDIFF_TYPE__)(X))
165 #elif !defined(__GNUC__)       /* Works for compilers other than LLVM */
166 # define SQLITE_INT_TO_PTR(X)  ((void*)&((char*)0)[X])
167 # define SQLITE_PTR_TO_INT(X)  ((int)(((char*)X)-(char*)0))
168 #elif defined(HAVE_STDINT_H)   /* Use this case if we have ANSI headers */
169 # define SQLITE_INT_TO_PTR(X)  ((void*)(intptr_t)(X))
170 # define SQLITE_PTR_TO_INT(X)  ((int)(intptr_t)(X))
171 #else                          /* Generates a warning - but it always works */
172 # define SQLITE_INT_TO_PTR(X)  ((void*)(X))
173 # define SQLITE_PTR_TO_INT(X)  ((int)(X))
174 #endif
175 
176 /*
177 ** The SQLITE_WITHIN(P,S,E) macro checks to see if pointer P points to
178 ** something between S (inclusive) and E (exclusive).
179 **
180 ** In other words, S is a buffer and E is a pointer to the first byte after
181 ** the end of buffer S.  This macro returns true if P points to something
182 ** contained within the buffer S.
183 */
184 #if defined(HAVE_STDINT_H)
185 # define SQLITE_WITHIN(P,S,E) \
186     ((uintptr_t)(P)>=(uintptr_t)(S) && (uintptr_t)(P)<(uintptr_t)(E))
187 #else
188 # define SQLITE_WITHIN(P,S,E) ((P)>=(S) && (P)<(E))
189 #endif
190 
191 /*
192 ** A macro to hint to the compiler that a function should not be
193 ** inlined.
194 */
195 #if defined(__GNUC__)
196 #  define SQLITE_NOINLINE  __attribute__((noinline))
197 #elif defined(_MSC_VER) && _MSC_VER>=1310
198 #  define SQLITE_NOINLINE  __declspec(noinline)
199 #else
200 #  define SQLITE_NOINLINE
201 #endif
202 
203 /*
204 ** Make sure that the compiler intrinsics we desire are enabled when
205 ** compiling with an appropriate version of MSVC unless prevented by
206 ** the SQLITE_DISABLE_INTRINSIC define.
207 */
208 #if !defined(SQLITE_DISABLE_INTRINSIC)
209 #  if defined(_MSC_VER) && _MSC_VER>=1300
210 #    if !defined(_WIN32_WCE)
211 #      include <intrin.h>
212 #      pragma intrinsic(_byteswap_ushort)
213 #      pragma intrinsic(_byteswap_ulong)
214 #      pragma intrinsic(_ReadWriteBarrier)
215 #    else
216 #      include <cmnintrin.h>
217 #    endif
218 #  endif
219 #endif
220 
221 /*
222 ** The SQLITE_THREADSAFE macro must be defined as 0, 1, or 2.
223 ** 0 means mutexes are permanently disable and the library is never
224 ** threadsafe.  1 means the library is serialized which is the highest
225 ** level of threadsafety.  2 means the library is multithreaded - multiple
226 ** threads can use SQLite as long as no two threads try to use the same
227 ** database connection at the same time.
228 **
229 ** Older versions of SQLite used an optional THREADSAFE macro.
230 ** We support that for legacy.
231 */
232 #if !defined(SQLITE_THREADSAFE)
233 # if defined(THREADSAFE)
234 #   define SQLITE_THREADSAFE THREADSAFE
235 # else
236 #   define SQLITE_THREADSAFE 1 /* IMP: R-07272-22309 */
237 # endif
238 #endif
239 
240 /*
241 ** Powersafe overwrite is on by default.  But can be turned off using
242 ** the -DSQLITE_POWERSAFE_OVERWRITE=0 command-line option.
243 */
244 #ifndef SQLITE_POWERSAFE_OVERWRITE
245 # define SQLITE_POWERSAFE_OVERWRITE 1
246 #endif
247 
248 /*
249 ** EVIDENCE-OF: R-25715-37072 Memory allocation statistics are enabled by
250 ** default unless SQLite is compiled with SQLITE_DEFAULT_MEMSTATUS=0 in
251 ** which case memory allocation statistics are disabled by default.
252 */
253 #if !defined(SQLITE_DEFAULT_MEMSTATUS)
254 # define SQLITE_DEFAULT_MEMSTATUS 1
255 #endif
256 
257 /*
258 ** Exactly one of the following macros must be defined in order to
259 ** specify which memory allocation subsystem to use.
260 **
261 **     SQLITE_SYSTEM_MALLOC          // Use normal system malloc()
262 **     SQLITE_WIN32_MALLOC           // Use Win32 native heap API
263 **     SQLITE_ZERO_MALLOC            // Use a stub allocator that always fails
264 **     SQLITE_MEMDEBUG               // Debugging version of system malloc()
265 **
266 ** On Windows, if the SQLITE_WIN32_MALLOC_VALIDATE macro is defined and the
267 ** assert() macro is enabled, each call into the Win32 native heap subsystem
268 ** will cause HeapValidate to be called.  If heap validation should fail, an
269 ** assertion will be triggered.
270 **
271 ** If none of the above are defined, then set SQLITE_SYSTEM_MALLOC as
272 ** the default.
273 */
274 #if defined(SQLITE_SYSTEM_MALLOC) \
275   + defined(SQLITE_WIN32_MALLOC) \
276   + defined(SQLITE_ZERO_MALLOC) \
277   + defined(SQLITE_MEMDEBUG)>1
278 # error "Two or more of the following compile-time configuration options\
279  are defined but at most one is allowed:\
280  SQLITE_SYSTEM_MALLOC, SQLITE_WIN32_MALLOC, SQLITE_MEMDEBUG,\
281  SQLITE_ZERO_MALLOC"
282 #endif
283 #if defined(SQLITE_SYSTEM_MALLOC) \
284   + defined(SQLITE_WIN32_MALLOC) \
285   + defined(SQLITE_ZERO_MALLOC) \
286   + defined(SQLITE_MEMDEBUG)==0
287 # define SQLITE_SYSTEM_MALLOC 1
288 #endif
289 
290 /*
291 ** If SQLITE_MALLOC_SOFT_LIMIT is not zero, then try to keep the
292 ** sizes of memory allocations below this value where possible.
293 */
294 #if !defined(SQLITE_MALLOC_SOFT_LIMIT)
295 # define SQLITE_MALLOC_SOFT_LIMIT 1024
296 #endif
297 
298 /*
299 ** We need to define _XOPEN_SOURCE as follows in order to enable
300 ** recursive mutexes on most Unix systems and fchmod() on OpenBSD.
301 ** But _XOPEN_SOURCE define causes problems for Mac OS X, so omit
302 ** it.
303 */
304 #if !defined(_XOPEN_SOURCE) && !defined(__DARWIN__) && !defined(__APPLE__)
305 #  define _XOPEN_SOURCE 600
306 #endif
307 
308 /*
309 ** NDEBUG and SQLITE_DEBUG are opposites.  It should always be true that
310 ** defined(NDEBUG)==!defined(SQLITE_DEBUG).  If this is not currently true,
311 ** make it true by defining or undefining NDEBUG.
312 **
313 ** Setting NDEBUG makes the code smaller and faster by disabling the
314 ** assert() statements in the code.  So we want the default action
315 ** to be for NDEBUG to be set and NDEBUG to be undefined only if SQLITE_DEBUG
316 ** is set.  Thus NDEBUG becomes an opt-in rather than an opt-out
317 ** feature.
318 */
319 #if !defined(NDEBUG) && !defined(SQLITE_DEBUG)
320 # define NDEBUG 1
321 #endif
322 #if defined(NDEBUG) && defined(SQLITE_DEBUG)
323 # undef NDEBUG
324 #endif
325 
326 /*
327 ** Enable SQLITE_ENABLE_EXPLAIN_COMMENTS if SQLITE_DEBUG is turned on.
328 */
329 #if !defined(SQLITE_ENABLE_EXPLAIN_COMMENTS) && defined(SQLITE_DEBUG)
330 # define SQLITE_ENABLE_EXPLAIN_COMMENTS 1
331 #endif
332 
333 /*
334 ** The testcase() macro is used to aid in coverage testing.  When
335 ** doing coverage testing, the condition inside the argument to
336 ** testcase() must be evaluated both true and false in order to
337 ** get full branch coverage.  The testcase() macro is inserted
338 ** to help ensure adequate test coverage in places where simple
339 ** condition/decision coverage is inadequate.  For example, testcase()
340 ** can be used to make sure boundary values are tested.  For
341 ** bitmask tests, testcase() can be used to make sure each bit
342 ** is significant and used at least once.  On switch statements
343 ** where multiple cases go to the same block of code, testcase()
344 ** can insure that all cases are evaluated.
345 **
346 */
347 #ifdef SQLITE_COVERAGE_TEST
348   void sqlite3Coverage(int);
349 # define testcase(X)  if( X ){ sqlite3Coverage(__LINE__); }
350 #else
351 # define testcase(X)
352 #endif
353 
354 /*
355 ** The TESTONLY macro is used to enclose variable declarations or
356 ** other bits of code that are needed to support the arguments
357 ** within testcase() and assert() macros.
358 */
359 #if !defined(NDEBUG) || defined(SQLITE_COVERAGE_TEST)
360 # define TESTONLY(X)  X
361 #else
362 # define TESTONLY(X)
363 #endif
364 
365 /*
366 ** Sometimes we need a small amount of code such as a variable initialization
367 ** to setup for a later assert() statement.  We do not want this code to
368 ** appear when assert() is disabled.  The following macro is therefore
369 ** used to contain that setup code.  The "VVA" acronym stands for
370 ** "Verification, Validation, and Accreditation".  In other words, the
371 ** code within VVA_ONLY() will only run during verification processes.
372 */
373 #ifndef NDEBUG
374 # define VVA_ONLY(X)  X
375 #else
376 # define VVA_ONLY(X)
377 #endif
378 
379 /*
380 ** The ALWAYS and NEVER macros surround boolean expressions which
381 ** are intended to always be true or false, respectively.  Such
382 ** expressions could be omitted from the code completely.  But they
383 ** are included in a few cases in order to enhance the resilience
384 ** of SQLite to unexpected behavior - to make the code "self-healing"
385 ** or "ductile" rather than being "brittle" and crashing at the first
386 ** hint of unplanned behavior.
387 **
388 ** In other words, ALWAYS and NEVER are added for defensive code.
389 **
390 ** When doing coverage testing ALWAYS and NEVER are hard-coded to
391 ** be true and false so that the unreachable code they specify will
392 ** not be counted as untested code.
393 */
394 #if defined(SQLITE_COVERAGE_TEST)
395 # define ALWAYS(X)      (1)
396 # define NEVER(X)       (0)
397 #elif !defined(NDEBUG)
398 # define ALWAYS(X)      ((X)?1:(assert(0),0))
399 # define NEVER(X)       ((X)?(assert(0),1):0)
400 #else
401 # define ALWAYS(X)      (X)
402 # define NEVER(X)       (X)
403 #endif
404 
405 /*
406 ** Some malloc failures are only possible if SQLITE_TEST_REALLOC_STRESS is
407 ** defined.  We need to defend against those failures when testing with
408 ** SQLITE_TEST_REALLOC_STRESS, but we don't want the unreachable branches
409 ** during a normal build.  The following macro can be used to disable tests
410 ** that are always false except when SQLITE_TEST_REALLOC_STRESS is set.
411 */
412 #if defined(SQLITE_TEST_REALLOC_STRESS)
413 # define ONLY_IF_REALLOC_STRESS(X)  (X)
414 #elif !defined(NDEBUG)
415 # define ONLY_IF_REALLOC_STRESS(X)  ((X)?(assert(0),1):0)
416 #else
417 # define ONLY_IF_REALLOC_STRESS(X)  (0)
418 #endif
419 
420 /*
421 ** Declarations used for tracing the operating system interfaces.
422 */
423 #if defined(SQLITE_FORCE_OS_TRACE) || defined(SQLITE_TEST) || \
424     (defined(SQLITE_DEBUG) && SQLITE_OS_WIN)
425   extern int sqlite3OSTrace;
426 # define OSTRACE(X)          if( sqlite3OSTrace ) sqlite3DebugPrintf X
427 # define SQLITE_HAVE_OS_TRACE
428 #else
429 # define OSTRACE(X)
430 # undef  SQLITE_HAVE_OS_TRACE
431 #endif
432 
433 /*
434 ** Is the sqlite3ErrName() function needed in the build?  Currently,
435 ** it is needed by "mutex_w32.c" (when debugging), "os_win.c" (when
436 ** OSTRACE is enabled), and by several "test*.c" files (which are
437 ** compiled using SQLITE_TEST).
438 */
439 #if defined(SQLITE_HAVE_OS_TRACE) || defined(SQLITE_TEST) || \
440     (defined(SQLITE_DEBUG) && SQLITE_OS_WIN)
441 # define SQLITE_NEED_ERR_NAME
442 #else
443 # undef  SQLITE_NEED_ERR_NAME
444 #endif
445 
446 /*
447 ** Return true (non-zero) if the input is an integer that is too large
448 ** to fit in 32-bits.  This macro is used inside of various testcase()
449 ** macros to verify that we have tested SQLite for large-file support.
450 */
451 #define IS_BIG_INT(X)  (((X)&~(i64)0xffffffff)!=0)
452 
453 /*
454 ** The macro unlikely() is a hint that surrounds a boolean
455 ** expression that is usually false.  Macro likely() surrounds
456 ** a boolean expression that is usually true.  These hints could,
457 ** in theory, be used by the compiler to generate better code, but
458 ** currently they are just comments for human readers.
459 */
460 #define likely(X)    (X)
461 #define unlikely(X)  (X)
462 
463 #include "hash.h"
464 #include "parse.h"
465 #include <stdio.h>
466 #include <stdlib.h>
467 #include <string.h>
468 #include <assert.h>
469 #include <stddef.h>
470 
471 /*
472 ** If compiling for a processor that lacks floating point support,
473 ** substitute integer for floating-point
474 */
475 #ifdef SQLITE_OMIT_FLOATING_POINT
476 # define double sqlite_int64
477 # define float sqlite_int64
478 # define LONGDOUBLE_TYPE sqlite_int64
479 # ifndef SQLITE_BIG_DBL
480 #   define SQLITE_BIG_DBL (((sqlite3_int64)1)<<50)
481 # endif
482 # define SQLITE_OMIT_DATETIME_FUNCS 1
483 # define SQLITE_OMIT_TRACE 1
484 # undef SQLITE_MIXED_ENDIAN_64BIT_FLOAT
485 # undef SQLITE_HAVE_ISNAN
486 #endif
487 #ifndef SQLITE_BIG_DBL
488 # define SQLITE_BIG_DBL (1e99)
489 #endif
490 
491 /*
492 ** OMIT_TEMPDB is set to 1 if SQLITE_OMIT_TEMPDB is defined, or 0
493 ** afterward. Having this macro allows us to cause the C compiler
494 ** to omit code used by TEMP tables without messy #ifndef statements.
495 */
496 #ifdef SQLITE_OMIT_TEMPDB
497 #define OMIT_TEMPDB 1
498 #else
499 #define OMIT_TEMPDB 0
500 #endif
501 
502 /*
503 ** The "file format" number is an integer that is incremented whenever
504 ** the VDBE-level file format changes.  The following macros define the
505 ** the default file format for new databases and the maximum file format
506 ** that the library can read.
507 */
508 #define SQLITE_MAX_FILE_FORMAT 4
509 #ifndef SQLITE_DEFAULT_FILE_FORMAT
510 # define SQLITE_DEFAULT_FILE_FORMAT 4
511 #endif
512 
513 /*
514 ** Determine whether triggers are recursive by default.  This can be
515 ** changed at run-time using a pragma.
516 */
517 #ifndef SQLITE_DEFAULT_RECURSIVE_TRIGGERS
518 # define SQLITE_DEFAULT_RECURSIVE_TRIGGERS 0
519 #endif
520 
521 /*
522 ** Provide a default value for SQLITE_TEMP_STORE in case it is not specified
523 ** on the command-line
524 */
525 #ifndef SQLITE_TEMP_STORE
526 # define SQLITE_TEMP_STORE 1
527 # define SQLITE_TEMP_STORE_xc 1  /* Exclude from ctime.c */
528 #endif
529 
530 /*
531 ** If no value has been provided for SQLITE_MAX_WORKER_THREADS, or if
532 ** SQLITE_TEMP_STORE is set to 3 (never use temporary files), set it
533 ** to zero.
534 */
535 #if SQLITE_TEMP_STORE==3 || SQLITE_THREADSAFE==0
536 # undef SQLITE_MAX_WORKER_THREADS
537 # define SQLITE_MAX_WORKER_THREADS 0
538 #endif
539 #ifndef SQLITE_MAX_WORKER_THREADS
540 # define SQLITE_MAX_WORKER_THREADS 8
541 #endif
542 #ifndef SQLITE_DEFAULT_WORKER_THREADS
543 # define SQLITE_DEFAULT_WORKER_THREADS 0
544 #endif
545 #if SQLITE_DEFAULT_WORKER_THREADS>SQLITE_MAX_WORKER_THREADS
546 # undef SQLITE_MAX_WORKER_THREADS
547 # define SQLITE_MAX_WORKER_THREADS SQLITE_DEFAULT_WORKER_THREADS
548 #endif
549 
550 /*
551 ** The default initial allocation for the pagecache when using separate
552 ** pagecaches for each database connection.  A positive number is the
553 ** number of pages.  A negative number N translations means that a buffer
554 ** of -1024*N bytes is allocated and used for as many pages as it will hold.
555 */
556 #ifndef SQLITE_DEFAULT_PCACHE_INITSZ
557 # define SQLITE_DEFAULT_PCACHE_INITSZ 100
558 #endif
559 
560 /*
561 ** GCC does not define the offsetof() macro so we'll have to do it
562 ** ourselves.
563 */
564 #ifndef offsetof
565 #define offsetof(STRUCTURE,FIELD) ((int)((char*)&((STRUCTURE*)0)->FIELD))
566 #endif
567 
568 /*
569 ** Macros to compute minimum and maximum of two numbers.
570 */
571 #define MIN(A,B) ((A)<(B)?(A):(B))
572 #define MAX(A,B) ((A)>(B)?(A):(B))
573 
574 /*
575 ** Swap two objects of type TYPE.
576 */
577 #define SWAP(TYPE,A,B) {TYPE t=A; A=B; B=t;}
578 
579 /*
580 ** Check to see if this machine uses EBCDIC.  (Yes, believe it or
581 ** not, there are still machines out there that use EBCDIC.)
582 */
583 #if 'A' == '\301'
584 # define SQLITE_EBCDIC 1
585 #else
586 # define SQLITE_ASCII 1
587 #endif
588 
589 /*
590 ** Integers of known sizes.  These typedefs might change for architectures
591 ** where the sizes very.  Preprocessor macros are available so that the
592 ** types can be conveniently redefined at compile-type.  Like this:
593 **
594 **         cc '-DUINTPTR_TYPE=long long int' ...
595 */
596 #ifndef UINT32_TYPE
597 # ifdef HAVE_UINT32_T
598 #  define UINT32_TYPE uint32_t
599 # else
600 #  define UINT32_TYPE unsigned int
601 # endif
602 #endif
603 #ifndef UINT16_TYPE
604 # ifdef HAVE_UINT16_T
605 #  define UINT16_TYPE uint16_t
606 # else
607 #  define UINT16_TYPE unsigned short int
608 # endif
609 #endif
610 #ifndef INT16_TYPE
611 # ifdef HAVE_INT16_T
612 #  define INT16_TYPE int16_t
613 # else
614 #  define INT16_TYPE short int
615 # endif
616 #endif
617 #ifndef UINT8_TYPE
618 # ifdef HAVE_UINT8_T
619 #  define UINT8_TYPE uint8_t
620 # else
621 #  define UINT8_TYPE unsigned char
622 # endif
623 #endif
624 #ifndef INT8_TYPE
625 # ifdef HAVE_INT8_T
626 #  define INT8_TYPE int8_t
627 # else
628 #  define INT8_TYPE signed char
629 # endif
630 #endif
631 #ifndef LONGDOUBLE_TYPE
632 # define LONGDOUBLE_TYPE long double
633 #endif
634 typedef sqlite_int64 i64;          /* 8-byte signed integer */
635 typedef sqlite_uint64 u64;         /* 8-byte unsigned integer */
636 typedef UINT32_TYPE u32;           /* 4-byte unsigned integer */
637 typedef UINT16_TYPE u16;           /* 2-byte unsigned integer */
638 typedef INT16_TYPE i16;            /* 2-byte signed integer */
639 typedef UINT8_TYPE u8;             /* 1-byte unsigned integer */
640 typedef INT8_TYPE i8;              /* 1-byte signed integer */
641 
642 /*
643 ** SQLITE_MAX_U32 is a u64 constant that is the maximum u64 value
644 ** that can be stored in a u32 without loss of data.  The value
645 ** is 0x00000000ffffffff.  But because of quirks of some compilers, we
646 ** have to specify the value in the less intuitive manner shown:
647 */
648 #define SQLITE_MAX_U32  ((((u64)1)<<32)-1)
649 
650 /*
651 ** The datatype used to store estimates of the number of rows in a
652 ** table or index.  This is an unsigned integer type.  For 99.9% of
653 ** the world, a 32-bit integer is sufficient.  But a 64-bit integer
654 ** can be used at compile-time if desired.
655 */
656 #ifdef SQLITE_64BIT_STATS
657  typedef u64 tRowcnt;    /* 64-bit only if requested at compile-time */
658 #else
659  typedef u32 tRowcnt;    /* 32-bit is the default */
660 #endif
661 
662 /*
663 ** Estimated quantities used for query planning are stored as 16-bit
664 ** logarithms.  For quantity X, the value stored is 10*log2(X).  This
665 ** gives a possible range of values of approximately 1.0e986 to 1e-986.
666 ** But the allowed values are "grainy".  Not every value is representable.
667 ** For example, quantities 16 and 17 are both represented by a LogEst
668 ** of 40.  However, since LogEst quantities are suppose to be estimates,
669 ** not exact values, this imprecision is not a problem.
670 **
671 ** "LogEst" is short for "Logarithmic Estimate".
672 **
673 ** Examples:
674 **      1 -> 0              20 -> 43          10000 -> 132
675 **      2 -> 10             25 -> 46          25000 -> 146
676 **      3 -> 16            100 -> 66        1000000 -> 199
677 **      4 -> 20           1000 -> 99        1048576 -> 200
678 **     10 -> 33           1024 -> 100    4294967296 -> 320
679 **
680 ** The LogEst can be negative to indicate fractional values.
681 ** Examples:
682 **
683 **    0.5 -> -10           0.1 -> -33        0.0625 -> -40
684 */
685 typedef INT16_TYPE LogEst;
686 
687 /*
688 ** Set the SQLITE_PTRSIZE macro to the number of bytes in a pointer
689 */
690 #ifndef SQLITE_PTRSIZE
691 # if defined(__SIZEOF_POINTER__)
692 #   define SQLITE_PTRSIZE __SIZEOF_POINTER__
693 # elif defined(i386)     || defined(__i386__)   || defined(_M_IX86) ||    \
694        defined(_M_ARM)   || defined(__arm__)    || defined(__x86)
695 #   define SQLITE_PTRSIZE 4
696 # else
697 #   define SQLITE_PTRSIZE 8
698 # endif
699 #endif
700 
701 /*
702 ** Macros to determine whether the machine is big or little endian,
703 ** and whether or not that determination is run-time or compile-time.
704 **
705 ** For best performance, an attempt is made to guess at the byte-order
706 ** using C-preprocessor macros.  If that is unsuccessful, or if
707 ** -DSQLITE_RUNTIME_BYTEORDER=1 is set, then byte-order is determined
708 ** at run-time.
709 */
710 #if (defined(i386)     || defined(__i386__)   || defined(_M_IX86) ||    \
711      defined(__x86_64) || defined(__x86_64__) || defined(_M_X64)  ||    \
712      defined(_M_AMD64) || defined(_M_ARM)     || defined(__x86)   ||    \
713      defined(__arm__)) && !defined(SQLITE_RUNTIME_BYTEORDER)
714 # define SQLITE_BYTEORDER    1234
715 # define SQLITE_BIGENDIAN    0
716 # define SQLITE_LITTLEENDIAN 1
717 # define SQLITE_UTF16NATIVE  SQLITE_UTF16LE
718 #endif
719 #if (defined(sparc)    || defined(__ppc__))  \
720     && !defined(SQLITE_RUNTIME_BYTEORDER)
721 # define SQLITE_BYTEORDER    4321
722 # define SQLITE_BIGENDIAN    1
723 # define SQLITE_LITTLEENDIAN 0
724 # define SQLITE_UTF16NATIVE  SQLITE_UTF16BE
725 #endif
726 #if !defined(SQLITE_BYTEORDER)
727 # ifdef SQLITE_AMALGAMATION
728   const int sqlite3one = 1;
729 # else
730   extern const int sqlite3one;
731 # endif
732 # define SQLITE_BYTEORDER    0     /* 0 means "unknown at compile-time" */
733 # define SQLITE_BIGENDIAN    (*(char *)(&sqlite3one)==0)
734 # define SQLITE_LITTLEENDIAN (*(char *)(&sqlite3one)==1)
735 # define SQLITE_UTF16NATIVE  (SQLITE_BIGENDIAN?SQLITE_UTF16BE:SQLITE_UTF16LE)
736 #endif
737 
738 /*
739 ** Constants for the largest and smallest possible 64-bit signed integers.
740 ** These macros are designed to work correctly on both 32-bit and 64-bit
741 ** compilers.
742 */
743 #define LARGEST_INT64  (0xffffffff|(((i64)0x7fffffff)<<32))
744 #define SMALLEST_INT64 (((i64)-1) - LARGEST_INT64)
745 
746 /*
747 ** Round up a number to the next larger multiple of 8.  This is used
748 ** to force 8-byte alignment on 64-bit architectures.
749 */
750 #define ROUND8(x)     (((x)+7)&~7)
751 
752 /*
753 ** Round down to the nearest multiple of 8
754 */
755 #define ROUNDDOWN8(x) ((x)&~7)
756 
757 /*
758 ** Assert that the pointer X is aligned to an 8-byte boundary.  This
759 ** macro is used only within assert() to verify that the code gets
760 ** all alignment restrictions correct.
761 **
762 ** Except, if SQLITE_4_BYTE_ALIGNED_MALLOC is defined, then the
763 ** underlying malloc() implementation might return us 4-byte aligned
764 ** pointers.  In that case, only verify 4-byte alignment.
765 */
766 #ifdef SQLITE_4_BYTE_ALIGNED_MALLOC
767 # define EIGHT_BYTE_ALIGNMENT(X)   ((((char*)(X) - (char*)0)&3)==0)
768 #else
769 # define EIGHT_BYTE_ALIGNMENT(X)   ((((char*)(X) - (char*)0)&7)==0)
770 #endif
771 
772 /*
773 ** Disable MMAP on platforms where it is known to not work
774 */
775 #if defined(__OpenBSD__) || defined(__QNXNTO__)
776 # undef SQLITE_MAX_MMAP_SIZE
777 # define SQLITE_MAX_MMAP_SIZE 0
778 #endif
779 
780 /*
781 ** Default maximum size of memory used by memory-mapped I/O in the VFS
782 */
783 #ifdef __APPLE__
784 # include <TargetConditionals.h>
785 #endif
786 #ifndef SQLITE_MAX_MMAP_SIZE
787 # if defined(__linux__) \
788   || defined(_WIN32) \
789   || (defined(__APPLE__) && defined(__MACH__)) \
790   || defined(__sun) \
791   || defined(__FreeBSD__) \
792   || defined(__DragonFly__)
793 #   define SQLITE_MAX_MMAP_SIZE 0x7fff0000  /* 2147418112 */
794 # else
795 #   define SQLITE_MAX_MMAP_SIZE 0
796 # endif
797 # define SQLITE_MAX_MMAP_SIZE_xc 1 /* exclude from ctime.c */
798 #endif
799 
800 /*
801 ** The default MMAP_SIZE is zero on all platforms.  Or, even if a larger
802 ** default MMAP_SIZE is specified at compile-time, make sure that it does
803 ** not exceed the maximum mmap size.
804 */
805 #ifndef SQLITE_DEFAULT_MMAP_SIZE
806 # define SQLITE_DEFAULT_MMAP_SIZE 0
807 # define SQLITE_DEFAULT_MMAP_SIZE_xc 1  /* Exclude from ctime.c */
808 #endif
809 #if SQLITE_DEFAULT_MMAP_SIZE>SQLITE_MAX_MMAP_SIZE
810 # undef SQLITE_DEFAULT_MMAP_SIZE
811 # define SQLITE_DEFAULT_MMAP_SIZE SQLITE_MAX_MMAP_SIZE
812 #endif
813 
814 /*
815 ** Only one of SQLITE_ENABLE_STAT3 or SQLITE_ENABLE_STAT4 can be defined.
816 ** Priority is given to SQLITE_ENABLE_STAT4.  If either are defined, also
817 ** define SQLITE_ENABLE_STAT3_OR_STAT4
818 */
819 #ifdef SQLITE_ENABLE_STAT4
820 # undef SQLITE_ENABLE_STAT3
821 # define SQLITE_ENABLE_STAT3_OR_STAT4 1
822 #elif SQLITE_ENABLE_STAT3
823 # define SQLITE_ENABLE_STAT3_OR_STAT4 1
824 #elif SQLITE_ENABLE_STAT3_OR_STAT4
825 # undef SQLITE_ENABLE_STAT3_OR_STAT4
826 #endif
827 
828 /*
829 ** SELECTTRACE_ENABLED will be either 1 or 0 depending on whether or not
830 ** the Select query generator tracing logic is turned on.
831 */
832 #if defined(SQLITE_DEBUG) || defined(SQLITE_ENABLE_SELECTTRACE)
833 # define SELECTTRACE_ENABLED 1
834 #else
835 # define SELECTTRACE_ENABLED 0
836 #endif
837 
838 /*
839 ** An instance of the following structure is used to store the busy-handler
840 ** callback for a given sqlite handle.
841 **
842 ** The sqlite.busyHandler member of the sqlite struct contains the busy
843 ** callback for the database handle. Each pager opened via the sqlite
844 ** handle is passed a pointer to sqlite.busyHandler. The busy-handler
845 ** callback is currently invoked only from within pager.c.
846 */
847 typedef struct BusyHandler BusyHandler;
848 struct BusyHandler {
849   int (*xFunc)(void *,int);  /* The busy callback */
850   void *pArg;                /* First arg to busy callback */
851   int nBusy;                 /* Incremented with each busy call */
852 };
853 
854 /*
855 ** Name of the master database table.  The master database table
856 ** is a special table that holds the names and attributes of all
857 ** user tables and indices.
858 */
859 #define MASTER_NAME       "sqlite_master"
860 #define TEMP_MASTER_NAME  "sqlite_temp_master"
861 
862 /*
863 ** The root-page of the master database table.
864 */
865 #define MASTER_ROOT       1
866 
867 /*
868 ** The name of the schema table.
869 */
870 #define SCHEMA_TABLE(x)  ((!OMIT_TEMPDB)&&(x==1)?TEMP_MASTER_NAME:MASTER_NAME)
871 
872 /*
873 ** A convenience macro that returns the number of elements in
874 ** an array.
875 */
876 #define ArraySize(X)    ((int)(sizeof(X)/sizeof(X[0])))
877 
878 /*
879 ** Determine if the argument is a power of two
880 */
881 #define IsPowerOfTwo(X) (((X)&((X)-1))==0)
882 
883 /*
884 ** The following value as a destructor means to use sqlite3DbFree().
885 ** The sqlite3DbFree() routine requires two parameters instead of the
886 ** one parameter that destructors normally want.  So we have to introduce
887 ** this magic value that the code knows to handle differently.  Any
888 ** pointer will work here as long as it is distinct from SQLITE_STATIC
889 ** and SQLITE_TRANSIENT.
890 */
891 #define SQLITE_DYNAMIC   ((sqlite3_destructor_type)sqlite3MallocSize)
892 
893 /*
894 ** When SQLITE_OMIT_WSD is defined, it means that the target platform does
895 ** not support Writable Static Data (WSD) such as global and static variables.
896 ** All variables must either be on the stack or dynamically allocated from
897 ** the heap.  When WSD is unsupported, the variable declarations scattered
898 ** throughout the SQLite code must become constants instead.  The SQLITE_WSD
899 ** macro is used for this purpose.  And instead of referencing the variable
900 ** directly, we use its constant as a key to lookup the run-time allocated
901 ** buffer that holds real variable.  The constant is also the initializer
902 ** for the run-time allocated buffer.
903 **
904 ** In the usual case where WSD is supported, the SQLITE_WSD and GLOBAL
905 ** macros become no-ops and have zero performance impact.
906 */
907 #ifdef SQLITE_OMIT_WSD
908   #define SQLITE_WSD const
909   #define GLOBAL(t,v) (*(t*)sqlite3_wsd_find((void*)&(v), sizeof(v)))
910   #define sqlite3GlobalConfig GLOBAL(struct Sqlite3Config, sqlite3Config)
911   int sqlite3_wsd_init(int N, int J);
912   void *sqlite3_wsd_find(void *K, int L);
913 #else
914   #define SQLITE_WSD
915   #define GLOBAL(t,v) v
916   #define sqlite3GlobalConfig sqlite3Config
917 #endif
918 
919 /*
920 ** The following macros are used to suppress compiler warnings and to
921 ** make it clear to human readers when a function parameter is deliberately
922 ** left unused within the body of a function. This usually happens when
923 ** a function is called via a function pointer. For example the
924 ** implementation of an SQL aggregate step callback may not use the
925 ** parameter indicating the number of arguments passed to the aggregate,
926 ** if it knows that this is enforced elsewhere.
927 **
928 ** When a function parameter is not used at all within the body of a function,
929 ** it is generally named "NotUsed" or "NotUsed2" to make things even clearer.
930 ** However, these macros may also be used to suppress warnings related to
931 ** parameters that may or may not be used depending on compilation options.
932 ** For example those parameters only used in assert() statements. In these
933 ** cases the parameters are named as per the usual conventions.
934 */
935 #define UNUSED_PARAMETER(x) (void)(x)
936 #define UNUSED_PARAMETER2(x,y) UNUSED_PARAMETER(x),UNUSED_PARAMETER(y)
937 
938 /*
939 ** Forward references to structures
940 */
941 typedef struct AggInfo AggInfo;
942 typedef struct AuthContext AuthContext;
943 typedef struct AutoincInfo AutoincInfo;
944 typedef struct Bitvec Bitvec;
945 typedef struct CollSeq CollSeq;
946 typedef struct Column Column;
947 typedef struct Db Db;
948 typedef struct Schema Schema;
949 typedef struct Expr Expr;
950 typedef struct ExprList ExprList;
951 typedef struct ExprSpan ExprSpan;
952 typedef struct FKey FKey;
953 typedef struct FuncDestructor FuncDestructor;
954 typedef struct FuncDef FuncDef;
955 typedef struct FuncDefHash FuncDefHash;
956 typedef struct IdList IdList;
957 typedef struct Index Index;
958 typedef struct IndexSample IndexSample;
959 typedef struct KeyClass KeyClass;
960 typedef struct KeyInfo KeyInfo;
961 typedef struct Lookaside Lookaside;
962 typedef struct LookasideSlot LookasideSlot;
963 typedef struct Module Module;
964 typedef struct NameContext NameContext;
965 typedef struct Parse Parse;
966 typedef struct PrintfArguments PrintfArguments;
967 typedef struct RowSet RowSet;
968 typedef struct Savepoint Savepoint;
969 typedef struct Select Select;
970 typedef struct SQLiteThread SQLiteThread;
971 typedef struct SelectDest SelectDest;
972 typedef struct SrcList SrcList;
973 typedef struct StrAccum StrAccum;
974 typedef struct Table Table;
975 typedef struct TableLock TableLock;
976 typedef struct Token Token;
977 typedef struct TreeView TreeView;
978 typedef struct Trigger Trigger;
979 typedef struct TriggerPrg TriggerPrg;
980 typedef struct TriggerStep TriggerStep;
981 typedef struct UnpackedRecord UnpackedRecord;
982 typedef struct VTable VTable;
983 typedef struct VtabCtx VtabCtx;
984 typedef struct Walker Walker;
985 typedef struct WhereInfo WhereInfo;
986 typedef struct With With;
987 
988 /*
989 ** Defer sourcing vdbe.h and btree.h until after the "u8" and
990 ** "BusyHandler" typedefs. vdbe.h also requires a few of the opaque
991 ** pointer types (i.e. FuncDef) defined above.
992 */
993 #include "btree.h"
994 #include "vdbe.h"
995 #include "pager.h"
996 #include "pcache.h"
997 
998 #include "os.h"
999 #include "mutex.h"
1000 
1001 
1002 /*
1003 ** Each database file to be accessed by the system is an instance
1004 ** of the following structure.  There are normally two of these structures
1005 ** in the sqlite.aDb[] array.  aDb[0] is the main database file and
1006 ** aDb[1] is the database file used to hold temporary tables.  Additional
1007 ** databases may be attached.
1008 */
1009 struct Db {
1010   char *zName;         /* Name of this database */
1011   Btree *pBt;          /* The B*Tree structure for this database file */
1012   u8 safety_level;     /* How aggressive at syncing data to disk */
1013   Schema *pSchema;     /* Pointer to database schema (possibly shared) */
1014 };
1015 
1016 /*
1017 ** An instance of the following structure stores a database schema.
1018 **
1019 ** Most Schema objects are associated with a Btree.  The exception is
1020 ** the Schema for the TEMP databaes (sqlite3.aDb[1]) which is free-standing.
1021 ** In shared cache mode, a single Schema object can be shared by multiple
1022 ** Btrees that refer to the same underlying BtShared object.
1023 **
1024 ** Schema objects are automatically deallocated when the last Btree that
1025 ** references them is destroyed.   The TEMP Schema is manually freed by
1026 ** sqlite3_close().
1027 *
1028 ** A thread must be holding a mutex on the corresponding Btree in order
1029 ** to access Schema content.  This implies that the thread must also be
1030 ** holding a mutex on the sqlite3 connection pointer that owns the Btree.
1031 ** For a TEMP Schema, only the connection mutex is required.
1032 */
1033 struct Schema {
1034   int schema_cookie;   /* Database schema version number for this file */
1035   int iGeneration;     /* Generation counter.  Incremented with each change */
1036   Hash tblHash;        /* All tables indexed by name */
1037   Hash idxHash;        /* All (named) indices indexed by name */
1038   Hash trigHash;       /* All triggers indexed by name */
1039   Hash fkeyHash;       /* All foreign keys by referenced table name */
1040   Table *pSeqTab;      /* The sqlite_sequence table used by AUTOINCREMENT */
1041   u8 file_format;      /* Schema format version for this file */
1042   u8 enc;              /* Text encoding used by this database */
1043   u16 schemaFlags;     /* Flags associated with this schema */
1044   int cache_size;      /* Number of pages to use in the cache */
1045 };
1046 
1047 /*
1048 ** These macros can be used to test, set, or clear bits in the
1049 ** Db.pSchema->flags field.
1050 */
1051 #define DbHasProperty(D,I,P)     (((D)->aDb[I].pSchema->schemaFlags&(P))==(P))
1052 #define DbHasAnyProperty(D,I,P)  (((D)->aDb[I].pSchema->schemaFlags&(P))!=0)
1053 #define DbSetProperty(D,I,P)     (D)->aDb[I].pSchema->schemaFlags|=(P)
1054 #define DbClearProperty(D,I,P)   (D)->aDb[I].pSchema->schemaFlags&=~(P)
1055 
1056 /*
1057 ** Allowed values for the DB.pSchema->flags field.
1058 **
1059 ** The DB_SchemaLoaded flag is set after the database schema has been
1060 ** read into internal hash tables.
1061 **
1062 ** DB_UnresetViews means that one or more views have column names that
1063 ** have been filled out.  If the schema changes, these column names might
1064 ** changes and so the view will need to be reset.
1065 */
1066 #define DB_SchemaLoaded    0x0001  /* The schema has been loaded */
1067 #define DB_UnresetViews    0x0002  /* Some views have defined column names */
1068 #define DB_Empty           0x0004  /* The file is empty (length 0 bytes) */
1069 
1070 /*
1071 ** The number of different kinds of things that can be limited
1072 ** using the sqlite3_limit() interface.
1073 */
1074 #define SQLITE_N_LIMIT (SQLITE_LIMIT_WORKER_THREADS+1)
1075 
1076 /*
1077 ** Lookaside malloc is a set of fixed-size buffers that can be used
1078 ** to satisfy small transient memory allocation requests for objects
1079 ** associated with a particular database connection.  The use of
1080 ** lookaside malloc provides a significant performance enhancement
1081 ** (approx 10%) by avoiding numerous malloc/free requests while parsing
1082 ** SQL statements.
1083 **
1084 ** The Lookaside structure holds configuration information about the
1085 ** lookaside malloc subsystem.  Each available memory allocation in
1086 ** the lookaside subsystem is stored on a linked list of LookasideSlot
1087 ** objects.
1088 **
1089 ** Lookaside allocations are only allowed for objects that are associated
1090 ** with a particular database connection.  Hence, schema information cannot
1091 ** be stored in lookaside because in shared cache mode the schema information
1092 ** is shared by multiple database connections.  Therefore, while parsing
1093 ** schema information, the Lookaside.bEnabled flag is cleared so that
1094 ** lookaside allocations are not used to construct the schema objects.
1095 */
1096 struct Lookaside {
1097   u32 bDisable;           /* Only operate the lookaside when zero */
1098   u16 sz;                 /* Size of each buffer in bytes */
1099   u8 bMalloced;           /* True if pStart obtained from sqlite3_malloc() */
1100   int nOut;               /* Number of buffers currently checked out */
1101   int mxOut;              /* Highwater mark for nOut */
1102   int anStat[3];          /* 0: hits.  1: size misses.  2: full misses */
1103   LookasideSlot *pFree;   /* List of available buffers */
1104   void *pStart;           /* First byte of available memory space */
1105   void *pEnd;             /* First byte past end of available space */
1106 };
1107 struct LookasideSlot {
1108   LookasideSlot *pNext;    /* Next buffer in the list of free buffers */
1109 };
1110 
1111 /*
1112 ** A hash table for function definitions.
1113 **
1114 ** Hash each FuncDef structure into one of the FuncDefHash.a[] slots.
1115 ** Collisions are on the FuncDef.pHash chain.
1116 */
1117 struct FuncDefHash {
1118   FuncDef *a[23];       /* Hash table for functions */
1119 };
1120 
1121 #ifdef SQLITE_USER_AUTHENTICATION
1122 /*
1123 ** Information held in the "sqlite3" database connection object and used
1124 ** to manage user authentication.
1125 */
1126 typedef struct sqlite3_userauth sqlite3_userauth;
1127 struct sqlite3_userauth {
1128   u8 authLevel;                 /* Current authentication level */
1129   int nAuthPW;                  /* Size of the zAuthPW in bytes */
1130   char *zAuthPW;                /* Password used to authenticate */
1131   char *zAuthUser;              /* User name used to authenticate */
1132 };
1133 
1134 /* Allowed values for sqlite3_userauth.authLevel */
1135 #define UAUTH_Unknown     0     /* Authentication not yet checked */
1136 #define UAUTH_Fail        1     /* User authentication failed */
1137 #define UAUTH_User        2     /* Authenticated as a normal user */
1138 #define UAUTH_Admin       3     /* Authenticated as an administrator */
1139 
1140 /* Functions used only by user authorization logic */
1141 int sqlite3UserAuthTable(const char*);
1142 int sqlite3UserAuthCheckLogin(sqlite3*,const char*,u8*);
1143 void sqlite3UserAuthInit(sqlite3*);
1144 void sqlite3CryptFunc(sqlite3_context*,int,sqlite3_value**);
1145 
1146 #endif /* SQLITE_USER_AUTHENTICATION */
1147 
1148 /*
1149 ** typedef for the authorization callback function.
1150 */
1151 #ifdef SQLITE_USER_AUTHENTICATION
1152   typedef int (*sqlite3_xauth)(void*,int,const char*,const char*,const char*,
1153                                const char*, const char*);
1154 #else
1155   typedef int (*sqlite3_xauth)(void*,int,const char*,const char*,const char*,
1156                                const char*);
1157 #endif
1158 
1159 
1160 /*
1161 ** Each database connection is an instance of the following structure.
1162 */
1163 struct sqlite3 {
1164   sqlite3_vfs *pVfs;            /* OS Interface */
1165   struct Vdbe *pVdbe;           /* List of active virtual machines */
1166   CollSeq *pDfltColl;           /* The default collating sequence (BINARY) */
1167   sqlite3_mutex *mutex;         /* Connection mutex */
1168   Db *aDb;                      /* All backends */
1169   int nDb;                      /* Number of backends currently in use */
1170   int flags;                    /* Miscellaneous flags. See below */
1171   i64 lastRowid;                /* ROWID of most recent insert (see above) */
1172   i64 szMmap;                   /* Default mmap_size setting */
1173   unsigned int openFlags;       /* Flags passed to sqlite3_vfs.xOpen() */
1174   int errCode;                  /* Most recent error code (SQLITE_*) */
1175   int errMask;                  /* & result codes with this before returning */
1176   u16 dbOptFlags;               /* Flags to enable/disable optimizations */
1177   u8 enc;                       /* Text encoding */
1178   u8 autoCommit;                /* The auto-commit flag. */
1179   u8 temp_store;                /* 1: file 2: memory 0: default */
1180   u8 mallocFailed;              /* True if we have seen a malloc failure */
1181   u8 bBenignMalloc;             /* Do not require OOMs if true */
1182   u8 dfltLockMode;              /* Default locking-mode for attached dbs */
1183   signed char nextAutovac;      /* Autovac setting after VACUUM if >=0 */
1184   u8 suppressErr;               /* Do not issue error messages if true */
1185   u8 vtabOnConflict;            /* Value to return for s3_vtab_on_conflict() */
1186   u8 isTransactionSavepoint;    /* True if the outermost savepoint is a TS */
1187   int nextPagesize;             /* Pagesize after VACUUM if >0 */
1188   u32 magic;                    /* Magic number for detect library misuse */
1189   int nChange;                  /* Value returned by sqlite3_changes() */
1190   int nTotalChange;             /* Value returned by sqlite3_total_changes() */
1191   int aLimit[SQLITE_N_LIMIT];   /* Limits */
1192   int nMaxSorterMmap;           /* Maximum size of regions mapped by sorter */
1193   struct sqlite3InitInfo {      /* Information used during initialization */
1194     int newTnum;                /* Rootpage of table being initialized */
1195     u8 iDb;                     /* Which db file is being initialized */
1196     u8 busy;                    /* TRUE if currently initializing */
1197     u8 orphanTrigger;           /* Last statement is orphaned TEMP trigger */
1198     u8 imposterTable;           /* Building an imposter table */
1199   } init;
1200   int nVdbeActive;              /* Number of VDBEs currently running */
1201   int nVdbeRead;                /* Number of active VDBEs that read or write */
1202   int nVdbeWrite;               /* Number of active VDBEs that read and write */
1203   int nVdbeExec;                /* Number of nested calls to VdbeExec() */
1204   int nVDestroy;                /* Number of active OP_VDestroy operations */
1205   int nExtension;               /* Number of loaded extensions */
1206   void **aExtension;            /* Array of shared library handles */
1207   void (*xTrace)(void*,const char*);        /* Trace function */
1208   void *pTraceArg;                          /* Argument to the trace function */
1209   void (*xProfile)(void*,const char*,u64);  /* Profiling function */
1210   void *pProfileArg;                        /* Argument to profile function */
1211   void *pCommitArg;                 /* Argument to xCommitCallback() */
1212   int (*xCommitCallback)(void*);    /* Invoked at every commit. */
1213   void *pRollbackArg;               /* Argument to xRollbackCallback() */
1214   void (*xRollbackCallback)(void*); /* Invoked at every commit. */
1215   void *pUpdateArg;
1216   void (*xUpdateCallback)(void*,int, const char*,const char*,sqlite_int64);
1217 #ifndef SQLITE_OMIT_WAL
1218   int (*xWalCallback)(void *, sqlite3 *, const char *, int);
1219   void *pWalArg;
1220 #endif
1221   void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*);
1222   void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*);
1223   void *pCollNeededArg;
1224   sqlite3_value *pErr;          /* Most recent error message */
1225   union {
1226     volatile int isInterrupted; /* True if sqlite3_interrupt has been called */
1227     double notUsed1;            /* Spacer */
1228   } u1;
1229   Lookaside lookaside;          /* Lookaside malloc configuration */
1230 #ifndef SQLITE_OMIT_AUTHORIZATION
1231   sqlite3_xauth xAuth;          /* Access authorization function */
1232   void *pAuthArg;               /* 1st argument to the access auth function */
1233 #endif
1234 #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
1235   int (*xProgress)(void *);     /* The progress callback */
1236   void *pProgressArg;           /* Argument to the progress callback */
1237   unsigned nProgressOps;        /* Number of opcodes for progress callback */
1238 #endif
1239 #ifndef SQLITE_OMIT_VIRTUALTABLE
1240   int nVTrans;                  /* Allocated size of aVTrans */
1241   Hash aModule;                 /* populated by sqlite3_create_module() */
1242   VtabCtx *pVtabCtx;            /* Context for active vtab connect/create */
1243   VTable **aVTrans;             /* Virtual tables with open transactions */
1244   VTable *pDisconnect;    /* Disconnect these in next sqlite3_prepare() */
1245 #endif
1246   FuncDefHash aFunc;            /* Hash table of connection functions */
1247   Hash aCollSeq;                /* All collating sequences */
1248   BusyHandler busyHandler;      /* Busy callback */
1249   Db aDbStatic[2];              /* Static space for the 2 default backends */
1250   Savepoint *pSavepoint;        /* List of active savepoints */
1251   int busyTimeout;              /* Busy handler timeout, in msec */
1252   int nSavepoint;               /* Number of non-transaction savepoints */
1253   int nStatement;               /* Number of nested statement-transactions  */
1254   i64 nDeferredCons;            /* Net deferred constraints this transaction. */
1255   i64 nDeferredImmCons;         /* Net deferred immediate constraints */
1256   int *pnBytesFreed;            /* If not NULL, increment this in DbFree() */
1257 #ifdef SQLITE_ENABLE_UNLOCK_NOTIFY
1258   /* The following variables are all protected by the STATIC_MASTER
1259   ** mutex, not by sqlite3.mutex. They are used by code in notify.c.
1260   **
1261   ** When X.pUnlockConnection==Y, that means that X is waiting for Y to
1262   ** unlock so that it can proceed.
1263   **
1264   ** When X.pBlockingConnection==Y, that means that something that X tried
1265   ** tried to do recently failed with an SQLITE_LOCKED error due to locks
1266   ** held by Y.
1267   */
1268   sqlite3 *pBlockingConnection; /* Connection that caused SQLITE_LOCKED */
1269   sqlite3 *pUnlockConnection;           /* Connection to watch for unlock */
1270   void *pUnlockArg;                     /* Argument to xUnlockNotify */
1271   void (*xUnlockNotify)(void **, int);  /* Unlock notify callback */
1272   sqlite3 *pNextBlocked;        /* Next in list of all blocked connections */
1273 #endif
1274 #ifdef SQLITE_USER_AUTHENTICATION
1275   sqlite3_userauth auth;        /* User authentication information */
1276 #endif
1277 };
1278 
1279 /*
1280 ** A macro to discover the encoding of a database.
1281 */
1282 #define SCHEMA_ENC(db) ((db)->aDb[0].pSchema->enc)
1283 #define ENC(db)        ((db)->enc)
1284 
1285 /*
1286 ** Possible values for the sqlite3.flags.
1287 */
1288 #define SQLITE_VdbeTrace      0x00000001  /* True to trace VDBE execution */
1289 #define SQLITE_InternChanges  0x00000002  /* Uncommitted Hash table changes */
1290 #define SQLITE_FullColNames   0x00000004  /* Show full column names on SELECT */
1291 #define SQLITE_FullFSync      0x00000008  /* Use full fsync on the backend */
1292 #define SQLITE_CkptFullFSync  0x00000010  /* Use full fsync for checkpoint */
1293 #define SQLITE_CacheSpill     0x00000020  /* OK to spill pager cache */
1294 #define SQLITE_ShortColNames  0x00000040  /* Show short columns names */
1295 #define SQLITE_CountRows      0x00000080  /* Count rows changed by INSERT, */
1296                                           /*   DELETE, or UPDATE and return */
1297                                           /*   the count using a callback. */
1298 #define SQLITE_NullCallback   0x00000100  /* Invoke the callback once if the */
1299                                           /*   result set is empty */
1300 #define SQLITE_SqlTrace       0x00000200  /* Debug print SQL as it executes */
1301 #define SQLITE_VdbeListing    0x00000400  /* Debug listings of VDBE programs */
1302 #define SQLITE_WriteSchema    0x00000800  /* OK to update SQLITE_MASTER */
1303 #define SQLITE_VdbeAddopTrace 0x00001000  /* Trace sqlite3VdbeAddOp() calls */
1304 #define SQLITE_IgnoreChecks   0x00002000  /* Do not enforce check constraints */
1305 #define SQLITE_ReadUncommitted 0x0004000  /* For shared-cache mode */
1306 #define SQLITE_LegacyFileFmt  0x00008000  /* Create new databases in format 1 */
1307 #define SQLITE_RecoveryMode   0x00010000  /* Ignore schema errors */
1308 #define SQLITE_ReverseOrder   0x00020000  /* Reverse unordered SELECTs */
1309 #define SQLITE_RecTriggers    0x00040000  /* Enable recursive triggers */
1310 #define SQLITE_ForeignKeys    0x00080000  /* Enforce foreign key constraints  */
1311 #define SQLITE_AutoIndex      0x00100000  /* Enable automatic indexes */
1312 #define SQLITE_PreferBuiltin  0x00200000  /* Preference to built-in funcs */
1313 #define SQLITE_LoadExtension  0x00400000  /* Enable load_extension */
1314 #define SQLITE_EnableTrigger  0x00800000  /* True to enable triggers */
1315 #define SQLITE_DeferFKs       0x01000000  /* Defer all FK constraints */
1316 #define SQLITE_QueryOnly      0x02000000  /* Disable database changes */
1317 #define SQLITE_VdbeEQP        0x04000000  /* Debug EXPLAIN QUERY PLAN */
1318 #define SQLITE_Vacuum         0x08000000  /* Currently in a VACUUM */
1319 #define SQLITE_CellSizeCk     0x10000000  /* Check btree cell sizes on load */
1320 
1321 
1322 /*
1323 ** Bits of the sqlite3.dbOptFlags field that are used by the
1324 ** sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS,...) interface to
1325 ** selectively disable various optimizations.
1326 */
1327 #define SQLITE_QueryFlattener 0x0001   /* Query flattening */
1328 #define SQLITE_ColumnCache    0x0002   /* Column cache */
1329 #define SQLITE_GroupByOrder   0x0004   /* GROUPBY cover of ORDERBY */
1330 #define SQLITE_FactorOutConst 0x0008   /* Constant factoring */
1331 /*                not used    0x0010   // Was: SQLITE_IdxRealAsInt */
1332 #define SQLITE_DistinctOpt    0x0020   /* DISTINCT using indexes */
1333 #define SQLITE_CoverIdxScan   0x0040   /* Covering index scans */
1334 #define SQLITE_OrderByIdxJoin 0x0080   /* ORDER BY of joins via index */
1335 #define SQLITE_SubqCoroutine  0x0100   /* Evaluate subqueries as coroutines */
1336 #define SQLITE_Transitive     0x0200   /* Transitive constraints */
1337 #define SQLITE_OmitNoopJoin   0x0400   /* Omit unused tables in joins */
1338 #define SQLITE_Stat34         0x0800   /* Use STAT3 or STAT4 data */
1339 #define SQLITE_CursorHints    0x2000   /* Add OP_CursorHint opcodes */
1340 #define SQLITE_AllOpts        0xffff   /* All optimizations */
1341 
1342 /*
1343 ** Macros for testing whether or not optimizations are enabled or disabled.
1344 */
1345 #ifndef SQLITE_OMIT_BUILTIN_TEST
1346 #define OptimizationDisabled(db, mask)  (((db)->dbOptFlags&(mask))!=0)
1347 #define OptimizationEnabled(db, mask)   (((db)->dbOptFlags&(mask))==0)
1348 #else
1349 #define OptimizationDisabled(db, mask)  0
1350 #define OptimizationEnabled(db, mask)   1
1351 #endif
1352 
1353 /*
1354 ** Return true if it OK to factor constant expressions into the initialization
1355 ** code. The argument is a Parse object for the code generator.
1356 */
1357 #define ConstFactorOk(P) ((P)->okConstFactor)
1358 
1359 /*
1360 ** Possible values for the sqlite.magic field.
1361 ** The numbers are obtained at random and have no special meaning, other
1362 ** than being distinct from one another.
1363 */
1364 #define SQLITE_MAGIC_OPEN     0xa029a697  /* Database is open */
1365 #define SQLITE_MAGIC_CLOSED   0x9f3c2d33  /* Database is closed */
1366 #define SQLITE_MAGIC_SICK     0x4b771290  /* Error and awaiting close */
1367 #define SQLITE_MAGIC_BUSY     0xf03b7906  /* Database currently in use */
1368 #define SQLITE_MAGIC_ERROR    0xb5357930  /* An SQLITE_MISUSE error occurred */
1369 #define SQLITE_MAGIC_ZOMBIE   0x64cffc7f  /* Close with last statement close */
1370 
1371 /*
1372 ** Each SQL function is defined by an instance of the following
1373 ** structure.  A pointer to this structure is stored in the sqlite.aFunc
1374 ** hash table.  When multiple functions have the same name, the hash table
1375 ** points to a linked list of these structures.
1376 */
1377 struct FuncDef {
1378   i16 nArg;            /* Number of arguments.  -1 means unlimited */
1379   u16 funcFlags;       /* Some combination of SQLITE_FUNC_* */
1380   void *pUserData;     /* User data parameter */
1381   FuncDef *pNext;      /* Next function with same name */
1382   void (*xSFunc)(sqlite3_context*,int,sqlite3_value**); /* func or agg-step */
1383   void (*xFinalize)(sqlite3_context*);                  /* Agg finalizer */
1384   char *zName;         /* SQL name of the function. */
1385   FuncDef *pHash;      /* Next with a different name but the same hash */
1386   FuncDestructor *pDestructor;   /* Reference counted destructor function */
1387 };
1388 
1389 /*
1390 ** This structure encapsulates a user-function destructor callback (as
1391 ** configured using create_function_v2()) and a reference counter. When
1392 ** create_function_v2() is called to create a function with a destructor,
1393 ** a single object of this type is allocated. FuncDestructor.nRef is set to
1394 ** the number of FuncDef objects created (either 1 or 3, depending on whether
1395 ** or not the specified encoding is SQLITE_ANY). The FuncDef.pDestructor
1396 ** member of each of the new FuncDef objects is set to point to the allocated
1397 ** FuncDestructor.
1398 **
1399 ** Thereafter, when one of the FuncDef objects is deleted, the reference
1400 ** count on this object is decremented. When it reaches 0, the destructor
1401 ** is invoked and the FuncDestructor structure freed.
1402 */
1403 struct FuncDestructor {
1404   int nRef;
1405   void (*xDestroy)(void *);
1406   void *pUserData;
1407 };
1408 
1409 /*
1410 ** Possible values for FuncDef.flags.  Note that the _LENGTH and _TYPEOF
1411 ** values must correspond to OPFLAG_LENGTHARG and OPFLAG_TYPEOFARG.  And
1412 ** SQLITE_FUNC_CONSTANT must be the same as SQLITE_DETERMINISTIC.  There
1413 ** are assert() statements in the code to verify this.
1414 */
1415 #define SQLITE_FUNC_ENCMASK  0x0003 /* SQLITE_UTF8, SQLITE_UTF16BE or UTF16LE */
1416 #define SQLITE_FUNC_LIKE     0x0004 /* Candidate for the LIKE optimization */
1417 #define SQLITE_FUNC_CASE     0x0008 /* Case-sensitive LIKE-type function */
1418 #define SQLITE_FUNC_EPHEM    0x0010 /* Ephemeral.  Delete with VDBE */
1419 #define SQLITE_FUNC_NEEDCOLL 0x0020 /* sqlite3GetFuncCollSeq() might be called*/
1420 #define SQLITE_FUNC_LENGTH   0x0040 /* Built-in length() function */
1421 #define SQLITE_FUNC_TYPEOF   0x0080 /* Built-in typeof() function */
1422 #define SQLITE_FUNC_COUNT    0x0100 /* Built-in count(*) aggregate */
1423 #define SQLITE_FUNC_COALESCE 0x0200 /* Built-in coalesce() or ifnull() */
1424 #define SQLITE_FUNC_UNLIKELY 0x0400 /* Built-in unlikely() function */
1425 #define SQLITE_FUNC_CONSTANT 0x0800 /* Constant inputs give a constant output */
1426 #define SQLITE_FUNC_MINMAX   0x1000 /* True for min() and max() aggregates */
1427 #define SQLITE_FUNC_SLOCHNG  0x2000 /* "Slow Change". Value constant during a
1428                                     ** single query - might change over time */
1429 
1430 /*
1431 ** The following three macros, FUNCTION(), LIKEFUNC() and AGGREGATE() are
1432 ** used to create the initializers for the FuncDef structures.
1433 **
1434 **   FUNCTION(zName, nArg, iArg, bNC, xFunc)
1435 **     Used to create a scalar function definition of a function zName
1436 **     implemented by C function xFunc that accepts nArg arguments. The
1437 **     value passed as iArg is cast to a (void*) and made available
1438 **     as the user-data (sqlite3_user_data()) for the function. If
1439 **     argument bNC is true, then the SQLITE_FUNC_NEEDCOLL flag is set.
1440 **
1441 **   VFUNCTION(zName, nArg, iArg, bNC, xFunc)
1442 **     Like FUNCTION except it omits the SQLITE_FUNC_CONSTANT flag.
1443 **
1444 **   DFUNCTION(zName, nArg, iArg, bNC, xFunc)
1445 **     Like FUNCTION except it omits the SQLITE_FUNC_CONSTANT flag and
1446 **     adds the SQLITE_FUNC_SLOCHNG flag.  Used for date & time functions
1447 **     and functions like sqlite_version() that can change, but not during
1448 **     a single query.
1449 **
1450 **   AGGREGATE(zName, nArg, iArg, bNC, xStep, xFinal)
1451 **     Used to create an aggregate function definition implemented by
1452 **     the C functions xStep and xFinal. The first four parameters
1453 **     are interpreted in the same way as the first 4 parameters to
1454 **     FUNCTION().
1455 **
1456 **   LIKEFUNC(zName, nArg, pArg, flags)
1457 **     Used to create a scalar function definition of a function zName
1458 **     that accepts nArg arguments and is implemented by a call to C
1459 **     function likeFunc. Argument pArg is cast to a (void *) and made
1460 **     available as the function user-data (sqlite3_user_data()). The
1461 **     FuncDef.flags variable is set to the value passed as the flags
1462 **     parameter.
1463 */
1464 #define FUNCTION(zName, nArg, iArg, bNC, xFunc) \
1465   {nArg, SQLITE_FUNC_CONSTANT|SQLITE_UTF8|(bNC*SQLITE_FUNC_NEEDCOLL), \
1466    SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, #zName, 0, 0}
1467 #define VFUNCTION(zName, nArg, iArg, bNC, xFunc) \
1468   {nArg, SQLITE_UTF8|(bNC*SQLITE_FUNC_NEEDCOLL), \
1469    SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, #zName, 0, 0}
1470 #define DFUNCTION(zName, nArg, iArg, bNC, xFunc) \
1471   {nArg, SQLITE_FUNC_SLOCHNG|SQLITE_UTF8|(bNC*SQLITE_FUNC_NEEDCOLL), \
1472    SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, #zName, 0, 0}
1473 #define FUNCTION2(zName, nArg, iArg, bNC, xFunc, extraFlags) \
1474   {nArg,SQLITE_FUNC_CONSTANT|SQLITE_UTF8|(bNC*SQLITE_FUNC_NEEDCOLL)|extraFlags,\
1475    SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, #zName, 0, 0}
1476 #define STR_FUNCTION(zName, nArg, pArg, bNC, xFunc) \
1477   {nArg, SQLITE_FUNC_SLOCHNG|SQLITE_UTF8|(bNC*SQLITE_FUNC_NEEDCOLL), \
1478    pArg, 0, xFunc, 0, #zName, 0, 0}
1479 #define LIKEFUNC(zName, nArg, arg, flags) \
1480   {nArg, SQLITE_FUNC_CONSTANT|SQLITE_UTF8|flags, \
1481    (void *)arg, 0, likeFunc, 0, #zName, 0, 0}
1482 #define AGGREGATE(zName, nArg, arg, nc, xStep, xFinal) \
1483   {nArg, SQLITE_UTF8|(nc*SQLITE_FUNC_NEEDCOLL), \
1484    SQLITE_INT_TO_PTR(arg), 0, xStep,xFinal,#zName,0,0}
1485 #define AGGREGATE2(zName, nArg, arg, nc, xStep, xFinal, extraFlags) \
1486   {nArg, SQLITE_UTF8|(nc*SQLITE_FUNC_NEEDCOLL)|extraFlags, \
1487    SQLITE_INT_TO_PTR(arg), 0, xStep,xFinal,#zName,0,0}
1488 
1489 /*
1490 ** All current savepoints are stored in a linked list starting at
1491 ** sqlite3.pSavepoint. The first element in the list is the most recently
1492 ** opened savepoint. Savepoints are added to the list by the vdbe
1493 ** OP_Savepoint instruction.
1494 */
1495 struct Savepoint {
1496   char *zName;                        /* Savepoint name (nul-terminated) */
1497   i64 nDeferredCons;                  /* Number of deferred fk violations */
1498   i64 nDeferredImmCons;               /* Number of deferred imm fk. */
1499   Savepoint *pNext;                   /* Parent savepoint (if any) */
1500 };
1501 
1502 /*
1503 ** The following are used as the second parameter to sqlite3Savepoint(),
1504 ** and as the P1 argument to the OP_Savepoint instruction.
1505 */
1506 #define SAVEPOINT_BEGIN      0
1507 #define SAVEPOINT_RELEASE    1
1508 #define SAVEPOINT_ROLLBACK   2
1509 
1510 
1511 /*
1512 ** Each SQLite module (virtual table definition) is defined by an
1513 ** instance of the following structure, stored in the sqlite3.aModule
1514 ** hash table.
1515 */
1516 struct Module {
1517   const sqlite3_module *pModule;       /* Callback pointers */
1518   const char *zName;                   /* Name passed to create_module() */
1519   void *pAux;                          /* pAux passed to create_module() */
1520   void (*xDestroy)(void *);            /* Module destructor function */
1521   Table *pEpoTab;                      /* Eponymous table for this module */
1522 };
1523 
1524 /*
1525 ** information about each column of an SQL table is held in an instance
1526 ** of this structure.
1527 */
1528 struct Column {
1529   char *zName;     /* Name of this column */
1530   Expr *pDflt;     /* Default value of this column */
1531   char *zDflt;     /* Original text of the default value */
1532   char *zType;     /* Data type for this column */
1533   char *zColl;     /* Collating sequence.  If NULL, use the default */
1534   u8 notNull;      /* An OE_ code for handling a NOT NULL constraint */
1535   char affinity;   /* One of the SQLITE_AFF_... values */
1536   u8 szEst;        /* Estimated size of value in this column. sizeof(INT)==1 */
1537   u8 colFlags;     /* Boolean properties.  See COLFLAG_ defines below */
1538 };
1539 
1540 /* Allowed values for Column.colFlags:
1541 */
1542 #define COLFLAG_PRIMKEY  0x0001    /* Column is part of the primary key */
1543 #define COLFLAG_HIDDEN   0x0002    /* A hidden column in a virtual table */
1544 
1545 /*
1546 ** A "Collating Sequence" is defined by an instance of the following
1547 ** structure. Conceptually, a collating sequence consists of a name and
1548 ** a comparison routine that defines the order of that sequence.
1549 **
1550 ** If CollSeq.xCmp is NULL, it means that the
1551 ** collating sequence is undefined.  Indices built on an undefined
1552 ** collating sequence may not be read or written.
1553 */
1554 struct CollSeq {
1555   char *zName;          /* Name of the collating sequence, UTF-8 encoded */
1556   u8 enc;               /* Text encoding handled by xCmp() */
1557   void *pUser;          /* First argument to xCmp() */
1558   int (*xCmp)(void*,int, const void*, int, const void*);
1559   void (*xDel)(void*);  /* Destructor for pUser */
1560 };
1561 
1562 /*
1563 ** A sort order can be either ASC or DESC.
1564 */
1565 #define SQLITE_SO_ASC       0  /* Sort in ascending order */
1566 #define SQLITE_SO_DESC      1  /* Sort in ascending order */
1567 #define SQLITE_SO_UNDEFINED -1 /* No sort order specified */
1568 
1569 /*
1570 ** Column affinity types.
1571 **
1572 ** These used to have mnemonic name like 'i' for SQLITE_AFF_INTEGER and
1573 ** 't' for SQLITE_AFF_TEXT.  But we can save a little space and improve
1574 ** the speed a little by numbering the values consecutively.
1575 **
1576 ** But rather than start with 0 or 1, we begin with 'A'.  That way,
1577 ** when multiple affinity types are concatenated into a string and
1578 ** used as the P4 operand, they will be more readable.
1579 **
1580 ** Note also that the numeric types are grouped together so that testing
1581 ** for a numeric type is a single comparison.  And the BLOB type is first.
1582 */
1583 #define SQLITE_AFF_BLOB     'A'
1584 #define SQLITE_AFF_TEXT     'B'
1585 #define SQLITE_AFF_NUMERIC  'C'
1586 #define SQLITE_AFF_INTEGER  'D'
1587 #define SQLITE_AFF_REAL     'E'
1588 
1589 #define sqlite3IsNumericAffinity(X)  ((X)>=SQLITE_AFF_NUMERIC)
1590 
1591 /*
1592 ** The SQLITE_AFF_MASK values masks off the significant bits of an
1593 ** affinity value.
1594 */
1595 #define SQLITE_AFF_MASK     0x47
1596 
1597 /*
1598 ** Additional bit values that can be ORed with an affinity without
1599 ** changing the affinity.
1600 **
1601 ** The SQLITE_NOTNULL flag is a combination of NULLEQ and JUMPIFNULL.
1602 ** It causes an assert() to fire if either operand to a comparison
1603 ** operator is NULL.  It is added to certain comparison operators to
1604 ** prove that the operands are always NOT NULL.
1605 */
1606 #define SQLITE_JUMPIFNULL   0x10  /* jumps if either operand is NULL */
1607 #define SQLITE_STOREP2      0x20  /* Store result in reg[P2] rather than jump */
1608 #define SQLITE_NULLEQ       0x80  /* NULL=NULL */
1609 #define SQLITE_NOTNULL      0x90  /* Assert that operands are never NULL */
1610 
1611 /*
1612 ** An object of this type is created for each virtual table present in
1613 ** the database schema.
1614 **
1615 ** If the database schema is shared, then there is one instance of this
1616 ** structure for each database connection (sqlite3*) that uses the shared
1617 ** schema. This is because each database connection requires its own unique
1618 ** instance of the sqlite3_vtab* handle used to access the virtual table
1619 ** implementation. sqlite3_vtab* handles can not be shared between
1620 ** database connections, even when the rest of the in-memory database
1621 ** schema is shared, as the implementation often stores the database
1622 ** connection handle passed to it via the xConnect() or xCreate() method
1623 ** during initialization internally. This database connection handle may
1624 ** then be used by the virtual table implementation to access real tables
1625 ** within the database. So that they appear as part of the callers
1626 ** transaction, these accesses need to be made via the same database
1627 ** connection as that used to execute SQL operations on the virtual table.
1628 **
1629 ** All VTable objects that correspond to a single table in a shared
1630 ** database schema are initially stored in a linked-list pointed to by
1631 ** the Table.pVTable member variable of the corresponding Table object.
1632 ** When an sqlite3_prepare() operation is required to access the virtual
1633 ** table, it searches the list for the VTable that corresponds to the
1634 ** database connection doing the preparing so as to use the correct
1635 ** sqlite3_vtab* handle in the compiled query.
1636 **
1637 ** When an in-memory Table object is deleted (for example when the
1638 ** schema is being reloaded for some reason), the VTable objects are not
1639 ** deleted and the sqlite3_vtab* handles are not xDisconnect()ed
1640 ** immediately. Instead, they are moved from the Table.pVTable list to
1641 ** another linked list headed by the sqlite3.pDisconnect member of the
1642 ** corresponding sqlite3 structure. They are then deleted/xDisconnected
1643 ** next time a statement is prepared using said sqlite3*. This is done
1644 ** to avoid deadlock issues involving multiple sqlite3.mutex mutexes.
1645 ** Refer to comments above function sqlite3VtabUnlockList() for an
1646 ** explanation as to why it is safe to add an entry to an sqlite3.pDisconnect
1647 ** list without holding the corresponding sqlite3.mutex mutex.
1648 **
1649 ** The memory for objects of this type is always allocated by
1650 ** sqlite3DbMalloc(), using the connection handle stored in VTable.db as
1651 ** the first argument.
1652 */
1653 struct VTable {
1654   sqlite3 *db;              /* Database connection associated with this table */
1655   Module *pMod;             /* Pointer to module implementation */
1656   sqlite3_vtab *pVtab;      /* Pointer to vtab instance */
1657   int nRef;                 /* Number of pointers to this structure */
1658   u8 bConstraint;           /* True if constraints are supported */
1659   int iSavepoint;           /* Depth of the SAVEPOINT stack */
1660   VTable *pNext;            /* Next in linked list (see above) */
1661 };
1662 
1663 /*
1664 ** The schema for each SQL table and view is represented in memory
1665 ** by an instance of the following structure.
1666 */
1667 struct Table {
1668   char *zName;         /* Name of the table or view */
1669   Column *aCol;        /* Information about each column */
1670   Index *pIndex;       /* List of SQL indexes on this table. */
1671   Select *pSelect;     /* NULL for tables.  Points to definition if a view. */
1672   FKey *pFKey;         /* Linked list of all foreign keys in this table */
1673   char *zColAff;       /* String defining the affinity of each column */
1674   ExprList *pCheck;    /* All CHECK constraints */
1675                        /*   ... also used as column name list in a VIEW */
1676   int tnum;            /* Root BTree page for this table */
1677   i16 iPKey;           /* If not negative, use aCol[iPKey] as the rowid */
1678   i16 nCol;            /* Number of columns in this table */
1679   u16 nRef;            /* Number of pointers to this Table */
1680   LogEst nRowLogEst;   /* Estimated rows in table - from sqlite_stat1 table */
1681   LogEst szTabRow;     /* Estimated size of each table row in bytes */
1682 #ifdef SQLITE_ENABLE_COSTMULT
1683   LogEst costMult;     /* Cost multiplier for using this table */
1684 #endif
1685   u8 tabFlags;         /* Mask of TF_* values */
1686   u8 keyConf;          /* What to do in case of uniqueness conflict on iPKey */
1687 #ifndef SQLITE_OMIT_ALTERTABLE
1688   int addColOffset;    /* Offset in CREATE TABLE stmt to add a new column */
1689 #endif
1690 #ifndef SQLITE_OMIT_VIRTUALTABLE
1691   int nModuleArg;      /* Number of arguments to the module */
1692   char **azModuleArg;  /* 0: module 1: schema 2: vtab name 3...: args */
1693   VTable *pVTable;     /* List of VTable objects. */
1694 #endif
1695   Trigger *pTrigger;   /* List of triggers stored in pSchema */
1696   Schema *pSchema;     /* Schema that contains this table */
1697   Table *pNextZombie;  /* Next on the Parse.pZombieTab list */
1698 };
1699 
1700 /*
1701 ** Allowed values for Table.tabFlags.
1702 **
1703 ** TF_OOOHidden applies to tables or view that have hidden columns that are
1704 ** followed by non-hidden columns.  Example:  "CREATE VIRTUAL TABLE x USING
1705 ** vtab1(a HIDDEN, b);".  Since "b" is a non-hidden column but "a" is hidden,
1706 ** the TF_OOOHidden attribute would apply in this case.  Such tables require
1707 ** special handling during INSERT processing.
1708 */
1709 #define TF_Readonly        0x01    /* Read-only system table */
1710 #define TF_Ephemeral       0x02    /* An ephemeral table */
1711 #define TF_HasPrimaryKey   0x04    /* Table has a primary key */
1712 #define TF_Autoincrement   0x08    /* Integer primary key is autoincrement */
1713 #define TF_Virtual         0x10    /* Is a virtual table */
1714 #define TF_WithoutRowid    0x20    /* No rowid.  PRIMARY KEY is the key */
1715 #define TF_NoVisibleRowid  0x40    /* No user-visible "rowid" column */
1716 #define TF_OOOHidden       0x80    /* Out-of-Order hidden columns */
1717 
1718 
1719 /*
1720 ** Test to see whether or not a table is a virtual table.  This is
1721 ** done as a macro so that it will be optimized out when virtual
1722 ** table support is omitted from the build.
1723 */
1724 #ifndef SQLITE_OMIT_VIRTUALTABLE
1725 #  define IsVirtual(X)      (((X)->tabFlags & TF_Virtual)!=0)
1726 #else
1727 #  define IsVirtual(X)      0
1728 #endif
1729 
1730 /*
1731 ** Macros to determine if a column is hidden.  IsOrdinaryHiddenColumn()
1732 ** only works for non-virtual tables (ordinary tables and views) and is
1733 ** always false unless SQLITE_ENABLE_HIDDEN_COLUMNS is defined.  The
1734 ** IsHiddenColumn() macro is general purpose.
1735 */
1736 #if defined(SQLITE_ENABLE_HIDDEN_COLUMNS)
1737 #  define IsHiddenColumn(X)         (((X)->colFlags & COLFLAG_HIDDEN)!=0)
1738 #  define IsOrdinaryHiddenColumn(X) (((X)->colFlags & COLFLAG_HIDDEN)!=0)
1739 #elif !defined(SQLITE_OMIT_VIRTUALTABLE)
1740 #  define IsHiddenColumn(X)         (((X)->colFlags & COLFLAG_HIDDEN)!=0)
1741 #  define IsOrdinaryHiddenColumn(X) 0
1742 #else
1743 #  define IsHiddenColumn(X)         0
1744 #  define IsOrdinaryHiddenColumn(X) 0
1745 #endif
1746 
1747 
1748 /* Does the table have a rowid */
1749 #define HasRowid(X)     (((X)->tabFlags & TF_WithoutRowid)==0)
1750 #define VisibleRowid(X) (((X)->tabFlags & TF_NoVisibleRowid)==0)
1751 
1752 /*
1753 ** Each foreign key constraint is an instance of the following structure.
1754 **
1755 ** A foreign key is associated with two tables.  The "from" table is
1756 ** the table that contains the REFERENCES clause that creates the foreign
1757 ** key.  The "to" table is the table that is named in the REFERENCES clause.
1758 ** Consider this example:
1759 **
1760 **     CREATE TABLE ex1(
1761 **       a INTEGER PRIMARY KEY,
1762 **       b INTEGER CONSTRAINT fk1 REFERENCES ex2(x)
1763 **     );
1764 **
1765 ** For foreign key "fk1", the from-table is "ex1" and the to-table is "ex2".
1766 ** Equivalent names:
1767 **
1768 **     from-table == child-table
1769 **       to-table == parent-table
1770 **
1771 ** Each REFERENCES clause generates an instance of the following structure
1772 ** which is attached to the from-table.  The to-table need not exist when
1773 ** the from-table is created.  The existence of the to-table is not checked.
1774 **
1775 ** The list of all parents for child Table X is held at X.pFKey.
1776 **
1777 ** A list of all children for a table named Z (which might not even exist)
1778 ** is held in Schema.fkeyHash with a hash key of Z.
1779 */
1780 struct FKey {
1781   Table *pFrom;     /* Table containing the REFERENCES clause (aka: Child) */
1782   FKey *pNextFrom;  /* Next FKey with the same in pFrom. Next parent of pFrom */
1783   char *zTo;        /* Name of table that the key points to (aka: Parent) */
1784   FKey *pNextTo;    /* Next with the same zTo. Next child of zTo. */
1785   FKey *pPrevTo;    /* Previous with the same zTo */
1786   int nCol;         /* Number of columns in this key */
1787   /* EV: R-30323-21917 */
1788   u8 isDeferred;       /* True if constraint checking is deferred till COMMIT */
1789   u8 aAction[2];        /* ON DELETE and ON UPDATE actions, respectively */
1790   Trigger *apTrigger[2];/* Triggers for aAction[] actions */
1791   struct sColMap {      /* Mapping of columns in pFrom to columns in zTo */
1792     int iFrom;            /* Index of column in pFrom */
1793     char *zCol;           /* Name of column in zTo.  If NULL use PRIMARY KEY */
1794   } aCol[1];            /* One entry for each of nCol columns */
1795 };
1796 
1797 /*
1798 ** SQLite supports many different ways to resolve a constraint
1799 ** error.  ROLLBACK processing means that a constraint violation
1800 ** causes the operation in process to fail and for the current transaction
1801 ** to be rolled back.  ABORT processing means the operation in process
1802 ** fails and any prior changes from that one operation are backed out,
1803 ** but the transaction is not rolled back.  FAIL processing means that
1804 ** the operation in progress stops and returns an error code.  But prior
1805 ** changes due to the same operation are not backed out and no rollback
1806 ** occurs.  IGNORE means that the particular row that caused the constraint
1807 ** error is not inserted or updated.  Processing continues and no error
1808 ** is returned.  REPLACE means that preexisting database rows that caused
1809 ** a UNIQUE constraint violation are removed so that the new insert or
1810 ** update can proceed.  Processing continues and no error is reported.
1811 **
1812 ** RESTRICT, SETNULL, and CASCADE actions apply only to foreign keys.
1813 ** RESTRICT is the same as ABORT for IMMEDIATE foreign keys and the
1814 ** same as ROLLBACK for DEFERRED keys.  SETNULL means that the foreign
1815 ** key is set to NULL.  CASCADE means that a DELETE or UPDATE of the
1816 ** referenced table row is propagated into the row that holds the
1817 ** foreign key.
1818 **
1819 ** The following symbolic values are used to record which type
1820 ** of action to take.
1821 */
1822 #define OE_None     0   /* There is no constraint to check */
1823 #define OE_Rollback 1   /* Fail the operation and rollback the transaction */
1824 #define OE_Abort    2   /* Back out changes but do no rollback transaction */
1825 #define OE_Fail     3   /* Stop the operation but leave all prior changes */
1826 #define OE_Ignore   4   /* Ignore the error. Do not do the INSERT or UPDATE */
1827 #define OE_Replace  5   /* Delete existing record, then do INSERT or UPDATE */
1828 
1829 #define OE_Restrict 6   /* OE_Abort for IMMEDIATE, OE_Rollback for DEFERRED */
1830 #define OE_SetNull  7   /* Set the foreign key value to NULL */
1831 #define OE_SetDflt  8   /* Set the foreign key value to its default */
1832 #define OE_Cascade  9   /* Cascade the changes */
1833 
1834 #define OE_Default  10  /* Do whatever the default action is */
1835 
1836 
1837 /*
1838 ** An instance of the following structure is passed as the first
1839 ** argument to sqlite3VdbeKeyCompare and is used to control the
1840 ** comparison of the two index keys.
1841 **
1842 ** Note that aSortOrder[] and aColl[] have nField+1 slots.  There
1843 ** are nField slots for the columns of an index then one extra slot
1844 ** for the rowid at the end.
1845 */
1846 struct KeyInfo {
1847   u32 nRef;           /* Number of references to this KeyInfo object */
1848   u8 enc;             /* Text encoding - one of the SQLITE_UTF* values */
1849   u16 nField;         /* Number of key columns in the index */
1850   u16 nXField;        /* Number of columns beyond the key columns */
1851   sqlite3 *db;        /* The database connection */
1852   u8 *aSortOrder;     /* Sort order for each column. */
1853   CollSeq *aColl[1];  /* Collating sequence for each term of the key */
1854 };
1855 
1856 /*
1857 ** This object holds a record which has been parsed out into individual
1858 ** fields, for the purposes of doing a comparison.
1859 **
1860 ** A record is an object that contains one or more fields of data.
1861 ** Records are used to store the content of a table row and to store
1862 ** the key of an index.  A blob encoding of a record is created by
1863 ** the OP_MakeRecord opcode of the VDBE and is disassembled by the
1864 ** OP_Column opcode.
1865 **
1866 ** An instance of this object serves as a "key" for doing a search on
1867 ** an index b+tree. The goal of the search is to find the entry that
1868 ** is closed to the key described by this object.  This object might hold
1869 ** just a prefix of the key.  The number of fields is given by
1870 ** pKeyInfo->nField.
1871 **
1872 ** The r1 and r2 fields are the values to return if this key is less than
1873 ** or greater than a key in the btree, respectively.  These are normally
1874 ** -1 and +1 respectively, but might be inverted to +1 and -1 if the b-tree
1875 ** is in DESC order.
1876 **
1877 ** The key comparison functions actually return default_rc when they find
1878 ** an equals comparison.  default_rc can be -1, 0, or +1.  If there are
1879 ** multiple entries in the b-tree with the same key (when only looking
1880 ** at the first pKeyInfo->nFields,) then default_rc can be set to -1 to
1881 ** cause the search to find the last match, or +1 to cause the search to
1882 ** find the first match.
1883 **
1884 ** The key comparison functions will set eqSeen to true if they ever
1885 ** get and equal results when comparing this structure to a b-tree record.
1886 ** When default_rc!=0, the search might end up on the record immediately
1887 ** before the first match or immediately after the last match.  The
1888 ** eqSeen field will indicate whether or not an exact match exists in the
1889 ** b-tree.
1890 */
1891 struct UnpackedRecord {
1892   KeyInfo *pKeyInfo;  /* Collation and sort-order information */
1893   Mem *aMem;          /* Values */
1894   u16 nField;         /* Number of entries in apMem[] */
1895   i8 default_rc;      /* Comparison result if keys are equal */
1896   u8 errCode;         /* Error detected by xRecordCompare (CORRUPT or NOMEM) */
1897   i8 r1;              /* Value to return if (lhs > rhs) */
1898   i8 r2;              /* Value to return if (rhs < lhs) */
1899   u8 eqSeen;          /* True if an equality comparison has been seen */
1900 };
1901 
1902 
1903 /*
1904 ** Each SQL index is represented in memory by an
1905 ** instance of the following structure.
1906 **
1907 ** The columns of the table that are to be indexed are described
1908 ** by the aiColumn[] field of this structure.  For example, suppose
1909 ** we have the following table and index:
1910 **
1911 **     CREATE TABLE Ex1(c1 int, c2 int, c3 text);
1912 **     CREATE INDEX Ex2 ON Ex1(c3,c1);
1913 **
1914 ** In the Table structure describing Ex1, nCol==3 because there are
1915 ** three columns in the table.  In the Index structure describing
1916 ** Ex2, nColumn==2 since 2 of the 3 columns of Ex1 are indexed.
1917 ** The value of aiColumn is {2, 0}.  aiColumn[0]==2 because the
1918 ** first column to be indexed (c3) has an index of 2 in Ex1.aCol[].
1919 ** The second column to be indexed (c1) has an index of 0 in
1920 ** Ex1.aCol[], hence Ex2.aiColumn[1]==0.
1921 **
1922 ** The Index.onError field determines whether or not the indexed columns
1923 ** must be unique and what to do if they are not.  When Index.onError=OE_None,
1924 ** it means this is not a unique index.  Otherwise it is a unique index
1925 ** and the value of Index.onError indicate the which conflict resolution
1926 ** algorithm to employ whenever an attempt is made to insert a non-unique
1927 ** element.
1928 **
1929 ** While parsing a CREATE TABLE or CREATE INDEX statement in order to
1930 ** generate VDBE code (as opposed to parsing one read from an sqlite_master
1931 ** table as part of parsing an existing database schema), transient instances
1932 ** of this structure may be created. In this case the Index.tnum variable is
1933 ** used to store the address of a VDBE instruction, not a database page
1934 ** number (it cannot - the database page is not allocated until the VDBE
1935 ** program is executed). See convertToWithoutRowidTable() for details.
1936 */
1937 struct Index {
1938   char *zName;             /* Name of this index */
1939   i16 *aiColumn;           /* Which columns are used by this index.  1st is 0 */
1940   LogEst *aiRowLogEst;     /* From ANALYZE: Est. rows selected by each column */
1941   Table *pTable;           /* The SQL table being indexed */
1942   char *zColAff;           /* String defining the affinity of each column */
1943   Index *pNext;            /* The next index associated with the same table */
1944   Schema *pSchema;         /* Schema containing this index */
1945   u8 *aSortOrder;          /* for each column: True==DESC, False==ASC */
1946   const char **azColl;     /* Array of collation sequence names for index */
1947   Expr *pPartIdxWhere;     /* WHERE clause for partial indices */
1948   ExprList *aColExpr;      /* Column expressions */
1949   int tnum;                /* DB Page containing root of this index */
1950   LogEst szIdxRow;         /* Estimated average row size in bytes */
1951   u16 nKeyCol;             /* Number of columns forming the key */
1952   u16 nColumn;             /* Number of columns stored in the index */
1953   u8 onError;              /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
1954   unsigned idxType:2;      /* 1==UNIQUE, 2==PRIMARY KEY, 0==CREATE INDEX */
1955   unsigned bUnordered:1;   /* Use this index for == or IN queries only */
1956   unsigned uniqNotNull:1;  /* True if UNIQUE and NOT NULL for all columns */
1957   unsigned isResized:1;    /* True if resizeIndexObject() has been called */
1958   unsigned isCovering:1;   /* True if this is a covering index */
1959   unsigned noSkipScan:1;   /* Do not try to use skip-scan if true */
1960 #ifdef SQLITE_ENABLE_STAT3_OR_STAT4
1961   int nSample;             /* Number of elements in aSample[] */
1962   int nSampleCol;          /* Size of IndexSample.anEq[] and so on */
1963   tRowcnt *aAvgEq;         /* Average nEq values for keys not in aSample */
1964   IndexSample *aSample;    /* Samples of the left-most key */
1965   tRowcnt *aiRowEst;       /* Non-logarithmic stat1 data for this index */
1966   tRowcnt nRowEst0;        /* Non-logarithmic number of rows in the index */
1967 #endif
1968 };
1969 
1970 /*
1971 ** Allowed values for Index.idxType
1972 */
1973 #define SQLITE_IDXTYPE_APPDEF      0   /* Created using CREATE INDEX */
1974 #define SQLITE_IDXTYPE_UNIQUE      1   /* Implements a UNIQUE constraint */
1975 #define SQLITE_IDXTYPE_PRIMARYKEY  2   /* Is the PRIMARY KEY for the table */
1976 
1977 /* Return true if index X is a PRIMARY KEY index */
1978 #define IsPrimaryKeyIndex(X)  ((X)->idxType==SQLITE_IDXTYPE_PRIMARYKEY)
1979 
1980 /* Return true if index X is a UNIQUE index */
1981 #define IsUniqueIndex(X)      ((X)->onError!=OE_None)
1982 
1983 /* The Index.aiColumn[] values are normally positive integer.  But
1984 ** there are some negative values that have special meaning:
1985 */
1986 #define XN_ROWID     (-1)     /* Indexed column is the rowid */
1987 #define XN_EXPR      (-2)     /* Indexed column is an expression */
1988 
1989 /*
1990 ** Each sample stored in the sqlite_stat3 table is represented in memory
1991 ** using a structure of this type.  See documentation at the top of the
1992 ** analyze.c source file for additional information.
1993 */
1994 struct IndexSample {
1995   void *p;          /* Pointer to sampled record */
1996   int n;            /* Size of record in bytes */
1997   tRowcnt *anEq;    /* Est. number of rows where the key equals this sample */
1998   tRowcnt *anLt;    /* Est. number of rows where key is less than this sample */
1999   tRowcnt *anDLt;   /* Est. number of distinct keys less than this sample */
2000 };
2001 
2002 /*
2003 ** Each token coming out of the lexer is an instance of
2004 ** this structure.  Tokens are also used as part of an expression.
2005 **
2006 ** Note if Token.z==0 then Token.dyn and Token.n are undefined and
2007 ** may contain random values.  Do not make any assumptions about Token.dyn
2008 ** and Token.n when Token.z==0.
2009 */
2010 struct Token {
2011   const char *z;     /* Text of the token.  Not NULL-terminated! */
2012   unsigned int n;    /* Number of characters in this token */
2013 };
2014 
2015 /*
2016 ** An instance of this structure contains information needed to generate
2017 ** code for a SELECT that contains aggregate functions.
2018 **
2019 ** If Expr.op==TK_AGG_COLUMN or TK_AGG_FUNCTION then Expr.pAggInfo is a
2020 ** pointer to this structure.  The Expr.iColumn field is the index in
2021 ** AggInfo.aCol[] or AggInfo.aFunc[] of information needed to generate
2022 ** code for that node.
2023 **
2024 ** AggInfo.pGroupBy and AggInfo.aFunc.pExpr point to fields within the
2025 ** original Select structure that describes the SELECT statement.  These
2026 ** fields do not need to be freed when deallocating the AggInfo structure.
2027 */
2028 struct AggInfo {
2029   u8 directMode;          /* Direct rendering mode means take data directly
2030                           ** from source tables rather than from accumulators */
2031   u8 useSortingIdx;       /* In direct mode, reference the sorting index rather
2032                           ** than the source table */
2033   int sortingIdx;         /* Cursor number of the sorting index */
2034   int sortingIdxPTab;     /* Cursor number of pseudo-table */
2035   int nSortingColumn;     /* Number of columns in the sorting index */
2036   int mnReg, mxReg;       /* Range of registers allocated for aCol and aFunc */
2037   ExprList *pGroupBy;     /* The group by clause */
2038   struct AggInfo_col {    /* For each column used in source tables */
2039     Table *pTab;             /* Source table */
2040     int iTable;              /* Cursor number of the source table */
2041     int iColumn;             /* Column number within the source table */
2042     int iSorterColumn;       /* Column number in the sorting index */
2043     int iMem;                /* Memory location that acts as accumulator */
2044     Expr *pExpr;             /* The original expression */
2045   } *aCol;
2046   int nColumn;            /* Number of used entries in aCol[] */
2047   int nAccumulator;       /* Number of columns that show through to the output.
2048                           ** Additional columns are used only as parameters to
2049                           ** aggregate functions */
2050   struct AggInfo_func {   /* For each aggregate function */
2051     Expr *pExpr;             /* Expression encoding the function */
2052     FuncDef *pFunc;          /* The aggregate function implementation */
2053     int iMem;                /* Memory location that acts as accumulator */
2054     int iDistinct;           /* Ephemeral table used to enforce DISTINCT */
2055   } *aFunc;
2056   int nFunc;              /* Number of entries in aFunc[] */
2057 };
2058 
2059 /*
2060 ** The datatype ynVar is a signed integer, either 16-bit or 32-bit.
2061 ** Usually it is 16-bits.  But if SQLITE_MAX_VARIABLE_NUMBER is greater
2062 ** than 32767 we have to make it 32-bit.  16-bit is preferred because
2063 ** it uses less memory in the Expr object, which is a big memory user
2064 ** in systems with lots of prepared statements.  And few applications
2065 ** need more than about 10 or 20 variables.  But some extreme users want
2066 ** to have prepared statements with over 32767 variables, and for them
2067 ** the option is available (at compile-time).
2068 */
2069 #if SQLITE_MAX_VARIABLE_NUMBER<=32767
2070 typedef i16 ynVar;
2071 #else
2072 typedef int ynVar;
2073 #endif
2074 
2075 /*
2076 ** Each node of an expression in the parse tree is an instance
2077 ** of this structure.
2078 **
2079 ** Expr.op is the opcode. The integer parser token codes are reused
2080 ** as opcodes here. For example, the parser defines TK_GE to be an integer
2081 ** code representing the ">=" operator. This same integer code is reused
2082 ** to represent the greater-than-or-equal-to operator in the expression
2083 ** tree.
2084 **
2085 ** If the expression is an SQL literal (TK_INTEGER, TK_FLOAT, TK_BLOB,
2086 ** or TK_STRING), then Expr.token contains the text of the SQL literal. If
2087 ** the expression is a variable (TK_VARIABLE), then Expr.token contains the
2088 ** variable name. Finally, if the expression is an SQL function (TK_FUNCTION),
2089 ** then Expr.token contains the name of the function.
2090 **
2091 ** Expr.pRight and Expr.pLeft are the left and right subexpressions of a
2092 ** binary operator. Either or both may be NULL.
2093 **
2094 ** Expr.x.pList is a list of arguments if the expression is an SQL function,
2095 ** a CASE expression or an IN expression of the form "<lhs> IN (<y>, <z>...)".
2096 ** Expr.x.pSelect is used if the expression is a sub-select or an expression of
2097 ** the form "<lhs> IN (SELECT ...)". If the EP_xIsSelect bit is set in the
2098 ** Expr.flags mask, then Expr.x.pSelect is valid. Otherwise, Expr.x.pList is
2099 ** valid.
2100 **
2101 ** An expression of the form ID or ID.ID refers to a column in a table.
2102 ** For such expressions, Expr.op is set to TK_COLUMN and Expr.iTable is
2103 ** the integer cursor number of a VDBE cursor pointing to that table and
2104 ** Expr.iColumn is the column number for the specific column.  If the
2105 ** expression is used as a result in an aggregate SELECT, then the
2106 ** value is also stored in the Expr.iAgg column in the aggregate so that
2107 ** it can be accessed after all aggregates are computed.
2108 **
2109 ** If the expression is an unbound variable marker (a question mark
2110 ** character '?' in the original SQL) then the Expr.iTable holds the index
2111 ** number for that variable.
2112 **
2113 ** If the expression is a subquery then Expr.iColumn holds an integer
2114 ** register number containing the result of the subquery.  If the
2115 ** subquery gives a constant result, then iTable is -1.  If the subquery
2116 ** gives a different answer at different times during statement processing
2117 ** then iTable is the address of a subroutine that computes the subquery.
2118 **
2119 ** If the Expr is of type OP_Column, and the table it is selecting from
2120 ** is a disk table or the "old.*" pseudo-table, then pTab points to the
2121 ** corresponding table definition.
2122 **
2123 ** ALLOCATION NOTES:
2124 **
2125 ** Expr objects can use a lot of memory space in database schema.  To
2126 ** help reduce memory requirements, sometimes an Expr object will be
2127 ** truncated.  And to reduce the number of memory allocations, sometimes
2128 ** two or more Expr objects will be stored in a single memory allocation,
2129 ** together with Expr.zToken strings.
2130 **
2131 ** If the EP_Reduced and EP_TokenOnly flags are set when
2132 ** an Expr object is truncated.  When EP_Reduced is set, then all
2133 ** the child Expr objects in the Expr.pLeft and Expr.pRight subtrees
2134 ** are contained within the same memory allocation.  Note, however, that
2135 ** the subtrees in Expr.x.pList or Expr.x.pSelect are always separately
2136 ** allocated, regardless of whether or not EP_Reduced is set.
2137 */
2138 struct Expr {
2139   u8 op;                 /* Operation performed by this node */
2140   char affinity;         /* The affinity of the column or 0 if not a column */
2141   u32 flags;             /* Various flags.  EP_* See below */
2142   union {
2143     char *zToken;          /* Token value. Zero terminated and dequoted */
2144     int iValue;            /* Non-negative integer value if EP_IntValue */
2145   } u;
2146 
2147   /* If the EP_TokenOnly flag is set in the Expr.flags mask, then no
2148   ** space is allocated for the fields below this point. An attempt to
2149   ** access them will result in a segfault or malfunction.
2150   *********************************************************************/
2151 
2152   Expr *pLeft;           /* Left subnode */
2153   Expr *pRight;          /* Right subnode */
2154   union {
2155     ExprList *pList;     /* op = IN, EXISTS, SELECT, CASE, FUNCTION, BETWEEN */
2156     Select *pSelect;     /* EP_xIsSelect and op = IN, EXISTS, SELECT */
2157   } x;
2158 
2159   /* If the EP_Reduced flag is set in the Expr.flags mask, then no
2160   ** space is allocated for the fields below this point. An attempt to
2161   ** access them will result in a segfault or malfunction.
2162   *********************************************************************/
2163 
2164 #if SQLITE_MAX_EXPR_DEPTH>0
2165   int nHeight;           /* Height of the tree headed by this node */
2166 #endif
2167   int iTable;            /* TK_COLUMN: cursor number of table holding column
2168                          ** TK_REGISTER: register number
2169                          ** TK_TRIGGER: 1 -> new, 0 -> old
2170                          ** EP_Unlikely:  134217728 times likelihood */
2171   ynVar iColumn;         /* TK_COLUMN: column index.  -1 for rowid.
2172                          ** TK_VARIABLE: variable number (always >= 1). */
2173   i16 iAgg;              /* Which entry in pAggInfo->aCol[] or ->aFunc[] */
2174   i16 iRightJoinTable;   /* If EP_FromJoin, the right table of the join */
2175   u8 op2;                /* TK_REGISTER: original value of Expr.op
2176                          ** TK_COLUMN: the value of p5 for OP_Column
2177                          ** TK_AGG_FUNCTION: nesting depth */
2178   AggInfo *pAggInfo;     /* Used by TK_AGG_COLUMN and TK_AGG_FUNCTION */
2179   Table *pTab;           /* Table for TK_COLUMN expressions. */
2180 };
2181 
2182 /*
2183 ** The following are the meanings of bits in the Expr.flags field.
2184 */
2185 #define EP_FromJoin  0x000001 /* Originates in ON/USING clause of outer join */
2186 #define EP_Agg       0x000002 /* Contains one or more aggregate functions */
2187 #define EP_Resolved  0x000004 /* IDs have been resolved to COLUMNs */
2188 #define EP_Error     0x000008 /* Expression contains one or more errors */
2189 #define EP_Distinct  0x000010 /* Aggregate function with DISTINCT keyword */
2190 #define EP_VarSelect 0x000020 /* pSelect is correlated, not constant */
2191 #define EP_DblQuoted 0x000040 /* token.z was originally in "..." */
2192 #define EP_InfixFunc 0x000080 /* True for an infix function: LIKE, GLOB, etc */
2193 #define EP_Collate   0x000100 /* Tree contains a TK_COLLATE operator */
2194 #define EP_Generic   0x000200 /* Ignore COLLATE or affinity on this tree */
2195 #define EP_IntValue  0x000400 /* Integer value contained in u.iValue */
2196 #define EP_xIsSelect 0x000800 /* x.pSelect is valid (otherwise x.pList is) */
2197 #define EP_Skip      0x001000 /* COLLATE, AS, or UNLIKELY */
2198 #define EP_Reduced   0x002000 /* Expr struct EXPR_REDUCEDSIZE bytes only */
2199 #define EP_TokenOnly 0x004000 /* Expr struct EXPR_TOKENONLYSIZE bytes only */
2200 #define EP_Static    0x008000 /* Held in memory not obtained from malloc() */
2201 #define EP_MemToken  0x010000 /* Need to sqlite3DbFree() Expr.zToken */
2202 #define EP_NoReduce  0x020000 /* Cannot EXPRDUP_REDUCE this Expr */
2203 #define EP_Unlikely  0x040000 /* unlikely() or likelihood() function */
2204 #define EP_ConstFunc 0x080000 /* A SQLITE_FUNC_CONSTANT or _SLOCHNG function */
2205 #define EP_CanBeNull 0x100000 /* Can be null despite NOT NULL constraint */
2206 #define EP_Subquery  0x200000 /* Tree contains a TK_SELECT operator */
2207 #define EP_Alias     0x400000 /* Is an alias for a result set column */
2208 
2209 /*
2210 ** Combinations of two or more EP_* flags
2211 */
2212 #define EP_Propagate (EP_Collate|EP_Subquery) /* Propagate these bits up tree */
2213 
2214 /*
2215 ** These macros can be used to test, set, or clear bits in the
2216 ** Expr.flags field.
2217 */
2218 #define ExprHasProperty(E,P)     (((E)->flags&(P))!=0)
2219 #define ExprHasAllProperty(E,P)  (((E)->flags&(P))==(P))
2220 #define ExprSetProperty(E,P)     (E)->flags|=(P)
2221 #define ExprClearProperty(E,P)   (E)->flags&=~(P)
2222 
2223 /* The ExprSetVVAProperty() macro is used for Verification, Validation,
2224 ** and Accreditation only.  It works like ExprSetProperty() during VVA
2225 ** processes but is a no-op for delivery.
2226 */
2227 #ifdef SQLITE_DEBUG
2228 # define ExprSetVVAProperty(E,P)  (E)->flags|=(P)
2229 #else
2230 # define ExprSetVVAProperty(E,P)
2231 #endif
2232 
2233 /*
2234 ** Macros to determine the number of bytes required by a normal Expr
2235 ** struct, an Expr struct with the EP_Reduced flag set in Expr.flags
2236 ** and an Expr struct with the EP_TokenOnly flag set.
2237 */
2238 #define EXPR_FULLSIZE           sizeof(Expr)           /* Full size */
2239 #define EXPR_REDUCEDSIZE        offsetof(Expr,iTable)  /* Common features */
2240 #define EXPR_TOKENONLYSIZE      offsetof(Expr,pLeft)   /* Fewer features */
2241 
2242 /*
2243 ** Flags passed to the sqlite3ExprDup() function. See the header comment
2244 ** above sqlite3ExprDup() for details.
2245 */
2246 #define EXPRDUP_REDUCE         0x0001  /* Used reduced-size Expr nodes */
2247 
2248 /*
2249 ** A list of expressions.  Each expression may optionally have a
2250 ** name.  An expr/name combination can be used in several ways, such
2251 ** as the list of "expr AS ID" fields following a "SELECT" or in the
2252 ** list of "ID = expr" items in an UPDATE.  A list of expressions can
2253 ** also be used as the argument to a function, in which case the a.zName
2254 ** field is not used.
2255 **
2256 ** By default the Expr.zSpan field holds a human-readable description of
2257 ** the expression that is used in the generation of error messages and
2258 ** column labels.  In this case, Expr.zSpan is typically the text of a
2259 ** column expression as it exists in a SELECT statement.  However, if
2260 ** the bSpanIsTab flag is set, then zSpan is overloaded to mean the name
2261 ** of the result column in the form: DATABASE.TABLE.COLUMN.  This later
2262 ** form is used for name resolution with nested FROM clauses.
2263 */
2264 struct ExprList {
2265   int nExpr;             /* Number of expressions on the list */
2266   struct ExprList_item { /* For each expression in the list */
2267     Expr *pExpr;            /* The list of expressions */
2268     char *zName;            /* Token associated with this expression */
2269     char *zSpan;            /* Original text of the expression */
2270     u8 sortOrder;           /* 1 for DESC or 0 for ASC */
2271     unsigned done :1;       /* A flag to indicate when processing is finished */
2272     unsigned bSpanIsTab :1; /* zSpan holds DB.TABLE.COLUMN */
2273     unsigned reusable :1;   /* Constant expression is reusable */
2274     union {
2275       struct {
2276         u16 iOrderByCol;      /* For ORDER BY, column number in result set */
2277         u16 iAlias;           /* Index into Parse.aAlias[] for zName */
2278       } x;
2279       int iConstExprReg;      /* Register in which Expr value is cached */
2280     } u;
2281   } *a;                  /* Alloc a power of two greater or equal to nExpr */
2282 };
2283 
2284 /*
2285 ** An instance of this structure is used by the parser to record both
2286 ** the parse tree for an expression and the span of input text for an
2287 ** expression.
2288 */
2289 struct ExprSpan {
2290   Expr *pExpr;          /* The expression parse tree */
2291   const char *zStart;   /* First character of input text */
2292   const char *zEnd;     /* One character past the end of input text */
2293 };
2294 
2295 /*
2296 ** An instance of this structure can hold a simple list of identifiers,
2297 ** such as the list "a,b,c" in the following statements:
2298 **
2299 **      INSERT INTO t(a,b,c) VALUES ...;
2300 **      CREATE INDEX idx ON t(a,b,c);
2301 **      CREATE TRIGGER trig BEFORE UPDATE ON t(a,b,c) ...;
2302 **
2303 ** The IdList.a.idx field is used when the IdList represents the list of
2304 ** column names after a table name in an INSERT statement.  In the statement
2305 **
2306 **     INSERT INTO t(a,b,c) ...
2307 **
2308 ** If "a" is the k-th column of table "t", then IdList.a[0].idx==k.
2309 */
2310 struct IdList {
2311   struct IdList_item {
2312     char *zName;      /* Name of the identifier */
2313     int idx;          /* Index in some Table.aCol[] of a column named zName */
2314   } *a;
2315   int nId;         /* Number of identifiers on the list */
2316 };
2317 
2318 /*
2319 ** The bitmask datatype defined below is used for various optimizations.
2320 **
2321 ** Changing this from a 64-bit to a 32-bit type limits the number of
2322 ** tables in a join to 32 instead of 64.  But it also reduces the size
2323 ** of the library by 738 bytes on ix86.
2324 */
2325 typedef u64 Bitmask;
2326 
2327 /*
2328 ** The number of bits in a Bitmask.  "BMS" means "BitMask Size".
2329 */
2330 #define BMS  ((int)(sizeof(Bitmask)*8))
2331 
2332 /*
2333 ** A bit in a Bitmask
2334 */
2335 #define MASKBIT(n)   (((Bitmask)1)<<(n))
2336 #define MASKBIT32(n) (((unsigned int)1)<<(n))
2337 
2338 /*
2339 ** The following structure describes the FROM clause of a SELECT statement.
2340 ** Each table or subquery in the FROM clause is a separate element of
2341 ** the SrcList.a[] array.
2342 **
2343 ** With the addition of multiple database support, the following structure
2344 ** can also be used to describe a particular table such as the table that
2345 ** is modified by an INSERT, DELETE, or UPDATE statement.  In standard SQL,
2346 ** such a table must be a simple name: ID.  But in SQLite, the table can
2347 ** now be identified by a database name, a dot, then the table name: ID.ID.
2348 **
2349 ** The jointype starts out showing the join type between the current table
2350 ** and the next table on the list.  The parser builds the list this way.
2351 ** But sqlite3SrcListShiftJoinType() later shifts the jointypes so that each
2352 ** jointype expresses the join between the table and the previous table.
2353 **
2354 ** In the colUsed field, the high-order bit (bit 63) is set if the table
2355 ** contains more than 63 columns and the 64-th or later column is used.
2356 */
2357 struct SrcList {
2358   int nSrc;        /* Number of tables or subqueries in the FROM clause */
2359   u32 nAlloc;      /* Number of entries allocated in a[] below */
2360   struct SrcList_item {
2361     Schema *pSchema;  /* Schema to which this item is fixed */
2362     char *zDatabase;  /* Name of database holding this table */
2363     char *zName;      /* Name of the table */
2364     char *zAlias;     /* The "B" part of a "A AS B" phrase.  zName is the "A" */
2365     Table *pTab;      /* An SQL table corresponding to zName */
2366     Select *pSelect;  /* A SELECT statement used in place of a table name */
2367     int addrFillSub;  /* Address of subroutine to manifest a subquery */
2368     int regReturn;    /* Register holding return address of addrFillSub */
2369     int regResult;    /* Registers holding results of a co-routine */
2370     struct {
2371       u8 jointype;      /* Type of join between this able and the previous */
2372       unsigned notIndexed :1;    /* True if there is a NOT INDEXED clause */
2373       unsigned isIndexedBy :1;   /* True if there is an INDEXED BY clause */
2374       unsigned isTabFunc :1;     /* True if table-valued-function syntax */
2375       unsigned isCorrelated :1;  /* True if sub-query is correlated */
2376       unsigned viaCoroutine :1;  /* Implemented as a co-routine */
2377       unsigned isRecursive :1;   /* True for recursive reference in WITH */
2378     } fg;
2379 #ifndef SQLITE_OMIT_EXPLAIN
2380     u8 iSelectId;     /* If pSelect!=0, the id of the sub-select in EQP */
2381 #endif
2382     int iCursor;      /* The VDBE cursor number used to access this table */
2383     Expr *pOn;        /* The ON clause of a join */
2384     IdList *pUsing;   /* The USING clause of a join */
2385     Bitmask colUsed;  /* Bit N (1<<N) set if column N of pTab is used */
2386     union {
2387       char *zIndexedBy;    /* Identifier from "INDEXED BY <zIndex>" clause */
2388       ExprList *pFuncArg;  /* Arguments to table-valued-function */
2389     } u1;
2390     Index *pIBIndex;  /* Index structure corresponding to u1.zIndexedBy */
2391   } a[1];             /* One entry for each identifier on the list */
2392 };
2393 
2394 /*
2395 ** Permitted values of the SrcList.a.jointype field
2396 */
2397 #define JT_INNER     0x0001    /* Any kind of inner or cross join */
2398 #define JT_CROSS     0x0002    /* Explicit use of the CROSS keyword */
2399 #define JT_NATURAL   0x0004    /* True for a "natural" join */
2400 #define JT_LEFT      0x0008    /* Left outer join */
2401 #define JT_RIGHT     0x0010    /* Right outer join */
2402 #define JT_OUTER     0x0020    /* The "OUTER" keyword is present */
2403 #define JT_ERROR     0x0040    /* unknown or unsupported join type */
2404 
2405 
2406 /*
2407 ** Flags appropriate for the wctrlFlags parameter of sqlite3WhereBegin()
2408 ** and the WhereInfo.wctrlFlags member.
2409 */
2410 #define WHERE_ORDERBY_NORMAL   0x0000 /* No-op */
2411 #define WHERE_ORDERBY_MIN      0x0001 /* ORDER BY processing for min() func */
2412 #define WHERE_ORDERBY_MAX      0x0002 /* ORDER BY processing for max() func */
2413 #define WHERE_ONEPASS_DESIRED  0x0004 /* Want to do one-pass UPDATE/DELETE */
2414 #define WHERE_DUPLICATES_OK    0x0008 /* Ok to return a row more than once */
2415 #define WHERE_OMIT_OPEN_CLOSE  0x0010 /* Table cursors are already open */
2416 #define WHERE_FORCE_TABLE      0x0020 /* Do not use an index-only search */
2417 #define WHERE_ONETABLE_ONLY    0x0040 /* Only code the 1st table in pTabList */
2418 #define WHERE_NO_AUTOINDEX     0x0080 /* Disallow automatic indexes */
2419 #define WHERE_GROUPBY          0x0100 /* pOrderBy is really a GROUP BY */
2420 #define WHERE_DISTINCTBY       0x0200 /* pOrderby is really a DISTINCT clause */
2421 #define WHERE_WANT_DISTINCT    0x0400 /* All output needs to be distinct */
2422 #define WHERE_SORTBYGROUP      0x0800 /* Support sqlite3WhereIsSorted() */
2423 #define WHERE_REOPEN_IDX       0x1000 /* Try to use OP_ReopenIdx */
2424 #define WHERE_ONEPASS_MULTIROW 0x2000 /* ONEPASS is ok with multiple rows */
2425 
2426 /* Allowed return values from sqlite3WhereIsDistinct()
2427 */
2428 #define WHERE_DISTINCT_NOOP      0  /* DISTINCT keyword not used */
2429 #define WHERE_DISTINCT_UNIQUE    1  /* No duplicates */
2430 #define WHERE_DISTINCT_ORDERED   2  /* All duplicates are adjacent */
2431 #define WHERE_DISTINCT_UNORDERED 3  /* Duplicates are scattered */
2432 
2433 /*
2434 ** A NameContext defines a context in which to resolve table and column
2435 ** names.  The context consists of a list of tables (the pSrcList) field and
2436 ** a list of named expression (pEList).  The named expression list may
2437 ** be NULL.  The pSrc corresponds to the FROM clause of a SELECT or
2438 ** to the table being operated on by INSERT, UPDATE, or DELETE.  The
2439 ** pEList corresponds to the result set of a SELECT and is NULL for
2440 ** other statements.
2441 **
2442 ** NameContexts can be nested.  When resolving names, the inner-most
2443 ** context is searched first.  If no match is found, the next outer
2444 ** context is checked.  If there is still no match, the next context
2445 ** is checked.  This process continues until either a match is found
2446 ** or all contexts are check.  When a match is found, the nRef member of
2447 ** the context containing the match is incremented.
2448 **
2449 ** Each subquery gets a new NameContext.  The pNext field points to the
2450 ** NameContext in the parent query.  Thus the process of scanning the
2451 ** NameContext list corresponds to searching through successively outer
2452 ** subqueries looking for a match.
2453 */
2454 struct NameContext {
2455   Parse *pParse;       /* The parser */
2456   SrcList *pSrcList;   /* One or more tables used to resolve names */
2457   ExprList *pEList;    /* Optional list of result-set columns */
2458   AggInfo *pAggInfo;   /* Information about aggregates at this level */
2459   NameContext *pNext;  /* Next outer name context.  NULL for outermost */
2460   int nRef;            /* Number of names resolved by this context */
2461   int nErr;            /* Number of errors encountered while resolving names */
2462   u16 ncFlags;         /* Zero or more NC_* flags defined below */
2463 };
2464 
2465 /*
2466 ** Allowed values for the NameContext, ncFlags field.
2467 **
2468 ** Note:  NC_MinMaxAgg must have the same value as SF_MinMaxAgg and
2469 ** SQLITE_FUNC_MINMAX.
2470 **
2471 */
2472 #define NC_AllowAgg  0x0001  /* Aggregate functions are allowed here */
2473 #define NC_HasAgg    0x0002  /* One or more aggregate functions seen */
2474 #define NC_IsCheck   0x0004  /* True if resolving names in a CHECK constraint */
2475 #define NC_InAggFunc 0x0008  /* True if analyzing arguments to an agg func */
2476 #define NC_PartIdx   0x0010  /* True if resolving a partial index WHERE */
2477 #define NC_IdxExpr   0x0020  /* True if resolving columns of CREATE INDEX */
2478 #define NC_MinMaxAgg 0x1000  /* min/max aggregates seen.  See note above */
2479 
2480 /*
2481 ** An instance of the following structure contains all information
2482 ** needed to generate code for a single SELECT statement.
2483 **
2484 ** nLimit is set to -1 if there is no LIMIT clause.  nOffset is set to 0.
2485 ** If there is a LIMIT clause, the parser sets nLimit to the value of the
2486 ** limit and nOffset to the value of the offset (or 0 if there is not
2487 ** offset).  But later on, nLimit and nOffset become the memory locations
2488 ** in the VDBE that record the limit and offset counters.
2489 **
2490 ** addrOpenEphm[] entries contain the address of OP_OpenEphemeral opcodes.
2491 ** These addresses must be stored so that we can go back and fill in
2492 ** the P4_KEYINFO and P2 parameters later.  Neither the KeyInfo nor
2493 ** the number of columns in P2 can be computed at the same time
2494 ** as the OP_OpenEphm instruction is coded because not
2495 ** enough information about the compound query is known at that point.
2496 ** The KeyInfo for addrOpenTran[0] and [1] contains collating sequences
2497 ** for the result set.  The KeyInfo for addrOpenEphm[2] contains collating
2498 ** sequences for the ORDER BY clause.
2499 */
2500 struct Select {
2501   ExprList *pEList;      /* The fields of the result */
2502   u8 op;                 /* One of: TK_UNION TK_ALL TK_INTERSECT TK_EXCEPT */
2503   u16 selFlags;          /* Various SF_* values */
2504   int iLimit, iOffset;   /* Memory registers holding LIMIT & OFFSET counters */
2505 #if SELECTTRACE_ENABLED
2506   char zSelName[12];     /* Symbolic name of this SELECT use for debugging */
2507 #endif
2508   int addrOpenEphm[2];   /* OP_OpenEphem opcodes related to this select */
2509   u64 nSelectRow;        /* Estimated number of result rows */
2510   SrcList *pSrc;         /* The FROM clause */
2511   Expr *pWhere;          /* The WHERE clause */
2512   ExprList *pGroupBy;    /* The GROUP BY clause */
2513   Expr *pHaving;         /* The HAVING clause */
2514   ExprList *pOrderBy;    /* The ORDER BY clause */
2515   Select *pPrior;        /* Prior select in a compound select statement */
2516   Select *pNext;         /* Next select to the left in a compound */
2517   Expr *pLimit;          /* LIMIT expression. NULL means not used. */
2518   Expr *pOffset;         /* OFFSET expression. NULL means not used. */
2519   With *pWith;           /* WITH clause attached to this select. Or NULL. */
2520 };
2521 
2522 /*
2523 ** Allowed values for Select.selFlags.  The "SF" prefix stands for
2524 ** "Select Flag".
2525 */
2526 #define SF_Distinct        0x0001  /* Output should be DISTINCT */
2527 #define SF_All             0x0002  /* Includes the ALL keyword */
2528 #define SF_Resolved        0x0004  /* Identifiers have been resolved */
2529 #define SF_Aggregate       0x0008  /* Contains aggregate functions */
2530 #define SF_UsesEphemeral   0x0010  /* Uses the OpenEphemeral opcode */
2531 #define SF_Expanded        0x0020  /* sqlite3SelectExpand() called on this */
2532 #define SF_HasTypeInfo     0x0040  /* FROM subqueries have Table metadata */
2533 #define SF_Compound        0x0080  /* Part of a compound query */
2534 #define SF_Values          0x0100  /* Synthesized from VALUES clause */
2535 #define SF_MultiValue      0x0200  /* Single VALUES term with multiple rows */
2536 #define SF_NestedFrom      0x0400  /* Part of a parenthesized FROM clause */
2537 #define SF_MaybeConvert    0x0800  /* Need convertCompoundSelectToSubquery() */
2538 #define SF_MinMaxAgg       0x1000  /* Aggregate containing min() or max() */
2539 #define SF_Recursive       0x2000  /* The recursive part of a recursive CTE */
2540 #define SF_Converted       0x4000  /* By convertCompoundSelectToSubquery() */
2541 #define SF_IncludeHidden   0x8000  /* Include hidden columns in output */
2542 
2543 
2544 /*
2545 ** The results of a SELECT can be distributed in several ways, as defined
2546 ** by one of the following macros.  The "SRT" prefix means "SELECT Result
2547 ** Type".
2548 **
2549 **     SRT_Union       Store results as a key in a temporary index
2550 **                     identified by pDest->iSDParm.
2551 **
2552 **     SRT_Except      Remove results from the temporary index pDest->iSDParm.
2553 **
2554 **     SRT_Exists      Store a 1 in memory cell pDest->iSDParm if the result
2555 **                     set is not empty.
2556 **
2557 **     SRT_Discard     Throw the results away.  This is used by SELECT
2558 **                     statements within triggers whose only purpose is
2559 **                     the side-effects of functions.
2560 **
2561 ** All of the above are free to ignore their ORDER BY clause. Those that
2562 ** follow must honor the ORDER BY clause.
2563 **
2564 **     SRT_Output      Generate a row of output (using the OP_ResultRow
2565 **                     opcode) for each row in the result set.
2566 **
2567 **     SRT_Mem         Only valid if the result is a single column.
2568 **                     Store the first column of the first result row
2569 **                     in register pDest->iSDParm then abandon the rest
2570 **                     of the query.  This destination implies "LIMIT 1".
2571 **
2572 **     SRT_Set         The result must be a single column.  Store each
2573 **                     row of result as the key in table pDest->iSDParm.
2574 **                     Apply the affinity pDest->affSdst before storing
2575 **                     results.  Used to implement "IN (SELECT ...)".
2576 **
2577 **     SRT_EphemTab    Create an temporary table pDest->iSDParm and store
2578 **                     the result there. The cursor is left open after
2579 **                     returning.  This is like SRT_Table except that
2580 **                     this destination uses OP_OpenEphemeral to create
2581 **                     the table first.
2582 **
2583 **     SRT_Coroutine   Generate a co-routine that returns a new row of
2584 **                     results each time it is invoked.  The entry point
2585 **                     of the co-routine is stored in register pDest->iSDParm
2586 **                     and the result row is stored in pDest->nDest registers
2587 **                     starting with pDest->iSdst.
2588 **
2589 **     SRT_Table       Store results in temporary table pDest->iSDParm.
2590 **     SRT_Fifo        This is like SRT_EphemTab except that the table
2591 **                     is assumed to already be open.  SRT_Fifo has
2592 **                     the additional property of being able to ignore
2593 **                     the ORDER BY clause.
2594 **
2595 **     SRT_DistFifo    Store results in a temporary table pDest->iSDParm.
2596 **                     But also use temporary table pDest->iSDParm+1 as
2597 **                     a record of all prior results and ignore any duplicate
2598 **                     rows.  Name means:  "Distinct Fifo".
2599 **
2600 **     SRT_Queue       Store results in priority queue pDest->iSDParm (really
2601 **                     an index).  Append a sequence number so that all entries
2602 **                     are distinct.
2603 **
2604 **     SRT_DistQueue   Store results in priority queue pDest->iSDParm only if
2605 **                     the same record has never been stored before.  The
2606 **                     index at pDest->iSDParm+1 hold all prior stores.
2607 */
2608 #define SRT_Union        1  /* Store result as keys in an index */
2609 #define SRT_Except       2  /* Remove result from a UNION index */
2610 #define SRT_Exists       3  /* Store 1 if the result is not empty */
2611 #define SRT_Discard      4  /* Do not save the results anywhere */
2612 #define SRT_Fifo         5  /* Store result as data with an automatic rowid */
2613 #define SRT_DistFifo     6  /* Like SRT_Fifo, but unique results only */
2614 #define SRT_Queue        7  /* Store result in an queue */
2615 #define SRT_DistQueue    8  /* Like SRT_Queue, but unique results only */
2616 
2617 /* The ORDER BY clause is ignored for all of the above */
2618 #define IgnorableOrderby(X) ((X->eDest)<=SRT_DistQueue)
2619 
2620 #define SRT_Output       9  /* Output each row of result */
2621 #define SRT_Mem         10  /* Store result in a memory cell */
2622 #define SRT_Set         11  /* Store results as keys in an index */
2623 #define SRT_EphemTab    12  /* Create transient tab and store like SRT_Table */
2624 #define SRT_Coroutine   13  /* Generate a single row of result */
2625 #define SRT_Table       14  /* Store result as data with an automatic rowid */
2626 
2627 /*
2628 ** An instance of this object describes where to put of the results of
2629 ** a SELECT statement.
2630 */
2631 struct SelectDest {
2632   u8 eDest;            /* How to dispose of the results.  On of SRT_* above. */
2633   char affSdst;        /* Affinity used when eDest==SRT_Set */
2634   int iSDParm;         /* A parameter used by the eDest disposal method */
2635   int iSdst;           /* Base register where results are written */
2636   int nSdst;           /* Number of registers allocated */
2637   ExprList *pOrderBy;  /* Key columns for SRT_Queue and SRT_DistQueue */
2638 };
2639 
2640 /*
2641 ** During code generation of statements that do inserts into AUTOINCREMENT
2642 ** tables, the following information is attached to the Table.u.autoInc.p
2643 ** pointer of each autoincrement table to record some side information that
2644 ** the code generator needs.  We have to keep per-table autoincrement
2645 ** information in case inserts are done within triggers.  Triggers do not
2646 ** normally coordinate their activities, but we do need to coordinate the
2647 ** loading and saving of autoincrement information.
2648 */
2649 struct AutoincInfo {
2650   AutoincInfo *pNext;   /* Next info block in a list of them all */
2651   Table *pTab;          /* Table this info block refers to */
2652   int iDb;              /* Index in sqlite3.aDb[] of database holding pTab */
2653   int regCtr;           /* Memory register holding the rowid counter */
2654 };
2655 
2656 /*
2657 ** Size of the column cache
2658 */
2659 #ifndef SQLITE_N_COLCACHE
2660 # define SQLITE_N_COLCACHE 10
2661 #endif
2662 
2663 /*
2664 ** At least one instance of the following structure is created for each
2665 ** trigger that may be fired while parsing an INSERT, UPDATE or DELETE
2666 ** statement. All such objects are stored in the linked list headed at
2667 ** Parse.pTriggerPrg and deleted once statement compilation has been
2668 ** completed.
2669 **
2670 ** A Vdbe sub-program that implements the body and WHEN clause of trigger
2671 ** TriggerPrg.pTrigger, assuming a default ON CONFLICT clause of
2672 ** TriggerPrg.orconf, is stored in the TriggerPrg.pProgram variable.
2673 ** The Parse.pTriggerPrg list never contains two entries with the same
2674 ** values for both pTrigger and orconf.
2675 **
2676 ** The TriggerPrg.aColmask[0] variable is set to a mask of old.* columns
2677 ** accessed (or set to 0 for triggers fired as a result of INSERT
2678 ** statements). Similarly, the TriggerPrg.aColmask[1] variable is set to
2679 ** a mask of new.* columns used by the program.
2680 */
2681 struct TriggerPrg {
2682   Trigger *pTrigger;      /* Trigger this program was coded from */
2683   TriggerPrg *pNext;      /* Next entry in Parse.pTriggerPrg list */
2684   SubProgram *pProgram;   /* Program implementing pTrigger/orconf */
2685   int orconf;             /* Default ON CONFLICT policy */
2686   u32 aColmask[2];        /* Masks of old.*, new.* columns accessed */
2687 };
2688 
2689 /*
2690 ** The yDbMask datatype for the bitmask of all attached databases.
2691 */
2692 #if SQLITE_MAX_ATTACHED>30
2693   typedef unsigned char yDbMask[(SQLITE_MAX_ATTACHED+9)/8];
2694 # define DbMaskTest(M,I)    (((M)[(I)/8]&(1<<((I)&7)))!=0)
2695 # define DbMaskZero(M)      memset((M),0,sizeof(M))
2696 # define DbMaskSet(M,I)     (M)[(I)/8]|=(1<<((I)&7))
2697 # define DbMaskAllZero(M)   sqlite3DbMaskAllZero(M)
2698 # define DbMaskNonZero(M)   (sqlite3DbMaskAllZero(M)==0)
2699 #else
2700   typedef unsigned int yDbMask;
2701 # define DbMaskTest(M,I)    (((M)&(((yDbMask)1)<<(I)))!=0)
2702 # define DbMaskZero(M)      (M)=0
2703 # define DbMaskSet(M,I)     (M)|=(((yDbMask)1)<<(I))
2704 # define DbMaskAllZero(M)   (M)==0
2705 # define DbMaskNonZero(M)   (M)!=0
2706 #endif
2707 
2708 /*
2709 ** An SQL parser context.  A copy of this structure is passed through
2710 ** the parser and down into all the parser action routine in order to
2711 ** carry around information that is global to the entire parse.
2712 **
2713 ** The structure is divided into two parts.  When the parser and code
2714 ** generate call themselves recursively, the first part of the structure
2715 ** is constant but the second part is reset at the beginning and end of
2716 ** each recursion.
2717 **
2718 ** The nTableLock and aTableLock variables are only used if the shared-cache
2719 ** feature is enabled (if sqlite3Tsd()->useSharedData is true). They are
2720 ** used to store the set of table-locks required by the statement being
2721 ** compiled. Function sqlite3TableLock() is used to add entries to the
2722 ** list.
2723 */
2724 struct Parse {
2725   sqlite3 *db;         /* The main database structure */
2726   char *zErrMsg;       /* An error message */
2727   Vdbe *pVdbe;         /* An engine for executing database bytecode */
2728   int rc;              /* Return code from execution */
2729   u8 colNamesSet;      /* TRUE after OP_ColumnName has been issued to pVdbe */
2730   u8 checkSchema;      /* Causes schema cookie check after an error */
2731   u8 nested;           /* Number of nested calls to the parser/code generator */
2732   u8 nTempReg;         /* Number of temporary registers in aTempReg[] */
2733   u8 isMultiWrite;     /* True if statement may modify/insert multiple rows */
2734   u8 mayAbort;         /* True if statement may throw an ABORT exception */
2735   u8 hasCompound;      /* Need to invoke convertCompoundSelectToSubquery() */
2736   u8 okConstFactor;    /* OK to factor out constants */
2737   u8 disableLookaside; /* Number of times lookaside has been disabled */
2738   int aTempReg[8];     /* Holding area for temporary registers */
2739   int nRangeReg;       /* Size of the temporary register block */
2740   int iRangeReg;       /* First register in temporary register block */
2741   int nErr;            /* Number of errors seen */
2742   int nTab;            /* Number of previously allocated VDBE cursors */
2743   int nMem;            /* Number of memory cells used so far */
2744   int nSet;            /* Number of sets used so far */
2745   int nOnce;           /* Number of OP_Once instructions so far */
2746   int nOpAlloc;        /* Number of slots allocated for Vdbe.aOp[] */
2747   int szOpAlloc;       /* Bytes of memory space allocated for Vdbe.aOp[] */
2748   int iFixedOp;        /* Never back out opcodes iFixedOp-1 or earlier */
2749   int ckBase;          /* Base register of data during check constraints */
2750   int iSelfTab;        /* Table of an index whose exprs are being coded */
2751   int iCacheLevel;     /* ColCache valid when aColCache[].iLevel<=iCacheLevel */
2752   int iCacheCnt;       /* Counter used to generate aColCache[].lru values */
2753   int nLabel;          /* Number of labels used */
2754   int *aLabel;         /* Space to hold the labels */
2755   struct yColCache {
2756     int iTable;           /* Table cursor number */
2757     i16 iColumn;          /* Table column number */
2758     u8 tempReg;           /* iReg is a temp register that needs to be freed */
2759     int iLevel;           /* Nesting level */
2760     int iReg;             /* Reg with value of this column. 0 means none. */
2761     int lru;              /* Least recently used entry has the smallest value */
2762   } aColCache[SQLITE_N_COLCACHE];  /* One for each column cache entry */
2763   ExprList *pConstExpr;/* Constant expressions */
2764   Token constraintName;/* Name of the constraint currently being parsed */
2765   yDbMask writeMask;   /* Start a write transaction on these databases */
2766   yDbMask cookieMask;  /* Bitmask of schema verified databases */
2767   int cookieValue[SQLITE_MAX_ATTACHED+2];  /* Values of cookies to verify */
2768   int regRowid;        /* Register holding rowid of CREATE TABLE entry */
2769   int regRoot;         /* Register holding root page number for new objects */
2770   int nMaxArg;         /* Max args passed to user function by sub-program */
2771 #if SELECTTRACE_ENABLED
2772   int nSelect;         /* Number of SELECT statements seen */
2773   int nSelectIndent;   /* How far to indent SELECTTRACE() output */
2774 #endif
2775 #ifndef SQLITE_OMIT_SHARED_CACHE
2776   int nTableLock;        /* Number of locks in aTableLock */
2777   TableLock *aTableLock; /* Required table locks for shared-cache mode */
2778 #endif
2779   AutoincInfo *pAinc;  /* Information about AUTOINCREMENT counters */
2780 
2781   /* Information used while coding trigger programs. */
2782   Parse *pToplevel;    /* Parse structure for main program (or NULL) */
2783   Table *pTriggerTab;  /* Table triggers are being coded for */
2784   int addrCrTab;       /* Address of OP_CreateTable opcode on CREATE TABLE */
2785   u32 nQueryLoop;      /* Est number of iterations of a query (10*log2(N)) */
2786   u32 oldmask;         /* Mask of old.* columns referenced */
2787   u32 newmask;         /* Mask of new.* columns referenced */
2788   u8 eTriggerOp;       /* TK_UPDATE, TK_INSERT or TK_DELETE */
2789   u8 eOrconf;          /* Default ON CONFLICT policy for trigger steps */
2790   u8 disableTriggers;  /* True to disable triggers */
2791 
2792   /************************************************************************
2793   ** Above is constant between recursions.  Below is reset before and after
2794   ** each recursion.  The boundary between these two regions is determined
2795   ** using offsetof(Parse,nVar) so the nVar field must be the first field
2796   ** in the recursive region.
2797   ************************************************************************/
2798 
2799   ynVar nVar;               /* Number of '?' variables seen in the SQL so far */
2800   int nzVar;                /* Number of available slots in azVar[] */
2801   u8 iPkSortOrder;          /* ASC or DESC for INTEGER PRIMARY KEY */
2802   u8 explain;               /* True if the EXPLAIN flag is found on the query */
2803 #ifndef SQLITE_OMIT_VIRTUALTABLE
2804   u8 declareVtab;           /* True if inside sqlite3_declare_vtab() */
2805   int nVtabLock;            /* Number of virtual tables to lock */
2806 #endif
2807   int nAlias;               /* Number of aliased result set columns */
2808   int nHeight;              /* Expression tree height of current sub-select */
2809 #ifndef SQLITE_OMIT_EXPLAIN
2810   int iSelectId;            /* ID of current select for EXPLAIN output */
2811   int iNextSelectId;        /* Next available select ID for EXPLAIN output */
2812 #endif
2813   char **azVar;             /* Pointers to names of parameters */
2814   Vdbe *pReprepare;         /* VM being reprepared (sqlite3Reprepare()) */
2815   const char *zTail;        /* All SQL text past the last semicolon parsed */
2816   Table *pNewTable;         /* A table being constructed by CREATE TABLE */
2817   Trigger *pNewTrigger;     /* Trigger under construct by a CREATE TRIGGER */
2818   const char *zAuthContext; /* The 6th parameter to db->xAuth callbacks */
2819   Token sNameToken;         /* Token with unqualified schema object name */
2820   Token sLastToken;         /* The last token parsed */
2821 #ifndef SQLITE_OMIT_VIRTUALTABLE
2822   Token sArg;               /* Complete text of a module argument */
2823   Table **apVtabLock;       /* Pointer to virtual tables needing locking */
2824 #endif
2825   Table *pZombieTab;        /* List of Table objects to delete after code gen */
2826   TriggerPrg *pTriggerPrg;  /* Linked list of coded triggers */
2827   With *pWith;              /* Current WITH clause, or NULL */
2828   With *pWithToFree;        /* Free this WITH object at the end of the parse */
2829 };
2830 
2831 /*
2832 ** Return true if currently inside an sqlite3_declare_vtab() call.
2833 */
2834 #ifdef SQLITE_OMIT_VIRTUALTABLE
2835   #define IN_DECLARE_VTAB 0
2836 #else
2837   #define IN_DECLARE_VTAB (pParse->declareVtab)
2838 #endif
2839 
2840 /*
2841 ** An instance of the following structure can be declared on a stack and used
2842 ** to save the Parse.zAuthContext value so that it can be restored later.
2843 */
2844 struct AuthContext {
2845   const char *zAuthContext;   /* Put saved Parse.zAuthContext here */
2846   Parse *pParse;              /* The Parse structure */
2847 };
2848 
2849 /*
2850 ** Bitfield flags for P5 value in various opcodes.
2851 */
2852 #define OPFLAG_NCHANGE       0x01    /* OP_Insert: Set to update db->nChange */
2853                                      /* Also used in P2 (not P5) of OP_Delete */
2854 #define OPFLAG_EPHEM         0x01    /* OP_Column: Ephemeral output is ok */
2855 #define OPFLAG_LASTROWID     0x02    /* Set to update db->lastRowid */
2856 #define OPFLAG_ISUPDATE      0x04    /* This OP_Insert is an sql UPDATE */
2857 #define OPFLAG_APPEND        0x08    /* This is likely to be an append */
2858 #define OPFLAG_USESEEKRESULT 0x10    /* Try to avoid a seek in BtreeInsert() */
2859 #define OPFLAG_LENGTHARG     0x40    /* OP_Column only used for length() */
2860 #define OPFLAG_TYPEOFARG     0x80    /* OP_Column only used for typeof() */
2861 #define OPFLAG_BULKCSR       0x01    /* OP_Open** used to open bulk cursor */
2862 #define OPFLAG_SEEKEQ        0x02    /* OP_Open** cursor uses EQ seek only */
2863 #define OPFLAG_FORDELETE     0x08    /* OP_Open should use BTREE_FORDELETE */
2864 #define OPFLAG_P2ISREG       0x10    /* P2 to OP_Open** is a register number */
2865 #define OPFLAG_PERMUTE       0x01    /* OP_Compare: use the permutation */
2866 #define OPFLAG_SAVEPOSITION  0x02    /* OP_Delete: keep cursor position */
2867 #define OPFLAG_AUXDELETE     0x04    /* OP_Delete: index in a DELETE op */
2868 
2869 /*
2870  * Each trigger present in the database schema is stored as an instance of
2871  * struct Trigger.
2872  *
2873  * Pointers to instances of struct Trigger are stored in two ways.
2874  * 1. In the "trigHash" hash table (part of the sqlite3* that represents the
2875  *    database). This allows Trigger structures to be retrieved by name.
2876  * 2. All triggers associated with a single table form a linked list, using the
2877  *    pNext member of struct Trigger. A pointer to the first element of the
2878  *    linked list is stored as the "pTrigger" member of the associated
2879  *    struct Table.
2880  *
2881  * The "step_list" member points to the first element of a linked list
2882  * containing the SQL statements specified as the trigger program.
2883  */
2884 struct Trigger {
2885   char *zName;            /* The name of the trigger                        */
2886   char *table;            /* The table or view to which the trigger applies */
2887   u8 op;                  /* One of TK_DELETE, TK_UPDATE, TK_INSERT         */
2888   u8 tr_tm;               /* One of TRIGGER_BEFORE, TRIGGER_AFTER */
2889   Expr *pWhen;            /* The WHEN clause of the expression (may be NULL) */
2890   IdList *pColumns;       /* If this is an UPDATE OF <column-list> trigger,
2891                              the <column-list> is stored here */
2892   Schema *pSchema;        /* Schema containing the trigger */
2893   Schema *pTabSchema;     /* Schema containing the table */
2894   TriggerStep *step_list; /* Link list of trigger program steps             */
2895   Trigger *pNext;         /* Next trigger associated with the table */
2896 };
2897 
2898 /*
2899 ** A trigger is either a BEFORE or an AFTER trigger.  The following constants
2900 ** determine which.
2901 **
2902 ** If there are multiple triggers, you might of some BEFORE and some AFTER.
2903 ** In that cases, the constants below can be ORed together.
2904 */
2905 #define TRIGGER_BEFORE  1
2906 #define TRIGGER_AFTER   2
2907 
2908 /*
2909  * An instance of struct TriggerStep is used to store a single SQL statement
2910  * that is a part of a trigger-program.
2911  *
2912  * Instances of struct TriggerStep are stored in a singly linked list (linked
2913  * using the "pNext" member) referenced by the "step_list" member of the
2914  * associated struct Trigger instance. The first element of the linked list is
2915  * the first step of the trigger-program.
2916  *
2917  * The "op" member indicates whether this is a "DELETE", "INSERT", "UPDATE" or
2918  * "SELECT" statement. The meanings of the other members is determined by the
2919  * value of "op" as follows:
2920  *
2921  * (op == TK_INSERT)
2922  * orconf    -> stores the ON CONFLICT algorithm
2923  * pSelect   -> If this is an INSERT INTO ... SELECT ... statement, then
2924  *              this stores a pointer to the SELECT statement. Otherwise NULL.
2925  * zTarget   -> Dequoted name of the table to insert into.
2926  * pExprList -> If this is an INSERT INTO ... VALUES ... statement, then
2927  *              this stores values to be inserted. Otherwise NULL.
2928  * pIdList   -> If this is an INSERT INTO ... (<column-names>) VALUES ...
2929  *              statement, then this stores the column-names to be
2930  *              inserted into.
2931  *
2932  * (op == TK_DELETE)
2933  * zTarget   -> Dequoted name of the table to delete from.
2934  * pWhere    -> The WHERE clause of the DELETE statement if one is specified.
2935  *              Otherwise NULL.
2936  *
2937  * (op == TK_UPDATE)
2938  * zTarget   -> Dequoted name of the table to update.
2939  * pWhere    -> The WHERE clause of the UPDATE statement if one is specified.
2940  *              Otherwise NULL.
2941  * pExprList -> A list of the columns to update and the expressions to update
2942  *              them to. See sqlite3Update() documentation of "pChanges"
2943  *              argument.
2944  *
2945  */
2946 struct TriggerStep {
2947   u8 op;               /* One of TK_DELETE, TK_UPDATE, TK_INSERT, TK_SELECT */
2948   u8 orconf;           /* OE_Rollback etc. */
2949   Trigger *pTrig;      /* The trigger that this step is a part of */
2950   Select *pSelect;     /* SELECT statement or RHS of INSERT INTO SELECT ... */
2951   char *zTarget;       /* Target table for DELETE, UPDATE, INSERT */
2952   Expr *pWhere;        /* The WHERE clause for DELETE or UPDATE steps */
2953   ExprList *pExprList; /* SET clause for UPDATE. */
2954   IdList *pIdList;     /* Column names for INSERT */
2955   TriggerStep *pNext;  /* Next in the link-list */
2956   TriggerStep *pLast;  /* Last element in link-list. Valid for 1st elem only */
2957 };
2958 
2959 /*
2960 ** The following structure contains information used by the sqliteFix...
2961 ** routines as they walk the parse tree to make database references
2962 ** explicit.
2963 */
2964 typedef struct DbFixer DbFixer;
2965 struct DbFixer {
2966   Parse *pParse;      /* The parsing context.  Error messages written here */
2967   Schema *pSchema;    /* Fix items to this schema */
2968   int bVarOnly;       /* Check for variable references only */
2969   const char *zDb;    /* Make sure all objects are contained in this database */
2970   const char *zType;  /* Type of the container - used for error messages */
2971   const Token *pName; /* Name of the container - used for error messages */
2972 };
2973 
2974 /*
2975 ** An objected used to accumulate the text of a string where we
2976 ** do not necessarily know how big the string will be in the end.
2977 */
2978 struct StrAccum {
2979   sqlite3 *db;         /* Optional database for lookaside.  Can be NULL */
2980   char *zBase;         /* A base allocation.  Not from malloc. */
2981   char *zText;         /* The string collected so far */
2982   u32  nChar;          /* Length of the string so far */
2983   u32  nAlloc;         /* Amount of space allocated in zText */
2984   u32  mxAlloc;        /* Maximum allowed allocation.  0 for no malloc usage */
2985   u8   accError;       /* STRACCUM_NOMEM or STRACCUM_TOOBIG */
2986   u8   printfFlags;    /* SQLITE_PRINTF flags below */
2987 };
2988 #define STRACCUM_NOMEM   1
2989 #define STRACCUM_TOOBIG  2
2990 #define SQLITE_PRINTF_INTERNAL 0x01  /* Internal-use-only converters allowed */
2991 #define SQLITE_PRINTF_SQLFUNC  0x02  /* SQL function arguments to VXPrintf */
2992 #define SQLITE_PRINTF_MALLOCED 0x04  /* True if xText is allocated space */
2993 
2994 #define isMalloced(X)  (((X)->printfFlags & SQLITE_PRINTF_MALLOCED)!=0)
2995 
2996 
2997 /*
2998 ** A pointer to this structure is used to communicate information
2999 ** from sqlite3Init and OP_ParseSchema into the sqlite3InitCallback.
3000 */
3001 typedef struct {
3002   sqlite3 *db;        /* The database being initialized */
3003   char **pzErrMsg;    /* Error message stored here */
3004   int iDb;            /* 0 for main database.  1 for TEMP, 2.. for ATTACHed */
3005   int rc;             /* Result code stored here */
3006 } InitData;
3007 
3008 /*
3009 ** Structure containing global configuration data for the SQLite library.
3010 **
3011 ** This structure also contains some state information.
3012 */
3013 struct Sqlite3Config {
3014   int bMemstat;                     /* True to enable memory status */
3015   int bCoreMutex;                   /* True to enable core mutexing */
3016   int bFullMutex;                   /* True to enable full mutexing */
3017   int bOpenUri;                     /* True to interpret filenames as URIs */
3018   int bUseCis;                      /* Use covering indices for full-scans */
3019   int mxStrlen;                     /* Maximum string length */
3020   int neverCorrupt;                 /* Database is always well-formed */
3021   int szLookaside;                  /* Default lookaside buffer size */
3022   int nLookaside;                   /* Default lookaside buffer count */
3023   sqlite3_mem_methods m;            /* Low-level memory allocation interface */
3024   sqlite3_mutex_methods mutex;      /* Low-level mutex interface */
3025   sqlite3_pcache_methods2 pcache2;  /* Low-level page-cache interface */
3026   void *pHeap;                      /* Heap storage space */
3027   int nHeap;                        /* Size of pHeap[] */
3028   int mnReq, mxReq;                 /* Min and max heap requests sizes */
3029   sqlite3_int64 szMmap;             /* mmap() space per open file */
3030   sqlite3_int64 mxMmap;             /* Maximum value for szMmap */
3031   void *pScratch;                   /* Scratch memory */
3032   int szScratch;                    /* Size of each scratch buffer */
3033   int nScratch;                     /* Number of scratch buffers */
3034   void *pPage;                      /* Page cache memory */
3035   int szPage;                       /* Size of each page in pPage[] */
3036   int nPage;                        /* Number of pages in pPage[] */
3037   int mxParserStack;                /* maximum depth of the parser stack */
3038   int sharedCacheEnabled;           /* true if shared-cache mode enabled */
3039   u32 szPma;                        /* Maximum Sorter PMA size */
3040   /* The above might be initialized to non-zero.  The following need to always
3041   ** initially be zero, however. */
3042   int isInit;                       /* True after initialization has finished */
3043   int inProgress;                   /* True while initialization in progress */
3044   int isMutexInit;                  /* True after mutexes are initialized */
3045   int isMallocInit;                 /* True after malloc is initialized */
3046   int isPCacheInit;                 /* True after malloc is initialized */
3047   int nRefInitMutex;                /* Number of users of pInitMutex */
3048   sqlite3_mutex *pInitMutex;        /* Mutex used by sqlite3_initialize() */
3049   void (*xLog)(void*,int,const char*); /* Function for logging */
3050   void *pLogArg;                       /* First argument to xLog() */
3051 #ifdef SQLITE_ENABLE_SQLLOG
3052   void(*xSqllog)(void*,sqlite3*,const char*, int);
3053   void *pSqllogArg;
3054 #endif
3055 #ifdef SQLITE_VDBE_COVERAGE
3056   /* The following callback (if not NULL) is invoked on every VDBE branch
3057   ** operation.  Set the callback using SQLITE_TESTCTRL_VDBE_COVERAGE.
3058   */
3059   void (*xVdbeBranch)(void*,int iSrcLine,u8 eThis,u8 eMx);  /* Callback */
3060   void *pVdbeBranchArg;                                     /* 1st argument */
3061 #endif
3062 #ifndef SQLITE_OMIT_BUILTIN_TEST
3063   int (*xTestCallback)(int);        /* Invoked by sqlite3FaultSim() */
3064 #endif
3065   int bLocaltimeFault;              /* True to fail localtime() calls */
3066 };
3067 
3068 /*
3069 ** This macro is used inside of assert() statements to indicate that
3070 ** the assert is only valid on a well-formed database.  Instead of:
3071 **
3072 **     assert( X );
3073 **
3074 ** One writes:
3075 **
3076 **     assert( X || CORRUPT_DB );
3077 **
3078 ** CORRUPT_DB is true during normal operation.  CORRUPT_DB does not indicate
3079 ** that the database is definitely corrupt, only that it might be corrupt.
3080 ** For most test cases, CORRUPT_DB is set to false using a special
3081 ** sqlite3_test_control().  This enables assert() statements to prove
3082 ** things that are always true for well-formed databases.
3083 */
3084 #define CORRUPT_DB  (sqlite3Config.neverCorrupt==0)
3085 
3086 /*
3087 ** Context pointer passed down through the tree-walk.
3088 */
3089 struct Walker {
3090   Parse *pParse;                            /* Parser context.  */
3091   int (*xExprCallback)(Walker*, Expr*);     /* Callback for expressions */
3092   int (*xSelectCallback)(Walker*,Select*);  /* Callback for SELECTs */
3093   void (*xSelectCallback2)(Walker*,Select*);/* Second callback for SELECTs */
3094   int walkerDepth;                          /* Number of subqueries */
3095   u8 eCode;                                 /* A small processing code */
3096   union {                                   /* Extra data for callback */
3097     NameContext *pNC;                          /* Naming context */
3098     int n;                                     /* A counter */
3099     int iCur;                                  /* A cursor number */
3100     SrcList *pSrcList;                         /* FROM clause */
3101     struct SrcCount *pSrcCount;                /* Counting column references */
3102     struct CCurHint *pCCurHint;                /* Used by codeCursorHint() */
3103     int *aiCol;                                /* array of column indexes */
3104   } u;
3105 };
3106 
3107 /* Forward declarations */
3108 int sqlite3WalkExpr(Walker*, Expr*);
3109 int sqlite3WalkExprList(Walker*, ExprList*);
3110 int sqlite3WalkSelect(Walker*, Select*);
3111 int sqlite3WalkSelectExpr(Walker*, Select*);
3112 int sqlite3WalkSelectFrom(Walker*, Select*);
3113 int sqlite3ExprWalkNoop(Walker*, Expr*);
3114 
3115 /*
3116 ** Return code from the parse-tree walking primitives and their
3117 ** callbacks.
3118 */
3119 #define WRC_Continue    0   /* Continue down into children */
3120 #define WRC_Prune       1   /* Omit children but continue walking siblings */
3121 #define WRC_Abort       2   /* Abandon the tree walk */
3122 
3123 /*
3124 ** An instance of this structure represents a set of one or more CTEs
3125 ** (common table expressions) created by a single WITH clause.
3126 */
3127 struct With {
3128   int nCte;                       /* Number of CTEs in the WITH clause */
3129   With *pOuter;                   /* Containing WITH clause, or NULL */
3130   struct Cte {                    /* For each CTE in the WITH clause.... */
3131     char *zName;                    /* Name of this CTE */
3132     ExprList *pCols;                /* List of explicit column names, or NULL */
3133     Select *pSelect;                /* The definition of this CTE */
3134     const char *zCteErr;            /* Error message for circular references */
3135   } a[1];
3136 };
3137 
3138 #ifdef SQLITE_DEBUG
3139 /*
3140 ** An instance of the TreeView object is used for printing the content of
3141 ** data structures on sqlite3DebugPrintf() using a tree-like view.
3142 */
3143 struct TreeView {
3144   int iLevel;             /* Which level of the tree we are on */
3145   u8  bLine[100];         /* Draw vertical in column i if bLine[i] is true */
3146 };
3147 #endif /* SQLITE_DEBUG */
3148 
3149 /*
3150 ** Assuming zIn points to the first byte of a UTF-8 character,
3151 ** advance zIn to point to the first byte of the next UTF-8 character.
3152 */
3153 #define SQLITE_SKIP_UTF8(zIn) {                        \
3154   if( (*(zIn++))>=0xc0 ){                              \
3155     while( (*zIn & 0xc0)==0x80 ){ zIn++; }             \
3156   }                                                    \
3157 }
3158 
3159 /*
3160 ** The SQLITE_*_BKPT macros are substitutes for the error codes with
3161 ** the same name but without the _BKPT suffix.  These macros invoke
3162 ** routines that report the line-number on which the error originated
3163 ** using sqlite3_log().  The routines also provide a convenient place
3164 ** to set a debugger breakpoint.
3165 */
3166 int sqlite3CorruptError(int);
3167 int sqlite3MisuseError(int);
3168 int sqlite3CantopenError(int);
3169 #define SQLITE_CORRUPT_BKPT sqlite3CorruptError(__LINE__)
3170 #define SQLITE_MISUSE_BKPT sqlite3MisuseError(__LINE__)
3171 #define SQLITE_CANTOPEN_BKPT sqlite3CantopenError(__LINE__)
3172 
3173 /*
3174 ** FTS3 and FTS4 both require virtual table support
3175 */
3176 #if defined(SQLITE_OMIT_VIRTUALTABLE)
3177 # undef SQLITE_ENABLE_FTS3
3178 # undef SQLITE_ENABLE_FTS4
3179 #endif
3180 
3181 /*
3182 ** FTS4 is really an extension for FTS3.  It is enabled using the
3183 ** SQLITE_ENABLE_FTS3 macro.  But to avoid confusion we also call
3184 ** the SQLITE_ENABLE_FTS4 macro to serve as an alias for SQLITE_ENABLE_FTS3.
3185 */
3186 #if defined(SQLITE_ENABLE_FTS4) && !defined(SQLITE_ENABLE_FTS3)
3187 # define SQLITE_ENABLE_FTS3 1
3188 #endif
3189 
3190 /*
3191 ** The ctype.h header is needed for non-ASCII systems.  It is also
3192 ** needed by FTS3 when FTS3 is included in the amalgamation.
3193 */
3194 #if !defined(SQLITE_ASCII) || \
3195     (defined(SQLITE_ENABLE_FTS3) && defined(SQLITE_AMALGAMATION))
3196 # include <ctype.h>
3197 #endif
3198 
3199 /*
3200 ** The following macros mimic the standard library functions toupper(),
3201 ** isspace(), isalnum(), isdigit() and isxdigit(), respectively. The
3202 ** sqlite versions only work for ASCII characters, regardless of locale.
3203 */
3204 #ifdef SQLITE_ASCII
3205 # define sqlite3Toupper(x)  ((x)&~(sqlite3CtypeMap[(unsigned char)(x)]&0x20))
3206 # define sqlite3Isspace(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x01)
3207 # define sqlite3Isalnum(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x06)
3208 # define sqlite3Isalpha(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x02)
3209 # define sqlite3Isdigit(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x04)
3210 # define sqlite3Isxdigit(x)  (sqlite3CtypeMap[(unsigned char)(x)]&0x08)
3211 # define sqlite3Tolower(x)   (sqlite3UpperToLower[(unsigned char)(x)])
3212 #else
3213 # define sqlite3Toupper(x)   toupper((unsigned char)(x))
3214 # define sqlite3Isspace(x)   isspace((unsigned char)(x))
3215 # define sqlite3Isalnum(x)   isalnum((unsigned char)(x))
3216 # define sqlite3Isalpha(x)   isalpha((unsigned char)(x))
3217 # define sqlite3Isdigit(x)   isdigit((unsigned char)(x))
3218 # define sqlite3Isxdigit(x)  isxdigit((unsigned char)(x))
3219 # define sqlite3Tolower(x)   tolower((unsigned char)(x))
3220 #endif
3221 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
3222 int sqlite3IsIdChar(u8);
3223 #endif
3224 
3225 /*
3226 ** Internal function prototypes
3227 */
3228 #define sqlite3StrICmp sqlite3_stricmp
3229 int sqlite3Strlen30(const char*);
3230 #define sqlite3StrNICmp sqlite3_strnicmp
3231 
3232 int sqlite3MallocInit(void);
3233 void sqlite3MallocEnd(void);
3234 void *sqlite3Malloc(u64);
3235 void *sqlite3MallocZero(u64);
3236 void *sqlite3DbMallocZero(sqlite3*, u64);
3237 void *sqlite3DbMallocRaw(sqlite3*, u64);
3238 void *sqlite3DbMallocRawNN(sqlite3*, u64);
3239 char *sqlite3DbStrDup(sqlite3*,const char*);
3240 char *sqlite3DbStrNDup(sqlite3*,const char*, u64);
3241 void *sqlite3Realloc(void*, u64);
3242 void *sqlite3DbReallocOrFree(sqlite3 *, void *, u64);
3243 void *sqlite3DbRealloc(sqlite3 *, void *, u64);
3244 void sqlite3DbFree(sqlite3*, void*);
3245 int sqlite3MallocSize(void*);
3246 int sqlite3DbMallocSize(sqlite3*, void*);
3247 void *sqlite3ScratchMalloc(int);
3248 void sqlite3ScratchFree(void*);
3249 void *sqlite3PageMalloc(int);
3250 void sqlite3PageFree(void*);
3251 void sqlite3MemSetDefault(void);
3252 #ifndef SQLITE_OMIT_BUILTIN_TEST
3253 void sqlite3BenignMallocHooks(void (*)(void), void (*)(void));
3254 #endif
3255 int sqlite3HeapNearlyFull(void);
3256 
3257 /*
3258 ** On systems with ample stack space and that support alloca(), make
3259 ** use of alloca() to obtain space for large automatic objects.  By default,
3260 ** obtain space from malloc().
3261 **
3262 ** The alloca() routine never returns NULL.  This will cause code paths
3263 ** that deal with sqlite3StackAlloc() failures to be unreachable.
3264 */
3265 #ifdef SQLITE_USE_ALLOCA
3266 # define sqlite3StackAllocRaw(D,N)   alloca(N)
3267 # define sqlite3StackAllocZero(D,N)  memset(alloca(N), 0, N)
3268 # define sqlite3StackFree(D,P)
3269 #else
3270 # define sqlite3StackAllocRaw(D,N)   sqlite3DbMallocRaw(D,N)
3271 # define sqlite3StackAllocZero(D,N)  sqlite3DbMallocZero(D,N)
3272 # define sqlite3StackFree(D,P)       sqlite3DbFree(D,P)
3273 #endif
3274 
3275 #ifdef SQLITE_ENABLE_MEMSYS3
3276 const sqlite3_mem_methods *sqlite3MemGetMemsys3(void);
3277 #endif
3278 #ifdef SQLITE_ENABLE_MEMSYS5
3279 const sqlite3_mem_methods *sqlite3MemGetMemsys5(void);
3280 #endif
3281 
3282 
3283 #ifndef SQLITE_MUTEX_OMIT
3284   sqlite3_mutex_methods const *sqlite3DefaultMutex(void);
3285   sqlite3_mutex_methods const *sqlite3NoopMutex(void);
3286   sqlite3_mutex *sqlite3MutexAlloc(int);
3287   int sqlite3MutexInit(void);
3288   int sqlite3MutexEnd(void);
3289 #endif
3290 #if !defined(SQLITE_MUTEX_OMIT) && !defined(SQLITE_MUTEX_NOOP)
3291   void sqlite3MemoryBarrier(void);
3292 #else
3293 # define sqlite3MemoryBarrier()
3294 #endif
3295 
3296 sqlite3_int64 sqlite3StatusValue(int);
3297 void sqlite3StatusUp(int, int);
3298 void sqlite3StatusDown(int, int);
3299 void sqlite3StatusHighwater(int, int);
3300 
3301 /* Access to mutexes used by sqlite3_status() */
3302 sqlite3_mutex *sqlite3Pcache1Mutex(void);
3303 sqlite3_mutex *sqlite3MallocMutex(void);
3304 
3305 #ifndef SQLITE_OMIT_FLOATING_POINT
3306   int sqlite3IsNaN(double);
3307 #else
3308 # define sqlite3IsNaN(X)  0
3309 #endif
3310 
3311 /*
3312 ** An instance of the following structure holds information about SQL
3313 ** functions arguments that are the parameters to the printf() function.
3314 */
3315 struct PrintfArguments {
3316   int nArg;                /* Total number of arguments */
3317   int nUsed;               /* Number of arguments used so far */
3318   sqlite3_value **apArg;   /* The argument values */
3319 };
3320 
3321 void sqlite3VXPrintf(StrAccum*, const char*, va_list);
3322 void sqlite3XPrintf(StrAccum*, const char*, ...);
3323 char *sqlite3MPrintf(sqlite3*,const char*, ...);
3324 char *sqlite3VMPrintf(sqlite3*,const char*, va_list);
3325 #if defined(SQLITE_DEBUG) || defined(SQLITE_HAVE_OS_TRACE)
3326   void sqlite3DebugPrintf(const char*, ...);
3327 #endif
3328 #if defined(SQLITE_TEST)
3329   void *sqlite3TestTextToPtr(const char*);
3330 #endif
3331 
3332 #if defined(SQLITE_DEBUG)
3333   void sqlite3TreeViewExpr(TreeView*, const Expr*, u8);
3334   void sqlite3TreeViewExprList(TreeView*, const ExprList*, u8, const char*);
3335   void sqlite3TreeViewSelect(TreeView*, const Select*, u8);
3336   void sqlite3TreeViewWith(TreeView*, const With*, u8);
3337 #endif
3338 
3339 
3340 void sqlite3SetString(char **, sqlite3*, const char*);
3341 void sqlite3ErrorMsg(Parse*, const char*, ...);
3342 int sqlite3Dequote(char*);
3343 void sqlite3TokenInit(Token*,char*);
3344 int sqlite3KeywordCode(const unsigned char*, int);
3345 int sqlite3RunParser(Parse*, const char*, char **);
3346 void sqlite3FinishCoding(Parse*);
3347 int sqlite3GetTempReg(Parse*);
3348 void sqlite3ReleaseTempReg(Parse*,int);
3349 int sqlite3GetTempRange(Parse*,int);
3350 void sqlite3ReleaseTempRange(Parse*,int,int);
3351 void sqlite3ClearTempRegCache(Parse*);
3352 Expr *sqlite3ExprAlloc(sqlite3*,int,const Token*,int);
3353 Expr *sqlite3Expr(sqlite3*,int,const char*);
3354 void sqlite3ExprAttachSubtrees(sqlite3*,Expr*,Expr*,Expr*);
3355 Expr *sqlite3PExpr(Parse*, int, Expr*, Expr*, const Token*);
3356 Expr *sqlite3ExprAnd(sqlite3*,Expr*, Expr*);
3357 Expr *sqlite3ExprFunction(Parse*,ExprList*, Token*);
3358 void sqlite3ExprAssignVarNumber(Parse*, Expr*);
3359 void sqlite3ExprDelete(sqlite3*, Expr*);
3360 ExprList *sqlite3ExprListAppend(Parse*,ExprList*,Expr*);
3361 void sqlite3ExprListSetSortOrder(ExprList*,int);
3362 void sqlite3ExprListSetName(Parse*,ExprList*,Token*,int);
3363 void sqlite3ExprListSetSpan(Parse*,ExprList*,ExprSpan*);
3364 void sqlite3ExprListDelete(sqlite3*, ExprList*);
3365 u32 sqlite3ExprListFlags(const ExprList*);
3366 int sqlite3Init(sqlite3*, char**);
3367 int sqlite3InitCallback(void*, int, char**, char**);
3368 void sqlite3Pragma(Parse*,Token*,Token*,Token*,int);
3369 void sqlite3ResetAllSchemasOfConnection(sqlite3*);
3370 void sqlite3ResetOneSchema(sqlite3*,int);
3371 void sqlite3CollapseDatabaseArray(sqlite3*);
3372 void sqlite3CommitInternalChanges(sqlite3*);
3373 void sqlite3DeleteColumnNames(sqlite3*,Table*);
3374 int sqlite3ColumnsFromExprList(Parse*,ExprList*,i16*,Column**);
3375 Table *sqlite3ResultSetOfSelect(Parse*,Select*);
3376 void sqlite3OpenMasterTable(Parse *, int);
3377 Index *sqlite3PrimaryKeyIndex(Table*);
3378 i16 sqlite3ColumnOfIndex(Index*, i16);
3379 void sqlite3StartTable(Parse*,Token*,Token*,int,int,int,int);
3380 #if SQLITE_ENABLE_HIDDEN_COLUMNS
3381   void sqlite3ColumnPropertiesFromName(Table*, Column*);
3382 #else
3383 # define sqlite3ColumnPropertiesFromName(T,C) /* no-op */
3384 #endif
3385 void sqlite3AddColumn(Parse*,Token*);
3386 void sqlite3AddNotNull(Parse*, int);
3387 void sqlite3AddPrimaryKey(Parse*, ExprList*, int, int, int);
3388 void sqlite3AddCheckConstraint(Parse*, Expr*);
3389 void sqlite3AddColumnType(Parse*,Token*);
3390 void sqlite3AddDefaultValue(Parse*,ExprSpan*);
3391 void sqlite3AddCollateType(Parse*, Token*);
3392 void sqlite3EndTable(Parse*,Token*,Token*,u8,Select*);
3393 int sqlite3ParseUri(const char*,const char*,unsigned int*,
3394                     sqlite3_vfs**,char**,char **);
3395 Btree *sqlite3DbNameToBtree(sqlite3*,const char*);
3396 int sqlite3CodeOnce(Parse *);
3397 
3398 #ifdef SQLITE_OMIT_BUILTIN_TEST
3399 # define sqlite3FaultSim(X) SQLITE_OK
3400 #else
3401   int sqlite3FaultSim(int);
3402 #endif
3403 
3404 Bitvec *sqlite3BitvecCreate(u32);
3405 int sqlite3BitvecTest(Bitvec*, u32);
3406 int sqlite3BitvecTestNotNull(Bitvec*, u32);
3407 int sqlite3BitvecSet(Bitvec*, u32);
3408 void sqlite3BitvecClear(Bitvec*, u32, void*);
3409 void sqlite3BitvecDestroy(Bitvec*);
3410 u32 sqlite3BitvecSize(Bitvec*);
3411 #ifndef SQLITE_OMIT_BUILTIN_TEST
3412 int sqlite3BitvecBuiltinTest(int,int*);
3413 #endif
3414 
3415 RowSet *sqlite3RowSetInit(sqlite3*, void*, unsigned int);
3416 void sqlite3RowSetClear(RowSet*);
3417 void sqlite3RowSetInsert(RowSet*, i64);
3418 int sqlite3RowSetTest(RowSet*, int iBatch, i64);
3419 int sqlite3RowSetNext(RowSet*, i64*);
3420 
3421 void sqlite3CreateView(Parse*,Token*,Token*,Token*,ExprList*,Select*,int,int);
3422 
3423 #if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE)
3424   int sqlite3ViewGetColumnNames(Parse*,Table*);
3425 #else
3426 # define sqlite3ViewGetColumnNames(A,B) 0
3427 #endif
3428 
3429 #if SQLITE_MAX_ATTACHED>30
3430   int sqlite3DbMaskAllZero(yDbMask);
3431 #endif
3432 void sqlite3DropTable(Parse*, SrcList*, int, int);
3433 void sqlite3CodeDropTable(Parse*, Table*, int, int);
3434 void sqlite3DeleteTable(sqlite3*, Table*);
3435 #ifndef SQLITE_OMIT_AUTOINCREMENT
3436   void sqlite3AutoincrementBegin(Parse *pParse);
3437   void sqlite3AutoincrementEnd(Parse *pParse);
3438 #else
3439 # define sqlite3AutoincrementBegin(X)
3440 # define sqlite3AutoincrementEnd(X)
3441 #endif
3442 void sqlite3Insert(Parse*, SrcList*, Select*, IdList*, int);
3443 void *sqlite3ArrayAllocate(sqlite3*,void*,int,int*,int*);
3444 IdList *sqlite3IdListAppend(sqlite3*, IdList*, Token*);
3445 int sqlite3IdListIndex(IdList*,const char*);
3446 SrcList *sqlite3SrcListEnlarge(sqlite3*, SrcList*, int, int);
3447 SrcList *sqlite3SrcListAppend(sqlite3*, SrcList*, Token*, Token*);
3448 SrcList *sqlite3SrcListAppendFromTerm(Parse*, SrcList*, Token*, Token*,
3449                                       Token*, Select*, Expr*, IdList*);
3450 void sqlite3SrcListIndexedBy(Parse *, SrcList *, Token *);
3451 void sqlite3SrcListFuncArgs(Parse*, SrcList*, ExprList*);
3452 int sqlite3IndexedByLookup(Parse *, struct SrcList_item *);
3453 void sqlite3SrcListShiftJoinType(SrcList*);
3454 void sqlite3SrcListAssignCursors(Parse*, SrcList*);
3455 void sqlite3IdListDelete(sqlite3*, IdList*);
3456 void sqlite3SrcListDelete(sqlite3*, SrcList*);
3457 Index *sqlite3AllocateIndexObject(sqlite3*,i16,int,char**);
3458 Index *sqlite3CreateIndex(Parse*,Token*,Token*,SrcList*,ExprList*,int,Token*,
3459                           Expr*, int, int);
3460 void sqlite3DropIndex(Parse*, SrcList*, int);
3461 int sqlite3Select(Parse*, Select*, SelectDest*);
3462 Select *sqlite3SelectNew(Parse*,ExprList*,SrcList*,Expr*,ExprList*,
3463                          Expr*,ExprList*,u16,Expr*,Expr*);
3464 void sqlite3SelectDelete(sqlite3*, Select*);
3465 Table *sqlite3SrcListLookup(Parse*, SrcList*);
3466 int sqlite3IsReadOnly(Parse*, Table*, int);
3467 void sqlite3OpenTable(Parse*, int iCur, int iDb, Table*, int);
3468 #if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY)
3469 Expr *sqlite3LimitWhere(Parse*,SrcList*,Expr*,ExprList*,Expr*,Expr*,char*);
3470 #endif
3471 void sqlite3DeleteFrom(Parse*, SrcList*, Expr*);
3472 void sqlite3Update(Parse*, SrcList*, ExprList*, Expr*, int);
3473 WhereInfo *sqlite3WhereBegin(Parse*,SrcList*,Expr*,ExprList*,ExprList*,u16,int);
3474 void sqlite3WhereEnd(WhereInfo*);
3475 u64 sqlite3WhereOutputRowCount(WhereInfo*);
3476 int sqlite3WhereIsDistinct(WhereInfo*);
3477 int sqlite3WhereIsOrdered(WhereInfo*);
3478 int sqlite3WhereIsSorted(WhereInfo*);
3479 int sqlite3WhereContinueLabel(WhereInfo*);
3480 int sqlite3WhereBreakLabel(WhereInfo*);
3481 int sqlite3WhereOkOnePass(WhereInfo*, int*);
3482 #define ONEPASS_OFF      0        /* Use of ONEPASS not allowed */
3483 #define ONEPASS_SINGLE   1        /* ONEPASS valid for a single row update */
3484 #define ONEPASS_MULTI    2        /* ONEPASS is valid for multiple rows */
3485 void sqlite3ExprCodeLoadIndexColumn(Parse*, Index*, int, int, int);
3486 int sqlite3ExprCodeGetColumn(Parse*, Table*, int, int, int, u8);
3487 void sqlite3ExprCodeGetColumnToReg(Parse*, Table*, int, int, int);
3488 void sqlite3ExprCodeGetColumnOfTable(Vdbe*, Table*, int, int, int);
3489 void sqlite3ExprCodeMove(Parse*, int, int, int);
3490 void sqlite3ExprCacheStore(Parse*, int, int, int);
3491 void sqlite3ExprCachePush(Parse*);
3492 void sqlite3ExprCachePop(Parse*);
3493 void sqlite3ExprCacheRemove(Parse*, int, int);
3494 void sqlite3ExprCacheClear(Parse*);
3495 void sqlite3ExprCacheAffinityChange(Parse*, int, int);
3496 void sqlite3ExprCode(Parse*, Expr*, int);
3497 void sqlite3ExprCodeCopy(Parse*, Expr*, int);
3498 void sqlite3ExprCodeFactorable(Parse*, Expr*, int);
3499 void sqlite3ExprCodeAtInit(Parse*, Expr*, int, u8);
3500 int sqlite3ExprCodeTemp(Parse*, Expr*, int*);
3501 int sqlite3ExprCodeTarget(Parse*, Expr*, int);
3502 void sqlite3ExprCodeAndCache(Parse*, Expr*, int);
3503 int sqlite3ExprCodeExprList(Parse*, ExprList*, int, int, u8);
3504 #define SQLITE_ECEL_DUP      0x01  /* Deep, not shallow copies */
3505 #define SQLITE_ECEL_FACTOR   0x02  /* Factor out constant terms */
3506 #define SQLITE_ECEL_REF      0x04  /* Use ExprList.u.x.iOrderByCol */
3507 void sqlite3ExprIfTrue(Parse*, Expr*, int, int);
3508 void sqlite3ExprIfFalse(Parse*, Expr*, int, int);
3509 void sqlite3ExprIfFalseDup(Parse*, Expr*, int, int);
3510 Table *sqlite3FindTable(sqlite3*,const char*, const char*);
3511 Table *sqlite3LocateTable(Parse*,int isView,const char*, const char*);
3512 Table *sqlite3LocateTableItem(Parse*,int isView,struct SrcList_item *);
3513 Index *sqlite3FindIndex(sqlite3*,const char*, const char*);
3514 void sqlite3UnlinkAndDeleteTable(sqlite3*,int,const char*);
3515 void sqlite3UnlinkAndDeleteIndex(sqlite3*,int,const char*);
3516 void sqlite3Vacuum(Parse*);
3517 int sqlite3RunVacuum(char**, sqlite3*);
3518 char *sqlite3NameFromToken(sqlite3*, Token*);
3519 int sqlite3ExprCompare(Expr*, Expr*, int);
3520 int sqlite3ExprListCompare(ExprList*, ExprList*, int);
3521 int sqlite3ExprImpliesExpr(Expr*, Expr*, int);
3522 void sqlite3ExprAnalyzeAggregates(NameContext*, Expr*);
3523 void sqlite3ExprAnalyzeAggList(NameContext*,ExprList*);
3524 int sqlite3FunctionUsesThisSrc(Expr*, SrcList*);
3525 Vdbe *sqlite3GetVdbe(Parse*);
3526 #ifndef SQLITE_OMIT_BUILTIN_TEST
3527 void sqlite3PrngSaveState(void);
3528 void sqlite3PrngRestoreState(void);
3529 #endif
3530 void sqlite3RollbackAll(sqlite3*,int);
3531 void sqlite3CodeVerifySchema(Parse*, int);
3532 void sqlite3CodeVerifyNamedSchema(Parse*, const char *zDb);
3533 void sqlite3BeginTransaction(Parse*, int);
3534 void sqlite3CommitTransaction(Parse*);
3535 void sqlite3RollbackTransaction(Parse*);
3536 void sqlite3Savepoint(Parse*, int, Token*);
3537 void sqlite3CloseSavepoints(sqlite3 *);
3538 void sqlite3LeaveMutexAndCloseZombie(sqlite3*);
3539 int sqlite3ExprIsConstant(Expr*);
3540 int sqlite3ExprIsConstantNotJoin(Expr*);
3541 int sqlite3ExprIsConstantOrFunction(Expr*, u8);
3542 int sqlite3ExprIsTableConstant(Expr*,int);
3543 #ifdef SQLITE_ENABLE_CURSOR_HINTS
3544 int sqlite3ExprContainsSubquery(Expr*);
3545 #endif
3546 int sqlite3ExprIsInteger(Expr*, int*);
3547 int sqlite3ExprCanBeNull(const Expr*);
3548 int sqlite3ExprNeedsNoAffinityChange(const Expr*, char);
3549 int sqlite3IsRowid(const char*);
3550 void sqlite3GenerateRowDelete(
3551     Parse*,Table*,Trigger*,int,int,int,i16,u8,u8,u8,int);
3552 void sqlite3GenerateRowIndexDelete(Parse*, Table*, int, int, int*, int);
3553 int sqlite3GenerateIndexKey(Parse*, Index*, int, int, int, int*,Index*,int);
3554 void sqlite3ResolvePartIdxLabel(Parse*,int);
3555 void sqlite3GenerateConstraintChecks(Parse*,Table*,int*,int,int,int,int,
3556                                      u8,u8,int,int*,int*);
3557 void sqlite3CompleteInsertion(Parse*,Table*,int,int,int,int*,int,int,int);
3558 int sqlite3OpenTableAndIndices(Parse*, Table*, int, u8, int, u8*, int*, int*);
3559 void sqlite3BeginWriteOperation(Parse*, int, int);
3560 void sqlite3MultiWrite(Parse*);
3561 void sqlite3MayAbort(Parse*);
3562 void sqlite3HaltConstraint(Parse*, int, int, char*, i8, u8);
3563 void sqlite3UniqueConstraint(Parse*, int, Index*);
3564 void sqlite3RowidConstraint(Parse*, int, Table*);
3565 Expr *sqlite3ExprDup(sqlite3*,Expr*,int);
3566 ExprList *sqlite3ExprListDup(sqlite3*,ExprList*,int);
3567 SrcList *sqlite3SrcListDup(sqlite3*,SrcList*,int);
3568 IdList *sqlite3IdListDup(sqlite3*,IdList*);
3569 Select *sqlite3SelectDup(sqlite3*,Select*,int);
3570 #if SELECTTRACE_ENABLED
3571 void sqlite3SelectSetName(Select*,const char*);
3572 #else
3573 # define sqlite3SelectSetName(A,B)
3574 #endif
3575 void sqlite3FuncDefInsert(FuncDefHash*, FuncDef*);
3576 FuncDef *sqlite3FindFunction(sqlite3*,const char*,int,int,u8,u8);
3577 void sqlite3RegisterBuiltinFunctions(sqlite3*);
3578 void sqlite3RegisterDateTimeFunctions(void);
3579 void sqlite3RegisterGlobalFunctions(void);
3580 int sqlite3SafetyCheckOk(sqlite3*);
3581 int sqlite3SafetyCheckSickOrOk(sqlite3*);
3582 void sqlite3ChangeCookie(Parse*, int);
3583 
3584 #if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
3585 void sqlite3MaterializeView(Parse*, Table*, Expr*, int);
3586 #endif
3587 
3588 #ifndef SQLITE_OMIT_TRIGGER
3589   void sqlite3BeginTrigger(Parse*, Token*,Token*,int,int,IdList*,SrcList*,
3590                            Expr*,int, int);
3591   void sqlite3FinishTrigger(Parse*, TriggerStep*, Token*);
3592   void sqlite3DropTrigger(Parse*, SrcList*, int);
3593   void sqlite3DropTriggerPtr(Parse*, Trigger*);
3594   Trigger *sqlite3TriggersExist(Parse *, Table*, int, ExprList*, int *pMask);
3595   Trigger *sqlite3TriggerList(Parse *, Table *);
3596   void sqlite3CodeRowTrigger(Parse*, Trigger *, int, ExprList*, int, Table *,
3597                             int, int, int);
3598   void sqlite3CodeRowTriggerDirect(Parse *, Trigger *, Table *, int, int, int);
3599   void sqliteViewTriggers(Parse*, Table*, Expr*, int, ExprList*);
3600   void sqlite3DeleteTriggerStep(sqlite3*, TriggerStep*);
3601   TriggerStep *sqlite3TriggerSelectStep(sqlite3*,Select*);
3602   TriggerStep *sqlite3TriggerInsertStep(sqlite3*,Token*, IdList*,
3603                                         Select*,u8);
3604   TriggerStep *sqlite3TriggerUpdateStep(sqlite3*,Token*,ExprList*, Expr*, u8);
3605   TriggerStep *sqlite3TriggerDeleteStep(sqlite3*,Token*, Expr*);
3606   void sqlite3DeleteTrigger(sqlite3*, Trigger*);
3607   void sqlite3UnlinkAndDeleteTrigger(sqlite3*,int,const char*);
3608   u32 sqlite3TriggerColmask(Parse*,Trigger*,ExprList*,int,int,Table*,int);
3609 # define sqlite3ParseToplevel(p) ((p)->pToplevel ? (p)->pToplevel : (p))
3610 # define sqlite3IsToplevel(p) ((p)->pToplevel==0)
3611 #else
3612 # define sqlite3TriggersExist(B,C,D,E,F) 0
3613 # define sqlite3DeleteTrigger(A,B)
3614 # define sqlite3DropTriggerPtr(A,B)
3615 # define sqlite3UnlinkAndDeleteTrigger(A,B,C)
3616 # define sqlite3CodeRowTrigger(A,B,C,D,E,F,G,H,I)
3617 # define sqlite3CodeRowTriggerDirect(A,B,C,D,E,F)
3618 # define sqlite3TriggerList(X, Y) 0
3619 # define sqlite3ParseToplevel(p) p
3620 # define sqlite3IsToplevel(p) 1
3621 # define sqlite3TriggerColmask(A,B,C,D,E,F,G) 0
3622 #endif
3623 
3624 int sqlite3JoinType(Parse*, Token*, Token*, Token*);
3625 void sqlite3CreateForeignKey(Parse*, ExprList*, Token*, ExprList*, int);
3626 void sqlite3DeferForeignKey(Parse*, int);
3627 #ifndef SQLITE_OMIT_AUTHORIZATION
3628   void sqlite3AuthRead(Parse*,Expr*,Schema*,SrcList*);
3629   int sqlite3AuthCheck(Parse*,int, const char*, const char*, const char*);
3630   void sqlite3AuthContextPush(Parse*, AuthContext*, const char*);
3631   void sqlite3AuthContextPop(AuthContext*);
3632   int sqlite3AuthReadCol(Parse*, const char *, const char *, int);
3633 #else
3634 # define sqlite3AuthRead(a,b,c,d)
3635 # define sqlite3AuthCheck(a,b,c,d,e)    SQLITE_OK
3636 # define sqlite3AuthContextPush(a,b,c)
3637 # define sqlite3AuthContextPop(a)  ((void)(a))
3638 #endif
3639 void sqlite3Attach(Parse*, Expr*, Expr*, Expr*);
3640 void sqlite3Detach(Parse*, Expr*);
3641 void sqlite3FixInit(DbFixer*, Parse*, int, const char*, const Token*);
3642 int sqlite3FixSrcList(DbFixer*, SrcList*);
3643 int sqlite3FixSelect(DbFixer*, Select*);
3644 int sqlite3FixExpr(DbFixer*, Expr*);
3645 int sqlite3FixExprList(DbFixer*, ExprList*);
3646 int sqlite3FixTriggerStep(DbFixer*, TriggerStep*);
3647 int sqlite3AtoF(const char *z, double*, int, u8);
3648 int sqlite3GetInt32(const char *, int*);
3649 int sqlite3Atoi(const char*);
3650 int sqlite3Utf16ByteLen(const void *pData, int nChar);
3651 int sqlite3Utf8CharLen(const char *pData, int nByte);
3652 u32 sqlite3Utf8Read(const u8**);
3653 LogEst sqlite3LogEst(u64);
3654 LogEst sqlite3LogEstAdd(LogEst,LogEst);
3655 #ifndef SQLITE_OMIT_VIRTUALTABLE
3656 LogEst sqlite3LogEstFromDouble(double);
3657 #endif
3658 u64 sqlite3LogEstToInt(LogEst);
3659 
3660 /*
3661 ** Routines to read and write variable-length integers.  These used to
3662 ** be defined locally, but now we use the varint routines in the util.c
3663 ** file.
3664 */
3665 int sqlite3PutVarint(unsigned char*, u64);
3666 u8 sqlite3GetVarint(const unsigned char *, u64 *);
3667 u8 sqlite3GetVarint32(const unsigned char *, u32 *);
3668 int sqlite3VarintLen(u64 v);
3669 
3670 /*
3671 ** The common case is for a varint to be a single byte.  They following
3672 ** macros handle the common case without a procedure call, but then call
3673 ** the procedure for larger varints.
3674 */
3675 #define getVarint32(A,B)  \
3676   (u8)((*(A)<(u8)0x80)?((B)=(u32)*(A)),1:sqlite3GetVarint32((A),(u32 *)&(B)))
3677 #define putVarint32(A,B)  \
3678   (u8)(((u32)(B)<(u32)0x80)?(*(A)=(unsigned char)(B)),1:\
3679   sqlite3PutVarint((A),(B)))
3680 #define getVarint    sqlite3GetVarint
3681 #define putVarint    sqlite3PutVarint
3682 
3683 
3684 const char *sqlite3IndexAffinityStr(sqlite3*, Index*);
3685 void sqlite3TableAffinity(Vdbe*, Table*, int);
3686 char sqlite3CompareAffinity(Expr *pExpr, char aff2);
3687 int sqlite3IndexAffinityOk(Expr *pExpr, char idx_affinity);
3688 char sqlite3ExprAffinity(Expr *pExpr);
3689 int sqlite3Atoi64(const char*, i64*, int, u8);
3690 int sqlite3DecOrHexToI64(const char*, i64*);
3691 void sqlite3ErrorWithMsg(sqlite3*, int, const char*,...);
3692 void sqlite3Error(sqlite3*,int);
3693 void *sqlite3HexToBlob(sqlite3*, const char *z, int n);
3694 u8 sqlite3HexToInt(int h);
3695 int sqlite3TwoPartName(Parse *, Token *, Token *, Token **);
3696 
3697 #if defined(SQLITE_NEED_ERR_NAME)
3698 const char *sqlite3ErrName(int);
3699 #endif
3700 
3701 const char *sqlite3ErrStr(int);
3702 int sqlite3ReadSchema(Parse *pParse);
3703 CollSeq *sqlite3FindCollSeq(sqlite3*,u8 enc, const char*,int);
3704 CollSeq *sqlite3LocateCollSeq(Parse *pParse, const char*zName);
3705 CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr);
3706 Expr *sqlite3ExprAddCollateToken(Parse *pParse, Expr*, const Token*, int);
3707 Expr *sqlite3ExprAddCollateString(Parse*,Expr*,const char*);
3708 Expr *sqlite3ExprSkipCollate(Expr*);
3709 int sqlite3CheckCollSeq(Parse *, CollSeq *);
3710 int sqlite3CheckObjectName(Parse *, const char *);
3711 void sqlite3VdbeSetChanges(sqlite3 *, int);
3712 int sqlite3AddInt64(i64*,i64);
3713 int sqlite3SubInt64(i64*,i64);
3714 int sqlite3MulInt64(i64*,i64);
3715 int sqlite3AbsInt32(int);
3716 #ifdef SQLITE_ENABLE_8_3_NAMES
3717 void sqlite3FileSuffix3(const char*, char*);
3718 #else
3719 # define sqlite3FileSuffix3(X,Y)
3720 #endif
3721 u8 sqlite3GetBoolean(const char *z,u8);
3722 
3723 const void *sqlite3ValueText(sqlite3_value*, u8);
3724 int sqlite3ValueBytes(sqlite3_value*, u8);
3725 void sqlite3ValueSetStr(sqlite3_value*, int, const void *,u8,
3726                         void(*)(void*));
3727 void sqlite3ValueSetNull(sqlite3_value*);
3728 void sqlite3ValueFree(sqlite3_value*);
3729 sqlite3_value *sqlite3ValueNew(sqlite3 *);
3730 char *sqlite3Utf16to8(sqlite3 *, const void*, int, u8);
3731 int sqlite3ValueFromExpr(sqlite3 *, Expr *, u8, u8, sqlite3_value **);
3732 void sqlite3ValueApplyAffinity(sqlite3_value *, u8, u8);
3733 #ifndef SQLITE_AMALGAMATION
3734 extern const unsigned char sqlite3OpcodeProperty[];
3735 extern const char sqlite3StrBINARY[];
3736 extern const unsigned char sqlite3UpperToLower[];
3737 extern const unsigned char sqlite3CtypeMap[];
3738 extern const Token sqlite3IntTokens[];
3739 extern SQLITE_WSD struct Sqlite3Config sqlite3Config;
3740 extern SQLITE_WSD FuncDefHash sqlite3GlobalFunctions;
3741 #ifndef SQLITE_OMIT_WSD
3742 extern int sqlite3PendingByte;
3743 #endif
3744 #endif
3745 void sqlite3RootPageMoved(sqlite3*, int, int, int);
3746 void sqlite3Reindex(Parse*, Token*, Token*);
3747 void sqlite3AlterFunctions(void);
3748 void sqlite3AlterRenameTable(Parse*, SrcList*, Token*);
3749 int sqlite3GetToken(const unsigned char *, int *);
3750 void sqlite3NestedParse(Parse*, const char*, ...);
3751 void sqlite3ExpirePreparedStatements(sqlite3*);
3752 int sqlite3CodeSubselect(Parse *, Expr *, int, int);
3753 void sqlite3SelectPrep(Parse*, Select*, NameContext*);
3754 void sqlite3SelectWrongNumTermsError(Parse *pParse, Select *p);
3755 int sqlite3MatchSpanName(const char*, const char*, const char*, const char*);
3756 int sqlite3ResolveExprNames(NameContext*, Expr*);
3757 int sqlite3ResolveExprListNames(NameContext*, ExprList*);
3758 void sqlite3ResolveSelectNames(Parse*, Select*, NameContext*);
3759 void sqlite3ResolveSelfReference(Parse*,Table*,int,Expr*,ExprList*);
3760 int sqlite3ResolveOrderGroupBy(Parse*, Select*, ExprList*, const char*);
3761 void sqlite3ColumnDefault(Vdbe *, Table *, int, int);
3762 void sqlite3AlterFinishAddColumn(Parse *, Token *);
3763 void sqlite3AlterBeginAddColumn(Parse *, SrcList *);
3764 CollSeq *sqlite3GetCollSeq(Parse*, u8, CollSeq *, const char*);
3765 char sqlite3AffinityType(const char*, u8*);
3766 void sqlite3Analyze(Parse*, Token*, Token*);
3767 int sqlite3InvokeBusyHandler(BusyHandler*);
3768 int sqlite3FindDb(sqlite3*, Token*);
3769 int sqlite3FindDbName(sqlite3 *, const char *);
3770 int sqlite3AnalysisLoad(sqlite3*,int iDB);
3771 void sqlite3DeleteIndexSamples(sqlite3*,Index*);
3772 void sqlite3DefaultRowEst(Index*);
3773 void sqlite3RegisterLikeFunctions(sqlite3*, int);
3774 int sqlite3IsLikeFunction(sqlite3*,Expr*,int*,char*);
3775 void sqlite3SchemaClear(void *);
3776 Schema *sqlite3SchemaGet(sqlite3 *, Btree *);
3777 int sqlite3SchemaToIndex(sqlite3 *db, Schema *);
3778 KeyInfo *sqlite3KeyInfoAlloc(sqlite3*,int,int);
3779 void sqlite3KeyInfoUnref(KeyInfo*);
3780 KeyInfo *sqlite3KeyInfoRef(KeyInfo*);
3781 KeyInfo *sqlite3KeyInfoOfIndex(Parse*, Index*);
3782 #ifdef SQLITE_DEBUG
3783 int sqlite3KeyInfoIsWriteable(KeyInfo*);
3784 #endif
3785 int sqlite3CreateFunc(sqlite3 *, const char *, int, int, void *,
3786   void (*)(sqlite3_context*,int,sqlite3_value **),
3787   void (*)(sqlite3_context*,int,sqlite3_value **), void (*)(sqlite3_context*),
3788   FuncDestructor *pDestructor
3789 );
3790 void sqlite3OomFault(sqlite3*);
3791 void sqlite3OomClear(sqlite3*);
3792 int sqlite3ApiExit(sqlite3 *db, int);
3793 int sqlite3OpenTempDatabase(Parse *);
3794 
3795 void sqlite3StrAccumInit(StrAccum*, sqlite3*, char*, int, int);
3796 void sqlite3StrAccumAppend(StrAccum*,const char*,int);
3797 void sqlite3StrAccumAppendAll(StrAccum*,const char*);
3798 void sqlite3AppendChar(StrAccum*,int,char);
3799 char *sqlite3StrAccumFinish(StrAccum*);
3800 void sqlite3StrAccumReset(StrAccum*);
3801 void sqlite3SelectDestInit(SelectDest*,int,int);
3802 Expr *sqlite3CreateColumnExpr(sqlite3 *, SrcList *, int, int);
3803 
3804 void sqlite3BackupRestart(sqlite3_backup *);
3805 void sqlite3BackupUpdate(sqlite3_backup *, Pgno, const u8 *);
3806 
3807 #ifdef SQLITE_ENABLE_STAT3_OR_STAT4
3808 void sqlite3AnalyzeFunctions(void);
3809 int sqlite3Stat4ProbeSetValue(Parse*,Index*,UnpackedRecord**,Expr*,u8,int,int*);
3810 int sqlite3Stat4ValueFromExpr(Parse*, Expr*, u8, sqlite3_value**);
3811 void sqlite3Stat4ProbeFree(UnpackedRecord*);
3812 int sqlite3Stat4Column(sqlite3*, const void*, int, int, sqlite3_value**);
3813 #endif
3814 
3815 /*
3816 ** The interface to the LEMON-generated parser
3817 */
3818 void *sqlite3ParserAlloc(void*(*)(u64));
3819 void sqlite3ParserFree(void*, void(*)(void*));
3820 void sqlite3Parser(void*, int, Token, Parse*);
3821 #ifdef YYTRACKMAXSTACKDEPTH
3822   int sqlite3ParserStackPeak(void*);
3823 #endif
3824 
3825 void sqlite3AutoLoadExtensions(sqlite3*);
3826 #ifndef SQLITE_OMIT_LOAD_EXTENSION
3827   void sqlite3CloseExtensions(sqlite3*);
3828 #else
3829 # define sqlite3CloseExtensions(X)
3830 #endif
3831 
3832 #ifndef SQLITE_OMIT_SHARED_CACHE
3833   void sqlite3TableLock(Parse *, int, int, u8, const char *);
3834 #else
3835   #define sqlite3TableLock(v,w,x,y,z)
3836 #endif
3837 
3838 #ifdef SQLITE_TEST
3839   int sqlite3Utf8To8(unsigned char*);
3840 #endif
3841 
3842 #ifdef SQLITE_OMIT_VIRTUALTABLE
3843 #  define sqlite3VtabClear(Y)
3844 #  define sqlite3VtabSync(X,Y) SQLITE_OK
3845 #  define sqlite3VtabRollback(X)
3846 #  define sqlite3VtabCommit(X)
3847 #  define sqlite3VtabInSync(db) 0
3848 #  define sqlite3VtabLock(X)
3849 #  define sqlite3VtabUnlock(X)
3850 #  define sqlite3VtabUnlockList(X)
3851 #  define sqlite3VtabSavepoint(X, Y, Z) SQLITE_OK
3852 #  define sqlite3GetVTable(X,Y)  ((VTable*)0)
3853 #else
3854    void sqlite3VtabClear(sqlite3 *db, Table*);
3855    void sqlite3VtabDisconnect(sqlite3 *db, Table *p);
3856    int sqlite3VtabSync(sqlite3 *db, Vdbe*);
3857    int sqlite3VtabRollback(sqlite3 *db);
3858    int sqlite3VtabCommit(sqlite3 *db);
3859    void sqlite3VtabLock(VTable *);
3860    void sqlite3VtabUnlock(VTable *);
3861    void sqlite3VtabUnlockList(sqlite3*);
3862    int sqlite3VtabSavepoint(sqlite3 *, int, int);
3863    void sqlite3VtabImportErrmsg(Vdbe*, sqlite3_vtab*);
3864    VTable *sqlite3GetVTable(sqlite3*, Table*);
3865 #  define sqlite3VtabInSync(db) ((db)->nVTrans>0 && (db)->aVTrans==0)
3866 #endif
3867 int sqlite3VtabEponymousTableInit(Parse*,Module*);
3868 void sqlite3VtabEponymousTableClear(sqlite3*,Module*);
3869 void sqlite3VtabMakeWritable(Parse*,Table*);
3870 void sqlite3VtabBeginParse(Parse*, Token*, Token*, Token*, int);
3871 void sqlite3VtabFinishParse(Parse*, Token*);
3872 void sqlite3VtabArgInit(Parse*);
3873 void sqlite3VtabArgExtend(Parse*, Token*);
3874 int sqlite3VtabCallCreate(sqlite3*, int, const char *, char **);
3875 int sqlite3VtabCallConnect(Parse*, Table*);
3876 int sqlite3VtabCallDestroy(sqlite3*, int, const char *);
3877 int sqlite3VtabBegin(sqlite3 *, VTable *);
3878 FuncDef *sqlite3VtabOverloadFunction(sqlite3 *,FuncDef*, int nArg, Expr*);
3879 void sqlite3InvalidFunction(sqlite3_context*,int,sqlite3_value**);
3880 sqlite3_int64 sqlite3StmtCurrentTime(sqlite3_context*);
3881 int sqlite3VdbeParameterIndex(Vdbe*, const char*, int);
3882 int sqlite3TransferBindings(sqlite3_stmt *, sqlite3_stmt *);
3883 void sqlite3ParserReset(Parse*);
3884 int sqlite3Reprepare(Vdbe*);
3885 void sqlite3ExprListCheckLength(Parse*, ExprList*, const char*);
3886 CollSeq *sqlite3BinaryCompareCollSeq(Parse *, Expr *, Expr *);
3887 int sqlite3TempInMemory(const sqlite3*);
3888 const char *sqlite3JournalModename(int);
3889 #ifndef SQLITE_OMIT_WAL
3890   int sqlite3Checkpoint(sqlite3*, int, int, int*, int*);
3891   int sqlite3WalDefaultHook(void*,sqlite3*,const char*,int);
3892 #endif
3893 #ifndef SQLITE_OMIT_CTE
3894   With *sqlite3WithAdd(Parse*,With*,Token*,ExprList*,Select*);
3895   void sqlite3WithDelete(sqlite3*,With*);
3896   void sqlite3WithPush(Parse*, With*, u8);
3897 #else
3898 #define sqlite3WithPush(x,y,z)
3899 #define sqlite3WithDelete(x,y)
3900 #endif
3901 
3902 /* Declarations for functions in fkey.c. All of these are replaced by
3903 ** no-op macros if OMIT_FOREIGN_KEY is defined. In this case no foreign
3904 ** key functionality is available. If OMIT_TRIGGER is defined but
3905 ** OMIT_FOREIGN_KEY is not, only some of the functions are no-oped. In
3906 ** this case foreign keys are parsed, but no other functionality is
3907 ** provided (enforcement of FK constraints requires the triggers sub-system).
3908 */
3909 #if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)
3910   void sqlite3FkCheck(Parse*, Table*, int, int, int*, int);
3911   void sqlite3FkDropTable(Parse*, SrcList *, Table*);
3912   void sqlite3FkActions(Parse*, Table*, ExprList*, int, int*, int);
3913   int sqlite3FkRequired(Parse*, Table*, int*, int);
3914   u32 sqlite3FkOldmask(Parse*, Table*);
3915   FKey *sqlite3FkReferences(Table *);
3916 #else
3917   #define sqlite3FkActions(a,b,c,d,e,f)
3918   #define sqlite3FkCheck(a,b,c,d,e,f)
3919   #define sqlite3FkDropTable(a,b,c)
3920   #define sqlite3FkOldmask(a,b)         0
3921   #define sqlite3FkRequired(a,b,c,d)    0
3922 #endif
3923 #ifndef SQLITE_OMIT_FOREIGN_KEY
3924   void sqlite3FkDelete(sqlite3 *, Table*);
3925   int sqlite3FkLocateIndex(Parse*,Table*,FKey*,Index**,int**);
3926 #else
3927   #define sqlite3FkDelete(a,b)
3928   #define sqlite3FkLocateIndex(a,b,c,d,e)
3929 #endif
3930 
3931 
3932 /*
3933 ** Available fault injectors.  Should be numbered beginning with 0.
3934 */
3935 #define SQLITE_FAULTINJECTOR_MALLOC     0
3936 #define SQLITE_FAULTINJECTOR_COUNT      1
3937 
3938 /*
3939 ** The interface to the code in fault.c used for identifying "benign"
3940 ** malloc failures. This is only present if SQLITE_OMIT_BUILTIN_TEST
3941 ** is not defined.
3942 */
3943 #ifndef SQLITE_OMIT_BUILTIN_TEST
3944   void sqlite3BeginBenignMalloc(void);
3945   void sqlite3EndBenignMalloc(void);
3946 #else
3947   #define sqlite3BeginBenignMalloc()
3948   #define sqlite3EndBenignMalloc()
3949 #endif
3950 
3951 /*
3952 ** Allowed return values from sqlite3FindInIndex()
3953 */
3954 #define IN_INDEX_ROWID        1   /* Search the rowid of the table */
3955 #define IN_INDEX_EPH          2   /* Search an ephemeral b-tree */
3956 #define IN_INDEX_INDEX_ASC    3   /* Existing index ASCENDING */
3957 #define IN_INDEX_INDEX_DESC   4   /* Existing index DESCENDING */
3958 #define IN_INDEX_NOOP         5   /* No table available. Use comparisons */
3959 /*
3960 ** Allowed flags for the 3rd parameter to sqlite3FindInIndex().
3961 */
3962 #define IN_INDEX_NOOP_OK     0x0001  /* OK to return IN_INDEX_NOOP */
3963 #define IN_INDEX_MEMBERSHIP  0x0002  /* IN operator used for membership test */
3964 #define IN_INDEX_LOOP        0x0004  /* IN operator used as a loop */
3965 int sqlite3FindInIndex(Parse *, Expr *, u32, int*);
3966 
3967 #ifdef SQLITE_ENABLE_ATOMIC_WRITE
3968   int sqlite3JournalOpen(sqlite3_vfs *, const char *, sqlite3_file *, int, int);
3969   int sqlite3JournalSize(sqlite3_vfs *);
3970   int sqlite3JournalCreate(sqlite3_file *);
3971   int sqlite3JournalExists(sqlite3_file *p);
3972 #else
3973   #define sqlite3JournalSize(pVfs) ((pVfs)->szOsFile)
3974   #define sqlite3JournalExists(p) 1
3975 #endif
3976 
3977 void sqlite3MemJournalOpen(sqlite3_file *);
3978 int sqlite3MemJournalSize(void);
3979 int sqlite3IsMemJournal(sqlite3_file *);
3980 
3981 void sqlite3ExprSetHeightAndFlags(Parse *pParse, Expr *p);
3982 #if SQLITE_MAX_EXPR_DEPTH>0
3983   int sqlite3SelectExprHeight(Select *);
3984   int sqlite3ExprCheckHeight(Parse*, int);
3985 #else
3986   #define sqlite3SelectExprHeight(x) 0
3987   #define sqlite3ExprCheckHeight(x,y)
3988 #endif
3989 
3990 u32 sqlite3Get4byte(const u8*);
3991 void sqlite3Put4byte(u8*, u32);
3992 
3993 #ifdef SQLITE_ENABLE_UNLOCK_NOTIFY
3994   void sqlite3ConnectionBlocked(sqlite3 *, sqlite3 *);
3995   void sqlite3ConnectionUnlocked(sqlite3 *db);
3996   void sqlite3ConnectionClosed(sqlite3 *db);
3997 #else
3998   #define sqlite3ConnectionBlocked(x,y)
3999   #define sqlite3ConnectionUnlocked(x)
4000   #define sqlite3ConnectionClosed(x)
4001 #endif
4002 
4003 #ifdef SQLITE_DEBUG
4004   void sqlite3ParserTrace(FILE*, char *);
4005 #endif
4006 
4007 /*
4008 ** If the SQLITE_ENABLE IOTRACE exists then the global variable
4009 ** sqlite3IoTrace is a pointer to a printf-like routine used to
4010 ** print I/O tracing messages.
4011 */
4012 #ifdef SQLITE_ENABLE_IOTRACE
4013 # define IOTRACE(A)  if( sqlite3IoTrace ){ sqlite3IoTrace A; }
4014   void sqlite3VdbeIOTraceSql(Vdbe*);
4015 SQLITE_API SQLITE_EXTERN void (SQLITE_CDECL *sqlite3IoTrace)(const char*,...);
4016 #else
4017 # define IOTRACE(A)
4018 # define sqlite3VdbeIOTraceSql(X)
4019 #endif
4020 
4021 /*
4022 ** These routines are available for the mem2.c debugging memory allocator
4023 ** only.  They are used to verify that different "types" of memory
4024 ** allocations are properly tracked by the system.
4025 **
4026 ** sqlite3MemdebugSetType() sets the "type" of an allocation to one of
4027 ** the MEMTYPE_* macros defined below.  The type must be a bitmask with
4028 ** a single bit set.
4029 **
4030 ** sqlite3MemdebugHasType() returns true if any of the bits in its second
4031 ** argument match the type set by the previous sqlite3MemdebugSetType().
4032 ** sqlite3MemdebugHasType() is intended for use inside assert() statements.
4033 **
4034 ** sqlite3MemdebugNoType() returns true if none of the bits in its second
4035 ** argument match the type set by the previous sqlite3MemdebugSetType().
4036 **
4037 ** Perhaps the most important point is the difference between MEMTYPE_HEAP
4038 ** and MEMTYPE_LOOKASIDE.  If an allocation is MEMTYPE_LOOKASIDE, that means
4039 ** it might have been allocated by lookaside, except the allocation was
4040 ** too large or lookaside was already full.  It is important to verify
4041 ** that allocations that might have been satisfied by lookaside are not
4042 ** passed back to non-lookaside free() routines.  Asserts such as the
4043 ** example above are placed on the non-lookaside free() routines to verify
4044 ** this constraint.
4045 **
4046 ** All of this is no-op for a production build.  It only comes into
4047 ** play when the SQLITE_MEMDEBUG compile-time option is used.
4048 */
4049 #ifdef SQLITE_MEMDEBUG
4050   void sqlite3MemdebugSetType(void*,u8);
4051   int sqlite3MemdebugHasType(void*,u8);
4052   int sqlite3MemdebugNoType(void*,u8);
4053 #else
4054 # define sqlite3MemdebugSetType(X,Y)  /* no-op */
4055 # define sqlite3MemdebugHasType(X,Y)  1
4056 # define sqlite3MemdebugNoType(X,Y)   1
4057 #endif
4058 #define MEMTYPE_HEAP       0x01  /* General heap allocations */
4059 #define MEMTYPE_LOOKASIDE  0x02  /* Heap that might have been lookaside */
4060 #define MEMTYPE_SCRATCH    0x04  /* Scratch allocations */
4061 #define MEMTYPE_PCACHE     0x08  /* Page cache allocations */
4062 
4063 /*
4064 ** Threading interface
4065 */
4066 #if SQLITE_MAX_WORKER_THREADS>0
4067 int sqlite3ThreadCreate(SQLiteThread**,void*(*)(void*),void*);
4068 int sqlite3ThreadJoin(SQLiteThread*, void**);
4069 #endif
4070 
4071 #if defined(SQLITE_ENABLE_DBSTAT_VTAB) || defined(SQLITE_TEST)
4072 int sqlite3DbstatRegister(sqlite3*);
4073 #endif
4074 
4075 #endif /* _SQLITEINT_H_ */
4076