xref: /sqlite-3.40.0/src/sqliteInt.h (revision 50420545)
1 /*
2 ** 2001 September 15
3 **
4 ** The author disclaims copyright to this source code.  In place of
5 ** a legal notice, here is a blessing:
6 **
7 **    May you do good and not evil.
8 **    May you find forgiveness for yourself and forgive others.
9 **    May you share freely, never taking more than you give.
10 **
11 *************************************************************************
12 ** Internal interface definitions for SQLite.
13 **
14 */
15 #ifndef _SQLITEINT_H_
16 #define _SQLITEINT_H_
17 
18 /*
19 ** These #defines should enable >2GB file support on POSIX if the
20 ** underlying operating system supports it.  If the OS lacks
21 ** large file support, or if the OS is windows, these should be no-ops.
22 **
23 ** Ticket #2739:  The _LARGEFILE_SOURCE macro must appear before any
24 ** system #includes.  Hence, this block of code must be the very first
25 ** code in all source files.
26 **
27 ** Large file support can be disabled using the -DSQLITE_DISABLE_LFS switch
28 ** on the compiler command line.  This is necessary if you are compiling
29 ** on a recent machine (ex: Red Hat 7.2) but you want your code to work
30 ** on an older machine (ex: Red Hat 6.0).  If you compile on Red Hat 7.2
31 ** without this option, LFS is enable.  But LFS does not exist in the kernel
32 ** in Red Hat 6.0, so the code won't work.  Hence, for maximum binary
33 ** portability you should omit LFS.
34 **
35 ** Similar is true for Mac OS X.  LFS is only supported on Mac OS X 9 and later.
36 */
37 #ifndef SQLITE_DISABLE_LFS
38 # define _LARGE_FILE       1
39 # ifndef _FILE_OFFSET_BITS
40 #   define _FILE_OFFSET_BITS 64
41 # endif
42 # define _LARGEFILE_SOURCE 1
43 #endif
44 
45 /*
46 ** Include the configuration header output by 'configure' if we're using the
47 ** autoconf-based build
48 */
49 #ifdef _HAVE_SQLITE_CONFIG_H
50 #include "config.h"
51 #endif
52 
53 #include "sqliteLimit.h"
54 
55 /* Disable nuisance warnings on Borland compilers */
56 #if defined(__BORLANDC__)
57 #pragma warn -rch /* unreachable code */
58 #pragma warn -ccc /* Condition is always true or false */
59 #pragma warn -aus /* Assigned value is never used */
60 #pragma warn -csu /* Comparing signed and unsigned */
61 #pragma warn -spa /* Suspicious pointer arithmetic */
62 #endif
63 
64 /* Needed for various definitions... */
65 #ifndef _GNU_SOURCE
66 # define _GNU_SOURCE
67 #endif
68 
69 #if defined(__OpenBSD__) && !defined(_BSD_SOURCE)
70 # define _BSD_SOURCE
71 #endif
72 
73 /*
74 ** Include standard header files as necessary
75 */
76 #ifdef HAVE_STDINT_H
77 #include <stdint.h>
78 #endif
79 #ifdef HAVE_INTTYPES_H
80 #include <inttypes.h>
81 #endif
82 
83 /*
84 ** The following macros are used to cast pointers to integers and
85 ** integers to pointers.  The way you do this varies from one compiler
86 ** to the next, so we have developed the following set of #if statements
87 ** to generate appropriate macros for a wide range of compilers.
88 **
89 ** The correct "ANSI" way to do this is to use the intptr_t type.
90 ** Unfortunately, that typedef is not available on all compilers, or
91 ** if it is available, it requires an #include of specific headers
92 ** that vary from one machine to the next.
93 **
94 ** Ticket #3860:  The llvm-gcc-4.2 compiler from Apple chokes on
95 ** the ((void*)&((char*)0)[X]) construct.  But MSVC chokes on ((void*)(X)).
96 ** So we have to define the macros in different ways depending on the
97 ** compiler.
98 */
99 #if defined(__PTRDIFF_TYPE__)  /* This case should work for GCC */
100 # define SQLITE_INT_TO_PTR(X)  ((void*)(__PTRDIFF_TYPE__)(X))
101 # define SQLITE_PTR_TO_INT(X)  ((int)(__PTRDIFF_TYPE__)(X))
102 #elif !defined(__GNUC__)       /* Works for compilers other than LLVM */
103 # define SQLITE_INT_TO_PTR(X)  ((void*)&((char*)0)[X])
104 # define SQLITE_PTR_TO_INT(X)  ((int)(((char*)X)-(char*)0))
105 #elif defined(HAVE_STDINT_H)   /* Use this case if we have ANSI headers */
106 # define SQLITE_INT_TO_PTR(X)  ((void*)(intptr_t)(X))
107 # define SQLITE_PTR_TO_INT(X)  ((int)(intptr_t)(X))
108 #else                          /* Generates a warning - but it always works */
109 # define SQLITE_INT_TO_PTR(X)  ((void*)(X))
110 # define SQLITE_PTR_TO_INT(X)  ((int)(X))
111 #endif
112 
113 /*
114 ** The SQLITE_THREADSAFE macro must be defined as 0, 1, or 2.
115 ** 0 means mutexes are permanently disable and the library is never
116 ** threadsafe.  1 means the library is serialized which is the highest
117 ** level of threadsafety.  2 means the library is multithreaded - multiple
118 ** threads can use SQLite as long as no two threads try to use the same
119 ** database connection at the same time.
120 **
121 ** Older versions of SQLite used an optional THREADSAFE macro.
122 ** We support that for legacy.
123 */
124 #if !defined(SQLITE_THREADSAFE)
125 # if defined(THREADSAFE)
126 #   define SQLITE_THREADSAFE THREADSAFE
127 # else
128 #   define SQLITE_THREADSAFE 1 /* IMP: R-07272-22309 */
129 # endif
130 #endif
131 
132 /*
133 ** Powersafe overwrite is on by default.  But can be turned off using
134 ** the -DSQLITE_POWERSAFE_OVERWRITE=0 command-line option.
135 */
136 #ifndef SQLITE_POWERSAFE_OVERWRITE
137 # define SQLITE_POWERSAFE_OVERWRITE 1
138 #endif
139 
140 /*
141 ** The SQLITE_DEFAULT_MEMSTATUS macro must be defined as either 0 or 1.
142 ** It determines whether or not the features related to
143 ** SQLITE_CONFIG_MEMSTATUS are available by default or not. This value can
144 ** be overridden at runtime using the sqlite3_config() API.
145 */
146 #if !defined(SQLITE_DEFAULT_MEMSTATUS)
147 # define SQLITE_DEFAULT_MEMSTATUS 1
148 #endif
149 
150 /*
151 ** Exactly one of the following macros must be defined in order to
152 ** specify which memory allocation subsystem to use.
153 **
154 **     SQLITE_SYSTEM_MALLOC          // Use normal system malloc()
155 **     SQLITE_WIN32_MALLOC           // Use Win32 native heap API
156 **     SQLITE_ZERO_MALLOC            // Use a stub allocator that always fails
157 **     SQLITE_MEMDEBUG               // Debugging version of system malloc()
158 **
159 ** On Windows, if the SQLITE_WIN32_MALLOC_VALIDATE macro is defined and the
160 ** assert() macro is enabled, each call into the Win32 native heap subsystem
161 ** will cause HeapValidate to be called.  If heap validation should fail, an
162 ** assertion will be triggered.
163 **
164 ** (Historical note:  There used to be several other options, but we've
165 ** pared it down to just these three.)
166 **
167 ** If none of the above are defined, then set SQLITE_SYSTEM_MALLOC as
168 ** the default.
169 */
170 #if defined(SQLITE_SYSTEM_MALLOC) \
171   + defined(SQLITE_WIN32_MALLOC) \
172   + defined(SQLITE_ZERO_MALLOC) \
173   + defined(SQLITE_MEMDEBUG)>1
174 # error "Two or more of the following compile-time configuration options\
175  are defined but at most one is allowed:\
176  SQLITE_SYSTEM_MALLOC, SQLITE_WIN32_MALLOC, SQLITE_MEMDEBUG,\
177  SQLITE_ZERO_MALLOC"
178 #endif
179 #if defined(SQLITE_SYSTEM_MALLOC) \
180   + defined(SQLITE_WIN32_MALLOC) \
181   + defined(SQLITE_ZERO_MALLOC) \
182   + defined(SQLITE_MEMDEBUG)==0
183 # define SQLITE_SYSTEM_MALLOC 1
184 #endif
185 
186 /*
187 ** If SQLITE_MALLOC_SOFT_LIMIT is not zero, then try to keep the
188 ** sizes of memory allocations below this value where possible.
189 */
190 #if !defined(SQLITE_MALLOC_SOFT_LIMIT)
191 # define SQLITE_MALLOC_SOFT_LIMIT 1024
192 #endif
193 
194 /*
195 ** We need to define _XOPEN_SOURCE as follows in order to enable
196 ** recursive mutexes on most Unix systems and fchmod() on OpenBSD.
197 ** But _XOPEN_SOURCE define causes problems for Mac OS X, so omit
198 ** it.
199 */
200 #if !defined(_XOPEN_SOURCE) && !defined(__DARWIN__) && !defined(__APPLE__)
201 #  define _XOPEN_SOURCE 600
202 #endif
203 
204 /*
205 ** The TCL headers are only needed when compiling the TCL bindings.
206 */
207 #if defined(SQLITE_TCL) || defined(TCLSH)
208 # include <tcl.h>
209 #endif
210 
211 /*
212 ** NDEBUG and SQLITE_DEBUG are opposites.  It should always be true that
213 ** defined(NDEBUG)==!defined(SQLITE_DEBUG).  If this is not currently true,
214 ** make it true by defining or undefining NDEBUG.
215 **
216 ** Setting NDEBUG makes the code smaller and run faster by disabling the
217 ** number assert() statements in the code.  So we want the default action
218 ** to be for NDEBUG to be set and NDEBUG to be undefined only if SQLITE_DEBUG
219 ** is set.  Thus NDEBUG becomes an opt-in rather than an opt-out
220 ** feature.
221 */
222 #if !defined(NDEBUG) && !defined(SQLITE_DEBUG)
223 # define NDEBUG 1
224 #endif
225 #if defined(NDEBUG) && defined(SQLITE_DEBUG)
226 # undef NDEBUG
227 #endif
228 
229 /*
230 ** The testcase() macro is used to aid in coverage testing.  When
231 ** doing coverage testing, the condition inside the argument to
232 ** testcase() must be evaluated both true and false in order to
233 ** get full branch coverage.  The testcase() macro is inserted
234 ** to help ensure adequate test coverage in places where simple
235 ** condition/decision coverage is inadequate.  For example, testcase()
236 ** can be used to make sure boundary values are tested.  For
237 ** bitmask tests, testcase() can be used to make sure each bit
238 ** is significant and used at least once.  On switch statements
239 ** where multiple cases go to the same block of code, testcase()
240 ** can insure that all cases are evaluated.
241 **
242 */
243 #ifdef SQLITE_COVERAGE_TEST
244   void sqlite3Coverage(int);
245 # define testcase(X)  if( X ){ sqlite3Coverage(__LINE__); }
246 #else
247 # define testcase(X)
248 #endif
249 
250 /*
251 ** The TESTONLY macro is used to enclose variable declarations or
252 ** other bits of code that are needed to support the arguments
253 ** within testcase() and assert() macros.
254 */
255 #if !defined(NDEBUG) || defined(SQLITE_COVERAGE_TEST)
256 # define TESTONLY(X)  X
257 #else
258 # define TESTONLY(X)
259 #endif
260 
261 /*
262 ** Sometimes we need a small amount of code such as a variable initialization
263 ** to setup for a later assert() statement.  We do not want this code to
264 ** appear when assert() is disabled.  The following macro is therefore
265 ** used to contain that setup code.  The "VVA" acronym stands for
266 ** "Verification, Validation, and Accreditation".  In other words, the
267 ** code within VVA_ONLY() will only run during verification processes.
268 */
269 #ifndef NDEBUG
270 # define VVA_ONLY(X)  X
271 #else
272 # define VVA_ONLY(X)
273 #endif
274 
275 /*
276 ** The ALWAYS and NEVER macros surround boolean expressions which
277 ** are intended to always be true or false, respectively.  Such
278 ** expressions could be omitted from the code completely.  But they
279 ** are included in a few cases in order to enhance the resilience
280 ** of SQLite to unexpected behavior - to make the code "self-healing"
281 ** or "ductile" rather than being "brittle" and crashing at the first
282 ** hint of unplanned behavior.
283 **
284 ** In other words, ALWAYS and NEVER are added for defensive code.
285 **
286 ** When doing coverage testing ALWAYS and NEVER are hard-coded to
287 ** be true and false so that the unreachable code then specify will
288 ** not be counted as untested code.
289 */
290 #if defined(SQLITE_COVERAGE_TEST)
291 # define ALWAYS(X)      (1)
292 # define NEVER(X)       (0)
293 #elif !defined(NDEBUG)
294 # define ALWAYS(X)      ((X)?1:(assert(0),0))
295 # define NEVER(X)       ((X)?(assert(0),1):0)
296 #else
297 # define ALWAYS(X)      (X)
298 # define NEVER(X)       (X)
299 #endif
300 
301 /*
302 ** Return true (non-zero) if the input is a integer that is too large
303 ** to fit in 32-bits.  This macro is used inside of various testcase()
304 ** macros to verify that we have tested SQLite for large-file support.
305 */
306 #define IS_BIG_INT(X)  (((X)&~(i64)0xffffffff)!=0)
307 
308 /*
309 ** The macro unlikely() is a hint that surrounds a boolean
310 ** expression that is usually false.  Macro likely() surrounds
311 ** a boolean expression that is usually true.  GCC is able to
312 ** use these hints to generate better code, sometimes.
313 */
314 #if defined(__GNUC__) && 0
315 # define likely(X)    __builtin_expect((X),1)
316 # define unlikely(X)  __builtin_expect((X),0)
317 #else
318 # define likely(X)    !!(X)
319 # define unlikely(X)  !!(X)
320 #endif
321 
322 #include "sqlite3.h"
323 #include "hash.h"
324 #include "parse.h"
325 #include <stdio.h>
326 #include <stdlib.h>
327 #include <string.h>
328 #include <assert.h>
329 #include <stddef.h>
330 
331 /*
332 ** If compiling for a processor that lacks floating point support,
333 ** substitute integer for floating-point
334 */
335 #ifdef SQLITE_OMIT_FLOATING_POINT
336 # define double sqlite_int64
337 # define float sqlite_int64
338 # define LONGDOUBLE_TYPE sqlite_int64
339 # ifndef SQLITE_BIG_DBL
340 #   define SQLITE_BIG_DBL (((sqlite3_int64)1)<<50)
341 # endif
342 # define SQLITE_OMIT_DATETIME_FUNCS 1
343 # define SQLITE_OMIT_TRACE 1
344 # undef SQLITE_MIXED_ENDIAN_64BIT_FLOAT
345 # undef SQLITE_HAVE_ISNAN
346 #endif
347 #ifndef SQLITE_BIG_DBL
348 # define SQLITE_BIG_DBL (1e99)
349 #endif
350 
351 /*
352 ** OMIT_TEMPDB is set to 1 if SQLITE_OMIT_TEMPDB is defined, or 0
353 ** afterward. Having this macro allows us to cause the C compiler
354 ** to omit code used by TEMP tables without messy #ifndef statements.
355 */
356 #ifdef SQLITE_OMIT_TEMPDB
357 #define OMIT_TEMPDB 1
358 #else
359 #define OMIT_TEMPDB 0
360 #endif
361 
362 /*
363 ** The "file format" number is an integer that is incremented whenever
364 ** the VDBE-level file format changes.  The following macros define the
365 ** the default file format for new databases and the maximum file format
366 ** that the library can read.
367 */
368 #define SQLITE_MAX_FILE_FORMAT 4
369 #ifndef SQLITE_DEFAULT_FILE_FORMAT
370 # define SQLITE_DEFAULT_FILE_FORMAT 4
371 #endif
372 
373 /*
374 ** Determine whether triggers are recursive by default.  This can be
375 ** changed at run-time using a pragma.
376 */
377 #ifndef SQLITE_DEFAULT_RECURSIVE_TRIGGERS
378 # define SQLITE_DEFAULT_RECURSIVE_TRIGGERS 0
379 #endif
380 
381 /*
382 ** Provide a default value for SQLITE_TEMP_STORE in case it is not specified
383 ** on the command-line
384 */
385 #ifndef SQLITE_TEMP_STORE
386 # define SQLITE_TEMP_STORE 1
387 # define SQLITE_TEMP_STORE_xc 1  /* Exclude from ctime.c */
388 #endif
389 
390 /*
391 ** GCC does not define the offsetof() macro so we'll have to do it
392 ** ourselves.
393 */
394 #ifndef offsetof
395 #define offsetof(STRUCTURE,FIELD) ((int)((char*)&((STRUCTURE*)0)->FIELD))
396 #endif
397 
398 /*
399 ** Check to see if this machine uses EBCDIC.  (Yes, believe it or
400 ** not, there are still machines out there that use EBCDIC.)
401 */
402 #if 'A' == '\301'
403 # define SQLITE_EBCDIC 1
404 #else
405 # define SQLITE_ASCII 1
406 #endif
407 
408 /*
409 ** Integers of known sizes.  These typedefs might change for architectures
410 ** where the sizes very.  Preprocessor macros are available so that the
411 ** types can be conveniently redefined at compile-type.  Like this:
412 **
413 **         cc '-DUINTPTR_TYPE=long long int' ...
414 */
415 #ifndef UINT32_TYPE
416 # ifdef HAVE_UINT32_T
417 #  define UINT32_TYPE uint32_t
418 # else
419 #  define UINT32_TYPE unsigned int
420 # endif
421 #endif
422 #ifndef UINT16_TYPE
423 # ifdef HAVE_UINT16_T
424 #  define UINT16_TYPE uint16_t
425 # else
426 #  define UINT16_TYPE unsigned short int
427 # endif
428 #endif
429 #ifndef INT16_TYPE
430 # ifdef HAVE_INT16_T
431 #  define INT16_TYPE int16_t
432 # else
433 #  define INT16_TYPE short int
434 # endif
435 #endif
436 #ifndef UINT8_TYPE
437 # ifdef HAVE_UINT8_T
438 #  define UINT8_TYPE uint8_t
439 # else
440 #  define UINT8_TYPE unsigned char
441 # endif
442 #endif
443 #ifndef INT8_TYPE
444 # ifdef HAVE_INT8_T
445 #  define INT8_TYPE int8_t
446 # else
447 #  define INT8_TYPE signed char
448 # endif
449 #endif
450 #ifndef LONGDOUBLE_TYPE
451 # define LONGDOUBLE_TYPE long double
452 #endif
453 typedef sqlite_int64 i64;          /* 8-byte signed integer */
454 typedef sqlite_uint64 u64;         /* 8-byte unsigned integer */
455 typedef UINT32_TYPE u32;           /* 4-byte unsigned integer */
456 typedef UINT16_TYPE u16;           /* 2-byte unsigned integer */
457 typedef INT16_TYPE i16;            /* 2-byte signed integer */
458 typedef UINT8_TYPE u8;             /* 1-byte unsigned integer */
459 typedef INT8_TYPE i8;              /* 1-byte signed integer */
460 
461 /*
462 ** SQLITE_MAX_U32 is a u64 constant that is the maximum u64 value
463 ** that can be stored in a u32 without loss of data.  The value
464 ** is 0x00000000ffffffff.  But because of quirks of some compilers, we
465 ** have to specify the value in the less intuitive manner shown:
466 */
467 #define SQLITE_MAX_U32  ((((u64)1)<<32)-1)
468 
469 /*
470 ** The datatype used to store estimates of the number of rows in a
471 ** table or index.  This is an unsigned integer type.  For 99.9% of
472 ** the world, a 32-bit integer is sufficient.  But a 64-bit integer
473 ** can be used at compile-time if desired.
474 */
475 #ifdef SQLITE_64BIT_STATS
476  typedef u64 tRowcnt;    /* 64-bit only if requested at compile-time */
477 #else
478  typedef u32 tRowcnt;    /* 32-bit is the default */
479 #endif
480 
481 /*
482 ** Macros to determine whether the machine is big or little endian,
483 ** evaluated at runtime.
484 */
485 #ifdef SQLITE_AMALGAMATION
486 const int sqlite3one = 1;
487 #else
488 extern const int sqlite3one;
489 #endif
490 #if defined(i386) || defined(__i386__) || defined(_M_IX86)\
491                              || defined(__x86_64) || defined(__x86_64__)
492 # define SQLITE_BIGENDIAN    0
493 # define SQLITE_LITTLEENDIAN 1
494 # define SQLITE_UTF16NATIVE  SQLITE_UTF16LE
495 #else
496 # define SQLITE_BIGENDIAN    (*(char *)(&sqlite3one)==0)
497 # define SQLITE_LITTLEENDIAN (*(char *)(&sqlite3one)==1)
498 # define SQLITE_UTF16NATIVE (SQLITE_BIGENDIAN?SQLITE_UTF16BE:SQLITE_UTF16LE)
499 #endif
500 
501 /*
502 ** Constants for the largest and smallest possible 64-bit signed integers.
503 ** These macros are designed to work correctly on both 32-bit and 64-bit
504 ** compilers.
505 */
506 #define LARGEST_INT64  (0xffffffff|(((i64)0x7fffffff)<<32))
507 #define SMALLEST_INT64 (((i64)-1) - LARGEST_INT64)
508 
509 /*
510 ** Round up a number to the next larger multiple of 8.  This is used
511 ** to force 8-byte alignment on 64-bit architectures.
512 */
513 #define ROUND8(x)     (((x)+7)&~7)
514 
515 /*
516 ** Round down to the nearest multiple of 8
517 */
518 #define ROUNDDOWN8(x) ((x)&~7)
519 
520 /*
521 ** Assert that the pointer X is aligned to an 8-byte boundary.  This
522 ** macro is used only within assert() to verify that the code gets
523 ** all alignment restrictions correct.
524 **
525 ** Except, if SQLITE_4_BYTE_ALIGNED_MALLOC is defined, then the
526 ** underlying malloc() implemention might return us 4-byte aligned
527 ** pointers.  In that case, only verify 4-byte alignment.
528 */
529 #ifdef SQLITE_4_BYTE_ALIGNED_MALLOC
530 # define EIGHT_BYTE_ALIGNMENT(X)   ((((char*)(X) - (char*)0)&3)==0)
531 #else
532 # define EIGHT_BYTE_ALIGNMENT(X)   ((((char*)(X) - (char*)0)&7)==0)
533 #endif
534 
535 /*
536 ** Disable MMAP on platforms where it is known to not work
537 */
538 #if defined(__OpenBSD__) || defined(__QNXNTO__)
539 # undef SQLITE_MAX_MMAP_SIZE
540 # define SQLITE_MAX_MMAP_SIZE 0
541 #endif
542 
543 /*
544 ** Default maximum size of memory used by memory-mapped I/O in the VFS
545 */
546 #ifdef __APPLE__
547 # include <TargetConditionals.h>
548 # if TARGET_OS_IPHONE
549 #   undef SQLITE_MAX_MMAP_SIZE
550 #   define SQLITE_MAX_MMAP_SIZE 0
551 # endif
552 #endif
553 #ifndef SQLITE_MAX_MMAP_SIZE
554 # if defined(__linux__) \
555   || defined(_WIN32) \
556   || (defined(__APPLE__) && defined(__MACH__)) \
557   || defined(__sun)
558 #   define SQLITE_MAX_MMAP_SIZE 0x7fff0000  /* 2147418112 */
559 # else
560 #   define SQLITE_MAX_MMAP_SIZE 0
561 # endif
562 # define SQLITE_MAX_MMAP_SIZE_xc 1 /* exclude from ctime.c */
563 #endif
564 
565 /*
566 ** The default MMAP_SIZE is zero on all platforms.  Or, even if a larger
567 ** default MMAP_SIZE is specified at compile-time, make sure that it does
568 ** not exceed the maximum mmap size.
569 */
570 #ifndef SQLITE_DEFAULT_MMAP_SIZE
571 # define SQLITE_DEFAULT_MMAP_SIZE 0
572 # define SQLITE_DEFAULT_MMAP_SIZE_xc 1  /* Exclude from ctime.c */
573 #endif
574 #if SQLITE_DEFAULT_MMAP_SIZE>SQLITE_MAX_MMAP_SIZE
575 # undef SQLITE_DEFAULT_MMAP_SIZE
576 # define SQLITE_DEFAULT_MMAP_SIZE SQLITE_MAX_MMAP_SIZE
577 #endif
578 
579 /*
580 ** An instance of the following structure is used to store the busy-handler
581 ** callback for a given sqlite handle.
582 **
583 ** The sqlite.busyHandler member of the sqlite struct contains the busy
584 ** callback for the database handle. Each pager opened via the sqlite
585 ** handle is passed a pointer to sqlite.busyHandler. The busy-handler
586 ** callback is currently invoked only from within pager.c.
587 */
588 typedef struct BusyHandler BusyHandler;
589 struct BusyHandler {
590   int (*xFunc)(void *,int);  /* The busy callback */
591   void *pArg;                /* First arg to busy callback */
592   int nBusy;                 /* Incremented with each busy call */
593 };
594 
595 /*
596 ** Name of the master database table.  The master database table
597 ** is a special table that holds the names and attributes of all
598 ** user tables and indices.
599 */
600 #define MASTER_NAME       "sqlite_master"
601 #define TEMP_MASTER_NAME  "sqlite_temp_master"
602 
603 /*
604 ** The root-page of the master database table.
605 */
606 #define MASTER_ROOT       1
607 
608 /*
609 ** The name of the schema table.
610 */
611 #define SCHEMA_TABLE(x)  ((!OMIT_TEMPDB)&&(x==1)?TEMP_MASTER_NAME:MASTER_NAME)
612 
613 /*
614 ** A convenience macro that returns the number of elements in
615 ** an array.
616 */
617 #define ArraySize(X)    ((int)(sizeof(X)/sizeof(X[0])))
618 
619 /*
620 ** Determine if the argument is a power of two
621 */
622 #define IsPowerOfTwo(X) (((X)&((X)-1))==0)
623 
624 /*
625 ** The following value as a destructor means to use sqlite3DbFree().
626 ** The sqlite3DbFree() routine requires two parameters instead of the
627 ** one parameter that destructors normally want.  So we have to introduce
628 ** this magic value that the code knows to handle differently.  Any
629 ** pointer will work here as long as it is distinct from SQLITE_STATIC
630 ** and SQLITE_TRANSIENT.
631 */
632 #define SQLITE_DYNAMIC   ((sqlite3_destructor_type)sqlite3MallocSize)
633 
634 /*
635 ** When SQLITE_OMIT_WSD is defined, it means that the target platform does
636 ** not support Writable Static Data (WSD) such as global and static variables.
637 ** All variables must either be on the stack or dynamically allocated from
638 ** the heap.  When WSD is unsupported, the variable declarations scattered
639 ** throughout the SQLite code must become constants instead.  The SQLITE_WSD
640 ** macro is used for this purpose.  And instead of referencing the variable
641 ** directly, we use its constant as a key to lookup the run-time allocated
642 ** buffer that holds real variable.  The constant is also the initializer
643 ** for the run-time allocated buffer.
644 **
645 ** In the usual case where WSD is supported, the SQLITE_WSD and GLOBAL
646 ** macros become no-ops and have zero performance impact.
647 */
648 #ifdef SQLITE_OMIT_WSD
649   #define SQLITE_WSD const
650   #define GLOBAL(t,v) (*(t*)sqlite3_wsd_find((void*)&(v), sizeof(v)))
651   #define sqlite3GlobalConfig GLOBAL(struct Sqlite3Config, sqlite3Config)
652   int sqlite3_wsd_init(int N, int J);
653   void *sqlite3_wsd_find(void *K, int L);
654 #else
655   #define SQLITE_WSD
656   #define GLOBAL(t,v) v
657   #define sqlite3GlobalConfig sqlite3Config
658 #endif
659 
660 /*
661 ** The following macros are used to suppress compiler warnings and to
662 ** make it clear to human readers when a function parameter is deliberately
663 ** left unused within the body of a function. This usually happens when
664 ** a function is called via a function pointer. For example the
665 ** implementation of an SQL aggregate step callback may not use the
666 ** parameter indicating the number of arguments passed to the aggregate,
667 ** if it knows that this is enforced elsewhere.
668 **
669 ** When a function parameter is not used at all within the body of a function,
670 ** it is generally named "NotUsed" or "NotUsed2" to make things even clearer.
671 ** However, these macros may also be used to suppress warnings related to
672 ** parameters that may or may not be used depending on compilation options.
673 ** For example those parameters only used in assert() statements. In these
674 ** cases the parameters are named as per the usual conventions.
675 */
676 #define UNUSED_PARAMETER(x) (void)(x)
677 #define UNUSED_PARAMETER2(x,y) UNUSED_PARAMETER(x),UNUSED_PARAMETER(y)
678 
679 /*
680 ** Forward references to structures
681 */
682 typedef struct AggInfo AggInfo;
683 typedef struct AuthContext AuthContext;
684 typedef struct AutoincInfo AutoincInfo;
685 typedef struct Bitvec Bitvec;
686 typedef struct CollSeq CollSeq;
687 typedef struct Column Column;
688 typedef struct Db Db;
689 typedef struct Schema Schema;
690 typedef struct Expr Expr;
691 typedef struct ExprList ExprList;
692 typedef struct ExprSpan ExprSpan;
693 typedef struct FKey FKey;
694 typedef struct FuncDestructor FuncDestructor;
695 typedef struct FuncDef FuncDef;
696 typedef struct FuncDefHash FuncDefHash;
697 typedef struct IdList IdList;
698 typedef struct Index Index;
699 typedef struct IndexSample IndexSample;
700 typedef struct KeyClass KeyClass;
701 typedef struct KeyInfo KeyInfo;
702 typedef struct Lookaside Lookaside;
703 typedef struct LookasideSlot LookasideSlot;
704 typedef struct Module Module;
705 typedef struct NameContext NameContext;
706 typedef struct Parse Parse;
707 typedef struct RowSet RowSet;
708 typedef struct Savepoint Savepoint;
709 typedef struct Select Select;
710 typedef struct SelectDest SelectDest;
711 typedef struct SrcList SrcList;
712 typedef struct StrAccum StrAccum;
713 typedef struct Table Table;
714 typedef struct TableLock TableLock;
715 typedef struct Token Token;
716 typedef struct Trigger Trigger;
717 typedef struct TriggerPrg TriggerPrg;
718 typedef struct TriggerStep TriggerStep;
719 typedef struct UnpackedRecord UnpackedRecord;
720 typedef struct VTable VTable;
721 typedef struct VtabCtx VtabCtx;
722 typedef struct Walker Walker;
723 typedef struct WherePlan WherePlan;
724 typedef struct WhereInfo WhereInfo;
725 typedef struct WhereLevel WhereLevel;
726 
727 /*
728 ** Defer sourcing vdbe.h and btree.h until after the "u8" and
729 ** "BusyHandler" typedefs. vdbe.h also requires a few of the opaque
730 ** pointer types (i.e. FuncDef) defined above.
731 */
732 #include "btree.h"
733 #include "vdbe.h"
734 #include "pager.h"
735 #include "pcache.h"
736 
737 #include "os.h"
738 #include "mutex.h"
739 
740 
741 /*
742 ** Each database file to be accessed by the system is an instance
743 ** of the following structure.  There are normally two of these structures
744 ** in the sqlite.aDb[] array.  aDb[0] is the main database file and
745 ** aDb[1] is the database file used to hold temporary tables.  Additional
746 ** databases may be attached.
747 */
748 struct Db {
749   char *zName;         /* Name of this database */
750   Btree *pBt;          /* The B*Tree structure for this database file */
751   u8 safety_level;     /* How aggressive at syncing data to disk */
752   Schema *pSchema;     /* Pointer to database schema (possibly shared) */
753 };
754 
755 /*
756 ** An instance of the following structure stores a database schema.
757 **
758 ** Most Schema objects are associated with a Btree.  The exception is
759 ** the Schema for the TEMP databaes (sqlite3.aDb[1]) which is free-standing.
760 ** In shared cache mode, a single Schema object can be shared by multiple
761 ** Btrees that refer to the same underlying BtShared object.
762 **
763 ** Schema objects are automatically deallocated when the last Btree that
764 ** references them is destroyed.   The TEMP Schema is manually freed by
765 ** sqlite3_close().
766 *
767 ** A thread must be holding a mutex on the corresponding Btree in order
768 ** to access Schema content.  This implies that the thread must also be
769 ** holding a mutex on the sqlite3 connection pointer that owns the Btree.
770 ** For a TEMP Schema, only the connection mutex is required.
771 */
772 struct Schema {
773   int schema_cookie;   /* Database schema version number for this file */
774   int iGeneration;     /* Generation counter.  Incremented with each change */
775   Hash tblHash;        /* All tables indexed by name */
776   Hash idxHash;        /* All (named) indices indexed by name */
777   Hash trigHash;       /* All triggers indexed by name */
778   Hash fkeyHash;       /* All foreign keys by referenced table name */
779   Table *pSeqTab;      /* The sqlite_sequence table used by AUTOINCREMENT */
780   u8 file_format;      /* Schema format version for this file */
781   u8 enc;              /* Text encoding used by this database */
782   u16 flags;           /* Flags associated with this schema */
783   int cache_size;      /* Number of pages to use in the cache */
784 };
785 
786 /*
787 ** These macros can be used to test, set, or clear bits in the
788 ** Db.pSchema->flags field.
789 */
790 #define DbHasProperty(D,I,P)     (((D)->aDb[I].pSchema->flags&(P))==(P))
791 #define DbHasAnyProperty(D,I,P)  (((D)->aDb[I].pSchema->flags&(P))!=0)
792 #define DbSetProperty(D,I,P)     (D)->aDb[I].pSchema->flags|=(P)
793 #define DbClearProperty(D,I,P)   (D)->aDb[I].pSchema->flags&=~(P)
794 
795 /*
796 ** Allowed values for the DB.pSchema->flags field.
797 **
798 ** The DB_SchemaLoaded flag is set after the database schema has been
799 ** read into internal hash tables.
800 **
801 ** DB_UnresetViews means that one or more views have column names that
802 ** have been filled out.  If the schema changes, these column names might
803 ** changes and so the view will need to be reset.
804 */
805 #define DB_SchemaLoaded    0x0001  /* The schema has been loaded */
806 #define DB_UnresetViews    0x0002  /* Some views have defined column names */
807 #define DB_Empty           0x0004  /* The file is empty (length 0 bytes) */
808 
809 /*
810 ** The number of different kinds of things that can be limited
811 ** using the sqlite3_limit() interface.
812 */
813 #define SQLITE_N_LIMIT (SQLITE_LIMIT_TRIGGER_DEPTH+1)
814 
815 /*
816 ** Lookaside malloc is a set of fixed-size buffers that can be used
817 ** to satisfy small transient memory allocation requests for objects
818 ** associated with a particular database connection.  The use of
819 ** lookaside malloc provides a significant performance enhancement
820 ** (approx 10%) by avoiding numerous malloc/free requests while parsing
821 ** SQL statements.
822 **
823 ** The Lookaside structure holds configuration information about the
824 ** lookaside malloc subsystem.  Each available memory allocation in
825 ** the lookaside subsystem is stored on a linked list of LookasideSlot
826 ** objects.
827 **
828 ** Lookaside allocations are only allowed for objects that are associated
829 ** with a particular database connection.  Hence, schema information cannot
830 ** be stored in lookaside because in shared cache mode the schema information
831 ** is shared by multiple database connections.  Therefore, while parsing
832 ** schema information, the Lookaside.bEnabled flag is cleared so that
833 ** lookaside allocations are not used to construct the schema objects.
834 */
835 struct Lookaside {
836   u16 sz;                 /* Size of each buffer in bytes */
837   u8 bEnabled;            /* False to disable new lookaside allocations */
838   u8 bMalloced;           /* True if pStart obtained from sqlite3_malloc() */
839   int nOut;               /* Number of buffers currently checked out */
840   int mxOut;              /* Highwater mark for nOut */
841   int anStat[3];          /* 0: hits.  1: size misses.  2: full misses */
842   LookasideSlot *pFree;   /* List of available buffers */
843   void *pStart;           /* First byte of available memory space */
844   void *pEnd;             /* First byte past end of available space */
845 };
846 struct LookasideSlot {
847   LookasideSlot *pNext;    /* Next buffer in the list of free buffers */
848 };
849 
850 /*
851 ** A hash table for function definitions.
852 **
853 ** Hash each FuncDef structure into one of the FuncDefHash.a[] slots.
854 ** Collisions are on the FuncDef.pHash chain.
855 */
856 struct FuncDefHash {
857   FuncDef *a[23];       /* Hash table for functions */
858 };
859 
860 /*
861 ** Each database connection is an instance of the following structure.
862 */
863 struct sqlite3 {
864   sqlite3_vfs *pVfs;            /* OS Interface */
865   struct Vdbe *pVdbe;           /* List of active virtual machines */
866   CollSeq *pDfltColl;           /* The default collating sequence (BINARY) */
867   sqlite3_mutex *mutex;         /* Connection mutex */
868   Db *aDb;                      /* All backends */
869   int nDb;                      /* Number of backends currently in use */
870   int flags;                    /* Miscellaneous flags. See below */
871   i64 lastRowid;                /* ROWID of most recent insert (see above) */
872   i64 szMmap;                   /* Default mmap_size setting */
873   unsigned int openFlags;       /* Flags passed to sqlite3_vfs.xOpen() */
874   int errCode;                  /* Most recent error code (SQLITE_*) */
875   int errMask;                  /* & result codes with this before returning */
876   u16 dbOptFlags;               /* Flags to enable/disable optimizations */
877   u8 autoCommit;                /* The auto-commit flag. */
878   u8 temp_store;                /* 1: file 2: memory 0: default */
879   u8 mallocFailed;              /* True if we have seen a malloc failure */
880   u8 dfltLockMode;              /* Default locking-mode for attached dbs */
881   signed char nextAutovac;      /* Autovac setting after VACUUM if >=0 */
882   u8 suppressErr;               /* Do not issue error messages if true */
883   u8 vtabOnConflict;            /* Value to return for s3_vtab_on_conflict() */
884   u8 isTransactionSavepoint;    /* True if the outermost savepoint is a TS */
885   int nextPagesize;             /* Pagesize after VACUUM if >0 */
886   u32 magic;                    /* Magic number for detect library misuse */
887   int nChange;                  /* Value returned by sqlite3_changes() */
888   int nTotalChange;             /* Value returned by sqlite3_total_changes() */
889   int aLimit[SQLITE_N_LIMIT];   /* Limits */
890   struct sqlite3InitInfo {      /* Information used during initialization */
891     int newTnum;                /* Rootpage of table being initialized */
892     u8 iDb;                     /* Which db file is being initialized */
893     u8 busy;                    /* TRUE if currently initializing */
894     u8 orphanTrigger;           /* Last statement is orphaned TEMP trigger */
895   } init;
896   int activeVdbeCnt;            /* Number of VDBEs currently executing */
897   int writeVdbeCnt;             /* Number of active VDBEs that are writing */
898   int vdbeExecCnt;              /* Number of nested calls to VdbeExec() */
899   int nExtension;               /* Number of loaded extensions */
900   void **aExtension;            /* Array of shared library handles */
901   void (*xTrace)(void*,const char*);        /* Trace function */
902   void *pTraceArg;                          /* Argument to the trace function */
903   void (*xProfile)(void*,const char*,u64);  /* Profiling function */
904   void *pProfileArg;                        /* Argument to profile function */
905   void *pCommitArg;                 /* Argument to xCommitCallback() */
906   int (*xCommitCallback)(void*);    /* Invoked at every commit. */
907   void *pRollbackArg;               /* Argument to xRollbackCallback() */
908   void (*xRollbackCallback)(void*); /* Invoked at every commit. */
909   void *pUpdateArg;
910   void (*xUpdateCallback)(void*,int, const char*,const char*,sqlite_int64);
911 #ifndef SQLITE_OMIT_WAL
912   int (*xWalCallback)(void *, sqlite3 *, const char *, int);
913   void *pWalArg;
914 #endif
915   void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*);
916   void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*);
917   void *pCollNeededArg;
918   sqlite3_value *pErr;          /* Most recent error message */
919   char *zErrMsg;                /* Most recent error message (UTF-8 encoded) */
920   char *zErrMsg16;              /* Most recent error message (UTF-16 encoded) */
921   union {
922     volatile int isInterrupted; /* True if sqlite3_interrupt has been called */
923     double notUsed1;            /* Spacer */
924   } u1;
925   Lookaside lookaside;          /* Lookaside malloc configuration */
926 #ifndef SQLITE_OMIT_AUTHORIZATION
927   int (*xAuth)(void*,int,const char*,const char*,const char*,const char*);
928                                 /* Access authorization function */
929   void *pAuthArg;               /* 1st argument to the access auth function */
930 #endif
931 #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
932   int (*xProgress)(void *);     /* The progress callback */
933   void *pProgressArg;           /* Argument to the progress callback */
934   int nProgressOps;             /* Number of opcodes for progress callback */
935 #endif
936 #ifndef SQLITE_OMIT_VIRTUALTABLE
937   int nVTrans;                  /* Allocated size of aVTrans */
938   Hash aModule;                 /* populated by sqlite3_create_module() */
939   VtabCtx *pVtabCtx;            /* Context for active vtab connect/create */
940   VTable **aVTrans;             /* Virtual tables with open transactions */
941   VTable *pDisconnect;    /* Disconnect these in next sqlite3_prepare() */
942 #endif
943   FuncDefHash aFunc;            /* Hash table of connection functions */
944   Hash aCollSeq;                /* All collating sequences */
945   BusyHandler busyHandler;      /* Busy callback */
946   Db aDbStatic[2];              /* Static space for the 2 default backends */
947   Savepoint *pSavepoint;        /* List of active savepoints */
948   int busyTimeout;              /* Busy handler timeout, in msec */
949   int nSavepoint;               /* Number of non-transaction savepoints */
950   int nStatement;               /* Number of nested statement-transactions  */
951   i64 nDeferredCons;            /* Net deferred constraints this transaction. */
952   int *pnBytesFreed;            /* If not NULL, increment this in DbFree() */
953 
954 #ifdef SQLITE_ENABLE_UNLOCK_NOTIFY
955   /* The following variables are all protected by the STATIC_MASTER
956   ** mutex, not by sqlite3.mutex. They are used by code in notify.c.
957   **
958   ** When X.pUnlockConnection==Y, that means that X is waiting for Y to
959   ** unlock so that it can proceed.
960   **
961   ** When X.pBlockingConnection==Y, that means that something that X tried
962   ** tried to do recently failed with an SQLITE_LOCKED error due to locks
963   ** held by Y.
964   */
965   sqlite3 *pBlockingConnection; /* Connection that caused SQLITE_LOCKED */
966   sqlite3 *pUnlockConnection;           /* Connection to watch for unlock */
967   void *pUnlockArg;                     /* Argument to xUnlockNotify */
968   void (*xUnlockNotify)(void **, int);  /* Unlock notify callback */
969   sqlite3 *pNextBlocked;        /* Next in list of all blocked connections */
970 #endif
971 };
972 
973 /*
974 ** A macro to discover the encoding of a database.
975 */
976 #define ENC(db) ((db)->aDb[0].pSchema->enc)
977 
978 /*
979 ** Possible values for the sqlite3.flags.
980 */
981 #define SQLITE_VdbeTrace      0x00000001  /* True to trace VDBE execution */
982 #define SQLITE_InternChanges  0x00000002  /* Uncommitted Hash table changes */
983 #define SQLITE_FullColNames   0x00000004  /* Show full column names on SELECT */
984 #define SQLITE_ShortColNames  0x00000008  /* Show short columns names */
985 #define SQLITE_CountRows      0x00000010  /* Count rows changed by INSERT, */
986                                           /*   DELETE, or UPDATE and return */
987                                           /*   the count using a callback. */
988 #define SQLITE_NullCallback   0x00000020  /* Invoke the callback once if the */
989                                           /*   result set is empty */
990 #define SQLITE_SqlTrace       0x00000040  /* Debug print SQL as it executes */
991 #define SQLITE_VdbeListing    0x00000080  /* Debug listings of VDBE programs */
992 #define SQLITE_WriteSchema    0x00000100  /* OK to update SQLITE_MASTER */
993 #define SQLITE_VdbeAddopTrace 0x00000200  /* Trace sqlite3VdbeAddOp() calls */
994 #define SQLITE_IgnoreChecks   0x00000400  /* Do not enforce check constraints */
995 #define SQLITE_ReadUncommitted 0x0000800  /* For shared-cache mode */
996 #define SQLITE_LegacyFileFmt  0x00001000  /* Create new databases in format 1 */
997 #define SQLITE_FullFSync      0x00002000  /* Use full fsync on the backend */
998 #define SQLITE_CkptFullFSync  0x00004000  /* Use full fsync for checkpoint */
999 #define SQLITE_RecoveryMode   0x00008000  /* Ignore schema errors */
1000 #define SQLITE_ReverseOrder   0x00010000  /* Reverse unordered SELECTs */
1001 #define SQLITE_RecTriggers    0x00020000  /* Enable recursive triggers */
1002 #define SQLITE_ForeignKeys    0x00040000  /* Enforce foreign key constraints  */
1003 #define SQLITE_AutoIndex      0x00080000  /* Enable automatic indexes */
1004 #define SQLITE_PreferBuiltin  0x00100000  /* Preference to built-in funcs */
1005 #define SQLITE_LoadExtension  0x00200000  /* Enable load_extension */
1006 #define SQLITE_EnableTrigger  0x00400000  /* True to enable triggers */
1007 
1008 /*
1009 ** Bits of the sqlite3.dbOptFlags field that are used by the
1010 ** sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS,...) interface to
1011 ** selectively disable various optimizations.
1012 */
1013 #define SQLITE_QueryFlattener 0x0001   /* Query flattening */
1014 #define SQLITE_ColumnCache    0x0002   /* Column cache */
1015 #define SQLITE_GroupByOrder   0x0004   /* GROUPBY cover of ORDERBY */
1016 #define SQLITE_FactorOutConst 0x0008   /* Constant factoring */
1017 #define SQLITE_IdxRealAsInt   0x0010   /* Store REAL as INT in indices */
1018 #define SQLITE_DistinctOpt    0x0020   /* DISTINCT using indexes */
1019 #define SQLITE_CoverIdxScan   0x0040   /* Covering index scans */
1020 #define SQLITE_OrderByIdxJoin 0x0080   /* ORDER BY of joins via index */
1021 #define SQLITE_SubqCoroutine  0x0100   /* Evaluate subqueries as coroutines */
1022 #define SQLITE_Transitive     0x0200   /* Transitive constraints */
1023 #define SQLITE_AllOpts        0xffff   /* All optimizations */
1024 
1025 /*
1026 ** Macros for testing whether or not optimizations are enabled or disabled.
1027 */
1028 #ifndef SQLITE_OMIT_BUILTIN_TEST
1029 #define OptimizationDisabled(db, mask)  (((db)->dbOptFlags&(mask))!=0)
1030 #define OptimizationEnabled(db, mask)   (((db)->dbOptFlags&(mask))==0)
1031 #else
1032 #define OptimizationDisabled(db, mask)  0
1033 #define OptimizationEnabled(db, mask)   1
1034 #endif
1035 
1036 /*
1037 ** Possible values for the sqlite.magic field.
1038 ** The numbers are obtained at random and have no special meaning, other
1039 ** than being distinct from one another.
1040 */
1041 #define SQLITE_MAGIC_OPEN     0xa029a697  /* Database is open */
1042 #define SQLITE_MAGIC_CLOSED   0x9f3c2d33  /* Database is closed */
1043 #define SQLITE_MAGIC_SICK     0x4b771290  /* Error and awaiting close */
1044 #define SQLITE_MAGIC_BUSY     0xf03b7906  /* Database currently in use */
1045 #define SQLITE_MAGIC_ERROR    0xb5357930  /* An SQLITE_MISUSE error occurred */
1046 #define SQLITE_MAGIC_ZOMBIE   0x64cffc7f  /* Close with last statement close */
1047 
1048 /*
1049 ** Each SQL function is defined by an instance of the following
1050 ** structure.  A pointer to this structure is stored in the sqlite.aFunc
1051 ** hash table.  When multiple functions have the same name, the hash table
1052 ** points to a linked list of these structures.
1053 */
1054 struct FuncDef {
1055   i16 nArg;            /* Number of arguments.  -1 means unlimited */
1056   u8 iPrefEnc;         /* Preferred text encoding (SQLITE_UTF8, 16LE, 16BE) */
1057   u8 flags;            /* Some combination of SQLITE_FUNC_* */
1058   void *pUserData;     /* User data parameter */
1059   FuncDef *pNext;      /* Next function with same name */
1060   void (*xFunc)(sqlite3_context*,int,sqlite3_value**); /* Regular function */
1061   void (*xStep)(sqlite3_context*,int,sqlite3_value**); /* Aggregate step */
1062   void (*xFinalize)(sqlite3_context*);                /* Aggregate finalizer */
1063   char *zName;         /* SQL name of the function. */
1064   FuncDef *pHash;      /* Next with a different name but the same hash */
1065   FuncDestructor *pDestructor;   /* Reference counted destructor function */
1066 };
1067 
1068 /*
1069 ** This structure encapsulates a user-function destructor callback (as
1070 ** configured using create_function_v2()) and a reference counter. When
1071 ** create_function_v2() is called to create a function with a destructor,
1072 ** a single object of this type is allocated. FuncDestructor.nRef is set to
1073 ** the number of FuncDef objects created (either 1 or 3, depending on whether
1074 ** or not the specified encoding is SQLITE_ANY). The FuncDef.pDestructor
1075 ** member of each of the new FuncDef objects is set to point to the allocated
1076 ** FuncDestructor.
1077 **
1078 ** Thereafter, when one of the FuncDef objects is deleted, the reference
1079 ** count on this object is decremented. When it reaches 0, the destructor
1080 ** is invoked and the FuncDestructor structure freed.
1081 */
1082 struct FuncDestructor {
1083   int nRef;
1084   void (*xDestroy)(void *);
1085   void *pUserData;
1086 };
1087 
1088 /*
1089 ** Possible values for FuncDef.flags.  Note that the _LENGTH and _TYPEOF
1090 ** values must correspond to OPFLAG_LENGTHARG and OPFLAG_TYPEOFARG.  There
1091 ** are assert() statements in the code to verify this.
1092 */
1093 #define SQLITE_FUNC_LIKE     0x01 /* Candidate for the LIKE optimization */
1094 #define SQLITE_FUNC_CASE     0x02 /* Case-sensitive LIKE-type function */
1095 #define SQLITE_FUNC_EPHEM    0x04 /* Ephemeral.  Delete with VDBE */
1096 #define SQLITE_FUNC_NEEDCOLL 0x08 /* sqlite3GetFuncCollSeq() might be called */
1097 #define SQLITE_FUNC_COUNT    0x10 /* Built-in count(*) aggregate */
1098 #define SQLITE_FUNC_COALESCE 0x20 /* Built-in coalesce() or ifnull() function */
1099 #define SQLITE_FUNC_LENGTH   0x40 /* Built-in length() function */
1100 #define SQLITE_FUNC_TYPEOF   0x80 /* Built-in typeof() function */
1101 
1102 /*
1103 ** The following three macros, FUNCTION(), LIKEFUNC() and AGGREGATE() are
1104 ** used to create the initializers for the FuncDef structures.
1105 **
1106 **   FUNCTION(zName, nArg, iArg, bNC, xFunc)
1107 **     Used to create a scalar function definition of a function zName
1108 **     implemented by C function xFunc that accepts nArg arguments. The
1109 **     value passed as iArg is cast to a (void*) and made available
1110 **     as the user-data (sqlite3_user_data()) for the function. If
1111 **     argument bNC is true, then the SQLITE_FUNC_NEEDCOLL flag is set.
1112 **
1113 **   AGGREGATE(zName, nArg, iArg, bNC, xStep, xFinal)
1114 **     Used to create an aggregate function definition implemented by
1115 **     the C functions xStep and xFinal. The first four parameters
1116 **     are interpreted in the same way as the first 4 parameters to
1117 **     FUNCTION().
1118 **
1119 **   LIKEFUNC(zName, nArg, pArg, flags)
1120 **     Used to create a scalar function definition of a function zName
1121 **     that accepts nArg arguments and is implemented by a call to C
1122 **     function likeFunc. Argument pArg is cast to a (void *) and made
1123 **     available as the function user-data (sqlite3_user_data()). The
1124 **     FuncDef.flags variable is set to the value passed as the flags
1125 **     parameter.
1126 */
1127 #define FUNCTION(zName, nArg, iArg, bNC, xFunc) \
1128   {nArg, SQLITE_UTF8, (bNC*SQLITE_FUNC_NEEDCOLL), \
1129    SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, 0, #zName, 0, 0}
1130 #define FUNCTION2(zName, nArg, iArg, bNC, xFunc, extraFlags) \
1131   {nArg, SQLITE_UTF8, (bNC*SQLITE_FUNC_NEEDCOLL)|extraFlags, \
1132    SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, 0, #zName, 0, 0}
1133 #define STR_FUNCTION(zName, nArg, pArg, bNC, xFunc) \
1134   {nArg, SQLITE_UTF8, bNC*SQLITE_FUNC_NEEDCOLL, \
1135    pArg, 0, xFunc, 0, 0, #zName, 0, 0}
1136 #define LIKEFUNC(zName, nArg, arg, flags) \
1137   {nArg, SQLITE_UTF8, flags, (void *)arg, 0, likeFunc, 0, 0, #zName, 0, 0}
1138 #define AGGREGATE(zName, nArg, arg, nc, xStep, xFinal) \
1139   {nArg, SQLITE_UTF8, nc*SQLITE_FUNC_NEEDCOLL, \
1140    SQLITE_INT_TO_PTR(arg), 0, 0, xStep,xFinal,#zName,0,0}
1141 
1142 /*
1143 ** All current savepoints are stored in a linked list starting at
1144 ** sqlite3.pSavepoint. The first element in the list is the most recently
1145 ** opened savepoint. Savepoints are added to the list by the vdbe
1146 ** OP_Savepoint instruction.
1147 */
1148 struct Savepoint {
1149   char *zName;                        /* Savepoint name (nul-terminated) */
1150   i64 nDeferredCons;                  /* Number of deferred fk violations */
1151   Savepoint *pNext;                   /* Parent savepoint (if any) */
1152 };
1153 
1154 /*
1155 ** The following are used as the second parameter to sqlite3Savepoint(),
1156 ** and as the P1 argument to the OP_Savepoint instruction.
1157 */
1158 #define SAVEPOINT_BEGIN      0
1159 #define SAVEPOINT_RELEASE    1
1160 #define SAVEPOINT_ROLLBACK   2
1161 
1162 
1163 /*
1164 ** Each SQLite module (virtual table definition) is defined by an
1165 ** instance of the following structure, stored in the sqlite3.aModule
1166 ** hash table.
1167 */
1168 struct Module {
1169   const sqlite3_module *pModule;       /* Callback pointers */
1170   const char *zName;                   /* Name passed to create_module() */
1171   void *pAux;                          /* pAux passed to create_module() */
1172   void (*xDestroy)(void *);            /* Module destructor function */
1173 };
1174 
1175 /*
1176 ** information about each column of an SQL table is held in an instance
1177 ** of this structure.
1178 */
1179 struct Column {
1180   char *zName;     /* Name of this column */
1181   Expr *pDflt;     /* Default value of this column */
1182   char *zDflt;     /* Original text of the default value */
1183   char *zType;     /* Data type for this column */
1184   char *zColl;     /* Collating sequence.  If NULL, use the default */
1185   u8 notNull;      /* An OE_ code for handling a NOT NULL constraint */
1186   char affinity;   /* One of the SQLITE_AFF_... values */
1187   u16 colFlags;    /* Boolean properties.  See COLFLAG_ defines below */
1188 };
1189 
1190 /* Allowed values for Column.colFlags:
1191 */
1192 #define COLFLAG_PRIMKEY  0x0001    /* Column is part of the primary key */
1193 #define COLFLAG_HIDDEN   0x0002    /* A hidden column in a virtual table */
1194 
1195 /*
1196 ** A "Collating Sequence" is defined by an instance of the following
1197 ** structure. Conceptually, a collating sequence consists of a name and
1198 ** a comparison routine that defines the order of that sequence.
1199 **
1200 ** If CollSeq.xCmp is NULL, it means that the
1201 ** collating sequence is undefined.  Indices built on an undefined
1202 ** collating sequence may not be read or written.
1203 */
1204 struct CollSeq {
1205   char *zName;          /* Name of the collating sequence, UTF-8 encoded */
1206   u8 enc;               /* Text encoding handled by xCmp() */
1207   void *pUser;          /* First argument to xCmp() */
1208   int (*xCmp)(void*,int, const void*, int, const void*);
1209   void (*xDel)(void*);  /* Destructor for pUser */
1210 };
1211 
1212 /*
1213 ** A sort order can be either ASC or DESC.
1214 */
1215 #define SQLITE_SO_ASC       0  /* Sort in ascending order */
1216 #define SQLITE_SO_DESC      1  /* Sort in ascending order */
1217 
1218 /*
1219 ** Column affinity types.
1220 **
1221 ** These used to have mnemonic name like 'i' for SQLITE_AFF_INTEGER and
1222 ** 't' for SQLITE_AFF_TEXT.  But we can save a little space and improve
1223 ** the speed a little by numbering the values consecutively.
1224 **
1225 ** But rather than start with 0 or 1, we begin with 'a'.  That way,
1226 ** when multiple affinity types are concatenated into a string and
1227 ** used as the P4 operand, they will be more readable.
1228 **
1229 ** Note also that the numeric types are grouped together so that testing
1230 ** for a numeric type is a single comparison.
1231 */
1232 #define SQLITE_AFF_TEXT     'a'
1233 #define SQLITE_AFF_NONE     'b'
1234 #define SQLITE_AFF_NUMERIC  'c'
1235 #define SQLITE_AFF_INTEGER  'd'
1236 #define SQLITE_AFF_REAL     'e'
1237 
1238 #define sqlite3IsNumericAffinity(X)  ((X)>=SQLITE_AFF_NUMERIC)
1239 
1240 /*
1241 ** The SQLITE_AFF_MASK values masks off the significant bits of an
1242 ** affinity value.
1243 */
1244 #define SQLITE_AFF_MASK     0x67
1245 
1246 /*
1247 ** Additional bit values that can be ORed with an affinity without
1248 ** changing the affinity.
1249 */
1250 #define SQLITE_JUMPIFNULL   0x08  /* jumps if either operand is NULL */
1251 #define SQLITE_STOREP2      0x10  /* Store result in reg[P2] rather than jump */
1252 #define SQLITE_NULLEQ       0x80  /* NULL=NULL */
1253 
1254 /*
1255 ** An object of this type is created for each virtual table present in
1256 ** the database schema.
1257 **
1258 ** If the database schema is shared, then there is one instance of this
1259 ** structure for each database connection (sqlite3*) that uses the shared
1260 ** schema. This is because each database connection requires its own unique
1261 ** instance of the sqlite3_vtab* handle used to access the virtual table
1262 ** implementation. sqlite3_vtab* handles can not be shared between
1263 ** database connections, even when the rest of the in-memory database
1264 ** schema is shared, as the implementation often stores the database
1265 ** connection handle passed to it via the xConnect() or xCreate() method
1266 ** during initialization internally. This database connection handle may
1267 ** then be used by the virtual table implementation to access real tables
1268 ** within the database. So that they appear as part of the callers
1269 ** transaction, these accesses need to be made via the same database
1270 ** connection as that used to execute SQL operations on the virtual table.
1271 **
1272 ** All VTable objects that correspond to a single table in a shared
1273 ** database schema are initially stored in a linked-list pointed to by
1274 ** the Table.pVTable member variable of the corresponding Table object.
1275 ** When an sqlite3_prepare() operation is required to access the virtual
1276 ** table, it searches the list for the VTable that corresponds to the
1277 ** database connection doing the preparing so as to use the correct
1278 ** sqlite3_vtab* handle in the compiled query.
1279 **
1280 ** When an in-memory Table object is deleted (for example when the
1281 ** schema is being reloaded for some reason), the VTable objects are not
1282 ** deleted and the sqlite3_vtab* handles are not xDisconnect()ed
1283 ** immediately. Instead, they are moved from the Table.pVTable list to
1284 ** another linked list headed by the sqlite3.pDisconnect member of the
1285 ** corresponding sqlite3 structure. They are then deleted/xDisconnected
1286 ** next time a statement is prepared using said sqlite3*. This is done
1287 ** to avoid deadlock issues involving multiple sqlite3.mutex mutexes.
1288 ** Refer to comments above function sqlite3VtabUnlockList() for an
1289 ** explanation as to why it is safe to add an entry to an sqlite3.pDisconnect
1290 ** list without holding the corresponding sqlite3.mutex mutex.
1291 **
1292 ** The memory for objects of this type is always allocated by
1293 ** sqlite3DbMalloc(), using the connection handle stored in VTable.db as
1294 ** the first argument.
1295 */
1296 struct VTable {
1297   sqlite3 *db;              /* Database connection associated with this table */
1298   Module *pMod;             /* Pointer to module implementation */
1299   sqlite3_vtab *pVtab;      /* Pointer to vtab instance */
1300   int nRef;                 /* Number of pointers to this structure */
1301   u8 bConstraint;           /* True if constraints are supported */
1302   int iSavepoint;           /* Depth of the SAVEPOINT stack */
1303   VTable *pNext;            /* Next in linked list (see above) */
1304 };
1305 
1306 /*
1307 ** Each SQL table is represented in memory by an instance of the
1308 ** following structure.
1309 **
1310 ** Table.zName is the name of the table.  The case of the original
1311 ** CREATE TABLE statement is stored, but case is not significant for
1312 ** comparisons.
1313 **
1314 ** Table.nCol is the number of columns in this table.  Table.aCol is a
1315 ** pointer to an array of Column structures, one for each column.
1316 **
1317 ** If the table has an INTEGER PRIMARY KEY, then Table.iPKey is the index of
1318 ** the column that is that key.   Otherwise Table.iPKey is negative.  Note
1319 ** that the datatype of the PRIMARY KEY must be INTEGER for this field to
1320 ** be set.  An INTEGER PRIMARY KEY is used as the rowid for each row of
1321 ** the table.  If a table has no INTEGER PRIMARY KEY, then a random rowid
1322 ** is generated for each row of the table.  TF_HasPrimaryKey is set if
1323 ** the table has any PRIMARY KEY, INTEGER or otherwise.
1324 **
1325 ** Table.tnum is the page number for the root BTree page of the table in the
1326 ** database file.  If Table.iDb is the index of the database table backend
1327 ** in sqlite.aDb[].  0 is for the main database and 1 is for the file that
1328 ** holds temporary tables and indices.  If TF_Ephemeral is set
1329 ** then the table is stored in a file that is automatically deleted
1330 ** when the VDBE cursor to the table is closed.  In this case Table.tnum
1331 ** refers VDBE cursor number that holds the table open, not to the root
1332 ** page number.  Transient tables are used to hold the results of a
1333 ** sub-query that appears instead of a real table name in the FROM clause
1334 ** of a SELECT statement.
1335 */
1336 struct Table {
1337   char *zName;         /* Name of the table or view */
1338   Column *aCol;        /* Information about each column */
1339   Index *pIndex;       /* List of SQL indexes on this table. */
1340   Select *pSelect;     /* NULL for tables.  Points to definition if a view. */
1341   FKey *pFKey;         /* Linked list of all foreign keys in this table */
1342   char *zColAff;       /* String defining the affinity of each column */
1343 #ifndef SQLITE_OMIT_CHECK
1344   ExprList *pCheck;    /* All CHECK constraints */
1345 #endif
1346   tRowcnt nRowEst;     /* Estimated rows in table - from sqlite_stat1 table */
1347   int tnum;            /* Root BTree node for this table (see note above) */
1348   i16 iPKey;           /* If not negative, use aCol[iPKey] as the primary key */
1349   i16 nCol;            /* Number of columns in this table */
1350   u16 nRef;            /* Number of pointers to this Table */
1351   u8 tabFlags;         /* Mask of TF_* values */
1352   u8 keyConf;          /* What to do in case of uniqueness conflict on iPKey */
1353 #ifndef SQLITE_OMIT_ALTERTABLE
1354   int addColOffset;    /* Offset in CREATE TABLE stmt to add a new column */
1355 #endif
1356 #ifndef SQLITE_OMIT_VIRTUALTABLE
1357   int nModuleArg;      /* Number of arguments to the module */
1358   char **azModuleArg;  /* Text of all module args. [0] is module name */
1359   VTable *pVTable;     /* List of VTable objects. */
1360 #endif
1361   Trigger *pTrigger;   /* List of triggers stored in pSchema */
1362   Schema *pSchema;     /* Schema that contains this table */
1363   Table *pNextZombie;  /* Next on the Parse.pZombieTab list */
1364 };
1365 
1366 /*
1367 ** Allowed values for Tabe.tabFlags.
1368 */
1369 #define TF_Readonly        0x01    /* Read-only system table */
1370 #define TF_Ephemeral       0x02    /* An ephemeral table */
1371 #define TF_HasPrimaryKey   0x04    /* Table has a primary key */
1372 #define TF_Autoincrement   0x08    /* Integer primary key is autoincrement */
1373 #define TF_Virtual         0x10    /* Is a virtual table */
1374 
1375 
1376 /*
1377 ** Test to see whether or not a table is a virtual table.  This is
1378 ** done as a macro so that it will be optimized out when virtual
1379 ** table support is omitted from the build.
1380 */
1381 #ifndef SQLITE_OMIT_VIRTUALTABLE
1382 #  define IsVirtual(X)      (((X)->tabFlags & TF_Virtual)!=0)
1383 #  define IsHiddenColumn(X) (((X)->colFlags & COLFLAG_HIDDEN)!=0)
1384 #else
1385 #  define IsVirtual(X)      0
1386 #  define IsHiddenColumn(X) 0
1387 #endif
1388 
1389 /*
1390 ** Each foreign key constraint is an instance of the following structure.
1391 **
1392 ** A foreign key is associated with two tables.  The "from" table is
1393 ** the table that contains the REFERENCES clause that creates the foreign
1394 ** key.  The "to" table is the table that is named in the REFERENCES clause.
1395 ** Consider this example:
1396 **
1397 **     CREATE TABLE ex1(
1398 **       a INTEGER PRIMARY KEY,
1399 **       b INTEGER CONSTRAINT fk1 REFERENCES ex2(x)
1400 **     );
1401 **
1402 ** For foreign key "fk1", the from-table is "ex1" and the to-table is "ex2".
1403 **
1404 ** Each REFERENCES clause generates an instance of the following structure
1405 ** which is attached to the from-table.  The to-table need not exist when
1406 ** the from-table is created.  The existence of the to-table is not checked.
1407 */
1408 struct FKey {
1409   Table *pFrom;     /* Table containing the REFERENCES clause (aka: Child) */
1410   FKey *pNextFrom;  /* Next foreign key in pFrom */
1411   char *zTo;        /* Name of table that the key points to (aka: Parent) */
1412   FKey *pNextTo;    /* Next foreign key on table named zTo */
1413   FKey *pPrevTo;    /* Previous foreign key on table named zTo */
1414   int nCol;         /* Number of columns in this key */
1415   /* EV: R-30323-21917 */
1416   u8 isDeferred;    /* True if constraint checking is deferred till COMMIT */
1417   u8 aAction[2];          /* ON DELETE and ON UPDATE actions, respectively */
1418   Trigger *apTrigger[2];  /* Triggers for aAction[] actions */
1419   struct sColMap {  /* Mapping of columns in pFrom to columns in zTo */
1420     int iFrom;         /* Index of column in pFrom */
1421     char *zCol;        /* Name of column in zTo.  If 0 use PRIMARY KEY */
1422   } aCol[1];        /* One entry for each of nCol column s */
1423 };
1424 
1425 /*
1426 ** SQLite supports many different ways to resolve a constraint
1427 ** error.  ROLLBACK processing means that a constraint violation
1428 ** causes the operation in process to fail and for the current transaction
1429 ** to be rolled back.  ABORT processing means the operation in process
1430 ** fails and any prior changes from that one operation are backed out,
1431 ** but the transaction is not rolled back.  FAIL processing means that
1432 ** the operation in progress stops and returns an error code.  But prior
1433 ** changes due to the same operation are not backed out and no rollback
1434 ** occurs.  IGNORE means that the particular row that caused the constraint
1435 ** error is not inserted or updated.  Processing continues and no error
1436 ** is returned.  REPLACE means that preexisting database rows that caused
1437 ** a UNIQUE constraint violation are removed so that the new insert or
1438 ** update can proceed.  Processing continues and no error is reported.
1439 **
1440 ** RESTRICT, SETNULL, and CASCADE actions apply only to foreign keys.
1441 ** RESTRICT is the same as ABORT for IMMEDIATE foreign keys and the
1442 ** same as ROLLBACK for DEFERRED keys.  SETNULL means that the foreign
1443 ** key is set to NULL.  CASCADE means that a DELETE or UPDATE of the
1444 ** referenced table row is propagated into the row that holds the
1445 ** foreign key.
1446 **
1447 ** The following symbolic values are used to record which type
1448 ** of action to take.
1449 */
1450 #define OE_None     0   /* There is no constraint to check */
1451 #define OE_Rollback 1   /* Fail the operation and rollback the transaction */
1452 #define OE_Abort    2   /* Back out changes but do no rollback transaction */
1453 #define OE_Fail     3   /* Stop the operation but leave all prior changes */
1454 #define OE_Ignore   4   /* Ignore the error. Do not do the INSERT or UPDATE */
1455 #define OE_Replace  5   /* Delete existing record, then do INSERT or UPDATE */
1456 
1457 #define OE_Restrict 6   /* OE_Abort for IMMEDIATE, OE_Rollback for DEFERRED */
1458 #define OE_SetNull  7   /* Set the foreign key value to NULL */
1459 #define OE_SetDflt  8   /* Set the foreign key value to its default */
1460 #define OE_Cascade  9   /* Cascade the changes */
1461 
1462 #define OE_Default  99  /* Do whatever the default action is */
1463 
1464 
1465 /*
1466 ** An instance of the following structure is passed as the first
1467 ** argument to sqlite3VdbeKeyCompare and is used to control the
1468 ** comparison of the two index keys.
1469 */
1470 struct KeyInfo {
1471   sqlite3 *db;        /* The database connection */
1472   u8 enc;             /* Text encoding - one of the SQLITE_UTF* values */
1473   u16 nField;         /* Number of entries in aColl[] */
1474   u8 *aSortOrder;     /* Sort order for each column.  May be NULL */
1475   CollSeq *aColl[1];  /* Collating sequence for each term of the key */
1476 };
1477 
1478 /*
1479 ** An instance of the following structure holds information about a
1480 ** single index record that has already been parsed out into individual
1481 ** values.
1482 **
1483 ** A record is an object that contains one or more fields of data.
1484 ** Records are used to store the content of a table row and to store
1485 ** the key of an index.  A blob encoding of a record is created by
1486 ** the OP_MakeRecord opcode of the VDBE and is disassembled by the
1487 ** OP_Column opcode.
1488 **
1489 ** This structure holds a record that has already been disassembled
1490 ** into its constituent fields.
1491 */
1492 struct UnpackedRecord {
1493   KeyInfo *pKeyInfo;  /* Collation and sort-order information */
1494   u16 nField;         /* Number of entries in apMem[] */
1495   u8 flags;           /* Boolean settings.  UNPACKED_... below */
1496   i64 rowid;          /* Used by UNPACKED_PREFIX_SEARCH */
1497   Mem *aMem;          /* Values */
1498 };
1499 
1500 /*
1501 ** Allowed values of UnpackedRecord.flags
1502 */
1503 #define UNPACKED_INCRKEY       0x01  /* Make this key an epsilon larger */
1504 #define UNPACKED_PREFIX_MATCH  0x02  /* A prefix match is considered OK */
1505 #define UNPACKED_PREFIX_SEARCH 0x04  /* Ignore final (rowid) field */
1506 
1507 /*
1508 ** Each SQL index is represented in memory by an
1509 ** instance of the following structure.
1510 **
1511 ** The columns of the table that are to be indexed are described
1512 ** by the aiColumn[] field of this structure.  For example, suppose
1513 ** we have the following table and index:
1514 **
1515 **     CREATE TABLE Ex1(c1 int, c2 int, c3 text);
1516 **     CREATE INDEX Ex2 ON Ex1(c3,c1);
1517 **
1518 ** In the Table structure describing Ex1, nCol==3 because there are
1519 ** three columns in the table.  In the Index structure describing
1520 ** Ex2, nColumn==2 since 2 of the 3 columns of Ex1 are indexed.
1521 ** The value of aiColumn is {2, 0}.  aiColumn[0]==2 because the
1522 ** first column to be indexed (c3) has an index of 2 in Ex1.aCol[].
1523 ** The second column to be indexed (c1) has an index of 0 in
1524 ** Ex1.aCol[], hence Ex2.aiColumn[1]==0.
1525 **
1526 ** The Index.onError field determines whether or not the indexed columns
1527 ** must be unique and what to do if they are not.  When Index.onError=OE_None,
1528 ** it means this is not a unique index.  Otherwise it is a unique index
1529 ** and the value of Index.onError indicate the which conflict resolution
1530 ** algorithm to employ whenever an attempt is made to insert a non-unique
1531 ** element.
1532 */
1533 struct Index {
1534   char *zName;             /* Name of this index */
1535   int *aiColumn;           /* Which columns are used by this index.  1st is 0 */
1536   tRowcnt *aiRowEst;       /* From ANALYZE: Est. rows selected by each column */
1537   Table *pTable;           /* The SQL table being indexed */
1538   char *zColAff;           /* String defining the affinity of each column */
1539   Index *pNext;            /* The next index associated with the same table */
1540   Schema *pSchema;         /* Schema containing this index */
1541   u8 *aSortOrder;          /* for each column: True==DESC, False==ASC */
1542   char **azColl;           /* Array of collation sequence names for index */
1543   int tnum;                /* DB Page containing root of this index */
1544   u16 nColumn;             /* Number of columns in table used by this index */
1545   u8 onError;              /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
1546   unsigned autoIndex:2;    /* 1==UNIQUE, 2==PRIMARY KEY, 0==CREATE INDEX */
1547   unsigned bUnordered:1;   /* Use this index for == or IN queries only */
1548 #ifdef SQLITE_ENABLE_STAT3
1549   int nSample;             /* Number of elements in aSample[] */
1550   tRowcnt avgEq;           /* Average nEq value for key values not in aSample */
1551   IndexSample *aSample;    /* Samples of the left-most key */
1552 #endif
1553 };
1554 
1555 /*
1556 ** Each sample stored in the sqlite_stat3 table is represented in memory
1557 ** using a structure of this type.  See documentation at the top of the
1558 ** analyze.c source file for additional information.
1559 */
1560 struct IndexSample {
1561   union {
1562     char *z;        /* Value if eType is SQLITE_TEXT or SQLITE_BLOB */
1563     double r;       /* Value if eType is SQLITE_FLOAT */
1564     i64 i;          /* Value if eType is SQLITE_INTEGER */
1565   } u;
1566   u8 eType;         /* SQLITE_NULL, SQLITE_INTEGER ... etc. */
1567   int nByte;        /* Size in byte of text or blob. */
1568   tRowcnt nEq;      /* Est. number of rows where the key equals this sample */
1569   tRowcnt nLt;      /* Est. number of rows where key is less than this sample */
1570   tRowcnt nDLt;     /* Est. number of distinct keys less than this sample */
1571 };
1572 
1573 /*
1574 ** Each token coming out of the lexer is an instance of
1575 ** this structure.  Tokens are also used as part of an expression.
1576 **
1577 ** Note if Token.z==0 then Token.dyn and Token.n are undefined and
1578 ** may contain random values.  Do not make any assumptions about Token.dyn
1579 ** and Token.n when Token.z==0.
1580 */
1581 struct Token {
1582   const char *z;     /* Text of the token.  Not NULL-terminated! */
1583   unsigned int n;    /* Number of characters in this token */
1584 };
1585 
1586 /*
1587 ** An instance of this structure contains information needed to generate
1588 ** code for a SELECT that contains aggregate functions.
1589 **
1590 ** If Expr.op==TK_AGG_COLUMN or TK_AGG_FUNCTION then Expr.pAggInfo is a
1591 ** pointer to this structure.  The Expr.iColumn field is the index in
1592 ** AggInfo.aCol[] or AggInfo.aFunc[] of information needed to generate
1593 ** code for that node.
1594 **
1595 ** AggInfo.pGroupBy and AggInfo.aFunc.pExpr point to fields within the
1596 ** original Select structure that describes the SELECT statement.  These
1597 ** fields do not need to be freed when deallocating the AggInfo structure.
1598 */
1599 struct AggInfo {
1600   u8 directMode;          /* Direct rendering mode means take data directly
1601                           ** from source tables rather than from accumulators */
1602   u8 useSortingIdx;       /* In direct mode, reference the sorting index rather
1603                           ** than the source table */
1604   int sortingIdx;         /* Cursor number of the sorting index */
1605   int sortingIdxPTab;     /* Cursor number of pseudo-table */
1606   int nSortingColumn;     /* Number of columns in the sorting index */
1607   ExprList *pGroupBy;     /* The group by clause */
1608   struct AggInfo_col {    /* For each column used in source tables */
1609     Table *pTab;             /* Source table */
1610     int iTable;              /* Cursor number of the source table */
1611     int iColumn;             /* Column number within the source table */
1612     int iSorterColumn;       /* Column number in the sorting index */
1613     int iMem;                /* Memory location that acts as accumulator */
1614     Expr *pExpr;             /* The original expression */
1615   } *aCol;
1616   int nColumn;            /* Number of used entries in aCol[] */
1617   int nAccumulator;       /* Number of columns that show through to the output.
1618                           ** Additional columns are used only as parameters to
1619                           ** aggregate functions */
1620   struct AggInfo_func {   /* For each aggregate function */
1621     Expr *pExpr;             /* Expression encoding the function */
1622     FuncDef *pFunc;          /* The aggregate function implementation */
1623     int iMem;                /* Memory location that acts as accumulator */
1624     int iDistinct;           /* Ephemeral table used to enforce DISTINCT */
1625   } *aFunc;
1626   int nFunc;              /* Number of entries in aFunc[] */
1627 };
1628 
1629 /*
1630 ** The datatype ynVar is a signed integer, either 16-bit or 32-bit.
1631 ** Usually it is 16-bits.  But if SQLITE_MAX_VARIABLE_NUMBER is greater
1632 ** than 32767 we have to make it 32-bit.  16-bit is preferred because
1633 ** it uses less memory in the Expr object, which is a big memory user
1634 ** in systems with lots of prepared statements.  And few applications
1635 ** need more than about 10 or 20 variables.  But some extreme users want
1636 ** to have prepared statements with over 32767 variables, and for them
1637 ** the option is available (at compile-time).
1638 */
1639 #if SQLITE_MAX_VARIABLE_NUMBER<=32767
1640 typedef i16 ynVar;
1641 #else
1642 typedef int ynVar;
1643 #endif
1644 
1645 /*
1646 ** Each node of an expression in the parse tree is an instance
1647 ** of this structure.
1648 **
1649 ** Expr.op is the opcode. The integer parser token codes are reused
1650 ** as opcodes here. For example, the parser defines TK_GE to be an integer
1651 ** code representing the ">=" operator. This same integer code is reused
1652 ** to represent the greater-than-or-equal-to operator in the expression
1653 ** tree.
1654 **
1655 ** If the expression is an SQL literal (TK_INTEGER, TK_FLOAT, TK_BLOB,
1656 ** or TK_STRING), then Expr.token contains the text of the SQL literal. If
1657 ** the expression is a variable (TK_VARIABLE), then Expr.token contains the
1658 ** variable name. Finally, if the expression is an SQL function (TK_FUNCTION),
1659 ** then Expr.token contains the name of the function.
1660 **
1661 ** Expr.pRight and Expr.pLeft are the left and right subexpressions of a
1662 ** binary operator. Either or both may be NULL.
1663 **
1664 ** Expr.x.pList is a list of arguments if the expression is an SQL function,
1665 ** a CASE expression or an IN expression of the form "<lhs> IN (<y>, <z>...)".
1666 ** Expr.x.pSelect is used if the expression is a sub-select or an expression of
1667 ** the form "<lhs> IN (SELECT ...)". If the EP_xIsSelect bit is set in the
1668 ** Expr.flags mask, then Expr.x.pSelect is valid. Otherwise, Expr.x.pList is
1669 ** valid.
1670 **
1671 ** An expression of the form ID or ID.ID refers to a column in a table.
1672 ** For such expressions, Expr.op is set to TK_COLUMN and Expr.iTable is
1673 ** the integer cursor number of a VDBE cursor pointing to that table and
1674 ** Expr.iColumn is the column number for the specific column.  If the
1675 ** expression is used as a result in an aggregate SELECT, then the
1676 ** value is also stored in the Expr.iAgg column in the aggregate so that
1677 ** it can be accessed after all aggregates are computed.
1678 **
1679 ** If the expression is an unbound variable marker (a question mark
1680 ** character '?' in the original SQL) then the Expr.iTable holds the index
1681 ** number for that variable.
1682 **
1683 ** If the expression is a subquery then Expr.iColumn holds an integer
1684 ** register number containing the result of the subquery.  If the
1685 ** subquery gives a constant result, then iTable is -1.  If the subquery
1686 ** gives a different answer at different times during statement processing
1687 ** then iTable is the address of a subroutine that computes the subquery.
1688 **
1689 ** If the Expr is of type OP_Column, and the table it is selecting from
1690 ** is a disk table or the "old.*" pseudo-table, then pTab points to the
1691 ** corresponding table definition.
1692 **
1693 ** ALLOCATION NOTES:
1694 **
1695 ** Expr objects can use a lot of memory space in database schema.  To
1696 ** help reduce memory requirements, sometimes an Expr object will be
1697 ** truncated.  And to reduce the number of memory allocations, sometimes
1698 ** two or more Expr objects will be stored in a single memory allocation,
1699 ** together with Expr.zToken strings.
1700 **
1701 ** If the EP_Reduced and EP_TokenOnly flags are set when
1702 ** an Expr object is truncated.  When EP_Reduced is set, then all
1703 ** the child Expr objects in the Expr.pLeft and Expr.pRight subtrees
1704 ** are contained within the same memory allocation.  Note, however, that
1705 ** the subtrees in Expr.x.pList or Expr.x.pSelect are always separately
1706 ** allocated, regardless of whether or not EP_Reduced is set.
1707 */
1708 struct Expr {
1709   u8 op;                 /* Operation performed by this node */
1710   char affinity;         /* The affinity of the column or 0 if not a column */
1711   u16 flags;             /* Various flags.  EP_* See below */
1712   union {
1713     char *zToken;          /* Token value. Zero terminated and dequoted */
1714     int iValue;            /* Non-negative integer value if EP_IntValue */
1715   } u;
1716 
1717   /* If the EP_TokenOnly flag is set in the Expr.flags mask, then no
1718   ** space is allocated for the fields below this point. An attempt to
1719   ** access them will result in a segfault or malfunction.
1720   *********************************************************************/
1721 
1722   Expr *pLeft;           /* Left subnode */
1723   Expr *pRight;          /* Right subnode */
1724   union {
1725     ExprList *pList;     /* Function arguments or in "<expr> IN (<expr-list)" */
1726     Select *pSelect;     /* Used for sub-selects and "<expr> IN (<select>)" */
1727   } x;
1728 
1729   /* If the EP_Reduced flag is set in the Expr.flags mask, then no
1730   ** space is allocated for the fields below this point. An attempt to
1731   ** access them will result in a segfault or malfunction.
1732   *********************************************************************/
1733 
1734 #if SQLITE_MAX_EXPR_DEPTH>0
1735   int nHeight;           /* Height of the tree headed by this node */
1736 #endif
1737   int iTable;            /* TK_COLUMN: cursor number of table holding column
1738                          ** TK_REGISTER: register number
1739                          ** TK_TRIGGER: 1 -> new, 0 -> old */
1740   ynVar iColumn;         /* TK_COLUMN: column index.  -1 for rowid.
1741                          ** TK_VARIABLE: variable number (always >= 1). */
1742   i16 iAgg;              /* Which entry in pAggInfo->aCol[] or ->aFunc[] */
1743   i16 iRightJoinTable;   /* If EP_FromJoin, the right table of the join */
1744   u8 flags2;             /* Second set of flags.  EP2_... */
1745   u8 op2;                /* TK_REGISTER: original value of Expr.op
1746                          ** TK_COLUMN: the value of p5 for OP_Column
1747                          ** TK_AGG_FUNCTION: nesting depth */
1748   AggInfo *pAggInfo;     /* Used by TK_AGG_COLUMN and TK_AGG_FUNCTION */
1749   Table *pTab;           /* Table for TK_COLUMN expressions. */
1750 };
1751 
1752 /*
1753 ** The following are the meanings of bits in the Expr.flags field.
1754 */
1755 #define EP_FromJoin   0x0001  /* Originated in ON or USING clause of a join */
1756 #define EP_Agg        0x0002  /* Contains one or more aggregate functions */
1757 #define EP_Resolved   0x0004  /* IDs have been resolved to COLUMNs */
1758 #define EP_Error      0x0008  /* Expression contains one or more errors */
1759 #define EP_Distinct   0x0010  /* Aggregate function with DISTINCT keyword */
1760 #define EP_VarSelect  0x0020  /* pSelect is correlated, not constant */
1761 #define EP_DblQuoted  0x0040  /* token.z was originally in "..." */
1762 #define EP_InfixFunc  0x0080  /* True for an infix function: LIKE, GLOB, etc */
1763 #define EP_Collate    0x0100  /* Tree contains a TK_COLLATE opeartor */
1764 #define EP_FixedDest  0x0200  /* Result needed in a specific register */
1765 #define EP_IntValue   0x0400  /* Integer value contained in u.iValue */
1766 #define EP_xIsSelect  0x0800  /* x.pSelect is valid (otherwise x.pList is) */
1767 #define EP_Hint       0x1000  /* Not used */
1768 #define EP_Reduced    0x2000  /* Expr struct is EXPR_REDUCEDSIZE bytes only */
1769 #define EP_TokenOnly  0x4000  /* Expr struct is EXPR_TOKENONLYSIZE bytes only */
1770 #define EP_Static     0x8000  /* Held in memory not obtained from malloc() */
1771 
1772 /*
1773 ** The following are the meanings of bits in the Expr.flags2 field.
1774 */
1775 #define EP2_MallocedToken  0x0001  /* Need to sqlite3DbFree() Expr.zToken */
1776 #define EP2_Irreducible    0x0002  /* Cannot EXPRDUP_REDUCE this Expr */
1777 
1778 /*
1779 ** The pseudo-routine sqlite3ExprSetIrreducible sets the EP2_Irreducible
1780 ** flag on an expression structure.  This flag is used for VV&A only.  The
1781 ** routine is implemented as a macro that only works when in debugging mode,
1782 ** so as not to burden production code.
1783 */
1784 #ifdef SQLITE_DEBUG
1785 # define ExprSetIrreducible(X)  (X)->flags2 |= EP2_Irreducible
1786 #else
1787 # define ExprSetIrreducible(X)
1788 #endif
1789 
1790 /*
1791 ** These macros can be used to test, set, or clear bits in the
1792 ** Expr.flags field.
1793 */
1794 #define ExprHasProperty(E,P)     (((E)->flags&(P))==(P))
1795 #define ExprHasAnyProperty(E,P)  (((E)->flags&(P))!=0)
1796 #define ExprSetProperty(E,P)     (E)->flags|=(P)
1797 #define ExprClearProperty(E,P)   (E)->flags&=~(P)
1798 
1799 /*
1800 ** Macros to determine the number of bytes required by a normal Expr
1801 ** struct, an Expr struct with the EP_Reduced flag set in Expr.flags
1802 ** and an Expr struct with the EP_TokenOnly flag set.
1803 */
1804 #define EXPR_FULLSIZE           sizeof(Expr)           /* Full size */
1805 #define EXPR_REDUCEDSIZE        offsetof(Expr,iTable)  /* Common features */
1806 #define EXPR_TOKENONLYSIZE      offsetof(Expr,pLeft)   /* Fewer features */
1807 
1808 /*
1809 ** Flags passed to the sqlite3ExprDup() function. See the header comment
1810 ** above sqlite3ExprDup() for details.
1811 */
1812 #define EXPRDUP_REDUCE         0x0001  /* Used reduced-size Expr nodes */
1813 
1814 /*
1815 ** A list of expressions.  Each expression may optionally have a
1816 ** name.  An expr/name combination can be used in several ways, such
1817 ** as the list of "expr AS ID" fields following a "SELECT" or in the
1818 ** list of "ID = expr" items in an UPDATE.  A list of expressions can
1819 ** also be used as the argument to a function, in which case the a.zName
1820 ** field is not used.
1821 **
1822 ** By default the Expr.zSpan field holds a human-readable description of
1823 ** the expression that is used in the generation of error messages and
1824 ** column labels.  In this case, Expr.zSpan is typically the text of a
1825 ** column expression as it exists in a SELECT statement.  However, if
1826 ** the bSpanIsTab flag is set, then zSpan is overloaded to mean the name
1827 ** of the result column in the form: DATABASE.TABLE.COLUMN.  This later
1828 ** form is used for name resolution with nested FROM clauses.
1829 */
1830 struct ExprList {
1831   int nExpr;             /* Number of expressions on the list */
1832   int iECursor;          /* VDBE Cursor associated with this ExprList */
1833   struct ExprList_item { /* For each expression in the list */
1834     Expr *pExpr;            /* The list of expressions */
1835     char *zName;            /* Token associated with this expression */
1836     char *zSpan;            /* Original text of the expression */
1837     u8 sortOrder;           /* 1 for DESC or 0 for ASC */
1838     unsigned done :1;       /* A flag to indicate when processing is finished */
1839     unsigned bSpanIsTab :1; /* zSpan holds DB.TABLE.COLUMN */
1840     u16 iOrderByCol;        /* For ORDER BY, column number in result set */
1841     u16 iAlias;             /* Index into Parse.aAlias[] for zName */
1842   } *a;                  /* Alloc a power of two greater or equal to nExpr */
1843 };
1844 
1845 /*
1846 ** An instance of this structure is used by the parser to record both
1847 ** the parse tree for an expression and the span of input text for an
1848 ** expression.
1849 */
1850 struct ExprSpan {
1851   Expr *pExpr;          /* The expression parse tree */
1852   const char *zStart;   /* First character of input text */
1853   const char *zEnd;     /* One character past the end of input text */
1854 };
1855 
1856 /*
1857 ** An instance of this structure can hold a simple list of identifiers,
1858 ** such as the list "a,b,c" in the following statements:
1859 **
1860 **      INSERT INTO t(a,b,c) VALUES ...;
1861 **      CREATE INDEX idx ON t(a,b,c);
1862 **      CREATE TRIGGER trig BEFORE UPDATE ON t(a,b,c) ...;
1863 **
1864 ** The IdList.a.idx field is used when the IdList represents the list of
1865 ** column names after a table name in an INSERT statement.  In the statement
1866 **
1867 **     INSERT INTO t(a,b,c) ...
1868 **
1869 ** If "a" is the k-th column of table "t", then IdList.a[0].idx==k.
1870 */
1871 struct IdList {
1872   struct IdList_item {
1873     char *zName;      /* Name of the identifier */
1874     int idx;          /* Index in some Table.aCol[] of a column named zName */
1875   } *a;
1876   int nId;         /* Number of identifiers on the list */
1877 };
1878 
1879 /*
1880 ** The bitmask datatype defined below is used for various optimizations.
1881 **
1882 ** Changing this from a 64-bit to a 32-bit type limits the number of
1883 ** tables in a join to 32 instead of 64.  But it also reduces the size
1884 ** of the library by 738 bytes on ix86.
1885 */
1886 typedef u64 Bitmask;
1887 
1888 /*
1889 ** The number of bits in a Bitmask.  "BMS" means "BitMask Size".
1890 */
1891 #define BMS  ((int)(sizeof(Bitmask)*8))
1892 
1893 /*
1894 ** The following structure describes the FROM clause of a SELECT statement.
1895 ** Each table or subquery in the FROM clause is a separate element of
1896 ** the SrcList.a[] array.
1897 **
1898 ** With the addition of multiple database support, the following structure
1899 ** can also be used to describe a particular table such as the table that
1900 ** is modified by an INSERT, DELETE, or UPDATE statement.  In standard SQL,
1901 ** such a table must be a simple name: ID.  But in SQLite, the table can
1902 ** now be identified by a database name, a dot, then the table name: ID.ID.
1903 **
1904 ** The jointype starts out showing the join type between the current table
1905 ** and the next table on the list.  The parser builds the list this way.
1906 ** But sqlite3SrcListShiftJoinType() later shifts the jointypes so that each
1907 ** jointype expresses the join between the table and the previous table.
1908 **
1909 ** In the colUsed field, the high-order bit (bit 63) is set if the table
1910 ** contains more than 63 columns and the 64-th or later column is used.
1911 */
1912 struct SrcList {
1913   i16 nSrc;        /* Number of tables or subqueries in the FROM clause */
1914   i16 nAlloc;      /* Number of entries allocated in a[] below */
1915   struct SrcList_item {
1916     Schema *pSchema;  /* Schema to which this item is fixed */
1917     char *zDatabase;  /* Name of database holding this table */
1918     char *zName;      /* Name of the table */
1919     char *zAlias;     /* The "B" part of a "A AS B" phrase.  zName is the "A" */
1920     Table *pTab;      /* An SQL table corresponding to zName */
1921     Select *pSelect;  /* A SELECT statement used in place of a table name */
1922     int addrFillSub;  /* Address of subroutine to manifest a subquery */
1923     int regReturn;    /* Register holding return address of addrFillSub */
1924     u8 jointype;      /* Type of join between this able and the previous */
1925     unsigned notIndexed :1;    /* True if there is a NOT INDEXED clause */
1926     unsigned isCorrelated :1;  /* True if sub-query is correlated */
1927     unsigned viaCoroutine :1;  /* Implemented as a co-routine */
1928 #ifndef SQLITE_OMIT_EXPLAIN
1929     u8 iSelectId;     /* If pSelect!=0, the id of the sub-select in EQP */
1930 #endif
1931     int iCursor;      /* The VDBE cursor number used to access this table */
1932     Expr *pOn;        /* The ON clause of a join */
1933     IdList *pUsing;   /* The USING clause of a join */
1934     Bitmask colUsed;  /* Bit N (1<<N) set if column N of pTab is used */
1935     char *zIndex;     /* Identifier from "INDEXED BY <zIndex>" clause */
1936     Index *pIndex;    /* Index structure corresponding to zIndex, if any */
1937   } a[1];             /* One entry for each identifier on the list */
1938 };
1939 
1940 /*
1941 ** Permitted values of the SrcList.a.jointype field
1942 */
1943 #define JT_INNER     0x0001    /* Any kind of inner or cross join */
1944 #define JT_CROSS     0x0002    /* Explicit use of the CROSS keyword */
1945 #define JT_NATURAL   0x0004    /* True for a "natural" join */
1946 #define JT_LEFT      0x0008    /* Left outer join */
1947 #define JT_RIGHT     0x0010    /* Right outer join */
1948 #define JT_OUTER     0x0020    /* The "OUTER" keyword is present */
1949 #define JT_ERROR     0x0040    /* unknown or unsupported join type */
1950 
1951 
1952 /*
1953 ** A WherePlan object holds information that describes a lookup
1954 ** strategy.
1955 **
1956 ** This object is intended to be opaque outside of the where.c module.
1957 ** It is included here only so that that compiler will know how big it
1958 ** is.  None of the fields in this object should be used outside of
1959 ** the where.c module.
1960 **
1961 ** Within the union, pIdx is only used when wsFlags&WHERE_INDEXED is true.
1962 ** pTerm is only used when wsFlags&WHERE_MULTI_OR is true.  And pVtabIdx
1963 ** is only used when wsFlags&WHERE_VIRTUALTABLE is true.  It is never the
1964 ** case that more than one of these conditions is true.
1965 */
1966 struct WherePlan {
1967   u32 wsFlags;                   /* WHERE_* flags that describe the strategy */
1968   u16 nEq;                       /* Number of == constraints */
1969   u16 nOBSat;                    /* Number of ORDER BY terms satisfied */
1970   double nRow;                   /* Estimated number of rows (for EQP) */
1971   union {
1972     Index *pIdx;                   /* Index when WHERE_INDEXED is true */
1973     struct WhereTerm *pTerm;       /* WHERE clause term for OR-search */
1974     sqlite3_index_info *pVtabIdx;  /* Virtual table index to use */
1975   } u;
1976 };
1977 
1978 /*
1979 ** For each nested loop in a WHERE clause implementation, the WhereInfo
1980 ** structure contains a single instance of this structure.  This structure
1981 ** is intended to be private to the where.c module and should not be
1982 ** access or modified by other modules.
1983 **
1984 ** The pIdxInfo field is used to help pick the best index on a
1985 ** virtual table.  The pIdxInfo pointer contains indexing
1986 ** information for the i-th table in the FROM clause before reordering.
1987 ** All the pIdxInfo pointers are freed by whereInfoFree() in where.c.
1988 ** All other information in the i-th WhereLevel object for the i-th table
1989 ** after FROM clause ordering.
1990 */
1991 struct WhereLevel {
1992   WherePlan plan;       /* query plan for this element of the FROM clause */
1993   int iLeftJoin;        /* Memory cell used to implement LEFT OUTER JOIN */
1994   int iTabCur;          /* The VDBE cursor used to access the table */
1995   int iIdxCur;          /* The VDBE cursor used to access pIdx */
1996   int addrBrk;          /* Jump here to break out of the loop */
1997   int addrNxt;          /* Jump here to start the next IN combination */
1998   int addrCont;         /* Jump here to continue with the next loop cycle */
1999   int addrFirst;        /* First instruction of interior of the loop */
2000   u8 iFrom;             /* Which entry in the FROM clause */
2001   u8 op, p5;            /* Opcode and P5 of the opcode that ends the loop */
2002   int p1, p2;           /* Operands of the opcode used to ends the loop */
2003   union {               /* Information that depends on plan.wsFlags */
2004     struct {
2005       int nIn;              /* Number of entries in aInLoop[] */
2006       struct InLoop {
2007         int iCur;              /* The VDBE cursor used by this IN operator */
2008         int addrInTop;         /* Top of the IN loop */
2009         u8 eEndLoopOp;         /* IN Loop terminator. OP_Next or OP_Prev */
2010       } *aInLoop;           /* Information about each nested IN operator */
2011     } in;                 /* Used when plan.wsFlags&WHERE_IN_ABLE */
2012     Index *pCovidx;       /* Possible covering index for WHERE_MULTI_OR */
2013   } u;
2014   double rOptCost;      /* "Optimal" cost for this level */
2015 
2016   /* The following field is really not part of the current level.  But
2017   ** we need a place to cache virtual table index information for each
2018   ** virtual table in the FROM clause and the WhereLevel structure is
2019   ** a convenient place since there is one WhereLevel for each FROM clause
2020   ** element.
2021   */
2022   sqlite3_index_info *pIdxInfo;  /* Index info for n-th source table */
2023 };
2024 
2025 /*
2026 ** Flags appropriate for the wctrlFlags parameter of sqlite3WhereBegin()
2027 ** and the WhereInfo.wctrlFlags member.
2028 */
2029 #define WHERE_ORDERBY_NORMAL   0x0000 /* No-op */
2030 #define WHERE_ORDERBY_MIN      0x0001 /* ORDER BY processing for min() func */
2031 #define WHERE_ORDERBY_MAX      0x0002 /* ORDER BY processing for max() func */
2032 #define WHERE_ONEPASS_DESIRED  0x0004 /* Want to do one-pass UPDATE/DELETE */
2033 #define WHERE_DUPLICATES_OK    0x0008 /* Ok to return a row more than once */
2034 #define WHERE_OMIT_OPEN_CLOSE  0x0010 /* Table cursors are already open */
2035 #define WHERE_FORCE_TABLE      0x0020 /* Do not use an index-only search */
2036 #define WHERE_ONETABLE_ONLY    0x0040 /* Only code the 1st table in pTabList */
2037 #define WHERE_AND_ONLY         0x0080 /* Don't use indices for OR terms */
2038 
2039 /*
2040 ** The WHERE clause processing routine has two halves.  The
2041 ** first part does the start of the WHERE loop and the second
2042 ** half does the tail of the WHERE loop.  An instance of
2043 ** this structure is returned by the first half and passed
2044 ** into the second half to give some continuity.
2045 */
2046 struct WhereInfo {
2047   Parse *pParse;            /* Parsing and code generating context */
2048   SrcList *pTabList;        /* List of tables in the join */
2049   u16 nOBSat;               /* Number of ORDER BY terms satisfied by indices */
2050   u16 wctrlFlags;           /* Flags originally passed to sqlite3WhereBegin() */
2051   u8 okOnePass;             /* Ok to use one-pass algorithm for UPDATE/DELETE */
2052   u8 untestedTerms;         /* Not all WHERE terms resolved by outer loop */
2053   u8 eDistinct;             /* One of the WHERE_DISTINCT_* values below */
2054   int iTop;                 /* The very beginning of the WHERE loop */
2055   int iContinue;            /* Jump here to continue with next record */
2056   int iBreak;               /* Jump here to break out of the loop */
2057   int nLevel;               /* Number of nested loop */
2058   struct WhereClause *pWC;  /* Decomposition of the WHERE clause */
2059   double savedNQueryLoop;   /* pParse->nQueryLoop outside the WHERE loop */
2060   double nRowOut;           /* Estimated number of output rows */
2061   WhereLevel a[1];          /* Information about each nest loop in WHERE */
2062 };
2063 
2064 /* Allowed values for WhereInfo.eDistinct and DistinctCtx.eTnctType */
2065 #define WHERE_DISTINCT_NOOP      0  /* DISTINCT keyword not used */
2066 #define WHERE_DISTINCT_UNIQUE    1  /* No duplicates */
2067 #define WHERE_DISTINCT_ORDERED   2  /* All duplicates are adjacent */
2068 #define WHERE_DISTINCT_UNORDERED 3  /* Duplicates are scattered */
2069 
2070 /*
2071 ** A NameContext defines a context in which to resolve table and column
2072 ** names.  The context consists of a list of tables (the pSrcList) field and
2073 ** a list of named expression (pEList).  The named expression list may
2074 ** be NULL.  The pSrc corresponds to the FROM clause of a SELECT or
2075 ** to the table being operated on by INSERT, UPDATE, or DELETE.  The
2076 ** pEList corresponds to the result set of a SELECT and is NULL for
2077 ** other statements.
2078 **
2079 ** NameContexts can be nested.  When resolving names, the inner-most
2080 ** context is searched first.  If no match is found, the next outer
2081 ** context is checked.  If there is still no match, the next context
2082 ** is checked.  This process continues until either a match is found
2083 ** or all contexts are check.  When a match is found, the nRef member of
2084 ** the context containing the match is incremented.
2085 **
2086 ** Each subquery gets a new NameContext.  The pNext field points to the
2087 ** NameContext in the parent query.  Thus the process of scanning the
2088 ** NameContext list corresponds to searching through successively outer
2089 ** subqueries looking for a match.
2090 */
2091 struct NameContext {
2092   Parse *pParse;       /* The parser */
2093   SrcList *pSrcList;   /* One or more tables used to resolve names */
2094   ExprList *pEList;    /* Optional list of named expressions */
2095   AggInfo *pAggInfo;   /* Information about aggregates at this level */
2096   NameContext *pNext;  /* Next outer name context.  NULL for outermost */
2097   int nRef;            /* Number of names resolved by this context */
2098   int nErr;            /* Number of errors encountered while resolving names */
2099   u8 ncFlags;          /* Zero or more NC_* flags defined below */
2100 };
2101 
2102 /*
2103 ** Allowed values for the NameContext, ncFlags field.
2104 */
2105 #define NC_AllowAgg  0x01    /* Aggregate functions are allowed here */
2106 #define NC_HasAgg    0x02    /* One or more aggregate functions seen */
2107 #define NC_IsCheck   0x04    /* True if resolving names in a CHECK constraint */
2108 #define NC_InAggFunc 0x08    /* True if analyzing arguments to an agg func */
2109 #define NC_AsMaybe   0x10    /* Resolve to AS terms of the result set only
2110                              ** if no other resolution is available */
2111 
2112 /*
2113 ** An instance of the following structure contains all information
2114 ** needed to generate code for a single SELECT statement.
2115 **
2116 ** nLimit is set to -1 if there is no LIMIT clause.  nOffset is set to 0.
2117 ** If there is a LIMIT clause, the parser sets nLimit to the value of the
2118 ** limit and nOffset to the value of the offset (or 0 if there is not
2119 ** offset).  But later on, nLimit and nOffset become the memory locations
2120 ** in the VDBE that record the limit and offset counters.
2121 **
2122 ** addrOpenEphm[] entries contain the address of OP_OpenEphemeral opcodes.
2123 ** These addresses must be stored so that we can go back and fill in
2124 ** the P4_KEYINFO and P2 parameters later.  Neither the KeyInfo nor
2125 ** the number of columns in P2 can be computed at the same time
2126 ** as the OP_OpenEphm instruction is coded because not
2127 ** enough information about the compound query is known at that point.
2128 ** The KeyInfo for addrOpenTran[0] and [1] contains collating sequences
2129 ** for the result set.  The KeyInfo for addrOpenEphm[2] contains collating
2130 ** sequences for the ORDER BY clause.
2131 */
2132 struct Select {
2133   ExprList *pEList;      /* The fields of the result */
2134   u8 op;                 /* One of: TK_UNION TK_ALL TK_INTERSECT TK_EXCEPT */
2135   u16 selFlags;          /* Various SF_* values */
2136   int iLimit, iOffset;   /* Memory registers holding LIMIT & OFFSET counters */
2137   int addrOpenEphm[3];   /* OP_OpenEphem opcodes related to this select */
2138   double nSelectRow;     /* Estimated number of result rows */
2139   SrcList *pSrc;         /* The FROM clause */
2140   Expr *pWhere;          /* The WHERE clause */
2141   ExprList *pGroupBy;    /* The GROUP BY clause */
2142   Expr *pHaving;         /* The HAVING clause */
2143   ExprList *pOrderBy;    /* The ORDER BY clause */
2144   Select *pPrior;        /* Prior select in a compound select statement */
2145   Select *pNext;         /* Next select to the left in a compound */
2146   Select *pRightmost;    /* Right-most select in a compound select statement */
2147   Expr *pLimit;          /* LIMIT expression. NULL means not used. */
2148   Expr *pOffset;         /* OFFSET expression. NULL means not used. */
2149 };
2150 
2151 /*
2152 ** Allowed values for Select.selFlags.  The "SF" prefix stands for
2153 ** "Select Flag".
2154 */
2155 #define SF_Distinct        0x0001  /* Output should be DISTINCT */
2156 #define SF_Resolved        0x0002  /* Identifiers have been resolved */
2157 #define SF_Aggregate       0x0004  /* Contains aggregate functions */
2158 #define SF_UsesEphemeral   0x0008  /* Uses the OpenEphemeral opcode */
2159 #define SF_Expanded        0x0010  /* sqlite3SelectExpand() called on this */
2160 #define SF_HasTypeInfo     0x0020  /* FROM subqueries have Table metadata */
2161 #define SF_UseSorter       0x0040  /* Sort using a sorter */
2162 #define SF_Values          0x0080  /* Synthesized from VALUES clause */
2163 #define SF_Materialize     0x0100  /* Force materialization of views */
2164 #define SF_NestedFrom      0x0200  /* Part of a parenthesized FROM clause */
2165 
2166 
2167 /*
2168 ** The results of a select can be distributed in several ways.  The
2169 ** "SRT" prefix means "SELECT Result Type".
2170 */
2171 #define SRT_Union        1  /* Store result as keys in an index */
2172 #define SRT_Except       2  /* Remove result from a UNION index */
2173 #define SRT_Exists       3  /* Store 1 if the result is not empty */
2174 #define SRT_Discard      4  /* Do not save the results anywhere */
2175 
2176 /* The ORDER BY clause is ignored for all of the above */
2177 #define IgnorableOrderby(X) ((X->eDest)<=SRT_Discard)
2178 
2179 #define SRT_Output       5  /* Output each row of result */
2180 #define SRT_Mem          6  /* Store result in a memory cell */
2181 #define SRT_Set          7  /* Store results as keys in an index */
2182 #define SRT_Table        8  /* Store result as data with an automatic rowid */
2183 #define SRT_EphemTab     9  /* Create transient tab and store like SRT_Table */
2184 #define SRT_Coroutine   10  /* Generate a single row of result */
2185 
2186 /*
2187 ** An instance of this object describes where to put of the results of
2188 ** a SELECT statement.
2189 */
2190 struct SelectDest {
2191   u8 eDest;         /* How to dispose of the results.  On of SRT_* above. */
2192   char affSdst;     /* Affinity used when eDest==SRT_Set */
2193   int iSDParm;      /* A parameter used by the eDest disposal method */
2194   int iSdst;        /* Base register where results are written */
2195   int nSdst;        /* Number of registers allocated */
2196 };
2197 
2198 /*
2199 ** During code generation of statements that do inserts into AUTOINCREMENT
2200 ** tables, the following information is attached to the Table.u.autoInc.p
2201 ** pointer of each autoincrement table to record some side information that
2202 ** the code generator needs.  We have to keep per-table autoincrement
2203 ** information in case inserts are down within triggers.  Triggers do not
2204 ** normally coordinate their activities, but we do need to coordinate the
2205 ** loading and saving of autoincrement information.
2206 */
2207 struct AutoincInfo {
2208   AutoincInfo *pNext;   /* Next info block in a list of them all */
2209   Table *pTab;          /* Table this info block refers to */
2210   int iDb;              /* Index in sqlite3.aDb[] of database holding pTab */
2211   int regCtr;           /* Memory register holding the rowid counter */
2212 };
2213 
2214 /*
2215 ** Size of the column cache
2216 */
2217 #ifndef SQLITE_N_COLCACHE
2218 # define SQLITE_N_COLCACHE 10
2219 #endif
2220 
2221 /*
2222 ** At least one instance of the following structure is created for each
2223 ** trigger that may be fired while parsing an INSERT, UPDATE or DELETE
2224 ** statement. All such objects are stored in the linked list headed at
2225 ** Parse.pTriggerPrg and deleted once statement compilation has been
2226 ** completed.
2227 **
2228 ** A Vdbe sub-program that implements the body and WHEN clause of trigger
2229 ** TriggerPrg.pTrigger, assuming a default ON CONFLICT clause of
2230 ** TriggerPrg.orconf, is stored in the TriggerPrg.pProgram variable.
2231 ** The Parse.pTriggerPrg list never contains two entries with the same
2232 ** values for both pTrigger and orconf.
2233 **
2234 ** The TriggerPrg.aColmask[0] variable is set to a mask of old.* columns
2235 ** accessed (or set to 0 for triggers fired as a result of INSERT
2236 ** statements). Similarly, the TriggerPrg.aColmask[1] variable is set to
2237 ** a mask of new.* columns used by the program.
2238 */
2239 struct TriggerPrg {
2240   Trigger *pTrigger;      /* Trigger this program was coded from */
2241   TriggerPrg *pNext;      /* Next entry in Parse.pTriggerPrg list */
2242   SubProgram *pProgram;   /* Program implementing pTrigger/orconf */
2243   int orconf;             /* Default ON CONFLICT policy */
2244   u32 aColmask[2];        /* Masks of old.*, new.* columns accessed */
2245 };
2246 
2247 /*
2248 ** The yDbMask datatype for the bitmask of all attached databases.
2249 */
2250 #if SQLITE_MAX_ATTACHED>30
2251   typedef sqlite3_uint64 yDbMask;
2252 #else
2253   typedef unsigned int yDbMask;
2254 #endif
2255 
2256 /*
2257 ** An SQL parser context.  A copy of this structure is passed through
2258 ** the parser and down into all the parser action routine in order to
2259 ** carry around information that is global to the entire parse.
2260 **
2261 ** The structure is divided into two parts.  When the parser and code
2262 ** generate call themselves recursively, the first part of the structure
2263 ** is constant but the second part is reset at the beginning and end of
2264 ** each recursion.
2265 **
2266 ** The nTableLock and aTableLock variables are only used if the shared-cache
2267 ** feature is enabled (if sqlite3Tsd()->useSharedData is true). They are
2268 ** used to store the set of table-locks required by the statement being
2269 ** compiled. Function sqlite3TableLock() is used to add entries to the
2270 ** list.
2271 */
2272 struct Parse {
2273   sqlite3 *db;         /* The main database structure */
2274   char *zErrMsg;       /* An error message */
2275   Vdbe *pVdbe;         /* An engine for executing database bytecode */
2276   int rc;              /* Return code from execution */
2277   u8 colNamesSet;      /* TRUE after OP_ColumnName has been issued to pVdbe */
2278   u8 checkSchema;      /* Causes schema cookie check after an error */
2279   u8 nested;           /* Number of nested calls to the parser/code generator */
2280   u8 nTempReg;         /* Number of temporary registers in aTempReg[] */
2281   u8 nTempInUse;       /* Number of aTempReg[] currently checked out */
2282   u8 nColCache;        /* Number of entries in aColCache[] */
2283   u8 iColCache;        /* Next entry in aColCache[] to replace */
2284   u8 isMultiWrite;     /* True if statement may modify/insert multiple rows */
2285   u8 mayAbort;         /* True if statement may throw an ABORT exception */
2286   int aTempReg[8];     /* Holding area for temporary registers */
2287   int nRangeReg;       /* Size of the temporary register block */
2288   int iRangeReg;       /* First register in temporary register block */
2289   int nErr;            /* Number of errors seen */
2290   int nTab;            /* Number of previously allocated VDBE cursors */
2291   int nMem;            /* Number of memory cells used so far */
2292   int nSet;            /* Number of sets used so far */
2293   int nOnce;           /* Number of OP_Once instructions so far */
2294   int ckBase;          /* Base register of data during check constraints */
2295   int iCacheLevel;     /* ColCache valid when aColCache[].iLevel<=iCacheLevel */
2296   int iCacheCnt;       /* Counter used to generate aColCache[].lru values */
2297   struct yColCache {
2298     int iTable;           /* Table cursor number */
2299     int iColumn;          /* Table column number */
2300     u8 tempReg;           /* iReg is a temp register that needs to be freed */
2301     int iLevel;           /* Nesting level */
2302     int iReg;             /* Reg with value of this column. 0 means none. */
2303     int lru;              /* Least recently used entry has the smallest value */
2304   } aColCache[SQLITE_N_COLCACHE];  /* One for each column cache entry */
2305   yDbMask writeMask;   /* Start a write transaction on these databases */
2306   yDbMask cookieMask;  /* Bitmask of schema verified databases */
2307   int cookieGoto;      /* Address of OP_Goto to cookie verifier subroutine */
2308   int cookieValue[SQLITE_MAX_ATTACHED+2];  /* Values of cookies to verify */
2309   int regRowid;        /* Register holding rowid of CREATE TABLE entry */
2310   int regRoot;         /* Register holding root page number for new objects */
2311   int nMaxArg;         /* Max args passed to user function by sub-program */
2312   Token constraintName;/* Name of the constraint currently being parsed */
2313 #ifndef SQLITE_OMIT_SHARED_CACHE
2314   int nTableLock;        /* Number of locks in aTableLock */
2315   TableLock *aTableLock; /* Required table locks for shared-cache mode */
2316 #endif
2317   AutoincInfo *pAinc;  /* Information about AUTOINCREMENT counters */
2318 
2319   /* Information used while coding trigger programs. */
2320   Parse *pToplevel;    /* Parse structure for main program (or NULL) */
2321   Table *pTriggerTab;  /* Table triggers are being coded for */
2322   double nQueryLoop;   /* Estimated number of iterations of a query */
2323   u32 oldmask;         /* Mask of old.* columns referenced */
2324   u32 newmask;         /* Mask of new.* columns referenced */
2325   u8 eTriggerOp;       /* TK_UPDATE, TK_INSERT or TK_DELETE */
2326   u8 eOrconf;          /* Default ON CONFLICT policy for trigger steps */
2327   u8 disableTriggers;  /* True to disable triggers */
2328 
2329   /* Above is constant between recursions.  Below is reset before and after
2330   ** each recursion */
2331 
2332   int nVar;                 /* Number of '?' variables seen in the SQL so far */
2333   int nzVar;                /* Number of available slots in azVar[] */
2334   u8 explain;               /* True if the EXPLAIN flag is found on the query */
2335 #ifndef SQLITE_OMIT_VIRTUALTABLE
2336   u8 declareVtab;           /* True if inside sqlite3_declare_vtab() */
2337   int nVtabLock;            /* Number of virtual tables to lock */
2338 #endif
2339   int nAlias;               /* Number of aliased result set columns */
2340   int nHeight;              /* Expression tree height of current sub-select */
2341 #ifndef SQLITE_OMIT_EXPLAIN
2342   int iSelectId;            /* ID of current select for EXPLAIN output */
2343   int iNextSelectId;        /* Next available select ID for EXPLAIN output */
2344 #endif
2345   char **azVar;             /* Pointers to names of parameters */
2346   Vdbe *pReprepare;         /* VM being reprepared (sqlite3Reprepare()) */
2347   int *aAlias;              /* Register used to hold aliased result */
2348   const char *zTail;        /* All SQL text past the last semicolon parsed */
2349   Table *pNewTable;         /* A table being constructed by CREATE TABLE */
2350   Trigger *pNewTrigger;     /* Trigger under construct by a CREATE TRIGGER */
2351   const char *zAuthContext; /* The 6th parameter to db->xAuth callbacks */
2352   Token sNameToken;         /* Token with unqualified schema object name */
2353   Token sLastToken;         /* The last token parsed */
2354 #ifndef SQLITE_OMIT_VIRTUALTABLE
2355   Token sArg;               /* Complete text of a module argument */
2356   Table **apVtabLock;       /* Pointer to virtual tables needing locking */
2357 #endif
2358   Table *pZombieTab;        /* List of Table objects to delete after code gen */
2359   TriggerPrg *pTriggerPrg;  /* Linked list of coded triggers */
2360 };
2361 
2362 /*
2363 ** Return true if currently inside an sqlite3_declare_vtab() call.
2364 */
2365 #ifdef SQLITE_OMIT_VIRTUALTABLE
2366   #define IN_DECLARE_VTAB 0
2367 #else
2368   #define IN_DECLARE_VTAB (pParse->declareVtab)
2369 #endif
2370 
2371 /*
2372 ** An instance of the following structure can be declared on a stack and used
2373 ** to save the Parse.zAuthContext value so that it can be restored later.
2374 */
2375 struct AuthContext {
2376   const char *zAuthContext;   /* Put saved Parse.zAuthContext here */
2377   Parse *pParse;              /* The Parse structure */
2378 };
2379 
2380 /*
2381 ** Bitfield flags for P5 value in various opcodes.
2382 */
2383 #define OPFLAG_NCHANGE       0x01    /* Set to update db->nChange */
2384 #define OPFLAG_LASTROWID     0x02    /* Set to update db->lastRowid */
2385 #define OPFLAG_ISUPDATE      0x04    /* This OP_Insert is an sql UPDATE */
2386 #define OPFLAG_APPEND        0x08    /* This is likely to be an append */
2387 #define OPFLAG_USESEEKRESULT 0x10    /* Try to avoid a seek in BtreeInsert() */
2388 #define OPFLAG_CLEARCACHE    0x20    /* Clear pseudo-table cache in OP_Column */
2389 #define OPFLAG_LENGTHARG     0x40    /* OP_Column only used for length() */
2390 #define OPFLAG_TYPEOFARG     0x80    /* OP_Column only used for typeof() */
2391 #define OPFLAG_BULKCSR       0x01    /* OP_Open** used to open bulk cursor */
2392 #define OPFLAG_P2ISREG       0x02    /* P2 to OP_Open** is a register number */
2393 #define OPFLAG_PERMUTE       0x01    /* OP_Compare: use the permutation */
2394 
2395 /*
2396  * Each trigger present in the database schema is stored as an instance of
2397  * struct Trigger.
2398  *
2399  * Pointers to instances of struct Trigger are stored in two ways.
2400  * 1. In the "trigHash" hash table (part of the sqlite3* that represents the
2401  *    database). This allows Trigger structures to be retrieved by name.
2402  * 2. All triggers associated with a single table form a linked list, using the
2403  *    pNext member of struct Trigger. A pointer to the first element of the
2404  *    linked list is stored as the "pTrigger" member of the associated
2405  *    struct Table.
2406  *
2407  * The "step_list" member points to the first element of a linked list
2408  * containing the SQL statements specified as the trigger program.
2409  */
2410 struct Trigger {
2411   char *zName;            /* The name of the trigger                        */
2412   char *table;            /* The table or view to which the trigger applies */
2413   u8 op;                  /* One of TK_DELETE, TK_UPDATE, TK_INSERT         */
2414   u8 tr_tm;               /* One of TRIGGER_BEFORE, TRIGGER_AFTER */
2415   Expr *pWhen;            /* The WHEN clause of the expression (may be NULL) */
2416   IdList *pColumns;       /* If this is an UPDATE OF <column-list> trigger,
2417                              the <column-list> is stored here */
2418   Schema *pSchema;        /* Schema containing the trigger */
2419   Schema *pTabSchema;     /* Schema containing the table */
2420   TriggerStep *step_list; /* Link list of trigger program steps             */
2421   Trigger *pNext;         /* Next trigger associated with the table */
2422 };
2423 
2424 /*
2425 ** A trigger is either a BEFORE or an AFTER trigger.  The following constants
2426 ** determine which.
2427 **
2428 ** If there are multiple triggers, you might of some BEFORE and some AFTER.
2429 ** In that cases, the constants below can be ORed together.
2430 */
2431 #define TRIGGER_BEFORE  1
2432 #define TRIGGER_AFTER   2
2433 
2434 /*
2435  * An instance of struct TriggerStep is used to store a single SQL statement
2436  * that is a part of a trigger-program.
2437  *
2438  * Instances of struct TriggerStep are stored in a singly linked list (linked
2439  * using the "pNext" member) referenced by the "step_list" member of the
2440  * associated struct Trigger instance. The first element of the linked list is
2441  * the first step of the trigger-program.
2442  *
2443  * The "op" member indicates whether this is a "DELETE", "INSERT", "UPDATE" or
2444  * "SELECT" statement. The meanings of the other members is determined by the
2445  * value of "op" as follows:
2446  *
2447  * (op == TK_INSERT)
2448  * orconf    -> stores the ON CONFLICT algorithm
2449  * pSelect   -> If this is an INSERT INTO ... SELECT ... statement, then
2450  *              this stores a pointer to the SELECT statement. Otherwise NULL.
2451  * target    -> A token holding the quoted name of the table to insert into.
2452  * pExprList -> If this is an INSERT INTO ... VALUES ... statement, then
2453  *              this stores values to be inserted. Otherwise NULL.
2454  * pIdList   -> If this is an INSERT INTO ... (<column-names>) VALUES ...
2455  *              statement, then this stores the column-names to be
2456  *              inserted into.
2457  *
2458  * (op == TK_DELETE)
2459  * target    -> A token holding the quoted name of the table to delete from.
2460  * pWhere    -> The WHERE clause of the DELETE statement if one is specified.
2461  *              Otherwise NULL.
2462  *
2463  * (op == TK_UPDATE)
2464  * target    -> A token holding the quoted name of the table to update rows of.
2465  * pWhere    -> The WHERE clause of the UPDATE statement if one is specified.
2466  *              Otherwise NULL.
2467  * pExprList -> A list of the columns to update and the expressions to update
2468  *              them to. See sqlite3Update() documentation of "pChanges"
2469  *              argument.
2470  *
2471  */
2472 struct TriggerStep {
2473   u8 op;               /* One of TK_DELETE, TK_UPDATE, TK_INSERT, TK_SELECT */
2474   u8 orconf;           /* OE_Rollback etc. */
2475   Trigger *pTrig;      /* The trigger that this step is a part of */
2476   Select *pSelect;     /* SELECT statment or RHS of INSERT INTO .. SELECT ... */
2477   Token target;        /* Target table for DELETE, UPDATE, INSERT */
2478   Expr *pWhere;        /* The WHERE clause for DELETE or UPDATE steps */
2479   ExprList *pExprList; /* SET clause for UPDATE.  VALUES clause for INSERT */
2480   IdList *pIdList;     /* Column names for INSERT */
2481   TriggerStep *pNext;  /* Next in the link-list */
2482   TriggerStep *pLast;  /* Last element in link-list. Valid for 1st elem only */
2483 };
2484 
2485 /*
2486 ** The following structure contains information used by the sqliteFix...
2487 ** routines as they walk the parse tree to make database references
2488 ** explicit.
2489 */
2490 typedef struct DbFixer DbFixer;
2491 struct DbFixer {
2492   Parse *pParse;      /* The parsing context.  Error messages written here */
2493   Schema *pSchema;    /* Fix items to this schema */
2494   const char *zDb;    /* Make sure all objects are contained in this database */
2495   const char *zType;  /* Type of the container - used for error messages */
2496   const Token *pName; /* Name of the container - used for error messages */
2497 };
2498 
2499 /*
2500 ** An objected used to accumulate the text of a string where we
2501 ** do not necessarily know how big the string will be in the end.
2502 */
2503 struct StrAccum {
2504   sqlite3 *db;         /* Optional database for lookaside.  Can be NULL */
2505   char *zBase;         /* A base allocation.  Not from malloc. */
2506   char *zText;         /* The string collected so far */
2507   int  nChar;          /* Length of the string so far */
2508   int  nAlloc;         /* Amount of space allocated in zText */
2509   int  mxAlloc;        /* Maximum allowed string length */
2510   u8   mallocFailed;   /* Becomes true if any memory allocation fails */
2511   u8   useMalloc;      /* 0: none,  1: sqlite3DbMalloc,  2: sqlite3_malloc */
2512   u8   tooBig;         /* Becomes true if string size exceeds limits */
2513 };
2514 
2515 /*
2516 ** A pointer to this structure is used to communicate information
2517 ** from sqlite3Init and OP_ParseSchema into the sqlite3InitCallback.
2518 */
2519 typedef struct {
2520   sqlite3 *db;        /* The database being initialized */
2521   char **pzErrMsg;    /* Error message stored here */
2522   int iDb;            /* 0 for main database.  1 for TEMP, 2.. for ATTACHed */
2523   int rc;             /* Result code stored here */
2524 } InitData;
2525 
2526 /*
2527 ** Structure containing global configuration data for the SQLite library.
2528 **
2529 ** This structure also contains some state information.
2530 */
2531 struct Sqlite3Config {
2532   int bMemstat;                     /* True to enable memory status */
2533   int bCoreMutex;                   /* True to enable core mutexing */
2534   int bFullMutex;                   /* True to enable full mutexing */
2535   int bOpenUri;                     /* True to interpret filenames as URIs */
2536   int bUseCis;                      /* Use covering indices for full-scans */
2537   int mxStrlen;                     /* Maximum string length */
2538   int szLookaside;                  /* Default lookaside buffer size */
2539   int nLookaside;                   /* Default lookaside buffer count */
2540   sqlite3_mem_methods m;            /* Low-level memory allocation interface */
2541   sqlite3_mutex_methods mutex;      /* Low-level mutex interface */
2542   sqlite3_pcache_methods2 pcache2;  /* Low-level page-cache interface */
2543   void *pHeap;                      /* Heap storage space */
2544   int nHeap;                        /* Size of pHeap[] */
2545   int mnReq, mxReq;                 /* Min and max heap requests sizes */
2546   sqlite3_int64 szMmap;             /* mmap() space per open file */
2547   sqlite3_int64 mxMmap;             /* Maximum value for szMmap */
2548   void *pScratch;                   /* Scratch memory */
2549   int szScratch;                    /* Size of each scratch buffer */
2550   int nScratch;                     /* Number of scratch buffers */
2551   void *pPage;                      /* Page cache memory */
2552   int szPage;                       /* Size of each page in pPage[] */
2553   int nPage;                        /* Number of pages in pPage[] */
2554   int mxParserStack;                /* maximum depth of the parser stack */
2555   int sharedCacheEnabled;           /* true if shared-cache mode enabled */
2556   /* The above might be initialized to non-zero.  The following need to always
2557   ** initially be zero, however. */
2558   int isInit;                       /* True after initialization has finished */
2559   int inProgress;                   /* True while initialization in progress */
2560   int isMutexInit;                  /* True after mutexes are initialized */
2561   int isMallocInit;                 /* True after malloc is initialized */
2562   int isPCacheInit;                 /* True after malloc is initialized */
2563   sqlite3_mutex *pInitMutex;        /* Mutex used by sqlite3_initialize() */
2564   int nRefInitMutex;                /* Number of users of pInitMutex */
2565   void (*xLog)(void*,int,const char*); /* Function for logging */
2566   void *pLogArg;                       /* First argument to xLog() */
2567   int bLocaltimeFault;              /* True to fail localtime() calls */
2568 #ifdef SQLITE_ENABLE_SQLLOG
2569   void(*xSqllog)(void*,sqlite3*,const char*, int);
2570   void *pSqllogArg;
2571 #endif
2572 };
2573 
2574 /*
2575 ** Context pointer passed down through the tree-walk.
2576 */
2577 struct Walker {
2578   int (*xExprCallback)(Walker*, Expr*);     /* Callback for expressions */
2579   int (*xSelectCallback)(Walker*,Select*);  /* Callback for SELECTs */
2580   Parse *pParse;                            /* Parser context.  */
2581   int walkerDepth;                          /* Number of subqueries */
2582   u8 bSelectDepthFirst;                     /* Do subqueries first */
2583   union {                                   /* Extra data for callback */
2584     NameContext *pNC;                          /* Naming context */
2585     int i;                                     /* Integer value */
2586     SrcList *pSrcList;                         /* FROM clause */
2587     struct SrcCount *pSrcCount;                /* Counting column references */
2588   } u;
2589 };
2590 
2591 /* Forward declarations */
2592 int sqlite3WalkExpr(Walker*, Expr*);
2593 int sqlite3WalkExprList(Walker*, ExprList*);
2594 int sqlite3WalkSelect(Walker*, Select*);
2595 int sqlite3WalkSelectExpr(Walker*, Select*);
2596 int sqlite3WalkSelectFrom(Walker*, Select*);
2597 
2598 /*
2599 ** Return code from the parse-tree walking primitives and their
2600 ** callbacks.
2601 */
2602 #define WRC_Continue    0   /* Continue down into children */
2603 #define WRC_Prune       1   /* Omit children but continue walking siblings */
2604 #define WRC_Abort       2   /* Abandon the tree walk */
2605 
2606 /*
2607 ** Assuming zIn points to the first byte of a UTF-8 character,
2608 ** advance zIn to point to the first byte of the next UTF-8 character.
2609 */
2610 #define SQLITE_SKIP_UTF8(zIn) {                        \
2611   if( (*(zIn++))>=0xc0 ){                              \
2612     while( (*zIn & 0xc0)==0x80 ){ zIn++; }             \
2613   }                                                    \
2614 }
2615 
2616 /*
2617 ** The SQLITE_*_BKPT macros are substitutes for the error codes with
2618 ** the same name but without the _BKPT suffix.  These macros invoke
2619 ** routines that report the line-number on which the error originated
2620 ** using sqlite3_log().  The routines also provide a convenient place
2621 ** to set a debugger breakpoint.
2622 */
2623 int sqlite3CorruptError(int);
2624 int sqlite3MisuseError(int);
2625 int sqlite3CantopenError(int);
2626 #define SQLITE_CORRUPT_BKPT sqlite3CorruptError(__LINE__)
2627 #define SQLITE_MISUSE_BKPT sqlite3MisuseError(__LINE__)
2628 #define SQLITE_CANTOPEN_BKPT sqlite3CantopenError(__LINE__)
2629 
2630 
2631 /*
2632 ** FTS4 is really an extension for FTS3.  It is enabled using the
2633 ** SQLITE_ENABLE_FTS3 macro.  But to avoid confusion we also all
2634 ** the SQLITE_ENABLE_FTS4 macro to serve as an alisse for SQLITE_ENABLE_FTS3.
2635 */
2636 #if defined(SQLITE_ENABLE_FTS4) && !defined(SQLITE_ENABLE_FTS3)
2637 # define SQLITE_ENABLE_FTS3
2638 #endif
2639 
2640 /*
2641 ** The ctype.h header is needed for non-ASCII systems.  It is also
2642 ** needed by FTS3 when FTS3 is included in the amalgamation.
2643 */
2644 #if !defined(SQLITE_ASCII) || \
2645     (defined(SQLITE_ENABLE_FTS3) && defined(SQLITE_AMALGAMATION))
2646 # include <ctype.h>
2647 #endif
2648 
2649 /*
2650 ** The following macros mimic the standard library functions toupper(),
2651 ** isspace(), isalnum(), isdigit() and isxdigit(), respectively. The
2652 ** sqlite versions only work for ASCII characters, regardless of locale.
2653 */
2654 #ifdef SQLITE_ASCII
2655 # define sqlite3Toupper(x)  ((x)&~(sqlite3CtypeMap[(unsigned char)(x)]&0x20))
2656 # define sqlite3Isspace(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x01)
2657 # define sqlite3Isalnum(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x06)
2658 # define sqlite3Isalpha(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x02)
2659 # define sqlite3Isdigit(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x04)
2660 # define sqlite3Isxdigit(x)  (sqlite3CtypeMap[(unsigned char)(x)]&0x08)
2661 # define sqlite3Tolower(x)   (sqlite3UpperToLower[(unsigned char)(x)])
2662 #else
2663 # define sqlite3Toupper(x)   toupper((unsigned char)(x))
2664 # define sqlite3Isspace(x)   isspace((unsigned char)(x))
2665 # define sqlite3Isalnum(x)   isalnum((unsigned char)(x))
2666 # define sqlite3Isalpha(x)   isalpha((unsigned char)(x))
2667 # define sqlite3Isdigit(x)   isdigit((unsigned char)(x))
2668 # define sqlite3Isxdigit(x)  isxdigit((unsigned char)(x))
2669 # define sqlite3Tolower(x)   tolower((unsigned char)(x))
2670 #endif
2671 
2672 /*
2673 ** Internal function prototypes
2674 */
2675 #define sqlite3StrICmp sqlite3_stricmp
2676 int sqlite3Strlen30(const char*);
2677 #define sqlite3StrNICmp sqlite3_strnicmp
2678 
2679 int sqlite3MallocInit(void);
2680 void sqlite3MallocEnd(void);
2681 void *sqlite3Malloc(int);
2682 void *sqlite3MallocZero(int);
2683 void *sqlite3DbMallocZero(sqlite3*, int);
2684 void *sqlite3DbMallocRaw(sqlite3*, int);
2685 char *sqlite3DbStrDup(sqlite3*,const char*);
2686 char *sqlite3DbStrNDup(sqlite3*,const char*, int);
2687 void *sqlite3Realloc(void*, int);
2688 void *sqlite3DbReallocOrFree(sqlite3 *, void *, int);
2689 void *sqlite3DbRealloc(sqlite3 *, void *, int);
2690 void sqlite3DbFree(sqlite3*, void*);
2691 int sqlite3MallocSize(void*);
2692 int sqlite3DbMallocSize(sqlite3*, void*);
2693 void *sqlite3ScratchMalloc(int);
2694 void sqlite3ScratchFree(void*);
2695 void *sqlite3PageMalloc(int);
2696 void sqlite3PageFree(void*);
2697 void sqlite3MemSetDefault(void);
2698 void sqlite3BenignMallocHooks(void (*)(void), void (*)(void));
2699 int sqlite3HeapNearlyFull(void);
2700 
2701 /*
2702 ** On systems with ample stack space and that support alloca(), make
2703 ** use of alloca() to obtain space for large automatic objects.  By default,
2704 ** obtain space from malloc().
2705 **
2706 ** The alloca() routine never returns NULL.  This will cause code paths
2707 ** that deal with sqlite3StackAlloc() failures to be unreachable.
2708 */
2709 #ifdef SQLITE_USE_ALLOCA
2710 # define sqlite3StackAllocRaw(D,N)   alloca(N)
2711 # define sqlite3StackAllocZero(D,N)  memset(alloca(N), 0, N)
2712 # define sqlite3StackFree(D,P)
2713 #else
2714 # define sqlite3StackAllocRaw(D,N)   sqlite3DbMallocRaw(D,N)
2715 # define sqlite3StackAllocZero(D,N)  sqlite3DbMallocZero(D,N)
2716 # define sqlite3StackFree(D,P)       sqlite3DbFree(D,P)
2717 #endif
2718 
2719 #ifdef SQLITE_ENABLE_MEMSYS3
2720 const sqlite3_mem_methods *sqlite3MemGetMemsys3(void);
2721 #endif
2722 #ifdef SQLITE_ENABLE_MEMSYS5
2723 const sqlite3_mem_methods *sqlite3MemGetMemsys5(void);
2724 #endif
2725 
2726 
2727 #ifndef SQLITE_MUTEX_OMIT
2728   sqlite3_mutex_methods const *sqlite3DefaultMutex(void);
2729   sqlite3_mutex_methods const *sqlite3NoopMutex(void);
2730   sqlite3_mutex *sqlite3MutexAlloc(int);
2731   int sqlite3MutexInit(void);
2732   int sqlite3MutexEnd(void);
2733 #endif
2734 
2735 int sqlite3StatusValue(int);
2736 void sqlite3StatusAdd(int, int);
2737 void sqlite3StatusSet(int, int);
2738 
2739 #ifndef SQLITE_OMIT_FLOATING_POINT
2740   int sqlite3IsNaN(double);
2741 #else
2742 # define sqlite3IsNaN(X)  0
2743 #endif
2744 
2745 void sqlite3VXPrintf(StrAccum*, int, const char*, va_list);
2746 #ifndef SQLITE_OMIT_TRACE
2747 void sqlite3XPrintf(StrAccum*, const char*, ...);
2748 #endif
2749 char *sqlite3MPrintf(sqlite3*,const char*, ...);
2750 char *sqlite3VMPrintf(sqlite3*,const char*, va_list);
2751 char *sqlite3MAppendf(sqlite3*,char*,const char*,...);
2752 #if defined(SQLITE_TEST) || defined(SQLITE_DEBUG)
2753   void sqlite3DebugPrintf(const char*, ...);
2754 #endif
2755 #if defined(SQLITE_TEST)
2756   void *sqlite3TestTextToPtr(const char*);
2757 #endif
2758 
2759 /* Output formatting for SQLITE_TESTCTRL_EXPLAIN */
2760 #if defined(SQLITE_ENABLE_TREE_EXPLAIN)
2761   void sqlite3ExplainBegin(Vdbe*);
2762   void sqlite3ExplainPrintf(Vdbe*, const char*, ...);
2763   void sqlite3ExplainNL(Vdbe*);
2764   void sqlite3ExplainPush(Vdbe*);
2765   void sqlite3ExplainPop(Vdbe*);
2766   void sqlite3ExplainFinish(Vdbe*);
2767   void sqlite3ExplainSelect(Vdbe*, Select*);
2768   void sqlite3ExplainExpr(Vdbe*, Expr*);
2769   void sqlite3ExplainExprList(Vdbe*, ExprList*);
2770   const char *sqlite3VdbeExplanation(Vdbe*);
2771 #else
2772 # define sqlite3ExplainBegin(X)
2773 # define sqlite3ExplainSelect(A,B)
2774 # define sqlite3ExplainExpr(A,B)
2775 # define sqlite3ExplainExprList(A,B)
2776 # define sqlite3ExplainFinish(X)
2777 # define sqlite3VdbeExplanation(X) 0
2778 #endif
2779 
2780 
2781 void sqlite3SetString(char **, sqlite3*, const char*, ...);
2782 void sqlite3ErrorMsg(Parse*, const char*, ...);
2783 int sqlite3Dequote(char*);
2784 int sqlite3KeywordCode(const unsigned char*, int);
2785 int sqlite3RunParser(Parse*, const char*, char **);
2786 void sqlite3FinishCoding(Parse*);
2787 int sqlite3GetTempReg(Parse*);
2788 void sqlite3ReleaseTempReg(Parse*,int);
2789 int sqlite3GetTempRange(Parse*,int);
2790 void sqlite3ReleaseTempRange(Parse*,int,int);
2791 void sqlite3ClearTempRegCache(Parse*);
2792 Expr *sqlite3ExprAlloc(sqlite3*,int,const Token*,int);
2793 Expr *sqlite3Expr(sqlite3*,int,const char*);
2794 void sqlite3ExprAttachSubtrees(sqlite3*,Expr*,Expr*,Expr*);
2795 Expr *sqlite3PExpr(Parse*, int, Expr*, Expr*, const Token*);
2796 Expr *sqlite3ExprAnd(sqlite3*,Expr*, Expr*);
2797 Expr *sqlite3ExprFunction(Parse*,ExprList*, Token*);
2798 void sqlite3ExprAssignVarNumber(Parse*, Expr*);
2799 void sqlite3ExprDelete(sqlite3*, Expr*);
2800 ExprList *sqlite3ExprListAppend(Parse*,ExprList*,Expr*);
2801 void sqlite3ExprListSetName(Parse*,ExprList*,Token*,int);
2802 void sqlite3ExprListSetSpan(Parse*,ExprList*,ExprSpan*);
2803 void sqlite3ExprListDelete(sqlite3*, ExprList*);
2804 int sqlite3Init(sqlite3*, char**);
2805 int sqlite3InitCallback(void*, int, char**, char**);
2806 void sqlite3Pragma(Parse*,Token*,Token*,Token*,int);
2807 void sqlite3ResetAllSchemasOfConnection(sqlite3*);
2808 void sqlite3ResetOneSchema(sqlite3*,int);
2809 void sqlite3CollapseDatabaseArray(sqlite3*);
2810 void sqlite3BeginParse(Parse*,int);
2811 void sqlite3CommitInternalChanges(sqlite3*);
2812 Table *sqlite3ResultSetOfSelect(Parse*,Select*);
2813 void sqlite3OpenMasterTable(Parse *, int);
2814 void sqlite3StartTable(Parse*,Token*,Token*,int,int,int,int);
2815 void sqlite3AddColumn(Parse*,Token*);
2816 void sqlite3AddNotNull(Parse*, int);
2817 void sqlite3AddPrimaryKey(Parse*, ExprList*, int, int, int);
2818 void sqlite3AddCheckConstraint(Parse*, Expr*);
2819 void sqlite3AddColumnType(Parse*,Token*);
2820 void sqlite3AddDefaultValue(Parse*,ExprSpan*);
2821 void sqlite3AddCollateType(Parse*, Token*);
2822 void sqlite3EndTable(Parse*,Token*,Token*,Select*);
2823 int sqlite3ParseUri(const char*,const char*,unsigned int*,
2824                     sqlite3_vfs**,char**,char **);
2825 Btree *sqlite3DbNameToBtree(sqlite3*,const char*);
2826 int sqlite3CodeOnce(Parse *);
2827 
2828 Bitvec *sqlite3BitvecCreate(u32);
2829 int sqlite3BitvecTest(Bitvec*, u32);
2830 int sqlite3BitvecSet(Bitvec*, u32);
2831 void sqlite3BitvecClear(Bitvec*, u32, void*);
2832 void sqlite3BitvecDestroy(Bitvec*);
2833 u32 sqlite3BitvecSize(Bitvec*);
2834 int sqlite3BitvecBuiltinTest(int,int*);
2835 
2836 RowSet *sqlite3RowSetInit(sqlite3*, void*, unsigned int);
2837 void sqlite3RowSetClear(RowSet*);
2838 void sqlite3RowSetInsert(RowSet*, i64);
2839 int sqlite3RowSetTest(RowSet*, u8 iBatch, i64);
2840 int sqlite3RowSetNext(RowSet*, i64*);
2841 
2842 void sqlite3CreateView(Parse*,Token*,Token*,Token*,Select*,int,int);
2843 
2844 #if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE)
2845   int sqlite3ViewGetColumnNames(Parse*,Table*);
2846 #else
2847 # define sqlite3ViewGetColumnNames(A,B) 0
2848 #endif
2849 
2850 void sqlite3DropTable(Parse*, SrcList*, int, int);
2851 void sqlite3CodeDropTable(Parse*, Table*, int, int);
2852 void sqlite3DeleteTable(sqlite3*, Table*);
2853 #ifndef SQLITE_OMIT_AUTOINCREMENT
2854   void sqlite3AutoincrementBegin(Parse *pParse);
2855   void sqlite3AutoincrementEnd(Parse *pParse);
2856 #else
2857 # define sqlite3AutoincrementBegin(X)
2858 # define sqlite3AutoincrementEnd(X)
2859 #endif
2860 int sqlite3CodeCoroutine(Parse*, Select*, SelectDest*);
2861 void sqlite3Insert(Parse*, SrcList*, ExprList*, Select*, IdList*, int);
2862 void *sqlite3ArrayAllocate(sqlite3*,void*,int,int*,int*);
2863 IdList *sqlite3IdListAppend(sqlite3*, IdList*, Token*);
2864 int sqlite3IdListIndex(IdList*,const char*);
2865 SrcList *sqlite3SrcListEnlarge(sqlite3*, SrcList*, int, int);
2866 SrcList *sqlite3SrcListAppend(sqlite3*, SrcList*, Token*, Token*);
2867 SrcList *sqlite3SrcListAppendFromTerm(Parse*, SrcList*, Token*, Token*,
2868                                       Token*, Select*, Expr*, IdList*);
2869 void sqlite3SrcListIndexedBy(Parse *, SrcList *, Token *);
2870 int sqlite3IndexedByLookup(Parse *, struct SrcList_item *);
2871 void sqlite3SrcListShiftJoinType(SrcList*);
2872 void sqlite3SrcListAssignCursors(Parse*, SrcList*);
2873 void sqlite3IdListDelete(sqlite3*, IdList*);
2874 void sqlite3SrcListDelete(sqlite3*, SrcList*);
2875 Index *sqlite3CreateIndex(Parse*,Token*,Token*,SrcList*,ExprList*,int,Token*,
2876                         Token*, int, int);
2877 void sqlite3DropIndex(Parse*, SrcList*, int);
2878 int sqlite3Select(Parse*, Select*, SelectDest*);
2879 Select *sqlite3SelectNew(Parse*,ExprList*,SrcList*,Expr*,ExprList*,
2880                          Expr*,ExprList*,u16,Expr*,Expr*);
2881 void sqlite3SelectDelete(sqlite3*, Select*);
2882 Table *sqlite3SrcListLookup(Parse*, SrcList*);
2883 int sqlite3IsReadOnly(Parse*, Table*, int);
2884 void sqlite3OpenTable(Parse*, int iCur, int iDb, Table*, int);
2885 #if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY)
2886 Expr *sqlite3LimitWhere(Parse*,SrcList*,Expr*,ExprList*,Expr*,Expr*,char*);
2887 #endif
2888 void sqlite3DeleteFrom(Parse*, SrcList*, Expr*);
2889 void sqlite3Update(Parse*, SrcList*, ExprList*, Expr*, int);
2890 WhereInfo *sqlite3WhereBegin(Parse*,SrcList*,Expr*,ExprList*,ExprList*,u16,int);
2891 void sqlite3WhereEnd(WhereInfo*);
2892 int sqlite3ExprCodeGetColumn(Parse*, Table*, int, int, int, u8);
2893 void sqlite3ExprCodeGetColumnOfTable(Vdbe*, Table*, int, int, int);
2894 void sqlite3ExprCodeMove(Parse*, int, int, int);
2895 void sqlite3ExprCacheStore(Parse*, int, int, int);
2896 void sqlite3ExprCachePush(Parse*);
2897 void sqlite3ExprCachePop(Parse*, int);
2898 void sqlite3ExprCacheRemove(Parse*, int, int);
2899 void sqlite3ExprCacheClear(Parse*);
2900 void sqlite3ExprCacheAffinityChange(Parse*, int, int);
2901 int sqlite3ExprCode(Parse*, Expr*, int);
2902 int sqlite3ExprCodeTemp(Parse*, Expr*, int*);
2903 int sqlite3ExprCodeTarget(Parse*, Expr*, int);
2904 int sqlite3ExprCodeAndCache(Parse*, Expr*, int);
2905 void sqlite3ExprCodeConstants(Parse*, Expr*);
2906 int sqlite3ExprCodeExprList(Parse*, ExprList*, int, int);
2907 void sqlite3ExprIfTrue(Parse*, Expr*, int, int);
2908 void sqlite3ExprIfFalse(Parse*, Expr*, int, int);
2909 Table *sqlite3FindTable(sqlite3*,const char*, const char*);
2910 Table *sqlite3LocateTable(Parse*,int isView,const char*, const char*);
2911 Table *sqlite3LocateTableItem(Parse*,int isView,struct SrcList_item *);
2912 Index *sqlite3FindIndex(sqlite3*,const char*, const char*);
2913 void sqlite3UnlinkAndDeleteTable(sqlite3*,int,const char*);
2914 void sqlite3UnlinkAndDeleteIndex(sqlite3*,int,const char*);
2915 void sqlite3Vacuum(Parse*);
2916 int sqlite3RunVacuum(char**, sqlite3*);
2917 char *sqlite3NameFromToken(sqlite3*, Token*);
2918 int sqlite3ExprCompare(Expr*, Expr*);
2919 int sqlite3ExprListCompare(ExprList*, ExprList*);
2920 void sqlite3ExprAnalyzeAggregates(NameContext*, Expr*);
2921 void sqlite3ExprAnalyzeAggList(NameContext*,ExprList*);
2922 int sqlite3FunctionUsesThisSrc(Expr*, SrcList*);
2923 Vdbe *sqlite3GetVdbe(Parse*);
2924 void sqlite3PrngSaveState(void);
2925 void sqlite3PrngRestoreState(void);
2926 void sqlite3PrngResetState(void);
2927 void sqlite3RollbackAll(sqlite3*,int);
2928 void sqlite3CodeVerifySchema(Parse*, int);
2929 void sqlite3CodeVerifyNamedSchema(Parse*, const char *zDb);
2930 void sqlite3BeginTransaction(Parse*, int);
2931 void sqlite3CommitTransaction(Parse*);
2932 void sqlite3RollbackTransaction(Parse*);
2933 void sqlite3Savepoint(Parse*, int, Token*);
2934 void sqlite3CloseSavepoints(sqlite3 *);
2935 void sqlite3LeaveMutexAndCloseZombie(sqlite3*);
2936 int sqlite3ExprIsConstant(Expr*);
2937 int sqlite3ExprIsConstantNotJoin(Expr*);
2938 int sqlite3ExprIsConstantOrFunction(Expr*);
2939 int sqlite3ExprIsInteger(Expr*, int*);
2940 int sqlite3ExprCanBeNull(const Expr*);
2941 void sqlite3ExprCodeIsNullJump(Vdbe*, const Expr*, int, int);
2942 int sqlite3ExprNeedsNoAffinityChange(const Expr*, char);
2943 int sqlite3IsRowid(const char*);
2944 void sqlite3GenerateRowDelete(Parse*, Table*, int, int, int, Trigger *, int);
2945 void sqlite3GenerateRowIndexDelete(Parse*, Table*, int, int*);
2946 int sqlite3GenerateIndexKey(Parse*, Index*, int, int, int);
2947 void sqlite3GenerateConstraintChecks(Parse*,Table*,int,int,
2948                                      int*,int,int,int,int,int*);
2949 void sqlite3CompleteInsertion(Parse*, Table*, int, int, int*, int, int, int);
2950 int sqlite3OpenTableAndIndices(Parse*, Table*, int, int);
2951 void sqlite3BeginWriteOperation(Parse*, int, int);
2952 void sqlite3MultiWrite(Parse*);
2953 void sqlite3MayAbort(Parse*);
2954 void sqlite3HaltConstraint(Parse*, int, int, char*, int);
2955 Expr *sqlite3ExprDup(sqlite3*,Expr*,int);
2956 ExprList *sqlite3ExprListDup(sqlite3*,ExprList*,int);
2957 SrcList *sqlite3SrcListDup(sqlite3*,SrcList*,int);
2958 IdList *sqlite3IdListDup(sqlite3*,IdList*);
2959 Select *sqlite3SelectDup(sqlite3*,Select*,int);
2960 void sqlite3FuncDefInsert(FuncDefHash*, FuncDef*);
2961 FuncDef *sqlite3FindFunction(sqlite3*,const char*,int,int,u8,u8);
2962 void sqlite3RegisterBuiltinFunctions(sqlite3*);
2963 void sqlite3RegisterDateTimeFunctions(void);
2964 void sqlite3RegisterGlobalFunctions(void);
2965 int sqlite3SafetyCheckOk(sqlite3*);
2966 int sqlite3SafetyCheckSickOrOk(sqlite3*);
2967 void sqlite3ChangeCookie(Parse*, int);
2968 
2969 #if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
2970 void sqlite3MaterializeView(Parse*, Table*, Expr*, int);
2971 #endif
2972 
2973 #ifndef SQLITE_OMIT_TRIGGER
2974   void sqlite3BeginTrigger(Parse*, Token*,Token*,int,int,IdList*,SrcList*,
2975                            Expr*,int, int);
2976   void sqlite3FinishTrigger(Parse*, TriggerStep*, Token*);
2977   void sqlite3DropTrigger(Parse*, SrcList*, int);
2978   void sqlite3DropTriggerPtr(Parse*, Trigger*);
2979   Trigger *sqlite3TriggersExist(Parse *, Table*, int, ExprList*, int *pMask);
2980   Trigger *sqlite3TriggerList(Parse *, Table *);
2981   void sqlite3CodeRowTrigger(Parse*, Trigger *, int, ExprList*, int, Table *,
2982                             int, int, int);
2983   void sqlite3CodeRowTriggerDirect(Parse *, Trigger *, Table *, int, int, int);
2984   void sqliteViewTriggers(Parse*, Table*, Expr*, int, ExprList*);
2985   void sqlite3DeleteTriggerStep(sqlite3*, TriggerStep*);
2986   TriggerStep *sqlite3TriggerSelectStep(sqlite3*,Select*);
2987   TriggerStep *sqlite3TriggerInsertStep(sqlite3*,Token*, IdList*,
2988                                         ExprList*,Select*,u8);
2989   TriggerStep *sqlite3TriggerUpdateStep(sqlite3*,Token*,ExprList*, Expr*, u8);
2990   TriggerStep *sqlite3TriggerDeleteStep(sqlite3*,Token*, Expr*);
2991   void sqlite3DeleteTrigger(sqlite3*, Trigger*);
2992   void sqlite3UnlinkAndDeleteTrigger(sqlite3*,int,const char*);
2993   u32 sqlite3TriggerColmask(Parse*,Trigger*,ExprList*,int,int,Table*,int);
2994 # define sqlite3ParseToplevel(p) ((p)->pToplevel ? (p)->pToplevel : (p))
2995 #else
2996 # define sqlite3TriggersExist(B,C,D,E,F) 0
2997 # define sqlite3DeleteTrigger(A,B)
2998 # define sqlite3DropTriggerPtr(A,B)
2999 # define sqlite3UnlinkAndDeleteTrigger(A,B,C)
3000 # define sqlite3CodeRowTrigger(A,B,C,D,E,F,G,H,I)
3001 # define sqlite3CodeRowTriggerDirect(A,B,C,D,E,F)
3002 # define sqlite3TriggerList(X, Y) 0
3003 # define sqlite3ParseToplevel(p) p
3004 # define sqlite3TriggerColmask(A,B,C,D,E,F,G) 0
3005 #endif
3006 
3007 int sqlite3JoinType(Parse*, Token*, Token*, Token*);
3008 void sqlite3CreateForeignKey(Parse*, ExprList*, Token*, ExprList*, int);
3009 void sqlite3DeferForeignKey(Parse*, int);
3010 #ifndef SQLITE_OMIT_AUTHORIZATION
3011   void sqlite3AuthRead(Parse*,Expr*,Schema*,SrcList*);
3012   int sqlite3AuthCheck(Parse*,int, const char*, const char*, const char*);
3013   void sqlite3AuthContextPush(Parse*, AuthContext*, const char*);
3014   void sqlite3AuthContextPop(AuthContext*);
3015   int sqlite3AuthReadCol(Parse*, const char *, const char *, int);
3016 #else
3017 # define sqlite3AuthRead(a,b,c,d)
3018 # define sqlite3AuthCheck(a,b,c,d,e)    SQLITE_OK
3019 # define sqlite3AuthContextPush(a,b,c)
3020 # define sqlite3AuthContextPop(a)  ((void)(a))
3021 #endif
3022 void sqlite3Attach(Parse*, Expr*, Expr*, Expr*);
3023 void sqlite3Detach(Parse*, Expr*);
3024 int sqlite3FixInit(DbFixer*, Parse*, int, const char*, const Token*);
3025 int sqlite3FixSrcList(DbFixer*, SrcList*);
3026 int sqlite3FixSelect(DbFixer*, Select*);
3027 int sqlite3FixExpr(DbFixer*, Expr*);
3028 int sqlite3FixExprList(DbFixer*, ExprList*);
3029 int sqlite3FixTriggerStep(DbFixer*, TriggerStep*);
3030 int sqlite3AtoF(const char *z, double*, int, u8);
3031 int sqlite3GetInt32(const char *, int*);
3032 int sqlite3Atoi(const char*);
3033 int sqlite3Utf16ByteLen(const void *pData, int nChar);
3034 int sqlite3Utf8CharLen(const char *pData, int nByte);
3035 u32 sqlite3Utf8Read(const u8**);
3036 
3037 /*
3038 ** Routines to read and write variable-length integers.  These used to
3039 ** be defined locally, but now we use the varint routines in the util.c
3040 ** file.  Code should use the MACRO forms below, as the Varint32 versions
3041 ** are coded to assume the single byte case is already handled (which
3042 ** the MACRO form does).
3043 */
3044 int sqlite3PutVarint(unsigned char*, u64);
3045 int sqlite3PutVarint32(unsigned char*, u32);
3046 u8 sqlite3GetVarint(const unsigned char *, u64 *);
3047 u8 sqlite3GetVarint32(const unsigned char *, u32 *);
3048 int sqlite3VarintLen(u64 v);
3049 
3050 /*
3051 ** The header of a record consists of a sequence variable-length integers.
3052 ** These integers are almost always small and are encoded as a single byte.
3053 ** The following macros take advantage this fact to provide a fast encode
3054 ** and decode of the integers in a record header.  It is faster for the common
3055 ** case where the integer is a single byte.  It is a little slower when the
3056 ** integer is two or more bytes.  But overall it is faster.
3057 **
3058 ** The following expressions are equivalent:
3059 **
3060 **     x = sqlite3GetVarint32( A, &B );
3061 **     x = sqlite3PutVarint32( A, B );
3062 **
3063 **     x = getVarint32( A, B );
3064 **     x = putVarint32( A, B );
3065 **
3066 */
3067 #define getVarint32(A,B)  \
3068   (u8)((*(A)<(u8)0x80)?((B)=(u32)*(A)),1:sqlite3GetVarint32((A),(u32 *)&(B)))
3069 #define putVarint32(A,B)  \
3070   (u8)(((u32)(B)<(u32)0x80)?(*(A)=(unsigned char)(B)),1:\
3071   sqlite3PutVarint32((A),(B)))
3072 #define getVarint    sqlite3GetVarint
3073 #define putVarint    sqlite3PutVarint
3074 
3075 
3076 const char *sqlite3IndexAffinityStr(Vdbe *, Index *);
3077 void sqlite3TableAffinityStr(Vdbe *, Table *);
3078 char sqlite3CompareAffinity(Expr *pExpr, char aff2);
3079 int sqlite3IndexAffinityOk(Expr *pExpr, char idx_affinity);
3080 char sqlite3ExprAffinity(Expr *pExpr);
3081 int sqlite3Atoi64(const char*, i64*, int, u8);
3082 void sqlite3Error(sqlite3*, int, const char*,...);
3083 void *sqlite3HexToBlob(sqlite3*, const char *z, int n);
3084 u8 sqlite3HexToInt(int h);
3085 int sqlite3TwoPartName(Parse *, Token *, Token *, Token **);
3086 
3087 #if defined(SQLITE_DEBUG) || defined(SQLITE_TEST) || \
3088     defined(SQLITE_DEBUG_OS_TRACE)
3089 const char *sqlite3ErrName(int);
3090 #endif
3091 
3092 const char *sqlite3ErrStr(int);
3093 int sqlite3ReadSchema(Parse *pParse);
3094 CollSeq *sqlite3FindCollSeq(sqlite3*,u8 enc, const char*,int);
3095 CollSeq *sqlite3LocateCollSeq(Parse *pParse, const char*zName);
3096 CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr);
3097 Expr *sqlite3ExprAddCollateToken(Parse *pParse, Expr*, Token*);
3098 Expr *sqlite3ExprAddCollateString(Parse*,Expr*,const char*);
3099 Expr *sqlite3ExprSkipCollate(Expr*);
3100 int sqlite3CheckCollSeq(Parse *, CollSeq *);
3101 int sqlite3CheckObjectName(Parse *, const char *);
3102 void sqlite3VdbeSetChanges(sqlite3 *, int);
3103 int sqlite3AddInt64(i64*,i64);
3104 int sqlite3SubInt64(i64*,i64);
3105 int sqlite3MulInt64(i64*,i64);
3106 int sqlite3AbsInt32(int);
3107 #ifdef SQLITE_ENABLE_8_3_NAMES
3108 void sqlite3FileSuffix3(const char*, char*);
3109 #else
3110 # define sqlite3FileSuffix3(X,Y)
3111 #endif
3112 u8 sqlite3GetBoolean(const char *z,int);
3113 
3114 const void *sqlite3ValueText(sqlite3_value*, u8);
3115 int sqlite3ValueBytes(sqlite3_value*, u8);
3116 void sqlite3ValueSetStr(sqlite3_value*, int, const void *,u8,
3117                         void(*)(void*));
3118 void sqlite3ValueFree(sqlite3_value*);
3119 sqlite3_value *sqlite3ValueNew(sqlite3 *);
3120 char *sqlite3Utf16to8(sqlite3 *, const void*, int, u8);
3121 #ifdef SQLITE_ENABLE_STAT3
3122 char *sqlite3Utf8to16(sqlite3 *, u8, char *, int, int *);
3123 #endif
3124 int sqlite3ValueFromExpr(sqlite3 *, Expr *, u8, u8, sqlite3_value **);
3125 void sqlite3ValueApplyAffinity(sqlite3_value *, u8, u8);
3126 #ifndef SQLITE_AMALGAMATION
3127 extern const unsigned char sqlite3OpcodeProperty[];
3128 extern const unsigned char sqlite3UpperToLower[];
3129 extern const unsigned char sqlite3CtypeMap[];
3130 extern const Token sqlite3IntTokens[];
3131 extern SQLITE_WSD struct Sqlite3Config sqlite3Config;
3132 extern SQLITE_WSD FuncDefHash sqlite3GlobalFunctions;
3133 #ifndef SQLITE_OMIT_WSD
3134 extern int sqlite3PendingByte;
3135 #endif
3136 #endif
3137 void sqlite3RootPageMoved(sqlite3*, int, int, int);
3138 void sqlite3Reindex(Parse*, Token*, Token*);
3139 void sqlite3AlterFunctions(void);
3140 void sqlite3AlterRenameTable(Parse*, SrcList*, Token*);
3141 int sqlite3GetToken(const unsigned char *, int *);
3142 void sqlite3NestedParse(Parse*, const char*, ...);
3143 void sqlite3ExpirePreparedStatements(sqlite3*);
3144 int sqlite3CodeSubselect(Parse *, Expr *, int, int);
3145 void sqlite3SelectPrep(Parse*, Select*, NameContext*);
3146 int sqlite3MatchSpanName(const char*, const char*, const char*, const char*);
3147 int sqlite3ResolveExprNames(NameContext*, Expr*);
3148 void sqlite3ResolveSelectNames(Parse*, Select*, NameContext*);
3149 int sqlite3ResolveOrderGroupBy(Parse*, Select*, ExprList*, const char*);
3150 void sqlite3ColumnDefault(Vdbe *, Table *, int, int);
3151 void sqlite3AlterFinishAddColumn(Parse *, Token *);
3152 void sqlite3AlterBeginAddColumn(Parse *, SrcList *);
3153 CollSeq *sqlite3GetCollSeq(Parse*, u8, CollSeq *, const char*);
3154 char sqlite3AffinityType(const char*);
3155 void sqlite3Analyze(Parse*, Token*, Token*);
3156 int sqlite3InvokeBusyHandler(BusyHandler*);
3157 int sqlite3FindDb(sqlite3*, Token*);
3158 int sqlite3FindDbName(sqlite3 *, const char *);
3159 int sqlite3AnalysisLoad(sqlite3*,int iDB);
3160 void sqlite3DeleteIndexSamples(sqlite3*,Index*);
3161 void sqlite3DefaultRowEst(Index*);
3162 void sqlite3RegisterLikeFunctions(sqlite3*, int);
3163 int sqlite3IsLikeFunction(sqlite3*,Expr*,int*,char*);
3164 void sqlite3MinimumFileFormat(Parse*, int, int);
3165 void sqlite3SchemaClear(void *);
3166 Schema *sqlite3SchemaGet(sqlite3 *, Btree *);
3167 int sqlite3SchemaToIndex(sqlite3 *db, Schema *);
3168 KeyInfo *sqlite3IndexKeyinfo(Parse *, Index *);
3169 int sqlite3CreateFunc(sqlite3 *, const char *, int, int, void *,
3170   void (*)(sqlite3_context*,int,sqlite3_value **),
3171   void (*)(sqlite3_context*,int,sqlite3_value **), void (*)(sqlite3_context*),
3172   FuncDestructor *pDestructor
3173 );
3174 int sqlite3ApiExit(sqlite3 *db, int);
3175 int sqlite3OpenTempDatabase(Parse *);
3176 
3177 void sqlite3StrAccumInit(StrAccum*, char*, int, int);
3178 void sqlite3StrAccumAppend(StrAccum*,const char*,int);
3179 void sqlite3AppendSpace(StrAccum*,int);
3180 char *sqlite3StrAccumFinish(StrAccum*);
3181 void sqlite3StrAccumReset(StrAccum*);
3182 void sqlite3SelectDestInit(SelectDest*,int,int);
3183 Expr *sqlite3CreateColumnExpr(sqlite3 *, SrcList *, int, int);
3184 
3185 void sqlite3BackupRestart(sqlite3_backup *);
3186 void sqlite3BackupUpdate(sqlite3_backup *, Pgno, const u8 *);
3187 
3188 /*
3189 ** The interface to the LEMON-generated parser
3190 */
3191 void *sqlite3ParserAlloc(void*(*)(size_t));
3192 void sqlite3ParserFree(void*, void(*)(void*));
3193 void sqlite3Parser(void*, int, Token, Parse*);
3194 #ifdef YYTRACKMAXSTACKDEPTH
3195   int sqlite3ParserStackPeak(void*);
3196 #endif
3197 
3198 void sqlite3AutoLoadExtensions(sqlite3*);
3199 #ifndef SQLITE_OMIT_LOAD_EXTENSION
3200   void sqlite3CloseExtensions(sqlite3*);
3201 #else
3202 # define sqlite3CloseExtensions(X)
3203 #endif
3204 
3205 #ifndef SQLITE_OMIT_SHARED_CACHE
3206   void sqlite3TableLock(Parse *, int, int, u8, const char *);
3207 #else
3208   #define sqlite3TableLock(v,w,x,y,z)
3209 #endif
3210 
3211 #ifdef SQLITE_TEST
3212   int sqlite3Utf8To8(unsigned char*);
3213 #endif
3214 
3215 #ifdef SQLITE_OMIT_VIRTUALTABLE
3216 #  define sqlite3VtabClear(Y)
3217 #  define sqlite3VtabSync(X,Y) SQLITE_OK
3218 #  define sqlite3VtabRollback(X)
3219 #  define sqlite3VtabCommit(X)
3220 #  define sqlite3VtabInSync(db) 0
3221 #  define sqlite3VtabLock(X)
3222 #  define sqlite3VtabUnlock(X)
3223 #  define sqlite3VtabUnlockList(X)
3224 #  define sqlite3VtabSavepoint(X, Y, Z) SQLITE_OK
3225 #  define sqlite3GetVTable(X,Y)  ((VTable*)0)
3226 #else
3227    void sqlite3VtabClear(sqlite3 *db, Table*);
3228    void sqlite3VtabDisconnect(sqlite3 *db, Table *p);
3229    int sqlite3VtabSync(sqlite3 *db, char **);
3230    int sqlite3VtabRollback(sqlite3 *db);
3231    int sqlite3VtabCommit(sqlite3 *db);
3232    void sqlite3VtabLock(VTable *);
3233    void sqlite3VtabUnlock(VTable *);
3234    void sqlite3VtabUnlockList(sqlite3*);
3235    int sqlite3VtabSavepoint(sqlite3 *, int, int);
3236    VTable *sqlite3GetVTable(sqlite3*, Table*);
3237 #  define sqlite3VtabInSync(db) ((db)->nVTrans>0 && (db)->aVTrans==0)
3238 #endif
3239 void sqlite3VtabMakeWritable(Parse*,Table*);
3240 void sqlite3VtabBeginParse(Parse*, Token*, Token*, Token*, int);
3241 void sqlite3VtabFinishParse(Parse*, Token*);
3242 void sqlite3VtabArgInit(Parse*);
3243 void sqlite3VtabArgExtend(Parse*, Token*);
3244 int sqlite3VtabCallCreate(sqlite3*, int, const char *, char **);
3245 int sqlite3VtabCallConnect(Parse*, Table*);
3246 int sqlite3VtabCallDestroy(sqlite3*, int, const char *);
3247 int sqlite3VtabBegin(sqlite3 *, VTable *);
3248 FuncDef *sqlite3VtabOverloadFunction(sqlite3 *,FuncDef*, int nArg, Expr*);
3249 void sqlite3InvalidFunction(sqlite3_context*,int,sqlite3_value**);
3250 int sqlite3VdbeParameterIndex(Vdbe*, const char*, int);
3251 int sqlite3TransferBindings(sqlite3_stmt *, sqlite3_stmt *);
3252 int sqlite3Reprepare(Vdbe*);
3253 void sqlite3ExprListCheckLength(Parse*, ExprList*, const char*);
3254 CollSeq *sqlite3BinaryCompareCollSeq(Parse *, Expr *, Expr *);
3255 int sqlite3TempInMemory(const sqlite3*);
3256 const char *sqlite3JournalModename(int);
3257 #ifndef SQLITE_OMIT_WAL
3258   int sqlite3Checkpoint(sqlite3*, int, int, int*, int*);
3259   int sqlite3WalDefaultHook(void*,sqlite3*,const char*,int);
3260 #endif
3261 
3262 /* Declarations for functions in fkey.c. All of these are replaced by
3263 ** no-op macros if OMIT_FOREIGN_KEY is defined. In this case no foreign
3264 ** key functionality is available. If OMIT_TRIGGER is defined but
3265 ** OMIT_FOREIGN_KEY is not, only some of the functions are no-oped. In
3266 ** this case foreign keys are parsed, but no other functionality is
3267 ** provided (enforcement of FK constraints requires the triggers sub-system).
3268 */
3269 #if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)
3270   void sqlite3FkCheck(Parse*, Table*, int, int);
3271   void sqlite3FkDropTable(Parse*, SrcList *, Table*);
3272   void sqlite3FkActions(Parse*, Table*, ExprList*, int);
3273   int sqlite3FkRequired(Parse*, Table*, int*, int);
3274   u32 sqlite3FkOldmask(Parse*, Table*);
3275   FKey *sqlite3FkReferences(Table *);
3276 #else
3277   #define sqlite3FkActions(a,b,c,d)
3278   #define sqlite3FkCheck(a,b,c,d)
3279   #define sqlite3FkDropTable(a,b,c)
3280   #define sqlite3FkOldmask(a,b)      0
3281   #define sqlite3FkRequired(a,b,c,d) 0
3282 #endif
3283 #ifndef SQLITE_OMIT_FOREIGN_KEY
3284   void sqlite3FkDelete(sqlite3 *, Table*);
3285   int sqlite3FkLocateIndex(Parse*,Table*,FKey*,Index**,int**);
3286 #else
3287   #define sqlite3FkDelete(a,b)
3288   #define sqlite3FkLocateIndex(a,b,c,d,e)
3289 #endif
3290 
3291 
3292 /*
3293 ** Available fault injectors.  Should be numbered beginning with 0.
3294 */
3295 #define SQLITE_FAULTINJECTOR_MALLOC     0
3296 #define SQLITE_FAULTINJECTOR_COUNT      1
3297 
3298 /*
3299 ** The interface to the code in fault.c used for identifying "benign"
3300 ** malloc failures. This is only present if SQLITE_OMIT_BUILTIN_TEST
3301 ** is not defined.
3302 */
3303 #ifndef SQLITE_OMIT_BUILTIN_TEST
3304   void sqlite3BeginBenignMalloc(void);
3305   void sqlite3EndBenignMalloc(void);
3306 #else
3307   #define sqlite3BeginBenignMalloc()
3308   #define sqlite3EndBenignMalloc()
3309 #endif
3310 
3311 #define IN_INDEX_ROWID           1
3312 #define IN_INDEX_EPH             2
3313 #define IN_INDEX_INDEX_ASC       3
3314 #define IN_INDEX_INDEX_DESC      4
3315 int sqlite3FindInIndex(Parse *, Expr *, int*);
3316 
3317 #ifdef SQLITE_ENABLE_ATOMIC_WRITE
3318   int sqlite3JournalOpen(sqlite3_vfs *, const char *, sqlite3_file *, int, int);
3319   int sqlite3JournalSize(sqlite3_vfs *);
3320   int sqlite3JournalCreate(sqlite3_file *);
3321   int sqlite3JournalExists(sqlite3_file *p);
3322 #else
3323   #define sqlite3JournalSize(pVfs) ((pVfs)->szOsFile)
3324   #define sqlite3JournalExists(p) 1
3325 #endif
3326 
3327 void sqlite3MemJournalOpen(sqlite3_file *);
3328 int sqlite3MemJournalSize(void);
3329 int sqlite3IsMemJournal(sqlite3_file *);
3330 
3331 #if SQLITE_MAX_EXPR_DEPTH>0
3332   void sqlite3ExprSetHeight(Parse *pParse, Expr *p);
3333   int sqlite3SelectExprHeight(Select *);
3334   int sqlite3ExprCheckHeight(Parse*, int);
3335 #else
3336   #define sqlite3ExprSetHeight(x,y)
3337   #define sqlite3SelectExprHeight(x) 0
3338   #define sqlite3ExprCheckHeight(x,y)
3339 #endif
3340 
3341 u32 sqlite3Get4byte(const u8*);
3342 void sqlite3Put4byte(u8*, u32);
3343 
3344 #ifdef SQLITE_ENABLE_UNLOCK_NOTIFY
3345   void sqlite3ConnectionBlocked(sqlite3 *, sqlite3 *);
3346   void sqlite3ConnectionUnlocked(sqlite3 *db);
3347   void sqlite3ConnectionClosed(sqlite3 *db);
3348 #else
3349   #define sqlite3ConnectionBlocked(x,y)
3350   #define sqlite3ConnectionUnlocked(x)
3351   #define sqlite3ConnectionClosed(x)
3352 #endif
3353 
3354 #ifdef SQLITE_DEBUG
3355   void sqlite3ParserTrace(FILE*, char *);
3356 #endif
3357 
3358 /*
3359 ** If the SQLITE_ENABLE IOTRACE exists then the global variable
3360 ** sqlite3IoTrace is a pointer to a printf-like routine used to
3361 ** print I/O tracing messages.
3362 */
3363 #ifdef SQLITE_ENABLE_IOTRACE
3364 # define IOTRACE(A)  if( sqlite3IoTrace ){ sqlite3IoTrace A; }
3365   void sqlite3VdbeIOTraceSql(Vdbe*);
3366 SQLITE_EXTERN void (*sqlite3IoTrace)(const char*,...);
3367 #else
3368 # define IOTRACE(A)
3369 # define sqlite3VdbeIOTraceSql(X)
3370 #endif
3371 
3372 /*
3373 ** These routines are available for the mem2.c debugging memory allocator
3374 ** only.  They are used to verify that different "types" of memory
3375 ** allocations are properly tracked by the system.
3376 **
3377 ** sqlite3MemdebugSetType() sets the "type" of an allocation to one of
3378 ** the MEMTYPE_* macros defined below.  The type must be a bitmask with
3379 ** a single bit set.
3380 **
3381 ** sqlite3MemdebugHasType() returns true if any of the bits in its second
3382 ** argument match the type set by the previous sqlite3MemdebugSetType().
3383 ** sqlite3MemdebugHasType() is intended for use inside assert() statements.
3384 **
3385 ** sqlite3MemdebugNoType() returns true if none of the bits in its second
3386 ** argument match the type set by the previous sqlite3MemdebugSetType().
3387 **
3388 ** Perhaps the most important point is the difference between MEMTYPE_HEAP
3389 ** and MEMTYPE_LOOKASIDE.  If an allocation is MEMTYPE_LOOKASIDE, that means
3390 ** it might have been allocated by lookaside, except the allocation was
3391 ** too large or lookaside was already full.  It is important to verify
3392 ** that allocations that might have been satisfied by lookaside are not
3393 ** passed back to non-lookaside free() routines.  Asserts such as the
3394 ** example above are placed on the non-lookaside free() routines to verify
3395 ** this constraint.
3396 **
3397 ** All of this is no-op for a production build.  It only comes into
3398 ** play when the SQLITE_MEMDEBUG compile-time option is used.
3399 */
3400 #ifdef SQLITE_MEMDEBUG
3401   void sqlite3MemdebugSetType(void*,u8);
3402   int sqlite3MemdebugHasType(void*,u8);
3403   int sqlite3MemdebugNoType(void*,u8);
3404 #else
3405 # define sqlite3MemdebugSetType(X,Y)  /* no-op */
3406 # define sqlite3MemdebugHasType(X,Y)  1
3407 # define sqlite3MemdebugNoType(X,Y)   1
3408 #endif
3409 #define MEMTYPE_HEAP       0x01  /* General heap allocations */
3410 #define MEMTYPE_LOOKASIDE  0x02  /* Might have been lookaside memory */
3411 #define MEMTYPE_SCRATCH    0x04  /* Scratch allocations */
3412 #define MEMTYPE_PCACHE     0x08  /* Page cache allocations */
3413 #define MEMTYPE_DB         0x10  /* Uses sqlite3DbMalloc, not sqlite_malloc */
3414 
3415 #endif /* _SQLITEINT_H_ */
3416