xref: /sqlite-3.40.0/src/sqliteInt.h (revision ab755ac8)
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 libary 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.  But Mac OS X is different.
197 ** The _XOPEN_SOURCE define causes problems for Mac OS X we are told,
198 ** so it is omitted there.  See ticket #2673.
199 **
200 ** Later we learn that _XOPEN_SOURCE is poorly or incorrectly
201 ** implemented on some systems.  So we avoid defining it at all
202 ** if it is already defined or if it is unneeded because we are
203 ** not doing a threadsafe build.  Ticket #2681.
204 **
205 ** See also ticket #2741.
206 */
207 #if !defined(_XOPEN_SOURCE) && !defined(__DARWIN__) \
208  && !defined(__APPLE__) && SQLITE_THREADSAFE
209 #  define _XOPEN_SOURCE 500  /* Needed to enable pthread recursive mutexes */
210 #endif
211 
212 /*
213 ** The TCL headers are only needed when compiling the TCL bindings.
214 */
215 #if defined(SQLITE_TCL) || defined(TCLSH)
216 # include <tcl.h>
217 #endif
218 
219 /*
220 ** NDEBUG and SQLITE_DEBUG are opposites.  It should always be true that
221 ** defined(NDEBUG)==!defined(SQLITE_DEBUG).  If this is not currently true,
222 ** make it true by defining or undefining NDEBUG.
223 **
224 ** Setting NDEBUG makes the code smaller and run faster by disabling the
225 ** number assert() statements in the code.  So we want the default action
226 ** to be for NDEBUG to be set and NDEBUG to be undefined only if SQLITE_DEBUG
227 ** is set.  Thus NDEBUG becomes an opt-in rather than an opt-out
228 ** feature.
229 */
230 #if !defined(NDEBUG) && !defined(SQLITE_DEBUG)
231 # define NDEBUG 1
232 #endif
233 #if defined(NDEBUG) && defined(SQLITE_DEBUG)
234 # undef NDEBUG
235 #endif
236 
237 /*
238 ** The testcase() macro is used to aid in coverage testing.  When
239 ** doing coverage testing, the condition inside the argument to
240 ** testcase() must be evaluated both true and false in order to
241 ** get full branch coverage.  The testcase() macro is inserted
242 ** to help ensure adequate test coverage in places where simple
243 ** condition/decision coverage is inadequate.  For example, testcase()
244 ** can be used to make sure boundary values are tested.  For
245 ** bitmask tests, testcase() can be used to make sure each bit
246 ** is significant and used at least once.  On switch statements
247 ** where multiple cases go to the same block of code, testcase()
248 ** can insure that all cases are evaluated.
249 **
250 */
251 #ifdef SQLITE_COVERAGE_TEST
252   void sqlite3Coverage(int);
253 # define testcase(X)  if( X ){ sqlite3Coverage(__LINE__); }
254 #else
255 # define testcase(X)
256 #endif
257 
258 /*
259 ** The TESTONLY macro is used to enclose variable declarations or
260 ** other bits of code that are needed to support the arguments
261 ** within testcase() and assert() macros.
262 */
263 #if !defined(NDEBUG) || defined(SQLITE_COVERAGE_TEST)
264 # define TESTONLY(X)  X
265 #else
266 # define TESTONLY(X)
267 #endif
268 
269 /*
270 ** Sometimes we need a small amount of code such as a variable initialization
271 ** to setup for a later assert() statement.  We do not want this code to
272 ** appear when assert() is disabled.  The following macro is therefore
273 ** used to contain that setup code.  The "VVA" acronym stands for
274 ** "Verification, Validation, and Accreditation".  In other words, the
275 ** code within VVA_ONLY() will only run during verification processes.
276 */
277 #ifndef NDEBUG
278 # define VVA_ONLY(X)  X
279 #else
280 # define VVA_ONLY(X)
281 #endif
282 
283 /*
284 ** The ALWAYS and NEVER macros surround boolean expressions which
285 ** are intended to always be true or false, respectively.  Such
286 ** expressions could be omitted from the code completely.  But they
287 ** are included in a few cases in order to enhance the resilience
288 ** of SQLite to unexpected behavior - to make the code "self-healing"
289 ** or "ductile" rather than being "brittle" and crashing at the first
290 ** hint of unplanned behavior.
291 **
292 ** In other words, ALWAYS and NEVER are added for defensive code.
293 **
294 ** When doing coverage testing ALWAYS and NEVER are hard-coded to
295 ** be true and false so that the unreachable code then specify will
296 ** not be counted as untested code.
297 */
298 #if defined(SQLITE_COVERAGE_TEST)
299 # define ALWAYS(X)      (1)
300 # define NEVER(X)       (0)
301 #elif !defined(NDEBUG)
302 # define ALWAYS(X)      ((X)?1:(assert(0),0))
303 # define NEVER(X)       ((X)?(assert(0),1):0)
304 #else
305 # define ALWAYS(X)      (X)
306 # define NEVER(X)       (X)
307 #endif
308 
309 /*
310 ** Return true (non-zero) if the input is a integer that is too large
311 ** to fit in 32-bits.  This macro is used inside of various testcase()
312 ** macros to verify that we have tested SQLite for large-file support.
313 */
314 #define IS_BIG_INT(X)  (((X)&~(i64)0xffffffff)!=0)
315 
316 /*
317 ** The macro unlikely() is a hint that surrounds a boolean
318 ** expression that is usually false.  Macro likely() surrounds
319 ** a boolean expression that is usually true.  GCC is able to
320 ** use these hints to generate better code, sometimes.
321 */
322 #if defined(__GNUC__) && 0
323 # define likely(X)    __builtin_expect((X),1)
324 # define unlikely(X)  __builtin_expect((X),0)
325 #else
326 # define likely(X)    !!(X)
327 # define unlikely(X)  !!(X)
328 #endif
329 
330 #include "sqlite3.h"
331 #include "hash.h"
332 #include "parse.h"
333 #include <stdio.h>
334 #include <stdlib.h>
335 #include <string.h>
336 #include <assert.h>
337 #include <stddef.h>
338 
339 /*
340 ** If compiling for a processor that lacks floating point support,
341 ** substitute integer for floating-point
342 */
343 #ifdef SQLITE_OMIT_FLOATING_POINT
344 # define double sqlite_int64
345 # define float sqlite_int64
346 # define LONGDOUBLE_TYPE sqlite_int64
347 # ifndef SQLITE_BIG_DBL
348 #   define SQLITE_BIG_DBL (((sqlite3_int64)1)<<50)
349 # endif
350 # define SQLITE_OMIT_DATETIME_FUNCS 1
351 # define SQLITE_OMIT_TRACE 1
352 # undef SQLITE_MIXED_ENDIAN_64BIT_FLOAT
353 # undef SQLITE_HAVE_ISNAN
354 #endif
355 #ifndef SQLITE_BIG_DBL
356 # define SQLITE_BIG_DBL (1e99)
357 #endif
358 
359 /*
360 ** OMIT_TEMPDB is set to 1 if SQLITE_OMIT_TEMPDB is defined, or 0
361 ** afterward. Having this macro allows us to cause the C compiler
362 ** to omit code used by TEMP tables without messy #ifndef statements.
363 */
364 #ifdef SQLITE_OMIT_TEMPDB
365 #define OMIT_TEMPDB 1
366 #else
367 #define OMIT_TEMPDB 0
368 #endif
369 
370 /*
371 ** The "file format" number is an integer that is incremented whenever
372 ** the VDBE-level file format changes.  The following macros define the
373 ** the default file format for new databases and the maximum file format
374 ** that the library can read.
375 */
376 #define SQLITE_MAX_FILE_FORMAT 4
377 #ifndef SQLITE_DEFAULT_FILE_FORMAT
378 # define SQLITE_DEFAULT_FILE_FORMAT 4
379 #endif
380 
381 /*
382 ** Determine whether triggers are recursive by default.  This can be
383 ** changed at run-time using a pragma.
384 */
385 #ifndef SQLITE_DEFAULT_RECURSIVE_TRIGGERS
386 # define SQLITE_DEFAULT_RECURSIVE_TRIGGERS 0
387 #endif
388 
389 /*
390 ** Provide a default value for SQLITE_TEMP_STORE in case it is not specified
391 ** on the command-line
392 */
393 #ifndef SQLITE_TEMP_STORE
394 # define SQLITE_TEMP_STORE 1
395 #endif
396 
397 /*
398 ** GCC does not define the offsetof() macro so we'll have to do it
399 ** ourselves.
400 */
401 #ifndef offsetof
402 #define offsetof(STRUCTURE,FIELD) ((int)((char*)&((STRUCTURE*)0)->FIELD))
403 #endif
404 
405 /*
406 ** Check to see if this machine uses EBCDIC.  (Yes, believe it or
407 ** not, there are still machines out there that use EBCDIC.)
408 */
409 #if 'A' == '\301'
410 # define SQLITE_EBCDIC 1
411 #else
412 # define SQLITE_ASCII 1
413 #endif
414 
415 /*
416 ** Integers of known sizes.  These typedefs might change for architectures
417 ** where the sizes very.  Preprocessor macros are available so that the
418 ** types can be conveniently redefined at compile-type.  Like this:
419 **
420 **         cc '-DUINTPTR_TYPE=long long int' ...
421 */
422 #ifndef UINT32_TYPE
423 # ifdef HAVE_UINT32_T
424 #  define UINT32_TYPE uint32_t
425 # else
426 #  define UINT32_TYPE unsigned int
427 # endif
428 #endif
429 #ifndef UINT16_TYPE
430 # ifdef HAVE_UINT16_T
431 #  define UINT16_TYPE uint16_t
432 # else
433 #  define UINT16_TYPE unsigned short int
434 # endif
435 #endif
436 #ifndef INT16_TYPE
437 # ifdef HAVE_INT16_T
438 #  define INT16_TYPE int16_t
439 # else
440 #  define INT16_TYPE short int
441 # endif
442 #endif
443 #ifndef UINT8_TYPE
444 # ifdef HAVE_UINT8_T
445 #  define UINT8_TYPE uint8_t
446 # else
447 #  define UINT8_TYPE unsigned char
448 # endif
449 #endif
450 #ifndef INT8_TYPE
451 # ifdef HAVE_INT8_T
452 #  define INT8_TYPE int8_t
453 # else
454 #  define INT8_TYPE signed char
455 # endif
456 #endif
457 #ifndef LONGDOUBLE_TYPE
458 # define LONGDOUBLE_TYPE long double
459 #endif
460 typedef sqlite_int64 i64;          /* 8-byte signed integer */
461 typedef sqlite_uint64 u64;         /* 8-byte unsigned integer */
462 typedef UINT32_TYPE u32;           /* 4-byte unsigned integer */
463 typedef UINT16_TYPE u16;           /* 2-byte unsigned integer */
464 typedef INT16_TYPE i16;            /* 2-byte signed integer */
465 typedef UINT8_TYPE u8;             /* 1-byte unsigned integer */
466 typedef INT8_TYPE i8;              /* 1-byte signed integer */
467 
468 /*
469 ** SQLITE_MAX_U32 is a u64 constant that is the maximum u64 value
470 ** that can be stored in a u32 without loss of data.  The value
471 ** is 0x00000000ffffffff.  But because of quirks of some compilers, we
472 ** have to specify the value in the less intuitive manner shown:
473 */
474 #define SQLITE_MAX_U32  ((((u64)1)<<32)-1)
475 
476 /*
477 ** The datatype used to store estimates of the number of rows in a
478 ** table or index.  This is an unsigned integer type.  For 99.9% of
479 ** the world, a 32-bit integer is sufficient.  But a 64-bit integer
480 ** can be used at compile-time if desired.
481 */
482 #ifdef SQLITE_64BIT_STATS
483  typedef u64 tRowcnt;    /* 64-bit only if requested at compile-time */
484 #else
485  typedef u32 tRowcnt;    /* 32-bit is the default */
486 #endif
487 
488 /*
489 ** Macros to determine whether the machine is big or little endian,
490 ** evaluated at runtime.
491 */
492 #ifdef SQLITE_AMALGAMATION
493 const int sqlite3one = 1;
494 #else
495 extern const int sqlite3one;
496 #endif
497 #if defined(i386) || defined(__i386__) || defined(_M_IX86)\
498                              || defined(__x86_64) || defined(__x86_64__)
499 # define SQLITE_BIGENDIAN    0
500 # define SQLITE_LITTLEENDIAN 1
501 # define SQLITE_UTF16NATIVE  SQLITE_UTF16LE
502 #else
503 # define SQLITE_BIGENDIAN    (*(char *)(&sqlite3one)==0)
504 # define SQLITE_LITTLEENDIAN (*(char *)(&sqlite3one)==1)
505 # define SQLITE_UTF16NATIVE (SQLITE_BIGENDIAN?SQLITE_UTF16BE:SQLITE_UTF16LE)
506 #endif
507 
508 /*
509 ** Constants for the largest and smallest possible 64-bit signed integers.
510 ** These macros are designed to work correctly on both 32-bit and 64-bit
511 ** compilers.
512 */
513 #define LARGEST_INT64  (0xffffffff|(((i64)0x7fffffff)<<32))
514 #define SMALLEST_INT64 (((i64)-1) - LARGEST_INT64)
515 
516 /*
517 ** Round up a number to the next larger multiple of 8.  This is used
518 ** to force 8-byte alignment on 64-bit architectures.
519 */
520 #define ROUND8(x)     (((x)+7)&~7)
521 
522 /*
523 ** Round down to the nearest multiple of 8
524 */
525 #define ROUNDDOWN8(x) ((x)&~7)
526 
527 /*
528 ** Assert that the pointer X is aligned to an 8-byte boundary.  This
529 ** macro is used only within assert() to verify that the code gets
530 ** all alignment restrictions correct.
531 **
532 ** Except, if SQLITE_4_BYTE_ALIGNED_MALLOC is defined, then the
533 ** underlying malloc() implemention might return us 4-byte aligned
534 ** pointers.  In that case, only verify 4-byte alignment.
535 */
536 #ifdef SQLITE_4_BYTE_ALIGNED_MALLOC
537 # define EIGHT_BYTE_ALIGNMENT(X)   ((((char*)(X) - (char*)0)&3)==0)
538 #else
539 # define EIGHT_BYTE_ALIGNMENT(X)   ((((char*)(X) - (char*)0)&7)==0)
540 #endif
541 
542 /*
543 ** Disable MMAP on platforms where it is not supported
544 */
545 #if defined(__OpenBSD__) || defined(__QNXNTO__)
546 # undef SQLITE_DISABLE_MMAP
547 # define SQLITE_DISABLE_MMAP 1
548 #endif
549 
550 
551 /*
552 ** An instance of the following structure is used to store the busy-handler
553 ** callback for a given sqlite handle.
554 **
555 ** The sqlite.busyHandler member of the sqlite struct contains the busy
556 ** callback for the database handle. Each pager opened via the sqlite
557 ** handle is passed a pointer to sqlite.busyHandler. The busy-handler
558 ** callback is currently invoked only from within pager.c.
559 */
560 typedef struct BusyHandler BusyHandler;
561 struct BusyHandler {
562   int (*xFunc)(void *,int);  /* The busy callback */
563   void *pArg;                /* First arg to busy callback */
564   int nBusy;                 /* Incremented with each busy call */
565 };
566 
567 /*
568 ** Name of the master database table.  The master database table
569 ** is a special table that holds the names and attributes of all
570 ** user tables and indices.
571 */
572 #define MASTER_NAME       "sqlite_master"
573 #define TEMP_MASTER_NAME  "sqlite_temp_master"
574 
575 /*
576 ** The root-page of the master database table.
577 */
578 #define MASTER_ROOT       1
579 
580 /*
581 ** The name of the schema table.
582 */
583 #define SCHEMA_TABLE(x)  ((!OMIT_TEMPDB)&&(x==1)?TEMP_MASTER_NAME:MASTER_NAME)
584 
585 /*
586 ** A convenience macro that returns the number of elements in
587 ** an array.
588 */
589 #define ArraySize(X)    ((int)(sizeof(X)/sizeof(X[0])))
590 
591 /*
592 ** Determine if the argument is a power of two
593 */
594 #define IsPowerOfTwo(X) (((X)&((X)-1))==0)
595 
596 /*
597 ** The following value as a destructor means to use sqlite3DbFree().
598 ** The sqlite3DbFree() routine requires two parameters instead of the
599 ** one parameter that destructors normally want.  So we have to introduce
600 ** this magic value that the code knows to handle differently.  Any
601 ** pointer will work here as long as it is distinct from SQLITE_STATIC
602 ** and SQLITE_TRANSIENT.
603 */
604 #define SQLITE_DYNAMIC   ((sqlite3_destructor_type)sqlite3MallocSize)
605 
606 /*
607 ** When SQLITE_OMIT_WSD is defined, it means that the target platform does
608 ** not support Writable Static Data (WSD) such as global and static variables.
609 ** All variables must either be on the stack or dynamically allocated from
610 ** the heap.  When WSD is unsupported, the variable declarations scattered
611 ** throughout the SQLite code must become constants instead.  The SQLITE_WSD
612 ** macro is used for this purpose.  And instead of referencing the variable
613 ** directly, we use its constant as a key to lookup the run-time allocated
614 ** buffer that holds real variable.  The constant is also the initializer
615 ** for the run-time allocated buffer.
616 **
617 ** In the usual case where WSD is supported, the SQLITE_WSD and GLOBAL
618 ** macros become no-ops and have zero performance impact.
619 */
620 #ifdef SQLITE_OMIT_WSD
621   #define SQLITE_WSD const
622   #define GLOBAL(t,v) (*(t*)sqlite3_wsd_find((void*)&(v), sizeof(v)))
623   #define sqlite3GlobalConfig GLOBAL(struct Sqlite3Config, sqlite3Config)
624   int sqlite3_wsd_init(int N, int J);
625   void *sqlite3_wsd_find(void *K, int L);
626 #else
627   #define SQLITE_WSD
628   #define GLOBAL(t,v) v
629   #define sqlite3GlobalConfig sqlite3Config
630 #endif
631 
632 /*
633 ** The following macros are used to suppress compiler warnings and to
634 ** make it clear to human readers when a function parameter is deliberately
635 ** left unused within the body of a function. This usually happens when
636 ** a function is called via a function pointer. For example the
637 ** implementation of an SQL aggregate step callback may not use the
638 ** parameter indicating the number of arguments passed to the aggregate,
639 ** if it knows that this is enforced elsewhere.
640 **
641 ** When a function parameter is not used at all within the body of a function,
642 ** it is generally named "NotUsed" or "NotUsed2" to make things even clearer.
643 ** However, these macros may also be used to suppress warnings related to
644 ** parameters that may or may not be used depending on compilation options.
645 ** For example those parameters only used in assert() statements. In these
646 ** cases the parameters are named as per the usual conventions.
647 */
648 #define UNUSED_PARAMETER(x) (void)(x)
649 #define UNUSED_PARAMETER2(x,y) UNUSED_PARAMETER(x),UNUSED_PARAMETER(y)
650 
651 /*
652 ** Forward references to structures
653 */
654 typedef struct AggInfo AggInfo;
655 typedef struct AuthContext AuthContext;
656 typedef struct AutoincInfo AutoincInfo;
657 typedef struct Bitvec Bitvec;
658 typedef struct CollSeq CollSeq;
659 typedef struct Column Column;
660 typedef struct Db Db;
661 typedef struct Schema Schema;
662 typedef struct Expr Expr;
663 typedef struct ExprList ExprList;
664 typedef struct ExprSpan ExprSpan;
665 typedef struct FKey FKey;
666 typedef struct FuncDestructor FuncDestructor;
667 typedef struct FuncDef FuncDef;
668 typedef struct FuncDefHash FuncDefHash;
669 typedef struct IdList IdList;
670 typedef struct Index Index;
671 typedef struct IndexSample IndexSample;
672 typedef struct KeyClass KeyClass;
673 typedef struct KeyInfo KeyInfo;
674 typedef struct Lookaside Lookaside;
675 typedef struct LookasideSlot LookasideSlot;
676 typedef struct Module Module;
677 typedef struct NameContext NameContext;
678 typedef struct Parse Parse;
679 typedef struct RowSet RowSet;
680 typedef struct Savepoint Savepoint;
681 typedef struct Select Select;
682 typedef struct SelectDest SelectDest;
683 typedef struct SrcList SrcList;
684 typedef struct StrAccum StrAccum;
685 typedef struct Table Table;
686 typedef struct TableLock TableLock;
687 typedef struct Token Token;
688 typedef struct Trigger Trigger;
689 typedef struct TriggerPrg TriggerPrg;
690 typedef struct TriggerStep TriggerStep;
691 typedef struct UnpackedRecord UnpackedRecord;
692 typedef struct VTable VTable;
693 typedef struct VtabCtx VtabCtx;
694 typedef struct Walker Walker;
695 typedef struct WherePlan WherePlan;
696 typedef struct WhereInfo WhereInfo;
697 typedef struct WhereLevel WhereLevel;
698 
699 /*
700 ** Defer sourcing vdbe.h and btree.h until after the "u8" and
701 ** "BusyHandler" typedefs. vdbe.h also requires a few of the opaque
702 ** pointer types (i.e. FuncDef) defined above.
703 */
704 #include "btree.h"
705 #include "vdbe.h"
706 #include "pager.h"
707 #include "pcache.h"
708 
709 #include "os.h"
710 #include "mutex.h"
711 
712 
713 /*
714 ** Each database file to be accessed by the system is an instance
715 ** of the following structure.  There are normally two of these structures
716 ** in the sqlite.aDb[] array.  aDb[0] is the main database file and
717 ** aDb[1] is the database file used to hold temporary tables.  Additional
718 ** databases may be attached.
719 */
720 struct Db {
721   char *zName;         /* Name of this database */
722   Btree *pBt;          /* The B*Tree structure for this database file */
723   u8 inTrans;          /* 0: not writable.  1: Transaction.  2: Checkpoint */
724   u8 safety_level;     /* How aggressive at syncing data to disk */
725   Schema *pSchema;     /* Pointer to database schema (possibly shared) */
726 };
727 
728 /*
729 ** An instance of the following structure stores a database schema.
730 **
731 ** Most Schema objects are associated with a Btree.  The exception is
732 ** the Schema for the TEMP databaes (sqlite3.aDb[1]) which is free-standing.
733 ** In shared cache mode, a single Schema object can be shared by multiple
734 ** Btrees that refer to the same underlying BtShared object.
735 **
736 ** Schema objects are automatically deallocated when the last Btree that
737 ** references them is destroyed.   The TEMP Schema is manually freed by
738 ** sqlite3_close().
739 *
740 ** A thread must be holding a mutex on the corresponding Btree in order
741 ** to access Schema content.  This implies that the thread must also be
742 ** holding a mutex on the sqlite3 connection pointer that owns the Btree.
743 ** For a TEMP Schema, only the connection mutex is required.
744 */
745 struct Schema {
746   int schema_cookie;   /* Database schema version number for this file */
747   int iGeneration;     /* Generation counter.  Incremented with each change */
748   Hash tblHash;        /* All tables indexed by name */
749   Hash idxHash;        /* All (named) indices indexed by name */
750   Hash trigHash;       /* All triggers indexed by name */
751   Hash fkeyHash;       /* All foreign keys by referenced table name */
752   Table *pSeqTab;      /* The sqlite_sequence table used by AUTOINCREMENT */
753   u8 file_format;      /* Schema format version for this file */
754   u8 enc;              /* Text encoding used by this database */
755   u16 flags;           /* Flags associated with this schema */
756   int cache_size;      /* Number of pages to use in the cache */
757 };
758 
759 /*
760 ** These macros can be used to test, set, or clear bits in the
761 ** Db.pSchema->flags field.
762 */
763 #define DbHasProperty(D,I,P)     (((D)->aDb[I].pSchema->flags&(P))==(P))
764 #define DbHasAnyProperty(D,I,P)  (((D)->aDb[I].pSchema->flags&(P))!=0)
765 #define DbSetProperty(D,I,P)     (D)->aDb[I].pSchema->flags|=(P)
766 #define DbClearProperty(D,I,P)   (D)->aDb[I].pSchema->flags&=~(P)
767 
768 /*
769 ** Allowed values for the DB.pSchema->flags field.
770 **
771 ** The DB_SchemaLoaded flag is set after the database schema has been
772 ** read into internal hash tables.
773 **
774 ** DB_UnresetViews means that one or more views have column names that
775 ** have been filled out.  If the schema changes, these column names might
776 ** changes and so the view will need to be reset.
777 */
778 #define DB_SchemaLoaded    0x0001  /* The schema has been loaded */
779 #define DB_UnresetViews    0x0002  /* Some views have defined column names */
780 #define DB_Empty           0x0004  /* The file is empty (length 0 bytes) */
781 
782 /*
783 ** The number of different kinds of things that can be limited
784 ** using the sqlite3_limit() interface.
785 */
786 #define SQLITE_N_LIMIT (SQLITE_LIMIT_TRIGGER_DEPTH+1)
787 
788 /*
789 ** Lookaside malloc is a set of fixed-size buffers that can be used
790 ** to satisfy small transient memory allocation requests for objects
791 ** associated with a particular database connection.  The use of
792 ** lookaside malloc provides a significant performance enhancement
793 ** (approx 10%) by avoiding numerous malloc/free requests while parsing
794 ** SQL statements.
795 **
796 ** The Lookaside structure holds configuration information about the
797 ** lookaside malloc subsystem.  Each available memory allocation in
798 ** the lookaside subsystem is stored on a linked list of LookasideSlot
799 ** objects.
800 **
801 ** Lookaside allocations are only allowed for objects that are associated
802 ** with a particular database connection.  Hence, schema information cannot
803 ** be stored in lookaside because in shared cache mode the schema information
804 ** is shared by multiple database connections.  Therefore, while parsing
805 ** schema information, the Lookaside.bEnabled flag is cleared so that
806 ** lookaside allocations are not used to construct the schema objects.
807 */
808 struct Lookaside {
809   u16 sz;                 /* Size of each buffer in bytes */
810   u8 bEnabled;            /* False to disable new lookaside allocations */
811   u8 bMalloced;           /* True if pStart obtained from sqlite3_malloc() */
812   int nOut;               /* Number of buffers currently checked out */
813   int mxOut;              /* Highwater mark for nOut */
814   int anStat[3];          /* 0: hits.  1: size misses.  2: full misses */
815   LookasideSlot *pFree;   /* List of available buffers */
816   void *pStart;           /* First byte of available memory space */
817   void *pEnd;             /* First byte past end of available space */
818 };
819 struct LookasideSlot {
820   LookasideSlot *pNext;    /* Next buffer in the list of free buffers */
821 };
822 
823 /*
824 ** A hash table for function definitions.
825 **
826 ** Hash each FuncDef structure into one of the FuncDefHash.a[] slots.
827 ** Collisions are on the FuncDef.pHash chain.
828 */
829 struct FuncDefHash {
830   FuncDef *a[23];       /* Hash table for functions */
831 };
832 
833 /*
834 ** Each database connection is an instance of the following structure.
835 */
836 struct sqlite3 {
837   sqlite3_vfs *pVfs;            /* OS Interface */
838   struct Vdbe *pVdbe;           /* List of active virtual machines */
839   CollSeq *pDfltColl;           /* The default collating sequence (BINARY) */
840   sqlite3_mutex *mutex;         /* Connection mutex */
841   Db *aDb;                      /* All backends */
842   int nDb;                      /* Number of backends currently in use */
843   int flags;                    /* Miscellaneous flags. See below */
844   i64 lastRowid;                /* ROWID of most recent insert (see above) */
845   i64 mxMmap;                   /* Default mmap_limit setting */
846   unsigned int openFlags;       /* Flags passed to sqlite3_vfs.xOpen() */
847   int errCode;                  /* Most recent error code (SQLITE_*) */
848   int errMask;                  /* & result codes with this before returning */
849   u16 dbOptFlags;               /* Flags to enable/disable optimizations */
850   u8 autoCommit;                /* The auto-commit flag. */
851   u8 temp_store;                /* 1: file 2: memory 0: default */
852   u8 mallocFailed;              /* True if we have seen a malloc failure */
853   u8 dfltLockMode;              /* Default locking-mode for attached dbs */
854   signed char nextAutovac;      /* Autovac setting after VACUUM if >=0 */
855   u8 suppressErr;               /* Do not issue error messages if true */
856   u8 vtabOnConflict;            /* Value to return for s3_vtab_on_conflict() */
857   u8 isTransactionSavepoint;    /* True if the outermost savepoint is a TS */
858   int nextPagesize;             /* Pagesize after VACUUM if >0 */
859   u32 magic;                    /* Magic number for detect library misuse */
860   int nChange;                  /* Value returned by sqlite3_changes() */
861   int nTotalChange;             /* Value returned by sqlite3_total_changes() */
862   int aLimit[SQLITE_N_LIMIT];   /* Limits */
863   struct sqlite3InitInfo {      /* Information used during initialization */
864     int newTnum;                /* Rootpage of table being initialized */
865     u8 iDb;                     /* Which db file is being initialized */
866     u8 busy;                    /* TRUE if currently initializing */
867     u8 orphanTrigger;           /* Last statement is orphaned TEMP trigger */
868   } init;
869   int activeVdbeCnt;            /* Number of VDBEs currently executing */
870   int writeVdbeCnt;             /* Number of active VDBEs that are writing */
871   int vdbeExecCnt;              /* Number of nested calls to VdbeExec() */
872   int nExtension;               /* Number of loaded extensions */
873   void **aExtension;            /* Array of shared library handles */
874   void (*xTrace)(void*,const char*);        /* Trace function */
875   void *pTraceArg;                          /* Argument to the trace function */
876   void (*xProfile)(void*,const char*,u64);  /* Profiling function */
877   void *pProfileArg;                        /* Argument to profile function */
878   void *pCommitArg;                 /* Argument to xCommitCallback() */
879   int (*xCommitCallback)(void*);    /* Invoked at every commit. */
880   void *pRollbackArg;               /* Argument to xRollbackCallback() */
881   void (*xRollbackCallback)(void*); /* Invoked at every commit. */
882   void *pUpdateArg;
883   void (*xUpdateCallback)(void*,int, const char*,const char*,sqlite_int64);
884 #ifndef SQLITE_OMIT_WAL
885   int (*xWalCallback)(void *, sqlite3 *, const char *, int);
886   void *pWalArg;
887 #endif
888   void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*);
889   void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*);
890   void *pCollNeededArg;
891   sqlite3_value *pErr;          /* Most recent error message */
892   char *zErrMsg;                /* Most recent error message (UTF-8 encoded) */
893   char *zErrMsg16;              /* Most recent error message (UTF-16 encoded) */
894   union {
895     volatile int isInterrupted; /* True if sqlite3_interrupt has been called */
896     double notUsed1;            /* Spacer */
897   } u1;
898   Lookaside lookaside;          /* Lookaside malloc configuration */
899 #ifndef SQLITE_OMIT_AUTHORIZATION
900   int (*xAuth)(void*,int,const char*,const char*,const char*,const char*);
901                                 /* Access authorization function */
902   void *pAuthArg;               /* 1st argument to the access auth function */
903 #endif
904 #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
905   int (*xProgress)(void *);     /* The progress callback */
906   void *pProgressArg;           /* Argument to the progress callback */
907   int nProgressOps;             /* Number of opcodes for progress callback */
908 #endif
909 #ifndef SQLITE_OMIT_VIRTUALTABLE
910   int nVTrans;                  /* Allocated size of aVTrans */
911   Hash aModule;                 /* populated by sqlite3_create_module() */
912   VtabCtx *pVtabCtx;            /* Context for active vtab connect/create */
913   VTable **aVTrans;             /* Virtual tables with open transactions */
914   VTable *pDisconnect;    /* Disconnect these in next sqlite3_prepare() */
915 #endif
916   FuncDefHash aFunc;            /* Hash table of connection functions */
917   Hash aCollSeq;                /* All collating sequences */
918   BusyHandler busyHandler;      /* Busy callback */
919   Db aDbStatic[2];              /* Static space for the 2 default backends */
920   Savepoint *pSavepoint;        /* List of active savepoints */
921   int busyTimeout;              /* Busy handler timeout, in msec */
922   int nSavepoint;               /* Number of non-transaction savepoints */
923   int nStatement;               /* Number of nested statement-transactions  */
924   i64 nDeferredCons;            /* Net deferred constraints this transaction. */
925   int *pnBytesFreed;            /* If not NULL, increment this in DbFree() */
926 
927 #ifdef SQLITE_ENABLE_UNLOCK_NOTIFY
928   /* The following variables are all protected by the STATIC_MASTER
929   ** mutex, not by sqlite3.mutex. They are used by code in notify.c.
930   **
931   ** When X.pUnlockConnection==Y, that means that X is waiting for Y to
932   ** unlock so that it can proceed.
933   **
934   ** When X.pBlockingConnection==Y, that means that something that X tried
935   ** tried to do recently failed with an SQLITE_LOCKED error due to locks
936   ** held by Y.
937   */
938   sqlite3 *pBlockingConnection; /* Connection that caused SQLITE_LOCKED */
939   sqlite3 *pUnlockConnection;           /* Connection to watch for unlock */
940   void *pUnlockArg;                     /* Argument to xUnlockNotify */
941   void (*xUnlockNotify)(void **, int);  /* Unlock notify callback */
942   sqlite3 *pNextBlocked;        /* Next in list of all blocked connections */
943 #endif
944 };
945 
946 /*
947 ** A macro to discover the encoding of a database.
948 */
949 #define ENC(db) ((db)->aDb[0].pSchema->enc)
950 
951 /*
952 ** Possible values for the sqlite3.flags.
953 */
954 #define SQLITE_VdbeTrace      0x00000001  /* True to trace VDBE execution */
955 #define SQLITE_InternChanges  0x00000002  /* Uncommitted Hash table changes */
956 #define SQLITE_FullColNames   0x00000004  /* Show full column names on SELECT */
957 #define SQLITE_ShortColNames  0x00000008  /* Show short columns names */
958 #define SQLITE_CountRows      0x00000010  /* Count rows changed by INSERT, */
959                                           /*   DELETE, or UPDATE and return */
960                                           /*   the count using a callback. */
961 #define SQLITE_NullCallback   0x00000020  /* Invoke the callback once if the */
962                                           /*   result set is empty */
963 #define SQLITE_SqlTrace       0x00000040  /* Debug print SQL as it executes */
964 #define SQLITE_VdbeListing    0x00000080  /* Debug listings of VDBE programs */
965 #define SQLITE_WriteSchema    0x00000100  /* OK to update SQLITE_MASTER */
966 #define SQLITE_VdbeAddopTrace 0x00000200  /* Trace sqlite3VdbeAddOp() calls */
967 #define SQLITE_IgnoreChecks   0x00000400  /* Do not enforce check constraints */
968 #define SQLITE_ReadUncommitted 0x0000800  /* For shared-cache mode */
969 #define SQLITE_LegacyFileFmt  0x00001000  /* Create new databases in format 1 */
970 #define SQLITE_FullFSync      0x00002000  /* Use full fsync on the backend */
971 #define SQLITE_CkptFullFSync  0x00004000  /* Use full fsync for checkpoint */
972 #define SQLITE_RecoveryMode   0x00008000  /* Ignore schema errors */
973 #define SQLITE_ReverseOrder   0x00010000  /* Reverse unordered SELECTs */
974 #define SQLITE_RecTriggers    0x00020000  /* Enable recursive triggers */
975 #define SQLITE_ForeignKeys    0x00040000  /* Enforce foreign key constraints  */
976 #define SQLITE_AutoIndex      0x00080000  /* Enable automatic indexes */
977 #define SQLITE_PreferBuiltin  0x00100000  /* Preference to built-in funcs */
978 #define SQLITE_LoadExtension  0x00200000  /* Enable load_extension */
979 #define SQLITE_EnableTrigger  0x00400000  /* True to enable triggers */
980 
981 /*
982 ** Bits of the sqlite3.dbOptFlags field that are used by the
983 ** sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS,...) interface to
984 ** selectively disable various optimizations.
985 */
986 #define SQLITE_QueryFlattener 0x0001   /* Query flattening */
987 #define SQLITE_ColumnCache    0x0002   /* Column cache */
988 #define SQLITE_GroupByOrder   0x0004   /* GROUPBY cover of ORDERBY */
989 #define SQLITE_FactorOutConst 0x0008   /* Constant factoring */
990 #define SQLITE_IdxRealAsInt   0x0010   /* Store REAL as INT in indices */
991 #define SQLITE_DistinctOpt    0x0020   /* DISTINCT using indexes */
992 #define SQLITE_CoverIdxScan   0x0040   /* Covering index scans */
993 #define SQLITE_OrderByIdxJoin 0x0080   /* ORDER BY of joins via index */
994 #define SQLITE_SubqCoroutine  0x0100   /* Evaluate subqueries as coroutines */
995 #define SQLITE_Transitive     0x0200   /* Transitive constraints */
996 #define SQLITE_AllOpts        0xffff   /* All optimizations */
997 
998 /*
999 ** Macros for testing whether or not optimizations are enabled or disabled.
1000 */
1001 #ifndef SQLITE_OMIT_BUILTIN_TEST
1002 #define OptimizationDisabled(db, mask)  (((db)->dbOptFlags&(mask))!=0)
1003 #define OptimizationEnabled(db, mask)   (((db)->dbOptFlags&(mask))==0)
1004 #else
1005 #define OptimizationDisabled(db, mask)  0
1006 #define OptimizationEnabled(db, mask)   1
1007 #endif
1008 
1009 /*
1010 ** Possible values for the sqlite.magic field.
1011 ** The numbers are obtained at random and have no special meaning, other
1012 ** than being distinct from one another.
1013 */
1014 #define SQLITE_MAGIC_OPEN     0xa029a697  /* Database is open */
1015 #define SQLITE_MAGIC_CLOSED   0x9f3c2d33  /* Database is closed */
1016 #define SQLITE_MAGIC_SICK     0x4b771290  /* Error and awaiting close */
1017 #define SQLITE_MAGIC_BUSY     0xf03b7906  /* Database currently in use */
1018 #define SQLITE_MAGIC_ERROR    0xb5357930  /* An SQLITE_MISUSE error occurred */
1019 #define SQLITE_MAGIC_ZOMBIE   0x64cffc7f  /* Close with last statement close */
1020 
1021 /*
1022 ** Each SQL function is defined by an instance of the following
1023 ** structure.  A pointer to this structure is stored in the sqlite.aFunc
1024 ** hash table.  When multiple functions have the same name, the hash table
1025 ** points to a linked list of these structures.
1026 */
1027 struct FuncDef {
1028   i16 nArg;            /* Number of arguments.  -1 means unlimited */
1029   u8 iPrefEnc;         /* Preferred text encoding (SQLITE_UTF8, 16LE, 16BE) */
1030   u8 flags;            /* Some combination of SQLITE_FUNC_* */
1031   void *pUserData;     /* User data parameter */
1032   FuncDef *pNext;      /* Next function with same name */
1033   void (*xFunc)(sqlite3_context*,int,sqlite3_value**); /* Regular function */
1034   void (*xStep)(sqlite3_context*,int,sqlite3_value**); /* Aggregate step */
1035   void (*xFinalize)(sqlite3_context*);                /* Aggregate finalizer */
1036   char *zName;         /* SQL name of the function. */
1037   FuncDef *pHash;      /* Next with a different name but the same hash */
1038   FuncDestructor *pDestructor;   /* Reference counted destructor function */
1039 };
1040 
1041 /*
1042 ** This structure encapsulates a user-function destructor callback (as
1043 ** configured using create_function_v2()) and a reference counter. When
1044 ** create_function_v2() is called to create a function with a destructor,
1045 ** a single object of this type is allocated. FuncDestructor.nRef is set to
1046 ** the number of FuncDef objects created (either 1 or 3, depending on whether
1047 ** or not the specified encoding is SQLITE_ANY). The FuncDef.pDestructor
1048 ** member of each of the new FuncDef objects is set to point to the allocated
1049 ** FuncDestructor.
1050 **
1051 ** Thereafter, when one of the FuncDef objects is deleted, the reference
1052 ** count on this object is decremented. When it reaches 0, the destructor
1053 ** is invoked and the FuncDestructor structure freed.
1054 */
1055 struct FuncDestructor {
1056   int nRef;
1057   void (*xDestroy)(void *);
1058   void *pUserData;
1059 };
1060 
1061 /*
1062 ** Possible values for FuncDef.flags.  Note that the _LENGTH and _TYPEOF
1063 ** values must correspond to OPFLAG_LENGTHARG and OPFLAG_TYPEOFARG.  There
1064 ** are assert() statements in the code to verify this.
1065 */
1066 #define SQLITE_FUNC_LIKE     0x01 /* Candidate for the LIKE optimization */
1067 #define SQLITE_FUNC_CASE     0x02 /* Case-sensitive LIKE-type function */
1068 #define SQLITE_FUNC_EPHEM    0x04 /* Ephemeral.  Delete with VDBE */
1069 #define SQLITE_FUNC_NEEDCOLL 0x08 /* sqlite3GetFuncCollSeq() might be called */
1070 #define SQLITE_FUNC_COUNT    0x10 /* Built-in count(*) aggregate */
1071 #define SQLITE_FUNC_COALESCE 0x20 /* Built-in coalesce() or ifnull() function */
1072 #define SQLITE_FUNC_LENGTH   0x40 /* Built-in length() function */
1073 #define SQLITE_FUNC_TYPEOF   0x80 /* Built-in typeof() function */
1074 
1075 /*
1076 ** The following three macros, FUNCTION(), LIKEFUNC() and AGGREGATE() are
1077 ** used to create the initializers for the FuncDef structures.
1078 **
1079 **   FUNCTION(zName, nArg, iArg, bNC, xFunc)
1080 **     Used to create a scalar function definition of a function zName
1081 **     implemented by C function xFunc that accepts nArg arguments. The
1082 **     value passed as iArg is cast to a (void*) and made available
1083 **     as the user-data (sqlite3_user_data()) for the function. If
1084 **     argument bNC is true, then the SQLITE_FUNC_NEEDCOLL flag is set.
1085 **
1086 **   AGGREGATE(zName, nArg, iArg, bNC, xStep, xFinal)
1087 **     Used to create an aggregate function definition implemented by
1088 **     the C functions xStep and xFinal. The first four parameters
1089 **     are interpreted in the same way as the first 4 parameters to
1090 **     FUNCTION().
1091 **
1092 **   LIKEFUNC(zName, nArg, pArg, flags)
1093 **     Used to create a scalar function definition of a function zName
1094 **     that accepts nArg arguments and is implemented by a call to C
1095 **     function likeFunc. Argument pArg is cast to a (void *) and made
1096 **     available as the function user-data (sqlite3_user_data()). The
1097 **     FuncDef.flags variable is set to the value passed as the flags
1098 **     parameter.
1099 */
1100 #define FUNCTION(zName, nArg, iArg, bNC, xFunc) \
1101   {nArg, SQLITE_UTF8, (bNC*SQLITE_FUNC_NEEDCOLL), \
1102    SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, 0, #zName, 0, 0}
1103 #define FUNCTION2(zName, nArg, iArg, bNC, xFunc, extraFlags) \
1104   {nArg, SQLITE_UTF8, (bNC*SQLITE_FUNC_NEEDCOLL)|extraFlags, \
1105    SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, 0, #zName, 0, 0}
1106 #define STR_FUNCTION(zName, nArg, pArg, bNC, xFunc) \
1107   {nArg, SQLITE_UTF8, bNC*SQLITE_FUNC_NEEDCOLL, \
1108    pArg, 0, xFunc, 0, 0, #zName, 0, 0}
1109 #define LIKEFUNC(zName, nArg, arg, flags) \
1110   {nArg, SQLITE_UTF8, flags, (void *)arg, 0, likeFunc, 0, 0, #zName, 0, 0}
1111 #define AGGREGATE(zName, nArg, arg, nc, xStep, xFinal) \
1112   {nArg, SQLITE_UTF8, nc*SQLITE_FUNC_NEEDCOLL, \
1113    SQLITE_INT_TO_PTR(arg), 0, 0, xStep,xFinal,#zName,0,0}
1114 
1115 /*
1116 ** All current savepoints are stored in a linked list starting at
1117 ** sqlite3.pSavepoint. The first element in the list is the most recently
1118 ** opened savepoint. Savepoints are added to the list by the vdbe
1119 ** OP_Savepoint instruction.
1120 */
1121 struct Savepoint {
1122   char *zName;                        /* Savepoint name (nul-terminated) */
1123   i64 nDeferredCons;                  /* Number of deferred fk violations */
1124   Savepoint *pNext;                   /* Parent savepoint (if any) */
1125 };
1126 
1127 /*
1128 ** The following are used as the second parameter to sqlite3Savepoint(),
1129 ** and as the P1 argument to the OP_Savepoint instruction.
1130 */
1131 #define SAVEPOINT_BEGIN      0
1132 #define SAVEPOINT_RELEASE    1
1133 #define SAVEPOINT_ROLLBACK   2
1134 
1135 
1136 /*
1137 ** Each SQLite module (virtual table definition) is defined by an
1138 ** instance of the following structure, stored in the sqlite3.aModule
1139 ** hash table.
1140 */
1141 struct Module {
1142   const sqlite3_module *pModule;       /* Callback pointers */
1143   const char *zName;                   /* Name passed to create_module() */
1144   void *pAux;                          /* pAux passed to create_module() */
1145   void (*xDestroy)(void *);            /* Module destructor function */
1146 };
1147 
1148 /*
1149 ** information about each column of an SQL table is held in an instance
1150 ** of this structure.
1151 */
1152 struct Column {
1153   char *zName;     /* Name of this column */
1154   Expr *pDflt;     /* Default value of this column */
1155   char *zDflt;     /* Original text of the default value */
1156   char *zType;     /* Data type for this column */
1157   char *zColl;     /* Collating sequence.  If NULL, use the default */
1158   u8 notNull;      /* An OE_ code for handling a NOT NULL constraint */
1159   char affinity;   /* One of the SQLITE_AFF_... values */
1160   u16 colFlags;    /* Boolean properties.  See COLFLAG_ defines below */
1161 };
1162 
1163 /* Allowed values for Column.colFlags:
1164 */
1165 #define COLFLAG_PRIMKEY  0x0001    /* Column is part of the primary key */
1166 #define COLFLAG_HIDDEN   0x0002    /* A hidden column in a virtual table */
1167 
1168 /*
1169 ** A "Collating Sequence" is defined by an instance of the following
1170 ** structure. Conceptually, a collating sequence consists of a name and
1171 ** a comparison routine that defines the order of that sequence.
1172 **
1173 ** If CollSeq.xCmp is NULL, it means that the
1174 ** collating sequence is undefined.  Indices built on an undefined
1175 ** collating sequence may not be read or written.
1176 */
1177 struct CollSeq {
1178   char *zName;          /* Name of the collating sequence, UTF-8 encoded */
1179   u8 enc;               /* Text encoding handled by xCmp() */
1180   void *pUser;          /* First argument to xCmp() */
1181   int (*xCmp)(void*,int, const void*, int, const void*);
1182   void (*xDel)(void*);  /* Destructor for pUser */
1183 };
1184 
1185 /*
1186 ** A sort order can be either ASC or DESC.
1187 */
1188 #define SQLITE_SO_ASC       0  /* Sort in ascending order */
1189 #define SQLITE_SO_DESC      1  /* Sort in ascending order */
1190 
1191 /*
1192 ** Column affinity types.
1193 **
1194 ** These used to have mnemonic name like 'i' for SQLITE_AFF_INTEGER and
1195 ** 't' for SQLITE_AFF_TEXT.  But we can save a little space and improve
1196 ** the speed a little by numbering the values consecutively.
1197 **
1198 ** But rather than start with 0 or 1, we begin with 'a'.  That way,
1199 ** when multiple affinity types are concatenated into a string and
1200 ** used as the P4 operand, they will be more readable.
1201 **
1202 ** Note also that the numeric types are grouped together so that testing
1203 ** for a numeric type is a single comparison.
1204 */
1205 #define SQLITE_AFF_TEXT     'a'
1206 #define SQLITE_AFF_NONE     'b'
1207 #define SQLITE_AFF_NUMERIC  'c'
1208 #define SQLITE_AFF_INTEGER  'd'
1209 #define SQLITE_AFF_REAL     'e'
1210 
1211 #define sqlite3IsNumericAffinity(X)  ((X)>=SQLITE_AFF_NUMERIC)
1212 
1213 /*
1214 ** The SQLITE_AFF_MASK values masks off the significant bits of an
1215 ** affinity value.
1216 */
1217 #define SQLITE_AFF_MASK     0x67
1218 
1219 /*
1220 ** Additional bit values that can be ORed with an affinity without
1221 ** changing the affinity.
1222 */
1223 #define SQLITE_JUMPIFNULL   0x08  /* jumps if either operand is NULL */
1224 #define SQLITE_STOREP2      0x10  /* Store result in reg[P2] rather than jump */
1225 #define SQLITE_NULLEQ       0x80  /* NULL=NULL */
1226 
1227 /*
1228 ** An object of this type is created for each virtual table present in
1229 ** the database schema.
1230 **
1231 ** If the database schema is shared, then there is one instance of this
1232 ** structure for each database connection (sqlite3*) that uses the shared
1233 ** schema. This is because each database connection requires its own unique
1234 ** instance of the sqlite3_vtab* handle used to access the virtual table
1235 ** implementation. sqlite3_vtab* handles can not be shared between
1236 ** database connections, even when the rest of the in-memory database
1237 ** schema is shared, as the implementation often stores the database
1238 ** connection handle passed to it via the xConnect() or xCreate() method
1239 ** during initialization internally. This database connection handle may
1240 ** then be used by the virtual table implementation to access real tables
1241 ** within the database. So that they appear as part of the callers
1242 ** transaction, these accesses need to be made via the same database
1243 ** connection as that used to execute SQL operations on the virtual table.
1244 **
1245 ** All VTable objects that correspond to a single table in a shared
1246 ** database schema are initially stored in a linked-list pointed to by
1247 ** the Table.pVTable member variable of the corresponding Table object.
1248 ** When an sqlite3_prepare() operation is required to access the virtual
1249 ** table, it searches the list for the VTable that corresponds to the
1250 ** database connection doing the preparing so as to use the correct
1251 ** sqlite3_vtab* handle in the compiled query.
1252 **
1253 ** When an in-memory Table object is deleted (for example when the
1254 ** schema is being reloaded for some reason), the VTable objects are not
1255 ** deleted and the sqlite3_vtab* handles are not xDisconnect()ed
1256 ** immediately. Instead, they are moved from the Table.pVTable list to
1257 ** another linked list headed by the sqlite3.pDisconnect member of the
1258 ** corresponding sqlite3 structure. They are then deleted/xDisconnected
1259 ** next time a statement is prepared using said sqlite3*. This is done
1260 ** to avoid deadlock issues involving multiple sqlite3.mutex mutexes.
1261 ** Refer to comments above function sqlite3VtabUnlockList() for an
1262 ** explanation as to why it is safe to add an entry to an sqlite3.pDisconnect
1263 ** list without holding the corresponding sqlite3.mutex mutex.
1264 **
1265 ** The memory for objects of this type is always allocated by
1266 ** sqlite3DbMalloc(), using the connection handle stored in VTable.db as
1267 ** the first argument.
1268 */
1269 struct VTable {
1270   sqlite3 *db;              /* Database connection associated with this table */
1271   Module *pMod;             /* Pointer to module implementation */
1272   sqlite3_vtab *pVtab;      /* Pointer to vtab instance */
1273   int nRef;                 /* Number of pointers to this structure */
1274   u8 bConstraint;           /* True if constraints are supported */
1275   int iSavepoint;           /* Depth of the SAVEPOINT stack */
1276   VTable *pNext;            /* Next in linked list (see above) */
1277 };
1278 
1279 /*
1280 ** Each SQL table is represented in memory by an instance of the
1281 ** following structure.
1282 **
1283 ** Table.zName is the name of the table.  The case of the original
1284 ** CREATE TABLE statement is stored, but case is not significant for
1285 ** comparisons.
1286 **
1287 ** Table.nCol is the number of columns in this table.  Table.aCol is a
1288 ** pointer to an array of Column structures, one for each column.
1289 **
1290 ** If the table has an INTEGER PRIMARY KEY, then Table.iPKey is the index of
1291 ** the column that is that key.   Otherwise Table.iPKey is negative.  Note
1292 ** that the datatype of the PRIMARY KEY must be INTEGER for this field to
1293 ** be set.  An INTEGER PRIMARY KEY is used as the rowid for each row of
1294 ** the table.  If a table has no INTEGER PRIMARY KEY, then a random rowid
1295 ** is generated for each row of the table.  TF_HasPrimaryKey is set if
1296 ** the table has any PRIMARY KEY, INTEGER or otherwise.
1297 **
1298 ** Table.tnum is the page number for the root BTree page of the table in the
1299 ** database file.  If Table.iDb is the index of the database table backend
1300 ** in sqlite.aDb[].  0 is for the main database and 1 is for the file that
1301 ** holds temporary tables and indices.  If TF_Ephemeral is set
1302 ** then the table is stored in a file that is automatically deleted
1303 ** when the VDBE cursor to the table is closed.  In this case Table.tnum
1304 ** refers VDBE cursor number that holds the table open, not to the root
1305 ** page number.  Transient tables are used to hold the results of a
1306 ** sub-query that appears instead of a real table name in the FROM clause
1307 ** of a SELECT statement.
1308 */
1309 struct Table {
1310   char *zName;         /* Name of the table or view */
1311   Column *aCol;        /* Information about each column */
1312   Index *pIndex;       /* List of SQL indexes on this table. */
1313   Select *pSelect;     /* NULL for tables.  Points to definition if a view. */
1314   FKey *pFKey;         /* Linked list of all foreign keys in this table */
1315   char *zColAff;       /* String defining the affinity of each column */
1316 #ifndef SQLITE_OMIT_CHECK
1317   ExprList *pCheck;    /* All CHECK constraints */
1318 #endif
1319   tRowcnt nRowEst;     /* Estimated rows in table - from sqlite_stat1 table */
1320   int tnum;            /* Root BTree node for this table (see note above) */
1321   i16 iPKey;           /* If not negative, use aCol[iPKey] as the primary key */
1322   i16 nCol;            /* Number of columns in this table */
1323   u16 nRef;            /* Number of pointers to this Table */
1324   u8 tabFlags;         /* Mask of TF_* values */
1325   u8 keyConf;          /* What to do in case of uniqueness conflict on iPKey */
1326 #ifndef SQLITE_OMIT_ALTERTABLE
1327   int addColOffset;    /* Offset in CREATE TABLE stmt to add a new column */
1328 #endif
1329 #ifndef SQLITE_OMIT_VIRTUALTABLE
1330   int nModuleArg;      /* Number of arguments to the module */
1331   char **azModuleArg;  /* Text of all module args. [0] is module name */
1332   VTable *pVTable;     /* List of VTable objects. */
1333 #endif
1334   Trigger *pTrigger;   /* List of triggers stored in pSchema */
1335   Schema *pSchema;     /* Schema that contains this table */
1336   Table *pNextZombie;  /* Next on the Parse.pZombieTab list */
1337 };
1338 
1339 /*
1340 ** Allowed values for Tabe.tabFlags.
1341 */
1342 #define TF_Readonly        0x01    /* Read-only system table */
1343 #define TF_Ephemeral       0x02    /* An ephemeral table */
1344 #define TF_HasPrimaryKey   0x04    /* Table has a primary key */
1345 #define TF_Autoincrement   0x08    /* Integer primary key is autoincrement */
1346 #define TF_Virtual         0x10    /* Is a virtual table */
1347 
1348 
1349 /*
1350 ** Test to see whether or not a table is a virtual table.  This is
1351 ** done as a macro so that it will be optimized out when virtual
1352 ** table support is omitted from the build.
1353 */
1354 #ifndef SQLITE_OMIT_VIRTUALTABLE
1355 #  define IsVirtual(X)      (((X)->tabFlags & TF_Virtual)!=0)
1356 #  define IsHiddenColumn(X) (((X)->colFlags & COLFLAG_HIDDEN)!=0)
1357 #else
1358 #  define IsVirtual(X)      0
1359 #  define IsHiddenColumn(X) 0
1360 #endif
1361 
1362 /*
1363 ** Each foreign key constraint is an instance of the following structure.
1364 **
1365 ** A foreign key is associated with two tables.  The "from" table is
1366 ** the table that contains the REFERENCES clause that creates the foreign
1367 ** key.  The "to" table is the table that is named in the REFERENCES clause.
1368 ** Consider this example:
1369 **
1370 **     CREATE TABLE ex1(
1371 **       a INTEGER PRIMARY KEY,
1372 **       b INTEGER CONSTRAINT fk1 REFERENCES ex2(x)
1373 **     );
1374 **
1375 ** For foreign key "fk1", the from-table is "ex1" and the to-table is "ex2".
1376 **
1377 ** Each REFERENCES clause generates an instance of the following structure
1378 ** which is attached to the from-table.  The to-table need not exist when
1379 ** the from-table is created.  The existence of the to-table is not checked.
1380 */
1381 struct FKey {
1382   Table *pFrom;     /* Table containing the REFERENCES clause (aka: Child) */
1383   FKey *pNextFrom;  /* Next foreign key in pFrom */
1384   char *zTo;        /* Name of table that the key points to (aka: Parent) */
1385   FKey *pNextTo;    /* Next foreign key on table named zTo */
1386   FKey *pPrevTo;    /* Previous foreign key on table named zTo */
1387   int nCol;         /* Number of columns in this key */
1388   /* EV: R-30323-21917 */
1389   u8 isDeferred;    /* True if constraint checking is deferred till COMMIT */
1390   u8 aAction[2];          /* ON DELETE and ON UPDATE actions, respectively */
1391   Trigger *apTrigger[2];  /* Triggers for aAction[] actions */
1392   struct sColMap {  /* Mapping of columns in pFrom to columns in zTo */
1393     int iFrom;         /* Index of column in pFrom */
1394     char *zCol;        /* Name of column in zTo.  If 0 use PRIMARY KEY */
1395   } aCol[1];        /* One entry for each of nCol column s */
1396 };
1397 
1398 /*
1399 ** SQLite supports many different ways to resolve a constraint
1400 ** error.  ROLLBACK processing means that a constraint violation
1401 ** causes the operation in process to fail and for the current transaction
1402 ** to be rolled back.  ABORT processing means the operation in process
1403 ** fails and any prior changes from that one operation are backed out,
1404 ** but the transaction is not rolled back.  FAIL processing means that
1405 ** the operation in progress stops and returns an error code.  But prior
1406 ** changes due to the same operation are not backed out and no rollback
1407 ** occurs.  IGNORE means that the particular row that caused the constraint
1408 ** error is not inserted or updated.  Processing continues and no error
1409 ** is returned.  REPLACE means that preexisting database rows that caused
1410 ** a UNIQUE constraint violation are removed so that the new insert or
1411 ** update can proceed.  Processing continues and no error is reported.
1412 **
1413 ** RESTRICT, SETNULL, and CASCADE actions apply only to foreign keys.
1414 ** RESTRICT is the same as ABORT for IMMEDIATE foreign keys and the
1415 ** same as ROLLBACK for DEFERRED keys.  SETNULL means that the foreign
1416 ** key is set to NULL.  CASCADE means that a DELETE or UPDATE of the
1417 ** referenced table row is propagated into the row that holds the
1418 ** foreign key.
1419 **
1420 ** The following symbolic values are used to record which type
1421 ** of action to take.
1422 */
1423 #define OE_None     0   /* There is no constraint to check */
1424 #define OE_Rollback 1   /* Fail the operation and rollback the transaction */
1425 #define OE_Abort    2   /* Back out changes but do no rollback transaction */
1426 #define OE_Fail     3   /* Stop the operation but leave all prior changes */
1427 #define OE_Ignore   4   /* Ignore the error. Do not do the INSERT or UPDATE */
1428 #define OE_Replace  5   /* Delete existing record, then do INSERT or UPDATE */
1429 
1430 #define OE_Restrict 6   /* OE_Abort for IMMEDIATE, OE_Rollback for DEFERRED */
1431 #define OE_SetNull  7   /* Set the foreign key value to NULL */
1432 #define OE_SetDflt  8   /* Set the foreign key value to its default */
1433 #define OE_Cascade  9   /* Cascade the changes */
1434 
1435 #define OE_Default  99  /* Do whatever the default action is */
1436 
1437 
1438 /*
1439 ** An instance of the following structure is passed as the first
1440 ** argument to sqlite3VdbeKeyCompare and is used to control the
1441 ** comparison of the two index keys.
1442 */
1443 struct KeyInfo {
1444   sqlite3 *db;        /* The database connection */
1445   u8 enc;             /* Text encoding - one of the SQLITE_UTF* values */
1446   u16 nField;         /* Number of entries in aColl[] */
1447   u8 *aSortOrder;     /* Sort order for each column.  May be NULL */
1448   CollSeq *aColl[1];  /* Collating sequence for each term of the key */
1449 };
1450 
1451 /*
1452 ** An instance of the following structure holds information about a
1453 ** single index record that has already been parsed out into individual
1454 ** values.
1455 **
1456 ** A record is an object that contains one or more fields of data.
1457 ** Records are used to store the content of a table row and to store
1458 ** the key of an index.  A blob encoding of a record is created by
1459 ** the OP_MakeRecord opcode of the VDBE and is disassembled by the
1460 ** OP_Column opcode.
1461 **
1462 ** This structure holds a record that has already been disassembled
1463 ** into its constituent fields.
1464 */
1465 struct UnpackedRecord {
1466   KeyInfo *pKeyInfo;  /* Collation and sort-order information */
1467   u16 nField;         /* Number of entries in apMem[] */
1468   u8 flags;           /* Boolean settings.  UNPACKED_... below */
1469   i64 rowid;          /* Used by UNPACKED_PREFIX_SEARCH */
1470   Mem *aMem;          /* Values */
1471 };
1472 
1473 /*
1474 ** Allowed values of UnpackedRecord.flags
1475 */
1476 #define UNPACKED_INCRKEY       0x01  /* Make this key an epsilon larger */
1477 #define UNPACKED_PREFIX_MATCH  0x02  /* A prefix match is considered OK */
1478 #define UNPACKED_PREFIX_SEARCH 0x04  /* Ignore final (rowid) field */
1479 
1480 /*
1481 ** Each SQL index is represented in memory by an
1482 ** instance of the following structure.
1483 **
1484 ** The columns of the table that are to be indexed are described
1485 ** by the aiColumn[] field of this structure.  For example, suppose
1486 ** we have the following table and index:
1487 **
1488 **     CREATE TABLE Ex1(c1 int, c2 int, c3 text);
1489 **     CREATE INDEX Ex2 ON Ex1(c3,c1);
1490 **
1491 ** In the Table structure describing Ex1, nCol==3 because there are
1492 ** three columns in the table.  In the Index structure describing
1493 ** Ex2, nColumn==2 since 2 of the 3 columns of Ex1 are indexed.
1494 ** The value of aiColumn is {2, 0}.  aiColumn[0]==2 because the
1495 ** first column to be indexed (c3) has an index of 2 in Ex1.aCol[].
1496 ** The second column to be indexed (c1) has an index of 0 in
1497 ** Ex1.aCol[], hence Ex2.aiColumn[1]==0.
1498 **
1499 ** The Index.onError field determines whether or not the indexed columns
1500 ** must be unique and what to do if they are not.  When Index.onError=OE_None,
1501 ** it means this is not a unique index.  Otherwise it is a unique index
1502 ** and the value of Index.onError indicate the which conflict resolution
1503 ** algorithm to employ whenever an attempt is made to insert a non-unique
1504 ** element.
1505 */
1506 struct Index {
1507   char *zName;             /* Name of this index */
1508   int *aiColumn;           /* Which columns are used by this index.  1st is 0 */
1509   tRowcnt *aiRowEst;       /* From ANALYZE: Est. rows selected by each column */
1510   Table *pTable;           /* The SQL table being indexed */
1511   char *zColAff;           /* String defining the affinity of each column */
1512   Index *pNext;            /* The next index associated with the same table */
1513   Schema *pSchema;         /* Schema containing this index */
1514   u8 *aSortOrder;          /* for each column: True==DESC, False==ASC */
1515   char **azColl;           /* Array of collation sequence names for index */
1516   int tnum;                /* DB Page containing root of this index */
1517   u16 nColumn;             /* Number of columns in table used by this index */
1518   u8 onError;              /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
1519   unsigned autoIndex:2;    /* 1==UNIQUE, 2==PRIMARY KEY, 0==CREATE INDEX */
1520   unsigned bUnordered:1;   /* Use this index for == or IN queries only */
1521 #ifdef SQLITE_ENABLE_STAT3
1522   int nSample;             /* Number of elements in aSample[] */
1523   tRowcnt avgEq;           /* Average nEq value for key values not in aSample */
1524   IndexSample *aSample;    /* Samples of the left-most key */
1525 #endif
1526 };
1527 
1528 /*
1529 ** Each sample stored in the sqlite_stat3 table is represented in memory
1530 ** using a structure of this type.  See documentation at the top of the
1531 ** analyze.c source file for additional information.
1532 */
1533 struct IndexSample {
1534   union {
1535     char *z;        /* Value if eType is SQLITE_TEXT or SQLITE_BLOB */
1536     double r;       /* Value if eType is SQLITE_FLOAT */
1537     i64 i;          /* Value if eType is SQLITE_INTEGER */
1538   } u;
1539   u8 eType;         /* SQLITE_NULL, SQLITE_INTEGER ... etc. */
1540   int nByte;        /* Size in byte of text or blob. */
1541   tRowcnt nEq;      /* Est. number of rows where the key equals this sample */
1542   tRowcnt nLt;      /* Est. number of rows where key is less than this sample */
1543   tRowcnt nDLt;     /* Est. number of distinct keys less than this sample */
1544 };
1545 
1546 /*
1547 ** Each token coming out of the lexer is an instance of
1548 ** this structure.  Tokens are also used as part of an expression.
1549 **
1550 ** Note if Token.z==0 then Token.dyn and Token.n are undefined and
1551 ** may contain random values.  Do not make any assumptions about Token.dyn
1552 ** and Token.n when Token.z==0.
1553 */
1554 struct Token {
1555   const char *z;     /* Text of the token.  Not NULL-terminated! */
1556   unsigned int n;    /* Number of characters in this token */
1557 };
1558 
1559 /*
1560 ** An instance of this structure contains information needed to generate
1561 ** code for a SELECT that contains aggregate functions.
1562 **
1563 ** If Expr.op==TK_AGG_COLUMN or TK_AGG_FUNCTION then Expr.pAggInfo is a
1564 ** pointer to this structure.  The Expr.iColumn field is the index in
1565 ** AggInfo.aCol[] or AggInfo.aFunc[] of information needed to generate
1566 ** code for that node.
1567 **
1568 ** AggInfo.pGroupBy and AggInfo.aFunc.pExpr point to fields within the
1569 ** original Select structure that describes the SELECT statement.  These
1570 ** fields do not need to be freed when deallocating the AggInfo structure.
1571 */
1572 struct AggInfo {
1573   u8 directMode;          /* Direct rendering mode means take data directly
1574                           ** from source tables rather than from accumulators */
1575   u8 useSortingIdx;       /* In direct mode, reference the sorting index rather
1576                           ** than the source table */
1577   int sortingIdx;         /* Cursor number of the sorting index */
1578   int sortingIdxPTab;     /* Cursor number of pseudo-table */
1579   int nSortingColumn;     /* Number of columns in the sorting index */
1580   ExprList *pGroupBy;     /* The group by clause */
1581   struct AggInfo_col {    /* For each column used in source tables */
1582     Table *pTab;             /* Source table */
1583     int iTable;              /* Cursor number of the source table */
1584     int iColumn;             /* Column number within the source table */
1585     int iSorterColumn;       /* Column number in the sorting index */
1586     int iMem;                /* Memory location that acts as accumulator */
1587     Expr *pExpr;             /* The original expression */
1588   } *aCol;
1589   int nColumn;            /* Number of used entries in aCol[] */
1590   int nAccumulator;       /* Number of columns that show through to the output.
1591                           ** Additional columns are used only as parameters to
1592                           ** aggregate functions */
1593   struct AggInfo_func {   /* For each aggregate function */
1594     Expr *pExpr;             /* Expression encoding the function */
1595     FuncDef *pFunc;          /* The aggregate function implementation */
1596     int iMem;                /* Memory location that acts as accumulator */
1597     int iDistinct;           /* Ephemeral table used to enforce DISTINCT */
1598   } *aFunc;
1599   int nFunc;              /* Number of entries in aFunc[] */
1600 };
1601 
1602 /*
1603 ** The datatype ynVar is a signed integer, either 16-bit or 32-bit.
1604 ** Usually it is 16-bits.  But if SQLITE_MAX_VARIABLE_NUMBER is greater
1605 ** than 32767 we have to make it 32-bit.  16-bit is preferred because
1606 ** it uses less memory in the Expr object, which is a big memory user
1607 ** in systems with lots of prepared statements.  And few applications
1608 ** need more than about 10 or 20 variables.  But some extreme users want
1609 ** to have prepared statements with over 32767 variables, and for them
1610 ** the option is available (at compile-time).
1611 */
1612 #if SQLITE_MAX_VARIABLE_NUMBER<=32767
1613 typedef i16 ynVar;
1614 #else
1615 typedef int ynVar;
1616 #endif
1617 
1618 /*
1619 ** Each node of an expression in the parse tree is an instance
1620 ** of this structure.
1621 **
1622 ** Expr.op is the opcode. The integer parser token codes are reused
1623 ** as opcodes here. For example, the parser defines TK_GE to be an integer
1624 ** code representing the ">=" operator. This same integer code is reused
1625 ** to represent the greater-than-or-equal-to operator in the expression
1626 ** tree.
1627 **
1628 ** If the expression is an SQL literal (TK_INTEGER, TK_FLOAT, TK_BLOB,
1629 ** or TK_STRING), then Expr.token contains the text of the SQL literal. If
1630 ** the expression is a variable (TK_VARIABLE), then Expr.token contains the
1631 ** variable name. Finally, if the expression is an SQL function (TK_FUNCTION),
1632 ** then Expr.token contains the name of the function.
1633 **
1634 ** Expr.pRight and Expr.pLeft are the left and right subexpressions of a
1635 ** binary operator. Either or both may be NULL.
1636 **
1637 ** Expr.x.pList is a list of arguments if the expression is an SQL function,
1638 ** a CASE expression or an IN expression of the form "<lhs> IN (<y>, <z>...)".
1639 ** Expr.x.pSelect is used if the expression is a sub-select or an expression of
1640 ** the form "<lhs> IN (SELECT ...)". If the EP_xIsSelect bit is set in the
1641 ** Expr.flags mask, then Expr.x.pSelect is valid. Otherwise, Expr.x.pList is
1642 ** valid.
1643 **
1644 ** An expression of the form ID or ID.ID refers to a column in a table.
1645 ** For such expressions, Expr.op is set to TK_COLUMN and Expr.iTable is
1646 ** the integer cursor number of a VDBE cursor pointing to that table and
1647 ** Expr.iColumn is the column number for the specific column.  If the
1648 ** expression is used as a result in an aggregate SELECT, then the
1649 ** value is also stored in the Expr.iAgg column in the aggregate so that
1650 ** it can be accessed after all aggregates are computed.
1651 **
1652 ** If the expression is an unbound variable marker (a question mark
1653 ** character '?' in the original SQL) then the Expr.iTable holds the index
1654 ** number for that variable.
1655 **
1656 ** If the expression is a subquery then Expr.iColumn holds an integer
1657 ** register number containing the result of the subquery.  If the
1658 ** subquery gives a constant result, then iTable is -1.  If the subquery
1659 ** gives a different answer at different times during statement processing
1660 ** then iTable is the address of a subroutine that computes the subquery.
1661 **
1662 ** If the Expr is of type OP_Column, and the table it is selecting from
1663 ** is a disk table or the "old.*" pseudo-table, then pTab points to the
1664 ** corresponding table definition.
1665 **
1666 ** ALLOCATION NOTES:
1667 **
1668 ** Expr objects can use a lot of memory space in database schema.  To
1669 ** help reduce memory requirements, sometimes an Expr object will be
1670 ** truncated.  And to reduce the number of memory allocations, sometimes
1671 ** two or more Expr objects will be stored in a single memory allocation,
1672 ** together with Expr.zToken strings.
1673 **
1674 ** If the EP_Reduced and EP_TokenOnly flags are set when
1675 ** an Expr object is truncated.  When EP_Reduced is set, then all
1676 ** the child Expr objects in the Expr.pLeft and Expr.pRight subtrees
1677 ** are contained within the same memory allocation.  Note, however, that
1678 ** the subtrees in Expr.x.pList or Expr.x.pSelect are always separately
1679 ** allocated, regardless of whether or not EP_Reduced is set.
1680 */
1681 struct Expr {
1682   u8 op;                 /* Operation performed by this node */
1683   char affinity;         /* The affinity of the column or 0 if not a column */
1684   u16 flags;             /* Various flags.  EP_* See below */
1685   union {
1686     char *zToken;          /* Token value. Zero terminated and dequoted */
1687     int iValue;            /* Non-negative integer value if EP_IntValue */
1688   } u;
1689 
1690   /* If the EP_TokenOnly flag is set in the Expr.flags mask, then no
1691   ** space is allocated for the fields below this point. An attempt to
1692   ** access them will result in a segfault or malfunction.
1693   *********************************************************************/
1694 
1695   Expr *pLeft;           /* Left subnode */
1696   Expr *pRight;          /* Right subnode */
1697   union {
1698     ExprList *pList;     /* Function arguments or in "<expr> IN (<expr-list)" */
1699     Select *pSelect;     /* Used for sub-selects and "<expr> IN (<select>)" */
1700   } x;
1701 
1702   /* If the EP_Reduced flag is set in the Expr.flags mask, then no
1703   ** space is allocated for the fields below this point. An attempt to
1704   ** access them will result in a segfault or malfunction.
1705   *********************************************************************/
1706 
1707 #if SQLITE_MAX_EXPR_DEPTH>0
1708   int nHeight;           /* Height of the tree headed by this node */
1709 #endif
1710   int iTable;            /* TK_COLUMN: cursor number of table holding column
1711                          ** TK_REGISTER: register number
1712                          ** TK_TRIGGER: 1 -> new, 0 -> old */
1713   ynVar iColumn;         /* TK_COLUMN: column index.  -1 for rowid.
1714                          ** TK_VARIABLE: variable number (always >= 1). */
1715   i16 iAgg;              /* Which entry in pAggInfo->aCol[] or ->aFunc[] */
1716   i16 iRightJoinTable;   /* If EP_FromJoin, the right table of the join */
1717   u8 flags2;             /* Second set of flags.  EP2_... */
1718   u8 op2;                /* TK_REGISTER: original value of Expr.op
1719                          ** TK_COLUMN: the value of p5 for OP_Column
1720                          ** TK_AGG_FUNCTION: nesting depth */
1721   AggInfo *pAggInfo;     /* Used by TK_AGG_COLUMN and TK_AGG_FUNCTION */
1722   Table *pTab;           /* Table for TK_COLUMN expressions. */
1723 };
1724 
1725 /*
1726 ** The following are the meanings of bits in the Expr.flags field.
1727 */
1728 #define EP_FromJoin   0x0001  /* Originated in ON or USING clause of a join */
1729 #define EP_Agg        0x0002  /* Contains one or more aggregate functions */
1730 #define EP_Resolved   0x0004  /* IDs have been resolved to COLUMNs */
1731 #define EP_Error      0x0008  /* Expression contains one or more errors */
1732 #define EP_Distinct   0x0010  /* Aggregate function with DISTINCT keyword */
1733 #define EP_VarSelect  0x0020  /* pSelect is correlated, not constant */
1734 #define EP_DblQuoted  0x0040  /* token.z was originally in "..." */
1735 #define EP_InfixFunc  0x0080  /* True for an infix function: LIKE, GLOB, etc */
1736 #define EP_Collate    0x0100  /* Tree contains a TK_COLLATE opeartor */
1737 #define EP_FixedDest  0x0200  /* Result needed in a specific register */
1738 #define EP_IntValue   0x0400  /* Integer value contained in u.iValue */
1739 #define EP_xIsSelect  0x0800  /* x.pSelect is valid (otherwise x.pList is) */
1740 #define EP_Hint       0x1000  /* Not used */
1741 #define EP_Reduced    0x2000  /* Expr struct is EXPR_REDUCEDSIZE bytes only */
1742 #define EP_TokenOnly  0x4000  /* Expr struct is EXPR_TOKENONLYSIZE bytes only */
1743 #define EP_Static     0x8000  /* Held in memory not obtained from malloc() */
1744 
1745 /*
1746 ** The following are the meanings of bits in the Expr.flags2 field.
1747 */
1748 #define EP2_MallocedToken  0x0001  /* Need to sqlite3DbFree() Expr.zToken */
1749 #define EP2_Irreducible    0x0002  /* Cannot EXPRDUP_REDUCE this Expr */
1750 
1751 /*
1752 ** The pseudo-routine sqlite3ExprSetIrreducible sets the EP2_Irreducible
1753 ** flag on an expression structure.  This flag is used for VV&A only.  The
1754 ** routine is implemented as a macro that only works when in debugging mode,
1755 ** so as not to burden production code.
1756 */
1757 #ifdef SQLITE_DEBUG
1758 # define ExprSetIrreducible(X)  (X)->flags2 |= EP2_Irreducible
1759 #else
1760 # define ExprSetIrreducible(X)
1761 #endif
1762 
1763 /*
1764 ** These macros can be used to test, set, or clear bits in the
1765 ** Expr.flags field.
1766 */
1767 #define ExprHasProperty(E,P)     (((E)->flags&(P))==(P))
1768 #define ExprHasAnyProperty(E,P)  (((E)->flags&(P))!=0)
1769 #define ExprSetProperty(E,P)     (E)->flags|=(P)
1770 #define ExprClearProperty(E,P)   (E)->flags&=~(P)
1771 
1772 /*
1773 ** Macros to determine the number of bytes required by a normal Expr
1774 ** struct, an Expr struct with the EP_Reduced flag set in Expr.flags
1775 ** and an Expr struct with the EP_TokenOnly flag set.
1776 */
1777 #define EXPR_FULLSIZE           sizeof(Expr)           /* Full size */
1778 #define EXPR_REDUCEDSIZE        offsetof(Expr,iTable)  /* Common features */
1779 #define EXPR_TOKENONLYSIZE      offsetof(Expr,pLeft)   /* Fewer features */
1780 
1781 /*
1782 ** Flags passed to the sqlite3ExprDup() function. See the header comment
1783 ** above sqlite3ExprDup() for details.
1784 */
1785 #define EXPRDUP_REDUCE         0x0001  /* Used reduced-size Expr nodes */
1786 
1787 /*
1788 ** A list of expressions.  Each expression may optionally have a
1789 ** name.  An expr/name combination can be used in several ways, such
1790 ** as the list of "expr AS ID" fields following a "SELECT" or in the
1791 ** list of "ID = expr" items in an UPDATE.  A list of expressions can
1792 ** also be used as the argument to a function, in which case the a.zName
1793 ** field is not used.
1794 **
1795 ** By default the Expr.zSpan field holds a human-readable description of
1796 ** the expression that is used in the generation of error messages and
1797 ** column labels.  In this case, Expr.zSpan is typically the text of a
1798 ** column expression as it exists in a SELECT statement.  However, if
1799 ** the bSpanIsTab flag is set, then zSpan is overloaded to mean the name
1800 ** of the result column in the form: DATABASE.TABLE.COLUMN.  This later
1801 ** form is used for name resolution with nested FROM clauses.
1802 */
1803 struct ExprList {
1804   int nExpr;             /* Number of expressions on the list */
1805   int iECursor;          /* VDBE Cursor associated with this ExprList */
1806   struct ExprList_item { /* For each expression in the list */
1807     Expr *pExpr;            /* The list of expressions */
1808     char *zName;            /* Token associated with this expression */
1809     char *zSpan;            /* Original text of the expression */
1810     u8 sortOrder;           /* 1 for DESC or 0 for ASC */
1811     unsigned done :1;       /* A flag to indicate when processing is finished */
1812     unsigned bSpanIsTab :1; /* zSpan holds DB.TABLE.COLUMN */
1813     u16 iOrderByCol;        /* For ORDER BY, column number in result set */
1814     u16 iAlias;             /* Index into Parse.aAlias[] for zName */
1815   } *a;                  /* Alloc a power of two greater or equal to nExpr */
1816 };
1817 
1818 /*
1819 ** An instance of this structure is used by the parser to record both
1820 ** the parse tree for an expression and the span of input text for an
1821 ** expression.
1822 */
1823 struct ExprSpan {
1824   Expr *pExpr;          /* The expression parse tree */
1825   const char *zStart;   /* First character of input text */
1826   const char *zEnd;     /* One character past the end of input text */
1827 };
1828 
1829 /*
1830 ** An instance of this structure can hold a simple list of identifiers,
1831 ** such as the list "a,b,c" in the following statements:
1832 **
1833 **      INSERT INTO t(a,b,c) VALUES ...;
1834 **      CREATE INDEX idx ON t(a,b,c);
1835 **      CREATE TRIGGER trig BEFORE UPDATE ON t(a,b,c) ...;
1836 **
1837 ** The IdList.a.idx field is used when the IdList represents the list of
1838 ** column names after a table name in an INSERT statement.  In the statement
1839 **
1840 **     INSERT INTO t(a,b,c) ...
1841 **
1842 ** If "a" is the k-th column of table "t", then IdList.a[0].idx==k.
1843 */
1844 struct IdList {
1845   struct IdList_item {
1846     char *zName;      /* Name of the identifier */
1847     int idx;          /* Index in some Table.aCol[] of a column named zName */
1848   } *a;
1849   int nId;         /* Number of identifiers on the list */
1850 };
1851 
1852 /*
1853 ** The bitmask datatype defined below is used for various optimizations.
1854 **
1855 ** Changing this from a 64-bit to a 32-bit type limits the number of
1856 ** tables in a join to 32 instead of 64.  But it also reduces the size
1857 ** of the library by 738 bytes on ix86.
1858 */
1859 typedef u64 Bitmask;
1860 
1861 /*
1862 ** The number of bits in a Bitmask.  "BMS" means "BitMask Size".
1863 */
1864 #define BMS  ((int)(sizeof(Bitmask)*8))
1865 
1866 /*
1867 ** The following structure describes the FROM clause of a SELECT statement.
1868 ** Each table or subquery in the FROM clause is a separate element of
1869 ** the SrcList.a[] array.
1870 **
1871 ** With the addition of multiple database support, the following structure
1872 ** can also be used to describe a particular table such as the table that
1873 ** is modified by an INSERT, DELETE, or UPDATE statement.  In standard SQL,
1874 ** such a table must be a simple name: ID.  But in SQLite, the table can
1875 ** now be identified by a database name, a dot, then the table name: ID.ID.
1876 **
1877 ** The jointype starts out showing the join type between the current table
1878 ** and the next table on the list.  The parser builds the list this way.
1879 ** But sqlite3SrcListShiftJoinType() later shifts the jointypes so that each
1880 ** jointype expresses the join between the table and the previous table.
1881 **
1882 ** In the colUsed field, the high-order bit (bit 63) is set if the table
1883 ** contains more than 63 columns and the 64-th or later column is used.
1884 */
1885 struct SrcList {
1886   i16 nSrc;        /* Number of tables or subqueries in the FROM clause */
1887   i16 nAlloc;      /* Number of entries allocated in a[] below */
1888   struct SrcList_item {
1889     Schema *pSchema;  /* Schema to which this item is fixed */
1890     char *zDatabase;  /* Name of database holding this table */
1891     char *zName;      /* Name of the table */
1892     char *zAlias;     /* The "B" part of a "A AS B" phrase.  zName is the "A" */
1893     Table *pTab;      /* An SQL table corresponding to zName */
1894     Select *pSelect;  /* A SELECT statement used in place of a table name */
1895     int addrFillSub;  /* Address of subroutine to manifest a subquery */
1896     int regReturn;    /* Register holding return address of addrFillSub */
1897     u8 jointype;      /* Type of join between this able and the previous */
1898     unsigned notIndexed :1;    /* True if there is a NOT INDEXED clause */
1899     unsigned isCorrelated :1;  /* True if sub-query is correlated */
1900     unsigned viaCoroutine :1;  /* Implemented as a co-routine */
1901 #ifndef SQLITE_OMIT_EXPLAIN
1902     u8 iSelectId;     /* If pSelect!=0, the id of the sub-select in EQP */
1903 #endif
1904     int iCursor;      /* The VDBE cursor number used to access this table */
1905     Expr *pOn;        /* The ON clause of a join */
1906     IdList *pUsing;   /* The USING clause of a join */
1907     Bitmask colUsed;  /* Bit N (1<<N) set if column N of pTab is used */
1908     char *zIndex;     /* Identifier from "INDEXED BY <zIndex>" clause */
1909     Index *pIndex;    /* Index structure corresponding to zIndex, if any */
1910   } a[1];             /* One entry for each identifier on the list */
1911 };
1912 
1913 /*
1914 ** Permitted values of the SrcList.a.jointype field
1915 */
1916 #define JT_INNER     0x0001    /* Any kind of inner or cross join */
1917 #define JT_CROSS     0x0002    /* Explicit use of the CROSS keyword */
1918 #define JT_NATURAL   0x0004    /* True for a "natural" join */
1919 #define JT_LEFT      0x0008    /* Left outer join */
1920 #define JT_RIGHT     0x0010    /* Right outer join */
1921 #define JT_OUTER     0x0020    /* The "OUTER" keyword is present */
1922 #define JT_ERROR     0x0040    /* unknown or unsupported join type */
1923 
1924 
1925 /*
1926 ** A WherePlan object holds information that describes a lookup
1927 ** strategy.
1928 **
1929 ** This object is intended to be opaque outside of the where.c module.
1930 ** It is included here only so that that compiler will know how big it
1931 ** is.  None of the fields in this object should be used outside of
1932 ** the where.c module.
1933 **
1934 ** Within the union, pIdx is only used when wsFlags&WHERE_INDEXED is true.
1935 ** pTerm is only used when wsFlags&WHERE_MULTI_OR is true.  And pVtabIdx
1936 ** is only used when wsFlags&WHERE_VIRTUALTABLE is true.  It is never the
1937 ** case that more than one of these conditions is true.
1938 */
1939 struct WherePlan {
1940   u32 wsFlags;                   /* WHERE_* flags that describe the strategy */
1941   u16 nEq;                       /* Number of == constraints */
1942   u16 nOBSat;                    /* Number of ORDER BY terms satisfied */
1943   double nRow;                   /* Estimated number of rows (for EQP) */
1944   union {
1945     Index *pIdx;                   /* Index when WHERE_INDEXED is true */
1946     struct WhereTerm *pTerm;       /* WHERE clause term for OR-search */
1947     sqlite3_index_info *pVtabIdx;  /* Virtual table index to use */
1948   } u;
1949 };
1950 
1951 /*
1952 ** For each nested loop in a WHERE clause implementation, the WhereInfo
1953 ** structure contains a single instance of this structure.  This structure
1954 ** is intended to be private to the where.c module and should not be
1955 ** access or modified by other modules.
1956 **
1957 ** The pIdxInfo field is used to help pick the best index on a
1958 ** virtual table.  The pIdxInfo pointer contains indexing
1959 ** information for the i-th table in the FROM clause before reordering.
1960 ** All the pIdxInfo pointers are freed by whereInfoFree() in where.c.
1961 ** All other information in the i-th WhereLevel object for the i-th table
1962 ** after FROM clause ordering.
1963 */
1964 struct WhereLevel {
1965   WherePlan plan;       /* query plan for this element of the FROM clause */
1966   int iLeftJoin;        /* Memory cell used to implement LEFT OUTER JOIN */
1967   int iTabCur;          /* The VDBE cursor used to access the table */
1968   int iIdxCur;          /* The VDBE cursor used to access pIdx */
1969   int addrBrk;          /* Jump here to break out of the loop */
1970   int addrNxt;          /* Jump here to start the next IN combination */
1971   int addrCont;         /* Jump here to continue with the next loop cycle */
1972   int addrFirst;        /* First instruction of interior of the loop */
1973   u8 iFrom;             /* Which entry in the FROM clause */
1974   u8 op, p5;            /* Opcode and P5 of the opcode that ends the loop */
1975   int p1, p2;           /* Operands of the opcode used to ends the loop */
1976   union {               /* Information that depends on plan.wsFlags */
1977     struct {
1978       int nIn;              /* Number of entries in aInLoop[] */
1979       struct InLoop {
1980         int iCur;              /* The VDBE cursor used by this IN operator */
1981         int addrInTop;         /* Top of the IN loop */
1982         u8 eEndLoopOp;         /* IN Loop terminator. OP_Next or OP_Prev */
1983       } *aInLoop;           /* Information about each nested IN operator */
1984     } in;                 /* Used when plan.wsFlags&WHERE_IN_ABLE */
1985     Index *pCovidx;       /* Possible covering index for WHERE_MULTI_OR */
1986   } u;
1987   double rOptCost;      /* "Optimal" cost for this level */
1988 
1989   /* The following field is really not part of the current level.  But
1990   ** we need a place to cache virtual table index information for each
1991   ** virtual table in the FROM clause and the WhereLevel structure is
1992   ** a convenient place since there is one WhereLevel for each FROM clause
1993   ** element.
1994   */
1995   sqlite3_index_info *pIdxInfo;  /* Index info for n-th source table */
1996 };
1997 
1998 /*
1999 ** Flags appropriate for the wctrlFlags parameter of sqlite3WhereBegin()
2000 ** and the WhereInfo.wctrlFlags member.
2001 */
2002 #define WHERE_ORDERBY_NORMAL   0x0000 /* No-op */
2003 #define WHERE_ORDERBY_MIN      0x0001 /* ORDER BY processing for min() func */
2004 #define WHERE_ORDERBY_MAX      0x0002 /* ORDER BY processing for max() func */
2005 #define WHERE_ONEPASS_DESIRED  0x0004 /* Want to do one-pass UPDATE/DELETE */
2006 #define WHERE_DUPLICATES_OK    0x0008 /* Ok to return a row more than once */
2007 #define WHERE_OMIT_OPEN_CLOSE  0x0010 /* Table cursors are already open */
2008 #define WHERE_FORCE_TABLE      0x0020 /* Do not use an index-only search */
2009 #define WHERE_ONETABLE_ONLY    0x0040 /* Only code the 1st table in pTabList */
2010 #define WHERE_AND_ONLY         0x0080 /* Don't use indices for OR terms */
2011 
2012 /*
2013 ** The WHERE clause processing routine has two halves.  The
2014 ** first part does the start of the WHERE loop and the second
2015 ** half does the tail of the WHERE loop.  An instance of
2016 ** this structure is returned by the first half and passed
2017 ** into the second half to give some continuity.
2018 */
2019 struct WhereInfo {
2020   Parse *pParse;            /* Parsing and code generating context */
2021   SrcList *pTabList;        /* List of tables in the join */
2022   u16 nOBSat;               /* Number of ORDER BY terms satisfied by indices */
2023   u16 wctrlFlags;           /* Flags originally passed to sqlite3WhereBegin() */
2024   u8 okOnePass;             /* Ok to use one-pass algorithm for UPDATE/DELETE */
2025   u8 untestedTerms;         /* Not all WHERE terms resolved by outer loop */
2026   u8 eDistinct;             /* One of the WHERE_DISTINCT_* values below */
2027   int iTop;                 /* The very beginning of the WHERE loop */
2028   int iContinue;            /* Jump here to continue with next record */
2029   int iBreak;               /* Jump here to break out of the loop */
2030   int nLevel;               /* Number of nested loop */
2031   struct WhereClause *pWC;  /* Decomposition of the WHERE clause */
2032   double savedNQueryLoop;   /* pParse->nQueryLoop outside the WHERE loop */
2033   double nRowOut;           /* Estimated number of output rows */
2034   WhereLevel a[1];          /* Information about each nest loop in WHERE */
2035 };
2036 
2037 /* Allowed values for WhereInfo.eDistinct and DistinctCtx.eTnctType */
2038 #define WHERE_DISTINCT_NOOP      0  /* DISTINCT keyword not used */
2039 #define WHERE_DISTINCT_UNIQUE    1  /* No duplicates */
2040 #define WHERE_DISTINCT_ORDERED   2  /* All duplicates are adjacent */
2041 #define WHERE_DISTINCT_UNORDERED 3  /* Duplicates are scattered */
2042 
2043 /*
2044 ** A NameContext defines a context in which to resolve table and column
2045 ** names.  The context consists of a list of tables (the pSrcList) field and
2046 ** a list of named expression (pEList).  The named expression list may
2047 ** be NULL.  The pSrc corresponds to the FROM clause of a SELECT or
2048 ** to the table being operated on by INSERT, UPDATE, or DELETE.  The
2049 ** pEList corresponds to the result set of a SELECT and is NULL for
2050 ** other statements.
2051 **
2052 ** NameContexts can be nested.  When resolving names, the inner-most
2053 ** context is searched first.  If no match is found, the next outer
2054 ** context is checked.  If there is still no match, the next context
2055 ** is checked.  This process continues until either a match is found
2056 ** or all contexts are check.  When a match is found, the nRef member of
2057 ** the context containing the match is incremented.
2058 **
2059 ** Each subquery gets a new NameContext.  The pNext field points to the
2060 ** NameContext in the parent query.  Thus the process of scanning the
2061 ** NameContext list corresponds to searching through successively outer
2062 ** subqueries looking for a match.
2063 */
2064 struct NameContext {
2065   Parse *pParse;       /* The parser */
2066   SrcList *pSrcList;   /* One or more tables used to resolve names */
2067   ExprList *pEList;    /* Optional list of named expressions */
2068   AggInfo *pAggInfo;   /* Information about aggregates at this level */
2069   NameContext *pNext;  /* Next outer name context.  NULL for outermost */
2070   int nRef;            /* Number of names resolved by this context */
2071   int nErr;            /* Number of errors encountered while resolving names */
2072   u8 ncFlags;          /* Zero or more NC_* flags defined below */
2073 };
2074 
2075 /*
2076 ** Allowed values for the NameContext, ncFlags field.
2077 */
2078 #define NC_AllowAgg  0x01    /* Aggregate functions are allowed here */
2079 #define NC_HasAgg    0x02    /* One or more aggregate functions seen */
2080 #define NC_IsCheck   0x04    /* True if resolving names in a CHECK constraint */
2081 #define NC_InAggFunc 0x08    /* True if analyzing arguments to an agg func */
2082 
2083 /*
2084 ** An instance of the following structure contains all information
2085 ** needed to generate code for a single SELECT statement.
2086 **
2087 ** nLimit is set to -1 if there is no LIMIT clause.  nOffset is set to 0.
2088 ** If there is a LIMIT clause, the parser sets nLimit to the value of the
2089 ** limit and nOffset to the value of the offset (or 0 if there is not
2090 ** offset).  But later on, nLimit and nOffset become the memory locations
2091 ** in the VDBE that record the limit and offset counters.
2092 **
2093 ** addrOpenEphm[] entries contain the address of OP_OpenEphemeral opcodes.
2094 ** These addresses must be stored so that we can go back and fill in
2095 ** the P4_KEYINFO and P2 parameters later.  Neither the KeyInfo nor
2096 ** the number of columns in P2 can be computed at the same time
2097 ** as the OP_OpenEphm instruction is coded because not
2098 ** enough information about the compound query is known at that point.
2099 ** The KeyInfo for addrOpenTran[0] and [1] contains collating sequences
2100 ** for the result set.  The KeyInfo for addrOpenEphm[2] contains collating
2101 ** sequences for the ORDER BY clause.
2102 */
2103 struct Select {
2104   ExprList *pEList;      /* The fields of the result */
2105   u8 op;                 /* One of: TK_UNION TK_ALL TK_INTERSECT TK_EXCEPT */
2106   u16 selFlags;          /* Various SF_* values */
2107   int iLimit, iOffset;   /* Memory registers holding LIMIT & OFFSET counters */
2108   int addrOpenEphm[3];   /* OP_OpenEphem opcodes related to this select */
2109   double nSelectRow;     /* Estimated number of result rows */
2110   SrcList *pSrc;         /* The FROM clause */
2111   Expr *pWhere;          /* The WHERE clause */
2112   ExprList *pGroupBy;    /* The GROUP BY clause */
2113   Expr *pHaving;         /* The HAVING clause */
2114   ExprList *pOrderBy;    /* The ORDER BY clause */
2115   Select *pPrior;        /* Prior select in a compound select statement */
2116   Select *pNext;         /* Next select to the left in a compound */
2117   Select *pRightmost;    /* Right-most select in a compound select statement */
2118   Expr *pLimit;          /* LIMIT expression. NULL means not used. */
2119   Expr *pOffset;         /* OFFSET expression. NULL means not used. */
2120 };
2121 
2122 /*
2123 ** Allowed values for Select.selFlags.  The "SF" prefix stands for
2124 ** "Select Flag".
2125 */
2126 #define SF_Distinct        0x0001  /* Output should be DISTINCT */
2127 #define SF_Resolved        0x0002  /* Identifiers have been resolved */
2128 #define SF_Aggregate       0x0004  /* Contains aggregate functions */
2129 #define SF_UsesEphemeral   0x0008  /* Uses the OpenEphemeral opcode */
2130 #define SF_Expanded        0x0010  /* sqlite3SelectExpand() called on this */
2131 #define SF_HasTypeInfo     0x0020  /* FROM subqueries have Table metadata */
2132 #define SF_UseSorter       0x0040  /* Sort using a sorter */
2133 #define SF_Values          0x0080  /* Synthesized from VALUES clause */
2134 #define SF_Materialize     0x0100  /* Force materialization of views */
2135 #define SF_NestedFrom      0x0200  /* Part of a parenthesized FROM clause */
2136 
2137 
2138 /*
2139 ** The results of a select can be distributed in several ways.  The
2140 ** "SRT" prefix means "SELECT Result Type".
2141 */
2142 #define SRT_Union        1  /* Store result as keys in an index */
2143 #define SRT_Except       2  /* Remove result from a UNION index */
2144 #define SRT_Exists       3  /* Store 1 if the result is not empty */
2145 #define SRT_Discard      4  /* Do not save the results anywhere */
2146 
2147 /* The ORDER BY clause is ignored for all of the above */
2148 #define IgnorableOrderby(X) ((X->eDest)<=SRT_Discard)
2149 
2150 #define SRT_Output       5  /* Output each row of result */
2151 #define SRT_Mem          6  /* Store result in a memory cell */
2152 #define SRT_Set          7  /* Store results as keys in an index */
2153 #define SRT_Table        8  /* Store result as data with an automatic rowid */
2154 #define SRT_EphemTab     9  /* Create transient tab and store like SRT_Table */
2155 #define SRT_Coroutine   10  /* Generate a single row of result */
2156 
2157 /*
2158 ** An instance of this object describes where to put of the results of
2159 ** a SELECT statement.
2160 */
2161 struct SelectDest {
2162   u8 eDest;         /* How to dispose of the results.  On of SRT_* above. */
2163   char affSdst;     /* Affinity used when eDest==SRT_Set */
2164   int iSDParm;      /* A parameter used by the eDest disposal method */
2165   int iSdst;        /* Base register where results are written */
2166   int nSdst;        /* Number of registers allocated */
2167 };
2168 
2169 /*
2170 ** During code generation of statements that do inserts into AUTOINCREMENT
2171 ** tables, the following information is attached to the Table.u.autoInc.p
2172 ** pointer of each autoincrement table to record some side information that
2173 ** the code generator needs.  We have to keep per-table autoincrement
2174 ** information in case inserts are down within triggers.  Triggers do not
2175 ** normally coordinate their activities, but we do need to coordinate the
2176 ** loading and saving of autoincrement information.
2177 */
2178 struct AutoincInfo {
2179   AutoincInfo *pNext;   /* Next info block in a list of them all */
2180   Table *pTab;          /* Table this info block refers to */
2181   int iDb;              /* Index in sqlite3.aDb[] of database holding pTab */
2182   int regCtr;           /* Memory register holding the rowid counter */
2183 };
2184 
2185 /*
2186 ** Size of the column cache
2187 */
2188 #ifndef SQLITE_N_COLCACHE
2189 # define SQLITE_N_COLCACHE 10
2190 #endif
2191 
2192 /*
2193 ** At least one instance of the following structure is created for each
2194 ** trigger that may be fired while parsing an INSERT, UPDATE or DELETE
2195 ** statement. All such objects are stored in the linked list headed at
2196 ** Parse.pTriggerPrg and deleted once statement compilation has been
2197 ** completed.
2198 **
2199 ** A Vdbe sub-program that implements the body and WHEN clause of trigger
2200 ** TriggerPrg.pTrigger, assuming a default ON CONFLICT clause of
2201 ** TriggerPrg.orconf, is stored in the TriggerPrg.pProgram variable.
2202 ** The Parse.pTriggerPrg list never contains two entries with the same
2203 ** values for both pTrigger and orconf.
2204 **
2205 ** The TriggerPrg.aColmask[0] variable is set to a mask of old.* columns
2206 ** accessed (or set to 0 for triggers fired as a result of INSERT
2207 ** statements). Similarly, the TriggerPrg.aColmask[1] variable is set to
2208 ** a mask of new.* columns used by the program.
2209 */
2210 struct TriggerPrg {
2211   Trigger *pTrigger;      /* Trigger this program was coded from */
2212   TriggerPrg *pNext;      /* Next entry in Parse.pTriggerPrg list */
2213   SubProgram *pProgram;   /* Program implementing pTrigger/orconf */
2214   int orconf;             /* Default ON CONFLICT policy */
2215   u32 aColmask[2];        /* Masks of old.*, new.* columns accessed */
2216 };
2217 
2218 /*
2219 ** The yDbMask datatype for the bitmask of all attached databases.
2220 */
2221 #if SQLITE_MAX_ATTACHED>30
2222   typedef sqlite3_uint64 yDbMask;
2223 #else
2224   typedef unsigned int yDbMask;
2225 #endif
2226 
2227 /*
2228 ** An SQL parser context.  A copy of this structure is passed through
2229 ** the parser and down into all the parser action routine in order to
2230 ** carry around information that is global to the entire parse.
2231 **
2232 ** The structure is divided into two parts.  When the parser and code
2233 ** generate call themselves recursively, the first part of the structure
2234 ** is constant but the second part is reset at the beginning and end of
2235 ** each recursion.
2236 **
2237 ** The nTableLock and aTableLock variables are only used if the shared-cache
2238 ** feature is enabled (if sqlite3Tsd()->useSharedData is true). They are
2239 ** used to store the set of table-locks required by the statement being
2240 ** compiled. Function sqlite3TableLock() is used to add entries to the
2241 ** list.
2242 */
2243 struct Parse {
2244   sqlite3 *db;         /* The main database structure */
2245   char *zErrMsg;       /* An error message */
2246   Vdbe *pVdbe;         /* An engine for executing database bytecode */
2247   int rc;              /* Return code from execution */
2248   u8 colNamesSet;      /* TRUE after OP_ColumnName has been issued to pVdbe */
2249   u8 checkSchema;      /* Causes schema cookie check after an error */
2250   u8 nested;           /* Number of nested calls to the parser/code generator */
2251   u8 nTempReg;         /* Number of temporary registers in aTempReg[] */
2252   u8 nTempInUse;       /* Number of aTempReg[] currently checked out */
2253   u8 nColCache;        /* Number of entries in aColCache[] */
2254   u8 iColCache;        /* Next entry in aColCache[] to replace */
2255   u8 isMultiWrite;     /* True if statement may modify/insert multiple rows */
2256   u8 mayAbort;         /* True if statement may throw an ABORT exception */
2257   int aTempReg[8];     /* Holding area for temporary registers */
2258   int nRangeReg;       /* Size of the temporary register block */
2259   int iRangeReg;       /* First register in temporary register block */
2260   int nErr;            /* Number of errors seen */
2261   int nTab;            /* Number of previously allocated VDBE cursors */
2262   int nMem;            /* Number of memory cells used so far */
2263   int nSet;            /* Number of sets used so far */
2264   int nOnce;           /* Number of OP_Once instructions so far */
2265   int ckBase;          /* Base register of data during check constraints */
2266   int iCacheLevel;     /* ColCache valid when aColCache[].iLevel<=iCacheLevel */
2267   int iCacheCnt;       /* Counter used to generate aColCache[].lru values */
2268   struct yColCache {
2269     int iTable;           /* Table cursor number */
2270     int iColumn;          /* Table column number */
2271     u8 tempReg;           /* iReg is a temp register that needs to be freed */
2272     int iLevel;           /* Nesting level */
2273     int iReg;             /* Reg with value of this column. 0 means none. */
2274     int lru;              /* Least recently used entry has the smallest value */
2275   } aColCache[SQLITE_N_COLCACHE];  /* One for each column cache entry */
2276   yDbMask writeMask;   /* Start a write transaction on these databases */
2277   yDbMask cookieMask;  /* Bitmask of schema verified databases */
2278   int cookieGoto;      /* Address of OP_Goto to cookie verifier subroutine */
2279   int cookieValue[SQLITE_MAX_ATTACHED+2];  /* Values of cookies to verify */
2280   int regRowid;        /* Register holding rowid of CREATE TABLE entry */
2281   int regRoot;         /* Register holding root page number for new objects */
2282   int nMaxArg;         /* Max args passed to user function by sub-program */
2283   Token constraintName;/* Name of the constraint currently being parsed */
2284 #ifndef SQLITE_OMIT_SHARED_CACHE
2285   int nTableLock;        /* Number of locks in aTableLock */
2286   TableLock *aTableLock; /* Required table locks for shared-cache mode */
2287 #endif
2288   AutoincInfo *pAinc;  /* Information about AUTOINCREMENT counters */
2289 
2290   /* Information used while coding trigger programs. */
2291   Parse *pToplevel;    /* Parse structure for main program (or NULL) */
2292   Table *pTriggerTab;  /* Table triggers are being coded for */
2293   double nQueryLoop;   /* Estimated number of iterations of a query */
2294   u32 oldmask;         /* Mask of old.* columns referenced */
2295   u32 newmask;         /* Mask of new.* columns referenced */
2296   u8 eTriggerOp;       /* TK_UPDATE, TK_INSERT or TK_DELETE */
2297   u8 eOrconf;          /* Default ON CONFLICT policy for trigger steps */
2298   u8 disableTriggers;  /* True to disable triggers */
2299 
2300   /* Above is constant between recursions.  Below is reset before and after
2301   ** each recursion */
2302 
2303   int nVar;                 /* Number of '?' variables seen in the SQL so far */
2304   int nzVar;                /* Number of available slots in azVar[] */
2305   u8 explain;               /* True if the EXPLAIN flag is found on the query */
2306 #ifndef SQLITE_OMIT_VIRTUALTABLE
2307   u8 declareVtab;           /* True if inside sqlite3_declare_vtab() */
2308   int nVtabLock;            /* Number of virtual tables to lock */
2309 #endif
2310   int nAlias;               /* Number of aliased result set columns */
2311   int nHeight;              /* Expression tree height of current sub-select */
2312 #ifndef SQLITE_OMIT_EXPLAIN
2313   int iSelectId;            /* ID of current select for EXPLAIN output */
2314   int iNextSelectId;        /* Next available select ID for EXPLAIN output */
2315 #endif
2316   char **azVar;             /* Pointers to names of parameters */
2317   Vdbe *pReprepare;         /* VM being reprepared (sqlite3Reprepare()) */
2318   int *aAlias;              /* Register used to hold aliased result */
2319   const char *zTail;        /* All SQL text past the last semicolon parsed */
2320   Table *pNewTable;         /* A table being constructed by CREATE TABLE */
2321   Trigger *pNewTrigger;     /* Trigger under construct by a CREATE TRIGGER */
2322   const char *zAuthContext; /* The 6th parameter to db->xAuth callbacks */
2323   Token sNameToken;         /* Token with unqualified schema object name */
2324   Token sLastToken;         /* The last token parsed */
2325 #ifndef SQLITE_OMIT_VIRTUALTABLE
2326   Token sArg;               /* Complete text of a module argument */
2327   Table **apVtabLock;       /* Pointer to virtual tables needing locking */
2328 #endif
2329   Table *pZombieTab;        /* List of Table objects to delete after code gen */
2330   TriggerPrg *pTriggerPrg;  /* Linked list of coded triggers */
2331 };
2332 
2333 /*
2334 ** Return true if currently inside an sqlite3_declare_vtab() call.
2335 */
2336 #ifdef SQLITE_OMIT_VIRTUALTABLE
2337   #define IN_DECLARE_VTAB 0
2338 #else
2339   #define IN_DECLARE_VTAB (pParse->declareVtab)
2340 #endif
2341 
2342 /*
2343 ** An instance of the following structure can be declared on a stack and used
2344 ** to save the Parse.zAuthContext value so that it can be restored later.
2345 */
2346 struct AuthContext {
2347   const char *zAuthContext;   /* Put saved Parse.zAuthContext here */
2348   Parse *pParse;              /* The Parse structure */
2349 };
2350 
2351 /*
2352 ** Bitfield flags for P5 value in various opcodes.
2353 */
2354 #define OPFLAG_NCHANGE       0x01    /* Set to update db->nChange */
2355 #define OPFLAG_LASTROWID     0x02    /* Set to update db->lastRowid */
2356 #define OPFLAG_ISUPDATE      0x04    /* This OP_Insert is an sql UPDATE */
2357 #define OPFLAG_APPEND        0x08    /* This is likely to be an append */
2358 #define OPFLAG_USESEEKRESULT 0x10    /* Try to avoid a seek in BtreeInsert() */
2359 #define OPFLAG_CLEARCACHE    0x20    /* Clear pseudo-table cache in OP_Column */
2360 #define OPFLAG_LENGTHARG     0x40    /* OP_Column only used for length() */
2361 #define OPFLAG_TYPEOFARG     0x80    /* OP_Column only used for typeof() */
2362 #define OPFLAG_BULKCSR       0x01    /* OP_Open** used to open bulk cursor */
2363 #define OPFLAG_P2ISREG       0x02    /* P2 to OP_Open** is a register number */
2364 #define OPFLAG_PERMUTE       0x01    /* OP_Compare: use the permutation */
2365 
2366 /*
2367  * Each trigger present in the database schema is stored as an instance of
2368  * struct Trigger.
2369  *
2370  * Pointers to instances of struct Trigger are stored in two ways.
2371  * 1. In the "trigHash" hash table (part of the sqlite3* that represents the
2372  *    database). This allows Trigger structures to be retrieved by name.
2373  * 2. All triggers associated with a single table form a linked list, using the
2374  *    pNext member of struct Trigger. A pointer to the first element of the
2375  *    linked list is stored as the "pTrigger" member of the associated
2376  *    struct Table.
2377  *
2378  * The "step_list" member points to the first element of a linked list
2379  * containing the SQL statements specified as the trigger program.
2380  */
2381 struct Trigger {
2382   char *zName;            /* The name of the trigger                        */
2383   char *table;            /* The table or view to which the trigger applies */
2384   u8 op;                  /* One of TK_DELETE, TK_UPDATE, TK_INSERT         */
2385   u8 tr_tm;               /* One of TRIGGER_BEFORE, TRIGGER_AFTER */
2386   Expr *pWhen;            /* The WHEN clause of the expression (may be NULL) */
2387   IdList *pColumns;       /* If this is an UPDATE OF <column-list> trigger,
2388                              the <column-list> is stored here */
2389   Schema *pSchema;        /* Schema containing the trigger */
2390   Schema *pTabSchema;     /* Schema containing the table */
2391   TriggerStep *step_list; /* Link list of trigger program steps             */
2392   Trigger *pNext;         /* Next trigger associated with the table */
2393 };
2394 
2395 /*
2396 ** A trigger is either a BEFORE or an AFTER trigger.  The following constants
2397 ** determine which.
2398 **
2399 ** If there are multiple triggers, you might of some BEFORE and some AFTER.
2400 ** In that cases, the constants below can be ORed together.
2401 */
2402 #define TRIGGER_BEFORE  1
2403 #define TRIGGER_AFTER   2
2404 
2405 /*
2406  * An instance of struct TriggerStep is used to store a single SQL statement
2407  * that is a part of a trigger-program.
2408  *
2409  * Instances of struct TriggerStep are stored in a singly linked list (linked
2410  * using the "pNext" member) referenced by the "step_list" member of the
2411  * associated struct Trigger instance. The first element of the linked list is
2412  * the first step of the trigger-program.
2413  *
2414  * The "op" member indicates whether this is a "DELETE", "INSERT", "UPDATE" or
2415  * "SELECT" statement. The meanings of the other members is determined by the
2416  * value of "op" as follows:
2417  *
2418  * (op == TK_INSERT)
2419  * orconf    -> stores the ON CONFLICT algorithm
2420  * pSelect   -> If this is an INSERT INTO ... SELECT ... statement, then
2421  *              this stores a pointer to the SELECT statement. Otherwise NULL.
2422  * target    -> A token holding the quoted name of the table to insert into.
2423  * pExprList -> If this is an INSERT INTO ... VALUES ... statement, then
2424  *              this stores values to be inserted. Otherwise NULL.
2425  * pIdList   -> If this is an INSERT INTO ... (<column-names>) VALUES ...
2426  *              statement, then this stores the column-names to be
2427  *              inserted into.
2428  *
2429  * (op == TK_DELETE)
2430  * target    -> A token holding the quoted name of the table to delete from.
2431  * pWhere    -> The WHERE clause of the DELETE statement if one is specified.
2432  *              Otherwise NULL.
2433  *
2434  * (op == TK_UPDATE)
2435  * target    -> A token holding the quoted name of the table to update rows of.
2436  * pWhere    -> The WHERE clause of the UPDATE statement if one is specified.
2437  *              Otherwise NULL.
2438  * pExprList -> A list of the columns to update and the expressions to update
2439  *              them to. See sqlite3Update() documentation of "pChanges"
2440  *              argument.
2441  *
2442  */
2443 struct TriggerStep {
2444   u8 op;               /* One of TK_DELETE, TK_UPDATE, TK_INSERT, TK_SELECT */
2445   u8 orconf;           /* OE_Rollback etc. */
2446   Trigger *pTrig;      /* The trigger that this step is a part of */
2447   Select *pSelect;     /* SELECT statment or RHS of INSERT INTO .. SELECT ... */
2448   Token target;        /* Target table for DELETE, UPDATE, INSERT */
2449   Expr *pWhere;        /* The WHERE clause for DELETE or UPDATE steps */
2450   ExprList *pExprList; /* SET clause for UPDATE.  VALUES clause for INSERT */
2451   IdList *pIdList;     /* Column names for INSERT */
2452   TriggerStep *pNext;  /* Next in the link-list */
2453   TriggerStep *pLast;  /* Last element in link-list. Valid for 1st elem only */
2454 };
2455 
2456 /*
2457 ** The following structure contains information used by the sqliteFix...
2458 ** routines as they walk the parse tree to make database references
2459 ** explicit.
2460 */
2461 typedef struct DbFixer DbFixer;
2462 struct DbFixer {
2463   Parse *pParse;      /* The parsing context.  Error messages written here */
2464   Schema *pSchema;    /* Fix items to this schema */
2465   const char *zDb;    /* Make sure all objects are contained in this database */
2466   const char *zType;  /* Type of the container - used for error messages */
2467   const Token *pName; /* Name of the container - used for error messages */
2468 };
2469 
2470 /*
2471 ** An objected used to accumulate the text of a string where we
2472 ** do not necessarily know how big the string will be in the end.
2473 */
2474 struct StrAccum {
2475   sqlite3 *db;         /* Optional database for lookaside.  Can be NULL */
2476   char *zBase;         /* A base allocation.  Not from malloc. */
2477   char *zText;         /* The string collected so far */
2478   int  nChar;          /* Length of the string so far */
2479   int  nAlloc;         /* Amount of space allocated in zText */
2480   int  mxAlloc;        /* Maximum allowed string length */
2481   u8   mallocFailed;   /* Becomes true if any memory allocation fails */
2482   u8   useMalloc;      /* 0: none,  1: sqlite3DbMalloc,  2: sqlite3_malloc */
2483   u8   tooBig;         /* Becomes true if string size exceeds limits */
2484 };
2485 
2486 /*
2487 ** A pointer to this structure is used to communicate information
2488 ** from sqlite3Init and OP_ParseSchema into the sqlite3InitCallback.
2489 */
2490 typedef struct {
2491   sqlite3 *db;        /* The database being initialized */
2492   char **pzErrMsg;    /* Error message stored here */
2493   int iDb;            /* 0 for main database.  1 for TEMP, 2.. for ATTACHed */
2494   int rc;             /* Result code stored here */
2495 } InitData;
2496 
2497 /*
2498 ** Structure containing global configuration data for the SQLite library.
2499 **
2500 ** This structure also contains some state information.
2501 */
2502 struct Sqlite3Config {
2503   int bMemstat;                     /* True to enable memory status */
2504   int bCoreMutex;                   /* True to enable core mutexing */
2505   int bFullMutex;                   /* True to enable full mutexing */
2506   int bOpenUri;                     /* True to interpret filenames as URIs */
2507   int bUseCis;                      /* Use covering indices for full-scans */
2508   int mxStrlen;                     /* Maximum string length */
2509   int szLookaside;                  /* Default lookaside buffer size */
2510   int nLookaside;                   /* Default lookaside buffer count */
2511   sqlite3_mem_methods m;            /* Low-level memory allocation interface */
2512   sqlite3_mutex_methods mutex;      /* Low-level mutex interface */
2513   sqlite3_pcache_methods2 pcache2;  /* Low-level page-cache interface */
2514   void *pHeap;                      /* Heap storage space */
2515   int nHeap;                        /* Size of pHeap[] */
2516   int mnReq, mxReq;                 /* Min and max heap requests sizes */
2517   sqlite3_int64 mxMmap;             /* Maximum mmap() space per open file */
2518   void *pScratch;                   /* Scratch memory */
2519   int szScratch;                    /* Size of each scratch buffer */
2520   int nScratch;                     /* Number of scratch buffers */
2521   void *pPage;                      /* Page cache memory */
2522   int szPage;                       /* Size of each page in pPage[] */
2523   int nPage;                        /* Number of pages in pPage[] */
2524   int mxParserStack;                /* maximum depth of the parser stack */
2525   int sharedCacheEnabled;           /* true if shared-cache mode enabled */
2526   /* The above might be initialized to non-zero.  The following need to always
2527   ** initially be zero, however. */
2528   int isInit;                       /* True after initialization has finished */
2529   int inProgress;                   /* True while initialization in progress */
2530   int isMutexInit;                  /* True after mutexes are initialized */
2531   int isMallocInit;                 /* True after malloc is initialized */
2532   int isPCacheInit;                 /* True after malloc is initialized */
2533   sqlite3_mutex *pInitMutex;        /* Mutex used by sqlite3_initialize() */
2534   int nRefInitMutex;                /* Number of users of pInitMutex */
2535   void (*xLog)(void*,int,const char*); /* Function for logging */
2536   void *pLogArg;                       /* First argument to xLog() */
2537   int bLocaltimeFault;              /* True to fail localtime() calls */
2538 #ifdef SQLITE_ENABLE_SQLLOG
2539   void(*xSqllog)(void*,sqlite3*,const char*, int);
2540   void *pSqllogArg;
2541 #endif
2542 };
2543 
2544 /*
2545 ** Context pointer passed down through the tree-walk.
2546 */
2547 struct Walker {
2548   int (*xExprCallback)(Walker*, Expr*);     /* Callback for expressions */
2549   int (*xSelectCallback)(Walker*,Select*);  /* Callback for SELECTs */
2550   Parse *pParse;                            /* Parser context.  */
2551   int walkerDepth;                          /* Number of subqueries */
2552   union {                                   /* Extra data for callback */
2553     NameContext *pNC;                          /* Naming context */
2554     int i;                                     /* Integer value */
2555     SrcList *pSrcList;                         /* FROM clause */
2556     struct SrcCount *pSrcCount;                /* Counting column references */
2557   } u;
2558 };
2559 
2560 /* Forward declarations */
2561 int sqlite3WalkExpr(Walker*, Expr*);
2562 int sqlite3WalkExprList(Walker*, ExprList*);
2563 int sqlite3WalkSelect(Walker*, Select*);
2564 int sqlite3WalkSelectExpr(Walker*, Select*);
2565 int sqlite3WalkSelectFrom(Walker*, Select*);
2566 
2567 /*
2568 ** Return code from the parse-tree walking primitives and their
2569 ** callbacks.
2570 */
2571 #define WRC_Continue    0   /* Continue down into children */
2572 #define WRC_Prune       1   /* Omit children but continue walking siblings */
2573 #define WRC_Abort       2   /* Abandon the tree walk */
2574 
2575 /*
2576 ** Assuming zIn points to the first byte of a UTF-8 character,
2577 ** advance zIn to point to the first byte of the next UTF-8 character.
2578 */
2579 #define SQLITE_SKIP_UTF8(zIn) {                        \
2580   if( (*(zIn++))>=0xc0 ){                              \
2581     while( (*zIn & 0xc0)==0x80 ){ zIn++; }             \
2582   }                                                    \
2583 }
2584 
2585 /*
2586 ** The SQLITE_*_BKPT macros are substitutes for the error codes with
2587 ** the same name but without the _BKPT suffix.  These macros invoke
2588 ** routines that report the line-number on which the error originated
2589 ** using sqlite3_log().  The routines also provide a convenient place
2590 ** to set a debugger breakpoint.
2591 */
2592 int sqlite3CorruptError(int);
2593 int sqlite3MisuseError(int);
2594 int sqlite3CantopenError(int);
2595 #define SQLITE_CORRUPT_BKPT sqlite3CorruptError(__LINE__)
2596 #define SQLITE_MISUSE_BKPT sqlite3MisuseError(__LINE__)
2597 #define SQLITE_CANTOPEN_BKPT sqlite3CantopenError(__LINE__)
2598 
2599 
2600 /*
2601 ** FTS4 is really an extension for FTS3.  It is enabled using the
2602 ** SQLITE_ENABLE_FTS3 macro.  But to avoid confusion we also all
2603 ** the SQLITE_ENABLE_FTS4 macro to serve as an alisse for SQLITE_ENABLE_FTS3.
2604 */
2605 #if defined(SQLITE_ENABLE_FTS4) && !defined(SQLITE_ENABLE_FTS3)
2606 # define SQLITE_ENABLE_FTS3
2607 #endif
2608 
2609 /*
2610 ** The ctype.h header is needed for non-ASCII systems.  It is also
2611 ** needed by FTS3 when FTS3 is included in the amalgamation.
2612 */
2613 #if !defined(SQLITE_ASCII) || \
2614     (defined(SQLITE_ENABLE_FTS3) && defined(SQLITE_AMALGAMATION))
2615 # include <ctype.h>
2616 #endif
2617 
2618 /*
2619 ** The following macros mimic the standard library functions toupper(),
2620 ** isspace(), isalnum(), isdigit() and isxdigit(), respectively. The
2621 ** sqlite versions only work for ASCII characters, regardless of locale.
2622 */
2623 #ifdef SQLITE_ASCII
2624 # define sqlite3Toupper(x)  ((x)&~(sqlite3CtypeMap[(unsigned char)(x)]&0x20))
2625 # define sqlite3Isspace(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x01)
2626 # define sqlite3Isalnum(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x06)
2627 # define sqlite3Isalpha(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x02)
2628 # define sqlite3Isdigit(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x04)
2629 # define sqlite3Isxdigit(x)  (sqlite3CtypeMap[(unsigned char)(x)]&0x08)
2630 # define sqlite3Tolower(x)   (sqlite3UpperToLower[(unsigned char)(x)])
2631 #else
2632 # define sqlite3Toupper(x)   toupper((unsigned char)(x))
2633 # define sqlite3Isspace(x)   isspace((unsigned char)(x))
2634 # define sqlite3Isalnum(x)   isalnum((unsigned char)(x))
2635 # define sqlite3Isalpha(x)   isalpha((unsigned char)(x))
2636 # define sqlite3Isdigit(x)   isdigit((unsigned char)(x))
2637 # define sqlite3Isxdigit(x)  isxdigit((unsigned char)(x))
2638 # define sqlite3Tolower(x)   tolower((unsigned char)(x))
2639 #endif
2640 
2641 /*
2642 ** Internal function prototypes
2643 */
2644 #define sqlite3StrICmp sqlite3_stricmp
2645 int sqlite3Strlen30(const char*);
2646 #define sqlite3StrNICmp sqlite3_strnicmp
2647 
2648 int sqlite3MallocInit(void);
2649 void sqlite3MallocEnd(void);
2650 void *sqlite3Malloc(int);
2651 void *sqlite3MallocZero(int);
2652 void *sqlite3DbMallocZero(sqlite3*, int);
2653 void *sqlite3DbMallocRaw(sqlite3*, int);
2654 char *sqlite3DbStrDup(sqlite3*,const char*);
2655 char *sqlite3DbStrNDup(sqlite3*,const char*, int);
2656 void *sqlite3Realloc(void*, int);
2657 void *sqlite3DbReallocOrFree(sqlite3 *, void *, int);
2658 void *sqlite3DbRealloc(sqlite3 *, void *, int);
2659 void sqlite3DbFree(sqlite3*, void*);
2660 int sqlite3MallocSize(void*);
2661 int sqlite3DbMallocSize(sqlite3*, void*);
2662 void *sqlite3ScratchMalloc(int);
2663 void sqlite3ScratchFree(void*);
2664 void *sqlite3PageMalloc(int);
2665 void sqlite3PageFree(void*);
2666 void sqlite3MemSetDefault(void);
2667 void sqlite3BenignMallocHooks(void (*)(void), void (*)(void));
2668 int sqlite3HeapNearlyFull(void);
2669 
2670 /*
2671 ** On systems with ample stack space and that support alloca(), make
2672 ** use of alloca() to obtain space for large automatic objects.  By default,
2673 ** obtain space from malloc().
2674 **
2675 ** The alloca() routine never returns NULL.  This will cause code paths
2676 ** that deal with sqlite3StackAlloc() failures to be unreachable.
2677 */
2678 #ifdef SQLITE_USE_ALLOCA
2679 # define sqlite3StackAllocRaw(D,N)   alloca(N)
2680 # define sqlite3StackAllocZero(D,N)  memset(alloca(N), 0, N)
2681 # define sqlite3StackFree(D,P)
2682 #else
2683 # define sqlite3StackAllocRaw(D,N)   sqlite3DbMallocRaw(D,N)
2684 # define sqlite3StackAllocZero(D,N)  sqlite3DbMallocZero(D,N)
2685 # define sqlite3StackFree(D,P)       sqlite3DbFree(D,P)
2686 #endif
2687 
2688 #ifdef SQLITE_ENABLE_MEMSYS3
2689 const sqlite3_mem_methods *sqlite3MemGetMemsys3(void);
2690 #endif
2691 #ifdef SQLITE_ENABLE_MEMSYS5
2692 const sqlite3_mem_methods *sqlite3MemGetMemsys5(void);
2693 #endif
2694 
2695 
2696 #ifndef SQLITE_MUTEX_OMIT
2697   sqlite3_mutex_methods const *sqlite3DefaultMutex(void);
2698   sqlite3_mutex_methods const *sqlite3NoopMutex(void);
2699   sqlite3_mutex *sqlite3MutexAlloc(int);
2700   int sqlite3MutexInit(void);
2701   int sqlite3MutexEnd(void);
2702 #endif
2703 
2704 int sqlite3StatusValue(int);
2705 void sqlite3StatusAdd(int, int);
2706 void sqlite3StatusSet(int, int);
2707 
2708 #ifndef SQLITE_OMIT_FLOATING_POINT
2709   int sqlite3IsNaN(double);
2710 #else
2711 # define sqlite3IsNaN(X)  0
2712 #endif
2713 
2714 void sqlite3VXPrintf(StrAccum*, int, const char*, va_list);
2715 #ifndef SQLITE_OMIT_TRACE
2716 void sqlite3XPrintf(StrAccum*, const char*, ...);
2717 #endif
2718 char *sqlite3MPrintf(sqlite3*,const char*, ...);
2719 char *sqlite3VMPrintf(sqlite3*,const char*, va_list);
2720 char *sqlite3MAppendf(sqlite3*,char*,const char*,...);
2721 #if defined(SQLITE_TEST) || defined(SQLITE_DEBUG)
2722   void sqlite3DebugPrintf(const char*, ...);
2723 #endif
2724 #if defined(SQLITE_TEST)
2725   void *sqlite3TestTextToPtr(const char*);
2726 #endif
2727 
2728 /* Output formatting for SQLITE_TESTCTRL_EXPLAIN */
2729 #if defined(SQLITE_ENABLE_TREE_EXPLAIN)
2730   void sqlite3ExplainBegin(Vdbe*);
2731   void sqlite3ExplainPrintf(Vdbe*, const char*, ...);
2732   void sqlite3ExplainNL(Vdbe*);
2733   void sqlite3ExplainPush(Vdbe*);
2734   void sqlite3ExplainPop(Vdbe*);
2735   void sqlite3ExplainFinish(Vdbe*);
2736   void sqlite3ExplainSelect(Vdbe*, Select*);
2737   void sqlite3ExplainExpr(Vdbe*, Expr*);
2738   void sqlite3ExplainExprList(Vdbe*, ExprList*);
2739   const char *sqlite3VdbeExplanation(Vdbe*);
2740 #else
2741 # define sqlite3ExplainBegin(X)
2742 # define sqlite3ExplainSelect(A,B)
2743 # define sqlite3ExplainExpr(A,B)
2744 # define sqlite3ExplainExprList(A,B)
2745 # define sqlite3ExplainFinish(X)
2746 # define sqlite3VdbeExplanation(X) 0
2747 #endif
2748 
2749 
2750 void sqlite3SetString(char **, sqlite3*, const char*, ...);
2751 void sqlite3ErrorMsg(Parse*, const char*, ...);
2752 int sqlite3Dequote(char*);
2753 int sqlite3KeywordCode(const unsigned char*, int);
2754 int sqlite3RunParser(Parse*, const char*, char **);
2755 void sqlite3FinishCoding(Parse*);
2756 int sqlite3GetTempReg(Parse*);
2757 void sqlite3ReleaseTempReg(Parse*,int);
2758 int sqlite3GetTempRange(Parse*,int);
2759 void sqlite3ReleaseTempRange(Parse*,int,int);
2760 void sqlite3ClearTempRegCache(Parse*);
2761 Expr *sqlite3ExprAlloc(sqlite3*,int,const Token*,int);
2762 Expr *sqlite3Expr(sqlite3*,int,const char*);
2763 void sqlite3ExprAttachSubtrees(sqlite3*,Expr*,Expr*,Expr*);
2764 Expr *sqlite3PExpr(Parse*, int, Expr*, Expr*, const Token*);
2765 Expr *sqlite3ExprAnd(sqlite3*,Expr*, Expr*);
2766 Expr *sqlite3ExprFunction(Parse*,ExprList*, Token*);
2767 void sqlite3ExprAssignVarNumber(Parse*, Expr*);
2768 void sqlite3ExprDelete(sqlite3*, Expr*);
2769 ExprList *sqlite3ExprListAppend(Parse*,ExprList*,Expr*);
2770 void sqlite3ExprListSetName(Parse*,ExprList*,Token*,int);
2771 void sqlite3ExprListSetSpan(Parse*,ExprList*,ExprSpan*);
2772 void sqlite3ExprListDelete(sqlite3*, ExprList*);
2773 int sqlite3Init(sqlite3*, char**);
2774 int sqlite3InitCallback(void*, int, char**, char**);
2775 void sqlite3Pragma(Parse*,Token*,Token*,Token*,int);
2776 void sqlite3ResetAllSchemasOfConnection(sqlite3*);
2777 void sqlite3ResetOneSchema(sqlite3*,int);
2778 void sqlite3CollapseDatabaseArray(sqlite3*);
2779 void sqlite3BeginParse(Parse*,int);
2780 void sqlite3CommitInternalChanges(sqlite3*);
2781 Table *sqlite3ResultSetOfSelect(Parse*,Select*);
2782 void sqlite3OpenMasterTable(Parse *, int);
2783 void sqlite3StartTable(Parse*,Token*,Token*,int,int,int,int);
2784 void sqlite3AddColumn(Parse*,Token*);
2785 void sqlite3AddNotNull(Parse*, int);
2786 void sqlite3AddPrimaryKey(Parse*, ExprList*, int, int, int);
2787 void sqlite3AddCheckConstraint(Parse*, Expr*);
2788 void sqlite3AddColumnType(Parse*,Token*);
2789 void sqlite3AddDefaultValue(Parse*,ExprSpan*);
2790 void sqlite3AddCollateType(Parse*, Token*);
2791 void sqlite3EndTable(Parse*,Token*,Token*,Select*);
2792 int sqlite3ParseUri(const char*,const char*,unsigned int*,
2793                     sqlite3_vfs**,char**,char **);
2794 Btree *sqlite3DbNameToBtree(sqlite3*,const char*);
2795 int sqlite3CodeOnce(Parse *);
2796 
2797 Bitvec *sqlite3BitvecCreate(u32);
2798 int sqlite3BitvecTest(Bitvec*, u32);
2799 int sqlite3BitvecSet(Bitvec*, u32);
2800 void sqlite3BitvecClear(Bitvec*, u32, void*);
2801 void sqlite3BitvecDestroy(Bitvec*);
2802 u32 sqlite3BitvecSize(Bitvec*);
2803 int sqlite3BitvecBuiltinTest(int,int*);
2804 
2805 RowSet *sqlite3RowSetInit(sqlite3*, void*, unsigned int);
2806 void sqlite3RowSetClear(RowSet*);
2807 void sqlite3RowSetInsert(RowSet*, i64);
2808 int sqlite3RowSetTest(RowSet*, u8 iBatch, i64);
2809 int sqlite3RowSetNext(RowSet*, i64*);
2810 
2811 void sqlite3CreateView(Parse*,Token*,Token*,Token*,Select*,int,int);
2812 
2813 #if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE)
2814   int sqlite3ViewGetColumnNames(Parse*,Table*);
2815 #else
2816 # define sqlite3ViewGetColumnNames(A,B) 0
2817 #endif
2818 
2819 void sqlite3DropTable(Parse*, SrcList*, int, int);
2820 void sqlite3CodeDropTable(Parse*, Table*, int, int);
2821 void sqlite3DeleteTable(sqlite3*, Table*);
2822 #ifndef SQLITE_OMIT_AUTOINCREMENT
2823   void sqlite3AutoincrementBegin(Parse *pParse);
2824   void sqlite3AutoincrementEnd(Parse *pParse);
2825 #else
2826 # define sqlite3AutoincrementBegin(X)
2827 # define sqlite3AutoincrementEnd(X)
2828 #endif
2829 int sqlite3CodeCoroutine(Parse*, Select*, SelectDest*);
2830 void sqlite3Insert(Parse*, SrcList*, ExprList*, Select*, IdList*, int);
2831 void *sqlite3ArrayAllocate(sqlite3*,void*,int,int*,int*);
2832 IdList *sqlite3IdListAppend(sqlite3*, IdList*, Token*);
2833 int sqlite3IdListIndex(IdList*,const char*);
2834 SrcList *sqlite3SrcListEnlarge(sqlite3*, SrcList*, int, int);
2835 SrcList *sqlite3SrcListAppend(sqlite3*, SrcList*, Token*, Token*);
2836 SrcList *sqlite3SrcListAppendFromTerm(Parse*, SrcList*, Token*, Token*,
2837                                       Token*, Select*, Expr*, IdList*);
2838 void sqlite3SrcListIndexedBy(Parse *, SrcList *, Token *);
2839 int sqlite3IndexedByLookup(Parse *, struct SrcList_item *);
2840 void sqlite3SrcListShiftJoinType(SrcList*);
2841 void sqlite3SrcListAssignCursors(Parse*, SrcList*);
2842 void sqlite3IdListDelete(sqlite3*, IdList*);
2843 void sqlite3SrcListDelete(sqlite3*, SrcList*);
2844 Index *sqlite3CreateIndex(Parse*,Token*,Token*,SrcList*,ExprList*,int,Token*,
2845                         Token*, int, int);
2846 void sqlite3DropIndex(Parse*, SrcList*, int);
2847 int sqlite3Select(Parse*, Select*, SelectDest*);
2848 Select *sqlite3SelectNew(Parse*,ExprList*,SrcList*,Expr*,ExprList*,
2849                          Expr*,ExprList*,u16,Expr*,Expr*);
2850 void sqlite3SelectDelete(sqlite3*, Select*);
2851 Table *sqlite3SrcListLookup(Parse*, SrcList*);
2852 int sqlite3IsReadOnly(Parse*, Table*, int);
2853 void sqlite3OpenTable(Parse*, int iCur, int iDb, Table*, int);
2854 #if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY)
2855 Expr *sqlite3LimitWhere(Parse*,SrcList*,Expr*,ExprList*,Expr*,Expr*,char*);
2856 #endif
2857 void sqlite3DeleteFrom(Parse*, SrcList*, Expr*);
2858 void sqlite3Update(Parse*, SrcList*, ExprList*, Expr*, int);
2859 WhereInfo *sqlite3WhereBegin(Parse*,SrcList*,Expr*,ExprList*,ExprList*,u16,int);
2860 void sqlite3WhereEnd(WhereInfo*);
2861 int sqlite3ExprCodeGetColumn(Parse*, Table*, int, int, int, u8);
2862 void sqlite3ExprCodeGetColumnOfTable(Vdbe*, Table*, int, int, int);
2863 void sqlite3ExprCodeMove(Parse*, int, int, int);
2864 void sqlite3ExprCacheStore(Parse*, int, int, int);
2865 void sqlite3ExprCachePush(Parse*);
2866 void sqlite3ExprCachePop(Parse*, int);
2867 void sqlite3ExprCacheRemove(Parse*, int, int);
2868 void sqlite3ExprCacheClear(Parse*);
2869 void sqlite3ExprCacheAffinityChange(Parse*, int, int);
2870 int sqlite3ExprCode(Parse*, Expr*, int);
2871 int sqlite3ExprCodeTemp(Parse*, Expr*, int*);
2872 int sqlite3ExprCodeTarget(Parse*, Expr*, int);
2873 int sqlite3ExprCodeAndCache(Parse*, Expr*, int);
2874 void sqlite3ExprCodeConstants(Parse*, Expr*);
2875 int sqlite3ExprCodeExprList(Parse*, ExprList*, int, int);
2876 void sqlite3ExprIfTrue(Parse*, Expr*, int, int);
2877 void sqlite3ExprIfFalse(Parse*, Expr*, int, int);
2878 Table *sqlite3FindTable(sqlite3*,const char*, const char*);
2879 Table *sqlite3LocateTable(Parse*,int isView,const char*, const char*);
2880 Table *sqlite3LocateTableItem(Parse*,int isView,struct SrcList_item *);
2881 Index *sqlite3FindIndex(sqlite3*,const char*, const char*);
2882 void sqlite3UnlinkAndDeleteTable(sqlite3*,int,const char*);
2883 void sqlite3UnlinkAndDeleteIndex(sqlite3*,int,const char*);
2884 void sqlite3Vacuum(Parse*);
2885 int sqlite3RunVacuum(char**, sqlite3*);
2886 char *sqlite3NameFromToken(sqlite3*, Token*);
2887 int sqlite3ExprCompare(Expr*, Expr*);
2888 int sqlite3ExprListCompare(ExprList*, ExprList*);
2889 void sqlite3ExprAnalyzeAggregates(NameContext*, Expr*);
2890 void sqlite3ExprAnalyzeAggList(NameContext*,ExprList*);
2891 int sqlite3FunctionUsesThisSrc(Expr*, SrcList*);
2892 Vdbe *sqlite3GetVdbe(Parse*);
2893 void sqlite3PrngSaveState(void);
2894 void sqlite3PrngRestoreState(void);
2895 void sqlite3PrngResetState(void);
2896 void sqlite3RollbackAll(sqlite3*,int);
2897 void sqlite3CodeVerifySchema(Parse*, int);
2898 void sqlite3CodeVerifyNamedSchema(Parse*, const char *zDb);
2899 void sqlite3BeginTransaction(Parse*, int);
2900 void sqlite3CommitTransaction(Parse*);
2901 void sqlite3RollbackTransaction(Parse*);
2902 void sqlite3Savepoint(Parse*, int, Token*);
2903 void sqlite3CloseSavepoints(sqlite3 *);
2904 void sqlite3LeaveMutexAndCloseZombie(sqlite3*);
2905 int sqlite3ExprIsConstant(Expr*);
2906 int sqlite3ExprIsConstantNotJoin(Expr*);
2907 int sqlite3ExprIsConstantOrFunction(Expr*);
2908 int sqlite3ExprIsInteger(Expr*, int*);
2909 int sqlite3ExprCanBeNull(const Expr*);
2910 void sqlite3ExprCodeIsNullJump(Vdbe*, const Expr*, int, int);
2911 int sqlite3ExprNeedsNoAffinityChange(const Expr*, char);
2912 int sqlite3IsRowid(const char*);
2913 void sqlite3GenerateRowDelete(Parse*, Table*, int, int, int, Trigger *, int);
2914 void sqlite3GenerateRowIndexDelete(Parse*, Table*, int, int*);
2915 int sqlite3GenerateIndexKey(Parse*, Index*, int, int, int);
2916 void sqlite3GenerateConstraintChecks(Parse*,Table*,int,int,
2917                                      int*,int,int,int,int,int*);
2918 void sqlite3CompleteInsertion(Parse*, Table*, int, int, int*, int, int, int);
2919 int sqlite3OpenTableAndIndices(Parse*, Table*, int, int);
2920 void sqlite3BeginWriteOperation(Parse*, int, int);
2921 void sqlite3MultiWrite(Parse*);
2922 void sqlite3MayAbort(Parse*);
2923 void sqlite3HaltConstraint(Parse*, int, int, char*, int);
2924 Expr *sqlite3ExprDup(sqlite3*,Expr*,int);
2925 ExprList *sqlite3ExprListDup(sqlite3*,ExprList*,int);
2926 SrcList *sqlite3SrcListDup(sqlite3*,SrcList*,int);
2927 IdList *sqlite3IdListDup(sqlite3*,IdList*);
2928 Select *sqlite3SelectDup(sqlite3*,Select*,int);
2929 void sqlite3FuncDefInsert(FuncDefHash*, FuncDef*);
2930 FuncDef *sqlite3FindFunction(sqlite3*,const char*,int,int,u8,u8);
2931 void sqlite3RegisterBuiltinFunctions(sqlite3*);
2932 void sqlite3RegisterDateTimeFunctions(void);
2933 void sqlite3RegisterGlobalFunctions(void);
2934 int sqlite3SafetyCheckOk(sqlite3*);
2935 int sqlite3SafetyCheckSickOrOk(sqlite3*);
2936 void sqlite3ChangeCookie(Parse*, int);
2937 
2938 #if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
2939 void sqlite3MaterializeView(Parse*, Table*, Expr*, int);
2940 #endif
2941 
2942 #ifndef SQLITE_OMIT_TRIGGER
2943   void sqlite3BeginTrigger(Parse*, Token*,Token*,int,int,IdList*,SrcList*,
2944                            Expr*,int, int);
2945   void sqlite3FinishTrigger(Parse*, TriggerStep*, Token*);
2946   void sqlite3DropTrigger(Parse*, SrcList*, int);
2947   void sqlite3DropTriggerPtr(Parse*, Trigger*);
2948   Trigger *sqlite3TriggersExist(Parse *, Table*, int, ExprList*, int *pMask);
2949   Trigger *sqlite3TriggerList(Parse *, Table *);
2950   void sqlite3CodeRowTrigger(Parse*, Trigger *, int, ExprList*, int, Table *,
2951                             int, int, int);
2952   void sqlite3CodeRowTriggerDirect(Parse *, Trigger *, Table *, int, int, int);
2953   void sqliteViewTriggers(Parse*, Table*, Expr*, int, ExprList*);
2954   void sqlite3DeleteTriggerStep(sqlite3*, TriggerStep*);
2955   TriggerStep *sqlite3TriggerSelectStep(sqlite3*,Select*);
2956   TriggerStep *sqlite3TriggerInsertStep(sqlite3*,Token*, IdList*,
2957                                         ExprList*,Select*,u8);
2958   TriggerStep *sqlite3TriggerUpdateStep(sqlite3*,Token*,ExprList*, Expr*, u8);
2959   TriggerStep *sqlite3TriggerDeleteStep(sqlite3*,Token*, Expr*);
2960   void sqlite3DeleteTrigger(sqlite3*, Trigger*);
2961   void sqlite3UnlinkAndDeleteTrigger(sqlite3*,int,const char*);
2962   u32 sqlite3TriggerColmask(Parse*,Trigger*,ExprList*,int,int,Table*,int);
2963 # define sqlite3ParseToplevel(p) ((p)->pToplevel ? (p)->pToplevel : (p))
2964 #else
2965 # define sqlite3TriggersExist(B,C,D,E,F) 0
2966 # define sqlite3DeleteTrigger(A,B)
2967 # define sqlite3DropTriggerPtr(A,B)
2968 # define sqlite3UnlinkAndDeleteTrigger(A,B,C)
2969 # define sqlite3CodeRowTrigger(A,B,C,D,E,F,G,H,I)
2970 # define sqlite3CodeRowTriggerDirect(A,B,C,D,E,F)
2971 # define sqlite3TriggerList(X, Y) 0
2972 # define sqlite3ParseToplevel(p) p
2973 # define sqlite3TriggerColmask(A,B,C,D,E,F,G) 0
2974 #endif
2975 
2976 int sqlite3JoinType(Parse*, Token*, Token*, Token*);
2977 void sqlite3CreateForeignKey(Parse*, ExprList*, Token*, ExprList*, int);
2978 void sqlite3DeferForeignKey(Parse*, int);
2979 #ifndef SQLITE_OMIT_AUTHORIZATION
2980   void sqlite3AuthRead(Parse*,Expr*,Schema*,SrcList*);
2981   int sqlite3AuthCheck(Parse*,int, const char*, const char*, const char*);
2982   void sqlite3AuthContextPush(Parse*, AuthContext*, const char*);
2983   void sqlite3AuthContextPop(AuthContext*);
2984   int sqlite3AuthReadCol(Parse*, const char *, const char *, int);
2985 #else
2986 # define sqlite3AuthRead(a,b,c,d)
2987 # define sqlite3AuthCheck(a,b,c,d,e)    SQLITE_OK
2988 # define sqlite3AuthContextPush(a,b,c)
2989 # define sqlite3AuthContextPop(a)  ((void)(a))
2990 #endif
2991 void sqlite3Attach(Parse*, Expr*, Expr*, Expr*);
2992 void sqlite3Detach(Parse*, Expr*);
2993 int sqlite3FixInit(DbFixer*, Parse*, int, const char*, const Token*);
2994 int sqlite3FixSrcList(DbFixer*, SrcList*);
2995 int sqlite3FixSelect(DbFixer*, Select*);
2996 int sqlite3FixExpr(DbFixer*, Expr*);
2997 int sqlite3FixExprList(DbFixer*, ExprList*);
2998 int sqlite3FixTriggerStep(DbFixer*, TriggerStep*);
2999 int sqlite3AtoF(const char *z, double*, int, u8);
3000 int sqlite3GetInt32(const char *, int*);
3001 int sqlite3Atoi(const char*);
3002 int sqlite3Utf16ByteLen(const void *pData, int nChar);
3003 int sqlite3Utf8CharLen(const char *pData, int nByte);
3004 u32 sqlite3Utf8Read(const u8**);
3005 
3006 /*
3007 ** Routines to read and write variable-length integers.  These used to
3008 ** be defined locally, but now we use the varint routines in the util.c
3009 ** file.  Code should use the MACRO forms below, as the Varint32 versions
3010 ** are coded to assume the single byte case is already handled (which
3011 ** the MACRO form does).
3012 */
3013 int sqlite3PutVarint(unsigned char*, u64);
3014 int sqlite3PutVarint32(unsigned char*, u32);
3015 u8 sqlite3GetVarint(const unsigned char *, u64 *);
3016 u8 sqlite3GetVarint32(const unsigned char *, u32 *);
3017 int sqlite3VarintLen(u64 v);
3018 
3019 /*
3020 ** The header of a record consists of a sequence variable-length integers.
3021 ** These integers are almost always small and are encoded as a single byte.
3022 ** The following macros take advantage this fact to provide a fast encode
3023 ** and decode of the integers in a record header.  It is faster for the common
3024 ** case where the integer is a single byte.  It is a little slower when the
3025 ** integer is two or more bytes.  But overall it is faster.
3026 **
3027 ** The following expressions are equivalent:
3028 **
3029 **     x = sqlite3GetVarint32( A, &B );
3030 **     x = sqlite3PutVarint32( A, B );
3031 **
3032 **     x = getVarint32( A, B );
3033 **     x = putVarint32( A, B );
3034 **
3035 */
3036 #define getVarint32(A,B)  \
3037   (u8)((*(A)<(u8)0x80)?((B)=(u32)*(A)),1:sqlite3GetVarint32((A),(u32 *)&(B)))
3038 #define putVarint32(A,B)  \
3039   (u8)(((u32)(B)<(u32)0x80)?(*(A)=(unsigned char)(B)),1:\
3040   sqlite3PutVarint32((A),(B)))
3041 #define getVarint    sqlite3GetVarint
3042 #define putVarint    sqlite3PutVarint
3043 
3044 
3045 const char *sqlite3IndexAffinityStr(Vdbe *, Index *);
3046 void sqlite3TableAffinityStr(Vdbe *, Table *);
3047 char sqlite3CompareAffinity(Expr *pExpr, char aff2);
3048 int sqlite3IndexAffinityOk(Expr *pExpr, char idx_affinity);
3049 char sqlite3ExprAffinity(Expr *pExpr);
3050 int sqlite3Atoi64(const char*, i64*, int, u8);
3051 void sqlite3Error(sqlite3*, int, const char*,...);
3052 void *sqlite3HexToBlob(sqlite3*, const char *z, int n);
3053 u8 sqlite3HexToInt(int h);
3054 int sqlite3TwoPartName(Parse *, Token *, Token *, Token **);
3055 const char *sqlite3ErrStr(int);
3056 int sqlite3ReadSchema(Parse *pParse);
3057 CollSeq *sqlite3FindCollSeq(sqlite3*,u8 enc, const char*,int);
3058 CollSeq *sqlite3LocateCollSeq(Parse *pParse, const char*zName);
3059 CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr);
3060 Expr *sqlite3ExprAddCollateToken(Parse *pParse, Expr*, Token*);
3061 Expr *sqlite3ExprAddCollateString(Parse*,Expr*,const char*);
3062 Expr *sqlite3ExprSkipCollate(Expr*);
3063 int sqlite3CheckCollSeq(Parse *, CollSeq *);
3064 int sqlite3CheckObjectName(Parse *, const char *);
3065 void sqlite3VdbeSetChanges(sqlite3 *, int);
3066 int sqlite3AddInt64(i64*,i64);
3067 int sqlite3SubInt64(i64*,i64);
3068 int sqlite3MulInt64(i64*,i64);
3069 int sqlite3AbsInt32(int);
3070 #ifdef SQLITE_ENABLE_8_3_NAMES
3071 void sqlite3FileSuffix3(const char*, char*);
3072 #else
3073 # define sqlite3FileSuffix3(X,Y)
3074 #endif
3075 u8 sqlite3GetBoolean(const char *z,int);
3076 
3077 const void *sqlite3ValueText(sqlite3_value*, u8);
3078 int sqlite3ValueBytes(sqlite3_value*, u8);
3079 void sqlite3ValueSetStr(sqlite3_value*, int, const void *,u8,
3080                         void(*)(void*));
3081 void sqlite3ValueFree(sqlite3_value*);
3082 sqlite3_value *sqlite3ValueNew(sqlite3 *);
3083 char *sqlite3Utf16to8(sqlite3 *, const void*, int, u8);
3084 #ifdef SQLITE_ENABLE_STAT3
3085 char *sqlite3Utf8to16(sqlite3 *, u8, char *, int, int *);
3086 #endif
3087 int sqlite3ValueFromExpr(sqlite3 *, Expr *, u8, u8, sqlite3_value **);
3088 void sqlite3ValueApplyAffinity(sqlite3_value *, u8, u8);
3089 #ifndef SQLITE_AMALGAMATION
3090 extern const unsigned char sqlite3OpcodeProperty[];
3091 extern const unsigned char sqlite3UpperToLower[];
3092 extern const unsigned char sqlite3CtypeMap[];
3093 extern const Token sqlite3IntTokens[];
3094 extern SQLITE_WSD struct Sqlite3Config sqlite3Config;
3095 extern SQLITE_WSD FuncDefHash sqlite3GlobalFunctions;
3096 #ifndef SQLITE_OMIT_WSD
3097 extern int sqlite3PendingByte;
3098 #endif
3099 #endif
3100 void sqlite3RootPageMoved(sqlite3*, int, int, int);
3101 void sqlite3Reindex(Parse*, Token*, Token*);
3102 void sqlite3AlterFunctions(void);
3103 void sqlite3AlterRenameTable(Parse*, SrcList*, Token*);
3104 int sqlite3GetToken(const unsigned char *, int *);
3105 void sqlite3NestedParse(Parse*, const char*, ...);
3106 void sqlite3ExpirePreparedStatements(sqlite3*);
3107 int sqlite3CodeSubselect(Parse *, Expr *, int, int);
3108 void sqlite3SelectPrep(Parse*, Select*, NameContext*);
3109 int sqlite3MatchSpanName(const char*, const char*, const char*, const char*);
3110 int sqlite3ResolveExprNames(NameContext*, Expr*);
3111 void sqlite3ResolveSelectNames(Parse*, Select*, NameContext*);
3112 int sqlite3ResolveOrderGroupBy(Parse*, Select*, ExprList*, const char*);
3113 void sqlite3ColumnDefault(Vdbe *, Table *, int, int);
3114 void sqlite3AlterFinishAddColumn(Parse *, Token *);
3115 void sqlite3AlterBeginAddColumn(Parse *, SrcList *);
3116 CollSeq *sqlite3GetCollSeq(Parse*, u8, CollSeq *, const char*);
3117 char sqlite3AffinityType(const char*);
3118 void sqlite3Analyze(Parse*, Token*, Token*);
3119 int sqlite3InvokeBusyHandler(BusyHandler*);
3120 int sqlite3FindDb(sqlite3*, Token*);
3121 int sqlite3FindDbName(sqlite3 *, const char *);
3122 int sqlite3AnalysisLoad(sqlite3*,int iDB);
3123 void sqlite3DeleteIndexSamples(sqlite3*,Index*);
3124 void sqlite3DefaultRowEst(Index*);
3125 void sqlite3RegisterLikeFunctions(sqlite3*, int);
3126 int sqlite3IsLikeFunction(sqlite3*,Expr*,int*,char*);
3127 void sqlite3MinimumFileFormat(Parse*, int, int);
3128 void sqlite3SchemaClear(void *);
3129 Schema *sqlite3SchemaGet(sqlite3 *, Btree *);
3130 int sqlite3SchemaToIndex(sqlite3 *db, Schema *);
3131 KeyInfo *sqlite3IndexKeyinfo(Parse *, Index *);
3132 int sqlite3CreateFunc(sqlite3 *, const char *, int, int, void *,
3133   void (*)(sqlite3_context*,int,sqlite3_value **),
3134   void (*)(sqlite3_context*,int,sqlite3_value **), void (*)(sqlite3_context*),
3135   FuncDestructor *pDestructor
3136 );
3137 int sqlite3ApiExit(sqlite3 *db, int);
3138 int sqlite3OpenTempDatabase(Parse *);
3139 
3140 void sqlite3StrAccumInit(StrAccum*, char*, int, int);
3141 void sqlite3StrAccumAppend(StrAccum*,const char*,int);
3142 void sqlite3AppendSpace(StrAccum*,int);
3143 char *sqlite3StrAccumFinish(StrAccum*);
3144 void sqlite3StrAccumReset(StrAccum*);
3145 void sqlite3SelectDestInit(SelectDest*,int,int);
3146 Expr *sqlite3CreateColumnExpr(sqlite3 *, SrcList *, int, int);
3147 
3148 void sqlite3BackupRestart(sqlite3_backup *);
3149 void sqlite3BackupUpdate(sqlite3_backup *, Pgno, const u8 *);
3150 
3151 /*
3152 ** The interface to the LEMON-generated parser
3153 */
3154 void *sqlite3ParserAlloc(void*(*)(size_t));
3155 void sqlite3ParserFree(void*, void(*)(void*));
3156 void sqlite3Parser(void*, int, Token, Parse*);
3157 #ifdef YYTRACKMAXSTACKDEPTH
3158   int sqlite3ParserStackPeak(void*);
3159 #endif
3160 
3161 void sqlite3AutoLoadExtensions(sqlite3*);
3162 #ifndef SQLITE_OMIT_LOAD_EXTENSION
3163   void sqlite3CloseExtensions(sqlite3*);
3164 #else
3165 # define sqlite3CloseExtensions(X)
3166 #endif
3167 
3168 #ifndef SQLITE_OMIT_SHARED_CACHE
3169   void sqlite3TableLock(Parse *, int, int, u8, const char *);
3170 #else
3171   #define sqlite3TableLock(v,w,x,y,z)
3172 #endif
3173 
3174 #ifdef SQLITE_TEST
3175   int sqlite3Utf8To8(unsigned char*);
3176 #endif
3177 
3178 #ifdef SQLITE_OMIT_VIRTUALTABLE
3179 #  define sqlite3VtabClear(Y)
3180 #  define sqlite3VtabSync(X,Y) SQLITE_OK
3181 #  define sqlite3VtabRollback(X)
3182 #  define sqlite3VtabCommit(X)
3183 #  define sqlite3VtabInSync(db) 0
3184 #  define sqlite3VtabLock(X)
3185 #  define sqlite3VtabUnlock(X)
3186 #  define sqlite3VtabUnlockList(X)
3187 #  define sqlite3VtabSavepoint(X, Y, Z) SQLITE_OK
3188 #  define sqlite3GetVTable(X,Y)  ((VTable*)0)
3189 #else
3190    void sqlite3VtabClear(sqlite3 *db, Table*);
3191    void sqlite3VtabDisconnect(sqlite3 *db, Table *p);
3192    int sqlite3VtabSync(sqlite3 *db, char **);
3193    int sqlite3VtabRollback(sqlite3 *db);
3194    int sqlite3VtabCommit(sqlite3 *db);
3195    void sqlite3VtabLock(VTable *);
3196    void sqlite3VtabUnlock(VTable *);
3197    void sqlite3VtabUnlockList(sqlite3*);
3198    int sqlite3VtabSavepoint(sqlite3 *, int, int);
3199    VTable *sqlite3GetVTable(sqlite3*, Table*);
3200 #  define sqlite3VtabInSync(db) ((db)->nVTrans>0 && (db)->aVTrans==0)
3201 #endif
3202 void sqlite3VtabMakeWritable(Parse*,Table*);
3203 void sqlite3VtabBeginParse(Parse*, Token*, Token*, Token*, int);
3204 void sqlite3VtabFinishParse(Parse*, Token*);
3205 void sqlite3VtabArgInit(Parse*);
3206 void sqlite3VtabArgExtend(Parse*, Token*);
3207 int sqlite3VtabCallCreate(sqlite3*, int, const char *, char **);
3208 int sqlite3VtabCallConnect(Parse*, Table*);
3209 int sqlite3VtabCallDestroy(sqlite3*, int, const char *);
3210 int sqlite3VtabBegin(sqlite3 *, VTable *);
3211 FuncDef *sqlite3VtabOverloadFunction(sqlite3 *,FuncDef*, int nArg, Expr*);
3212 void sqlite3InvalidFunction(sqlite3_context*,int,sqlite3_value**);
3213 int sqlite3VdbeParameterIndex(Vdbe*, const char*, int);
3214 int sqlite3TransferBindings(sqlite3_stmt *, sqlite3_stmt *);
3215 int sqlite3Reprepare(Vdbe*);
3216 void sqlite3ExprListCheckLength(Parse*, ExprList*, const char*);
3217 CollSeq *sqlite3BinaryCompareCollSeq(Parse *, Expr *, Expr *);
3218 int sqlite3TempInMemory(const sqlite3*);
3219 const char *sqlite3JournalModename(int);
3220 #ifndef SQLITE_OMIT_WAL
3221   int sqlite3Checkpoint(sqlite3*, int, int, int*, int*);
3222   int sqlite3WalDefaultHook(void*,sqlite3*,const char*,int);
3223 #endif
3224 
3225 /* Declarations for functions in fkey.c. All of these are replaced by
3226 ** no-op macros if OMIT_FOREIGN_KEY is defined. In this case no foreign
3227 ** key functionality is available. If OMIT_TRIGGER is defined but
3228 ** OMIT_FOREIGN_KEY is not, only some of the functions are no-oped. In
3229 ** this case foreign keys are parsed, but no other functionality is
3230 ** provided (enforcement of FK constraints requires the triggers sub-system).
3231 */
3232 #if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)
3233   void sqlite3FkCheck(Parse*, Table*, int, int);
3234   void sqlite3FkDropTable(Parse*, SrcList *, Table*);
3235   void sqlite3FkActions(Parse*, Table*, ExprList*, int);
3236   int sqlite3FkRequired(Parse*, Table*, int*, int);
3237   u32 sqlite3FkOldmask(Parse*, Table*);
3238   FKey *sqlite3FkReferences(Table *);
3239 #else
3240   #define sqlite3FkActions(a,b,c,d)
3241   #define sqlite3FkCheck(a,b,c,d)
3242   #define sqlite3FkDropTable(a,b,c)
3243   #define sqlite3FkOldmask(a,b)      0
3244   #define sqlite3FkRequired(a,b,c,d) 0
3245 #endif
3246 #ifndef SQLITE_OMIT_FOREIGN_KEY
3247   void sqlite3FkDelete(sqlite3 *, Table*);
3248   int sqlite3FkLocateIndex(Parse*,Table*,FKey*,Index**,int**);
3249 #else
3250   #define sqlite3FkDelete(a,b)
3251   #define sqlite3FkLocateIndex(a,b,c,d,e)
3252 #endif
3253 
3254 
3255 /*
3256 ** Available fault injectors.  Should be numbered beginning with 0.
3257 */
3258 #define SQLITE_FAULTINJECTOR_MALLOC     0
3259 #define SQLITE_FAULTINJECTOR_COUNT      1
3260 
3261 /*
3262 ** The interface to the code in fault.c used for identifying "benign"
3263 ** malloc failures. This is only present if SQLITE_OMIT_BUILTIN_TEST
3264 ** is not defined.
3265 */
3266 #ifndef SQLITE_OMIT_BUILTIN_TEST
3267   void sqlite3BeginBenignMalloc(void);
3268   void sqlite3EndBenignMalloc(void);
3269 #else
3270   #define sqlite3BeginBenignMalloc()
3271   #define sqlite3EndBenignMalloc()
3272 #endif
3273 
3274 #define IN_INDEX_ROWID           1
3275 #define IN_INDEX_EPH             2
3276 #define IN_INDEX_INDEX_ASC       3
3277 #define IN_INDEX_INDEX_DESC      4
3278 int sqlite3FindInIndex(Parse *, Expr *, int*);
3279 
3280 #ifdef SQLITE_ENABLE_ATOMIC_WRITE
3281   int sqlite3JournalOpen(sqlite3_vfs *, const char *, sqlite3_file *, int, int);
3282   int sqlite3JournalSize(sqlite3_vfs *);
3283   int sqlite3JournalCreate(sqlite3_file *);
3284   int sqlite3JournalExists(sqlite3_file *p);
3285 #else
3286   #define sqlite3JournalSize(pVfs) ((pVfs)->szOsFile)
3287   #define sqlite3JournalExists(p) 1
3288 #endif
3289 
3290 void sqlite3MemJournalOpen(sqlite3_file *);
3291 int sqlite3MemJournalSize(void);
3292 int sqlite3IsMemJournal(sqlite3_file *);
3293 
3294 #if SQLITE_MAX_EXPR_DEPTH>0
3295   void sqlite3ExprSetHeight(Parse *pParse, Expr *p);
3296   int sqlite3SelectExprHeight(Select *);
3297   int sqlite3ExprCheckHeight(Parse*, int);
3298 #else
3299   #define sqlite3ExprSetHeight(x,y)
3300   #define sqlite3SelectExprHeight(x) 0
3301   #define sqlite3ExprCheckHeight(x,y)
3302 #endif
3303 
3304 u32 sqlite3Get4byte(const u8*);
3305 void sqlite3Put4byte(u8*, u32);
3306 
3307 #ifdef SQLITE_ENABLE_UNLOCK_NOTIFY
3308   void sqlite3ConnectionBlocked(sqlite3 *, sqlite3 *);
3309   void sqlite3ConnectionUnlocked(sqlite3 *db);
3310   void sqlite3ConnectionClosed(sqlite3 *db);
3311 #else
3312   #define sqlite3ConnectionBlocked(x,y)
3313   #define sqlite3ConnectionUnlocked(x)
3314   #define sqlite3ConnectionClosed(x)
3315 #endif
3316 
3317 #ifdef SQLITE_DEBUG
3318   void sqlite3ParserTrace(FILE*, char *);
3319 #endif
3320 
3321 /*
3322 ** If the SQLITE_ENABLE IOTRACE exists then the global variable
3323 ** sqlite3IoTrace is a pointer to a printf-like routine used to
3324 ** print I/O tracing messages.
3325 */
3326 #ifdef SQLITE_ENABLE_IOTRACE
3327 # define IOTRACE(A)  if( sqlite3IoTrace ){ sqlite3IoTrace A; }
3328   void sqlite3VdbeIOTraceSql(Vdbe*);
3329 SQLITE_EXTERN void (*sqlite3IoTrace)(const char*,...);
3330 #else
3331 # define IOTRACE(A)
3332 # define sqlite3VdbeIOTraceSql(X)
3333 #endif
3334 
3335 /*
3336 ** These routines are available for the mem2.c debugging memory allocator
3337 ** only.  They are used to verify that different "types" of memory
3338 ** allocations are properly tracked by the system.
3339 **
3340 ** sqlite3MemdebugSetType() sets the "type" of an allocation to one of
3341 ** the MEMTYPE_* macros defined below.  The type must be a bitmask with
3342 ** a single bit set.
3343 **
3344 ** sqlite3MemdebugHasType() returns true if any of the bits in its second
3345 ** argument match the type set by the previous sqlite3MemdebugSetType().
3346 ** sqlite3MemdebugHasType() is intended for use inside assert() statements.
3347 **
3348 ** sqlite3MemdebugNoType() returns true if none of the bits in its second
3349 ** argument match the type set by the previous sqlite3MemdebugSetType().
3350 **
3351 ** Perhaps the most important point is the difference between MEMTYPE_HEAP
3352 ** and MEMTYPE_LOOKASIDE.  If an allocation is MEMTYPE_LOOKASIDE, that means
3353 ** it might have been allocated by lookaside, except the allocation was
3354 ** too large or lookaside was already full.  It is important to verify
3355 ** that allocations that might have been satisfied by lookaside are not
3356 ** passed back to non-lookaside free() routines.  Asserts such as the
3357 ** example above are placed on the non-lookaside free() routines to verify
3358 ** this constraint.
3359 **
3360 ** All of this is no-op for a production build.  It only comes into
3361 ** play when the SQLITE_MEMDEBUG compile-time option is used.
3362 */
3363 #ifdef SQLITE_MEMDEBUG
3364   void sqlite3MemdebugSetType(void*,u8);
3365   int sqlite3MemdebugHasType(void*,u8);
3366   int sqlite3MemdebugNoType(void*,u8);
3367 #else
3368 # define sqlite3MemdebugSetType(X,Y)  /* no-op */
3369 # define sqlite3MemdebugHasType(X,Y)  1
3370 # define sqlite3MemdebugNoType(X,Y)   1
3371 #endif
3372 #define MEMTYPE_HEAP       0x01  /* General heap allocations */
3373 #define MEMTYPE_LOOKASIDE  0x02  /* Might have been lookaside memory */
3374 #define MEMTYPE_SCRATCH    0x04  /* Scratch allocations */
3375 #define MEMTYPE_PCACHE     0x08  /* Page cache allocations */
3376 #define MEMTYPE_DB         0x10  /* Uses sqlite3DbMalloc, not sqlite_malloc */
3377 
3378 #endif /* _SQLITEINT_H_ */
3379