xref: /sqlite-3.40.0/src/sqliteInt.h (revision 48680190)
1 /*
2 ** 2001 September 15
3 **
4 ** The author disclaims copyright to this source code.  In place of
5 ** a legal notice, here is a blessing:
6 **
7 **    May you do good and not evil.
8 **    May you find forgiveness for yourself and forgive others.
9 **    May you share freely, never taking more than you give.
10 **
11 *************************************************************************
12 ** Internal interface definitions for SQLite.
13 **
14 */
15 #ifndef _SQLITEINT_H_
16 #define _SQLITEINT_H_
17 
18 /*
19 ** These #defines should enable >2GB file support on POSIX if the
20 ** underlying operating system supports it.  If the OS lacks
21 ** large file support, or if the OS is windows, these should be no-ops.
22 **
23 ** Ticket #2739:  The _LARGEFILE_SOURCE macro must appear before any
24 ** system #includes.  Hence, this block of code must be the very first
25 ** code in all source files.
26 **
27 ** Large file support can be disabled using the -DSQLITE_DISABLE_LFS switch
28 ** on the compiler command line.  This is necessary if you are compiling
29 ** on a recent machine (ex: Red Hat 7.2) but you want your code to work
30 ** on an older machine (ex: Red Hat 6.0).  If you compile on Red Hat 7.2
31 ** without this option, LFS is enable.  But LFS does not exist in the kernel
32 ** in Red Hat 6.0, so the code won't work.  Hence, for maximum binary
33 ** portability you should omit LFS.
34 **
35 ** Similar is true for Mac OS X.  LFS is only supported on Mac OS X 9 and later.
36 */
37 #ifndef SQLITE_DISABLE_LFS
38 # define _LARGE_FILE       1
39 # ifndef _FILE_OFFSET_BITS
40 #   define _FILE_OFFSET_BITS 64
41 # endif
42 # define _LARGEFILE_SOURCE 1
43 #endif
44 
45 /*
46 ** Include the configuration header output by 'configure' if we're using the
47 ** autoconf-based build
48 */
49 #ifdef _HAVE_SQLITE_CONFIG_H
50 #include "config.h"
51 #endif
52 
53 #include "sqliteLimit.h"
54 
55 /* Disable nuisance warnings on Borland compilers */
56 #if defined(__BORLANDC__)
57 #pragma warn -rch /* unreachable code */
58 #pragma warn -ccc /* Condition is always true or false */
59 #pragma warn -aus /* Assigned value is never used */
60 #pragma warn -csu /* Comparing signed and unsigned */
61 #pragma warn -spa /* Suspicious pointer arithmetic */
62 #endif
63 
64 /* Needed for various definitions... */
65 #ifndef _GNU_SOURCE
66 # define _GNU_SOURCE
67 #endif
68 
69 /*
70 ** Include standard header files as necessary
71 */
72 #ifdef HAVE_STDINT_H
73 #include <stdint.h>
74 #endif
75 #ifdef HAVE_INTTYPES_H
76 #include <inttypes.h>
77 #endif
78 
79 /*
80 ** The following macros are used to cast pointers to integers and
81 ** integers to pointers.  The way you do this varies from one compiler
82 ** to the next, so we have developed the following set of #if statements
83 ** to generate appropriate macros for a wide range of compilers.
84 **
85 ** The correct "ANSI" way to do this is to use the intptr_t type.
86 ** Unfortunately, that typedef is not available on all compilers, or
87 ** if it is available, it requires an #include of specific headers
88 ** that vary from one machine to the next.
89 **
90 ** Ticket #3860:  The llvm-gcc-4.2 compiler from Apple chokes on
91 ** the ((void*)&((char*)0)[X]) construct.  But MSVC chokes on ((void*)(X)).
92 ** So we have to define the macros in different ways depending on the
93 ** compiler.
94 */
95 #if defined(__PTRDIFF_TYPE__)  /* This case should work for GCC */
96 # define SQLITE_INT_TO_PTR(X)  ((void*)(__PTRDIFF_TYPE__)(X))
97 # define SQLITE_PTR_TO_INT(X)  ((int)(__PTRDIFF_TYPE__)(X))
98 #elif !defined(__GNUC__)       /* Works for compilers other than LLVM */
99 # define SQLITE_INT_TO_PTR(X)  ((void*)&((char*)0)[X])
100 # define SQLITE_PTR_TO_INT(X)  ((int)(((char*)X)-(char*)0))
101 #elif defined(HAVE_STDINT_H)   /* Use this case if we have ANSI headers */
102 # define SQLITE_INT_TO_PTR(X)  ((void*)(intptr_t)(X))
103 # define SQLITE_PTR_TO_INT(X)  ((int)(intptr_t)(X))
104 #else                          /* Generates a warning - but it always works */
105 # define SQLITE_INT_TO_PTR(X)  ((void*)(X))
106 # define SQLITE_PTR_TO_INT(X)  ((int)(X))
107 #endif
108 
109 /*
110 ** The SQLITE_THREADSAFE macro must be defined as 0, 1, or 2.
111 ** 0 means mutexes are permanently disable and the library is never
112 ** threadsafe.  1 means the library is serialized which is the highest
113 ** level of threadsafety.  2 means the libary is multithreaded - multiple
114 ** threads can use SQLite as long as no two threads try to use the same
115 ** database connection at the same time.
116 **
117 ** Older versions of SQLite used an optional THREADSAFE macro.
118 ** We support that for legacy.
119 */
120 #if !defined(SQLITE_THREADSAFE)
121 #if defined(THREADSAFE)
122 # define SQLITE_THREADSAFE THREADSAFE
123 #else
124 # define SQLITE_THREADSAFE 1 /* IMP: R-07272-22309 */
125 #endif
126 #endif
127 
128 /*
129 ** Powersafe overwrite is on by default.  But can be turned off using
130 ** the -DSQLITE_POWERSAFE_OVERWRITE=0 command-line option.
131 */
132 #ifndef SQLITE_POWERSAFE_OVERWRITE
133 # define SQLITE_POWERSAFE_OVERWRITE 1
134 #endif
135 
136 /*
137 ** The SQLITE_DEFAULT_MEMSTATUS macro must be defined as either 0 or 1.
138 ** It determines whether or not the features related to
139 ** SQLITE_CONFIG_MEMSTATUS are available by default or not. This value can
140 ** be overridden at runtime using the sqlite3_config() API.
141 */
142 #if !defined(SQLITE_DEFAULT_MEMSTATUS)
143 # define SQLITE_DEFAULT_MEMSTATUS 1
144 #endif
145 
146 /*
147 ** Exactly one of the following macros must be defined in order to
148 ** specify which memory allocation subsystem to use.
149 **
150 **     SQLITE_SYSTEM_MALLOC          // Use normal system malloc()
151 **     SQLITE_WIN32_MALLOC           // Use Win32 native heap API
152 **     SQLITE_ZERO_MALLOC            // Use a stub allocator that always fails
153 **     SQLITE_MEMDEBUG               // Debugging version of system malloc()
154 **
155 ** On Windows, if the SQLITE_WIN32_MALLOC_VALIDATE macro is defined and the
156 ** assert() macro is enabled, each call into the Win32 native heap subsystem
157 ** will cause HeapValidate to be called.  If heap validation should fail, an
158 ** assertion will be triggered.
159 **
160 ** (Historical note:  There used to be several other options, but we've
161 ** pared it down to just these three.)
162 **
163 ** If none of the above are defined, then set SQLITE_SYSTEM_MALLOC as
164 ** the default.
165 */
166 #if defined(SQLITE_SYSTEM_MALLOC) \
167   + defined(SQLITE_WIN32_MALLOC) \
168   + defined(SQLITE_ZERO_MALLOC) \
169   + defined(SQLITE_MEMDEBUG)>1
170 # error "Two or more of the following compile-time configuration options\
171  are defined but at most one is allowed:\
172  SQLITE_SYSTEM_MALLOC, SQLITE_WIN32_MALLOC, SQLITE_MEMDEBUG,\
173  SQLITE_ZERO_MALLOC"
174 #endif
175 #if defined(SQLITE_SYSTEM_MALLOC) \
176   + defined(SQLITE_WIN32_MALLOC) \
177   + defined(SQLITE_ZERO_MALLOC) \
178   + defined(SQLITE_MEMDEBUG)==0
179 # define SQLITE_SYSTEM_MALLOC 1
180 #endif
181 
182 /*
183 ** If SQLITE_MALLOC_SOFT_LIMIT is not zero, then try to keep the
184 ** sizes of memory allocations below this value where possible.
185 */
186 #if !defined(SQLITE_MALLOC_SOFT_LIMIT)
187 # define SQLITE_MALLOC_SOFT_LIMIT 1024
188 #endif
189 
190 /*
191 ** We need to define _XOPEN_SOURCE as follows in order to enable
192 ** recursive mutexes on most Unix systems.  But Mac OS X is different.
193 ** The _XOPEN_SOURCE define causes problems for Mac OS X we are told,
194 ** so it is omitted there.  See ticket #2673.
195 **
196 ** Later we learn that _XOPEN_SOURCE is poorly or incorrectly
197 ** implemented on some systems.  So we avoid defining it at all
198 ** if it is already defined or if it is unneeded because we are
199 ** not doing a threadsafe build.  Ticket #2681.
200 **
201 ** See also ticket #2741.
202 */
203 #if !defined(_XOPEN_SOURCE) && !defined(__DARWIN__) && !defined(__APPLE__) && SQLITE_THREADSAFE
204 #  define _XOPEN_SOURCE 500  /* Needed to enable pthread recursive mutexes */
205 #endif
206 
207 /*
208 ** The TCL headers are only needed when compiling the TCL bindings.
209 */
210 #if defined(SQLITE_TCL) || defined(TCLSH)
211 # include <tcl.h>
212 #endif
213 
214 /*
215 ** NDEBUG and SQLITE_DEBUG are opposites.  It should always be true that
216 ** defined(NDEBUG)==!defined(SQLITE_DEBUG).  If this is not currently true,
217 ** make it true by defining or undefining NDEBUG.
218 **
219 ** Setting NDEBUG makes the code smaller and run faster by disabling the
220 ** number assert() statements in the code.  So we want the default action
221 ** to be for NDEBUG to be set and NDEBUG to be undefined only if SQLITE_DEBUG
222 ** is set.  Thus NDEBUG becomes an opt-in rather than an opt-out
223 ** feature.
224 */
225 #if !defined(NDEBUG) && !defined(SQLITE_DEBUG)
226 # define NDEBUG 1
227 #endif
228 #if defined(NDEBUG) && defined(SQLITE_DEBUG)
229 # undef NDEBUG
230 #endif
231 
232 /*
233 ** The testcase() macro is used to aid in coverage testing.  When
234 ** doing coverage testing, the condition inside the argument to
235 ** testcase() must be evaluated both true and false in order to
236 ** get full branch coverage.  The testcase() macro is inserted
237 ** to help ensure adequate test coverage in places where simple
238 ** condition/decision coverage is inadequate.  For example, testcase()
239 ** can be used to make sure boundary values are tested.  For
240 ** bitmask tests, testcase() can be used to make sure each bit
241 ** is significant and used at least once.  On switch statements
242 ** where multiple cases go to the same block of code, testcase()
243 ** can insure that all cases are evaluated.
244 **
245 */
246 #ifdef SQLITE_COVERAGE_TEST
247   void sqlite3Coverage(int);
248 # define testcase(X)  if( X ){ sqlite3Coverage(__LINE__); }
249 #else
250 # define testcase(X)
251 #endif
252 
253 /*
254 ** The TESTONLY macro is used to enclose variable declarations or
255 ** other bits of code that are needed to support the arguments
256 ** within testcase() and assert() macros.
257 */
258 #if !defined(NDEBUG) || defined(SQLITE_COVERAGE_TEST)
259 # define TESTONLY(X)  X
260 #else
261 # define TESTONLY(X)
262 #endif
263 
264 /*
265 ** Sometimes we need a small amount of code such as a variable initialization
266 ** to setup for a later assert() statement.  We do not want this code to
267 ** appear when assert() is disabled.  The following macro is therefore
268 ** used to contain that setup code.  The "VVA" acronym stands for
269 ** "Verification, Validation, and Accreditation".  In other words, the
270 ** code within VVA_ONLY() will only run during verification processes.
271 */
272 #ifndef NDEBUG
273 # define VVA_ONLY(X)  X
274 #else
275 # define VVA_ONLY(X)
276 #endif
277 
278 /*
279 ** The ALWAYS and NEVER macros surround boolean expressions which
280 ** are intended to always be true or false, respectively.  Such
281 ** expressions could be omitted from the code completely.  But they
282 ** are included in a few cases in order to enhance the resilience
283 ** of SQLite to unexpected behavior - to make the code "self-healing"
284 ** or "ductile" rather than being "brittle" and crashing at the first
285 ** hint of unplanned behavior.
286 **
287 ** In other words, ALWAYS and NEVER are added for defensive code.
288 **
289 ** When doing coverage testing ALWAYS and NEVER are hard-coded to
290 ** be true and false so that the unreachable code then specify will
291 ** not be counted as untested code.
292 */
293 #if defined(SQLITE_COVERAGE_TEST)
294 # define ALWAYS(X)      (1)
295 # define NEVER(X)       (0)
296 #elif !defined(NDEBUG)
297 # define ALWAYS(X)      ((X)?1:(assert(0),0))
298 # define NEVER(X)       ((X)?(assert(0),1):0)
299 #else
300 # define ALWAYS(X)      (X)
301 # define NEVER(X)       (X)
302 #endif
303 
304 /*
305 ** Return true (non-zero) if the input is a integer that is too large
306 ** to fit in 32-bits.  This macro is used inside of various testcase()
307 ** macros to verify that we have tested SQLite for large-file support.
308 */
309 #define IS_BIG_INT(X)  (((X)&~(i64)0xffffffff)!=0)
310 
311 /*
312 ** The macro unlikely() is a hint that surrounds a boolean
313 ** expression that is usually false.  Macro likely() surrounds
314 ** a boolean expression that is usually true.  GCC is able to
315 ** use these hints to generate better code, sometimes.
316 */
317 #if defined(__GNUC__) && 0
318 # define likely(X)    __builtin_expect((X),1)
319 # define unlikely(X)  __builtin_expect((X),0)
320 #else
321 # define likely(X)    !!(X)
322 # define unlikely(X)  !!(X)
323 #endif
324 
325 #include "sqlite3.h"
326 #include "hash.h"
327 #include "parse.h"
328 #include <stdio.h>
329 #include <stdlib.h>
330 #include <string.h>
331 #include <assert.h>
332 #include <stddef.h>
333 
334 /*
335 ** If compiling for a processor that lacks floating point support,
336 ** substitute integer for floating-point
337 */
338 #ifdef SQLITE_OMIT_FLOATING_POINT
339 # define double sqlite_int64
340 # define float sqlite_int64
341 # define LONGDOUBLE_TYPE sqlite_int64
342 # ifndef SQLITE_BIG_DBL
343 #   define SQLITE_BIG_DBL (((sqlite3_int64)1)<<50)
344 # endif
345 # define SQLITE_OMIT_DATETIME_FUNCS 1
346 # define SQLITE_OMIT_TRACE 1
347 # undef SQLITE_MIXED_ENDIAN_64BIT_FLOAT
348 # undef SQLITE_HAVE_ISNAN
349 #endif
350 #ifndef SQLITE_BIG_DBL
351 # define SQLITE_BIG_DBL (1e99)
352 #endif
353 
354 /*
355 ** OMIT_TEMPDB is set to 1 if SQLITE_OMIT_TEMPDB is defined, or 0
356 ** afterward. Having this macro allows us to cause the C compiler
357 ** to omit code used by TEMP tables without messy #ifndef statements.
358 */
359 #ifdef SQLITE_OMIT_TEMPDB
360 #define OMIT_TEMPDB 1
361 #else
362 #define OMIT_TEMPDB 0
363 #endif
364 
365 /*
366 ** The "file format" number is an integer that is incremented whenever
367 ** the VDBE-level file format changes.  The following macros define the
368 ** the default file format for new databases and the maximum file format
369 ** that the library can read.
370 */
371 #define SQLITE_MAX_FILE_FORMAT 4
372 #ifndef SQLITE_DEFAULT_FILE_FORMAT
373 # define SQLITE_DEFAULT_FILE_FORMAT 4
374 #endif
375 
376 /*
377 ** Determine whether triggers are recursive by default.  This can be
378 ** changed at run-time using a pragma.
379 */
380 #ifndef SQLITE_DEFAULT_RECURSIVE_TRIGGERS
381 # define SQLITE_DEFAULT_RECURSIVE_TRIGGERS 0
382 #endif
383 
384 /*
385 ** Provide a default value for SQLITE_TEMP_STORE in case it is not specified
386 ** on the command-line
387 */
388 #ifndef SQLITE_TEMP_STORE
389 # define SQLITE_TEMP_STORE 1
390 #endif
391 
392 /*
393 ** GCC does not define the offsetof() macro so we'll have to do it
394 ** ourselves.
395 */
396 #ifndef offsetof
397 #define offsetof(STRUCTURE,FIELD) ((int)((char*)&((STRUCTURE*)0)->FIELD))
398 #endif
399 
400 /*
401 ** Check to see if this machine uses EBCDIC.  (Yes, believe it or
402 ** not, there are still machines out there that use EBCDIC.)
403 */
404 #if 'A' == '\301'
405 # define SQLITE_EBCDIC 1
406 #else
407 # define SQLITE_ASCII 1
408 #endif
409 
410 /*
411 ** Integers of known sizes.  These typedefs might change for architectures
412 ** where the sizes very.  Preprocessor macros are available so that the
413 ** types can be conveniently redefined at compile-type.  Like this:
414 **
415 **         cc '-DUINTPTR_TYPE=long long int' ...
416 */
417 #ifndef UINT32_TYPE
418 # ifdef HAVE_UINT32_T
419 #  define UINT32_TYPE uint32_t
420 # else
421 #  define UINT32_TYPE unsigned int
422 # endif
423 #endif
424 #ifndef UINT16_TYPE
425 # ifdef HAVE_UINT16_T
426 #  define UINT16_TYPE uint16_t
427 # else
428 #  define UINT16_TYPE unsigned short int
429 # endif
430 #endif
431 #ifndef INT16_TYPE
432 # ifdef HAVE_INT16_T
433 #  define INT16_TYPE int16_t
434 # else
435 #  define INT16_TYPE short int
436 # endif
437 #endif
438 #ifndef UINT8_TYPE
439 # ifdef HAVE_UINT8_T
440 #  define UINT8_TYPE uint8_t
441 # else
442 #  define UINT8_TYPE unsigned char
443 # endif
444 #endif
445 #ifndef INT8_TYPE
446 # ifdef HAVE_INT8_T
447 #  define INT8_TYPE int8_t
448 # else
449 #  define INT8_TYPE signed char
450 # endif
451 #endif
452 #ifndef LONGDOUBLE_TYPE
453 # define LONGDOUBLE_TYPE long double
454 #endif
455 typedef sqlite_int64 i64;          /* 8-byte signed integer */
456 typedef sqlite_uint64 u64;         /* 8-byte unsigned integer */
457 typedef UINT32_TYPE u32;           /* 4-byte unsigned integer */
458 typedef UINT16_TYPE u16;           /* 2-byte unsigned integer */
459 typedef INT16_TYPE i16;            /* 2-byte signed integer */
460 typedef UINT8_TYPE u8;             /* 1-byte unsigned integer */
461 typedef INT8_TYPE i8;              /* 1-byte signed integer */
462 
463 /*
464 ** SQLITE_MAX_U32 is a u64 constant that is the maximum u64 value
465 ** that can be stored in a u32 without loss of data.  The value
466 ** is 0x00000000ffffffff.  But because of quirks of some compilers, we
467 ** have to specify the value in the less intuitive manner shown:
468 */
469 #define SQLITE_MAX_U32  ((((u64)1)<<32)-1)
470 
471 /*
472 ** The datatype used to store estimates of the number of rows in a
473 ** table or index.  This is an unsigned integer type.  For 99.9% of
474 ** the world, a 32-bit integer is sufficient.  But a 64-bit integer
475 ** can be used at compile-time if desired.
476 */
477 #ifdef SQLITE_64BIT_STATS
478  typedef u64 tRowcnt;    /* 64-bit only if requested at compile-time */
479 #else
480  typedef u32 tRowcnt;    /* 32-bit is the default */
481 #endif
482 
483 /*
484 ** Macros to determine whether the machine is big or little endian,
485 ** evaluated at runtime.
486 */
487 #ifdef SQLITE_AMALGAMATION
488 const int sqlite3one = 1;
489 #else
490 extern const int sqlite3one;
491 #endif
492 #if defined(i386) || defined(__i386__) || defined(_M_IX86)\
493                              || defined(__x86_64) || defined(__x86_64__)
494 # define SQLITE_BIGENDIAN    0
495 # define SQLITE_LITTLEENDIAN 1
496 # define SQLITE_UTF16NATIVE  SQLITE_UTF16LE
497 #else
498 # define SQLITE_BIGENDIAN    (*(char *)(&sqlite3one)==0)
499 # define SQLITE_LITTLEENDIAN (*(char *)(&sqlite3one)==1)
500 # define SQLITE_UTF16NATIVE (SQLITE_BIGENDIAN?SQLITE_UTF16BE:SQLITE_UTF16LE)
501 #endif
502 
503 /*
504 ** Constants for the largest and smallest possible 64-bit signed integers.
505 ** These macros are designed to work correctly on both 32-bit and 64-bit
506 ** compilers.
507 */
508 #define LARGEST_INT64  (0xffffffff|(((i64)0x7fffffff)<<32))
509 #define SMALLEST_INT64 (((i64)-1) - LARGEST_INT64)
510 
511 /*
512 ** Round up a number to the next larger multiple of 8.  This is used
513 ** to force 8-byte alignment on 64-bit architectures.
514 */
515 #define ROUND8(x)     (((x)+7)&~7)
516 
517 /*
518 ** Round down to the nearest multiple of 8
519 */
520 #define ROUNDDOWN8(x) ((x)&~7)
521 
522 /*
523 ** Assert that the pointer X is aligned to an 8-byte boundary.  This
524 ** macro is used only within assert() to verify that the code gets
525 ** all alignment restrictions correct.
526 **
527 ** Except, if SQLITE_4_BYTE_ALIGNED_MALLOC is defined, then the
528 ** underlying malloc() implemention might return us 4-byte aligned
529 ** pointers.  In that case, only verify 4-byte alignment.
530 */
531 #ifdef SQLITE_4_BYTE_ALIGNED_MALLOC
532 # define EIGHT_BYTE_ALIGNMENT(X)   ((((char*)(X) - (char*)0)&3)==0)
533 #else
534 # define EIGHT_BYTE_ALIGNMENT(X)   ((((char*)(X) - (char*)0)&7)==0)
535 #endif
536 
537 
538 /*
539 ** An instance of the following structure is used to store the busy-handler
540 ** callback for a given sqlite handle.
541 **
542 ** The sqlite.busyHandler member of the sqlite struct contains the busy
543 ** callback for the database handle. Each pager opened via the sqlite
544 ** handle is passed a pointer to sqlite.busyHandler. The busy-handler
545 ** callback is currently invoked only from within pager.c.
546 */
547 typedef struct BusyHandler BusyHandler;
548 struct BusyHandler {
549   int (*xFunc)(void *,int);  /* The busy callback */
550   void *pArg;                /* First arg to busy callback */
551   int nBusy;                 /* Incremented with each busy call */
552 };
553 
554 /*
555 ** Name of the master database table.  The master database table
556 ** is a special table that holds the names and attributes of all
557 ** user tables and indices.
558 */
559 #define MASTER_NAME       "sqlite_master"
560 #define TEMP_MASTER_NAME  "sqlite_temp_master"
561 
562 /*
563 ** The root-page of the master database table.
564 */
565 #define MASTER_ROOT       1
566 
567 /*
568 ** The name of the schema table.
569 */
570 #define SCHEMA_TABLE(x)  ((!OMIT_TEMPDB)&&(x==1)?TEMP_MASTER_NAME:MASTER_NAME)
571 
572 /*
573 ** A convenience macro that returns the number of elements in
574 ** an array.
575 */
576 #define ArraySize(X)    ((int)(sizeof(X)/sizeof(X[0])))
577 
578 /*
579 ** The following value as a destructor means to use sqlite3DbFree().
580 ** The sqlite3DbFree() routine requires two parameters instead of the
581 ** one parameter that destructors normally want.  So we have to introduce
582 ** this magic value that the code knows to handle differently.  Any
583 ** pointer will work here as long as it is distinct from SQLITE_STATIC
584 ** and SQLITE_TRANSIENT.
585 */
586 #define SQLITE_DYNAMIC   ((sqlite3_destructor_type)sqlite3MallocSize)
587 
588 /*
589 ** When SQLITE_OMIT_WSD is defined, it means that the target platform does
590 ** not support Writable Static Data (WSD) such as global and static variables.
591 ** All variables must either be on the stack or dynamically allocated from
592 ** the heap.  When WSD is unsupported, the variable declarations scattered
593 ** throughout the SQLite code must become constants instead.  The SQLITE_WSD
594 ** macro is used for this purpose.  And instead of referencing the variable
595 ** directly, we use its constant as a key to lookup the run-time allocated
596 ** buffer that holds real variable.  The constant is also the initializer
597 ** for the run-time allocated buffer.
598 **
599 ** In the usual case where WSD is supported, the SQLITE_WSD and GLOBAL
600 ** macros become no-ops and have zero performance impact.
601 */
602 #ifdef SQLITE_OMIT_WSD
603   #define SQLITE_WSD const
604   #define GLOBAL(t,v) (*(t*)sqlite3_wsd_find((void*)&(v), sizeof(v)))
605   #define sqlite3GlobalConfig GLOBAL(struct Sqlite3Config, sqlite3Config)
606   int sqlite3_wsd_init(int N, int J);
607   void *sqlite3_wsd_find(void *K, int L);
608 #else
609   #define SQLITE_WSD
610   #define GLOBAL(t,v) v
611   #define sqlite3GlobalConfig sqlite3Config
612 #endif
613 
614 /*
615 ** The following macros are used to suppress compiler warnings and to
616 ** make it clear to human readers when a function parameter is deliberately
617 ** left unused within the body of a function. This usually happens when
618 ** a function is called via a function pointer. For example the
619 ** implementation of an SQL aggregate step callback may not use the
620 ** parameter indicating the number of arguments passed to the aggregate,
621 ** if it knows that this is enforced elsewhere.
622 **
623 ** When a function parameter is not used at all within the body of a function,
624 ** it is generally named "NotUsed" or "NotUsed2" to make things even clearer.
625 ** However, these macros may also be used to suppress warnings related to
626 ** parameters that may or may not be used depending on compilation options.
627 ** For example those parameters only used in assert() statements. In these
628 ** cases the parameters are named as per the usual conventions.
629 */
630 #define UNUSED_PARAMETER(x) (void)(x)
631 #define UNUSED_PARAMETER2(x,y) UNUSED_PARAMETER(x),UNUSED_PARAMETER(y)
632 
633 /*
634 ** Forward references to structures
635 */
636 typedef struct AggInfo AggInfo;
637 typedef struct AuthContext AuthContext;
638 typedef struct AutoincInfo AutoincInfo;
639 typedef struct Bitvec Bitvec;
640 typedef struct CollSeq CollSeq;
641 typedef struct Column Column;
642 typedef struct Db Db;
643 typedef struct Schema Schema;
644 typedef struct Expr Expr;
645 typedef struct ExprList ExprList;
646 typedef struct ExprSpan ExprSpan;
647 typedef struct FKey FKey;
648 typedef struct FuncDestructor FuncDestructor;
649 typedef struct FuncDef FuncDef;
650 typedef struct FuncDefHash FuncDefHash;
651 typedef struct IdList IdList;
652 typedef struct Index Index;
653 typedef struct IndexSample IndexSample;
654 typedef struct KeyClass KeyClass;
655 typedef struct KeyInfo KeyInfo;
656 typedef struct Lookaside Lookaside;
657 typedef struct LookasideSlot LookasideSlot;
658 typedef struct Module Module;
659 typedef struct NameContext NameContext;
660 typedef struct Parse Parse;
661 typedef struct RowSet RowSet;
662 typedef struct Savepoint Savepoint;
663 typedef struct Select Select;
664 typedef struct SrcList SrcList;
665 typedef struct StrAccum StrAccum;
666 typedef struct Table Table;
667 typedef struct TableLock TableLock;
668 typedef struct Token Token;
669 typedef struct Trigger Trigger;
670 typedef struct TriggerPrg TriggerPrg;
671 typedef struct TriggerStep TriggerStep;
672 typedef struct UnpackedRecord UnpackedRecord;
673 typedef struct VTable VTable;
674 typedef struct VtabCtx VtabCtx;
675 typedef struct Walker Walker;
676 typedef struct WherePlan WherePlan;
677 typedef struct WhereInfo WhereInfo;
678 typedef struct WhereLevel WhereLevel;
679 
680 /*
681 ** Defer sourcing vdbe.h and btree.h until after the "u8" and
682 ** "BusyHandler" typedefs. vdbe.h also requires a few of the opaque
683 ** pointer types (i.e. FuncDef) defined above.
684 */
685 #include "btree.h"
686 #include "vdbe.h"
687 #include "pager.h"
688 #include "pcache.h"
689 
690 #include "os.h"
691 #include "mutex.h"
692 
693 
694 /*
695 ** Each database file to be accessed by the system is an instance
696 ** of the following structure.  There are normally two of these structures
697 ** in the sqlite.aDb[] array.  aDb[0] is the main database file and
698 ** aDb[1] is the database file used to hold temporary tables.  Additional
699 ** databases may be attached.
700 */
701 struct Db {
702   char *zName;         /* Name of this database */
703   Btree *pBt;          /* The B*Tree structure for this database file */
704   u8 inTrans;          /* 0: not writable.  1: Transaction.  2: Checkpoint */
705   u8 safety_level;     /* How aggressive at syncing data to disk */
706   Schema *pSchema;     /* Pointer to database schema (possibly shared) */
707 };
708 
709 /*
710 ** An instance of the following structure stores a database schema.
711 **
712 ** Most Schema objects are associated with a Btree.  The exception is
713 ** the Schema for the TEMP databaes (sqlite3.aDb[1]) which is free-standing.
714 ** In shared cache mode, a single Schema object can be shared by multiple
715 ** Btrees that refer to the same underlying BtShared object.
716 **
717 ** Schema objects are automatically deallocated when the last Btree that
718 ** references them is destroyed.   The TEMP Schema is manually freed by
719 ** sqlite3_close().
720 *
721 ** A thread must be holding a mutex on the corresponding Btree in order
722 ** to access Schema content.  This implies that the thread must also be
723 ** holding a mutex on the sqlite3 connection pointer that owns the Btree.
724 ** For a TEMP Schema, only the connection mutex is required.
725 */
726 struct Schema {
727   int schema_cookie;   /* Database schema version number for this file */
728   int iGeneration;     /* Generation counter.  Incremented with each change */
729   Hash tblHash;        /* All tables indexed by name */
730   Hash idxHash;        /* All (named) indices indexed by name */
731   Hash trigHash;       /* All triggers indexed by name */
732   Hash fkeyHash;       /* All foreign keys by referenced table name */
733   Table *pSeqTab;      /* The sqlite_sequence table used by AUTOINCREMENT */
734   u8 file_format;      /* Schema format version for this file */
735   u8 enc;              /* Text encoding used by this database */
736   u16 flags;           /* Flags associated with this schema */
737   int cache_size;      /* Number of pages to use in the cache */
738 };
739 
740 /*
741 ** These macros can be used to test, set, or clear bits in the
742 ** Db.pSchema->flags field.
743 */
744 #define DbHasProperty(D,I,P)     (((D)->aDb[I].pSchema->flags&(P))==(P))
745 #define DbHasAnyProperty(D,I,P)  (((D)->aDb[I].pSchema->flags&(P))!=0)
746 #define DbSetProperty(D,I,P)     (D)->aDb[I].pSchema->flags|=(P)
747 #define DbClearProperty(D,I,P)   (D)->aDb[I].pSchema->flags&=~(P)
748 
749 /*
750 ** Allowed values for the DB.pSchema->flags field.
751 **
752 ** The DB_SchemaLoaded flag is set after the database schema has been
753 ** read into internal hash tables.
754 **
755 ** DB_UnresetViews means that one or more views have column names that
756 ** have been filled out.  If the schema changes, these column names might
757 ** changes and so the view will need to be reset.
758 */
759 #define DB_SchemaLoaded    0x0001  /* The schema has been loaded */
760 #define DB_UnresetViews    0x0002  /* Some views have defined column names */
761 #define DB_Empty           0x0004  /* The file is empty (length 0 bytes) */
762 
763 /*
764 ** The number of different kinds of things that can be limited
765 ** using the sqlite3_limit() interface.
766 */
767 #define SQLITE_N_LIMIT (SQLITE_LIMIT_TRIGGER_DEPTH+1)
768 
769 /*
770 ** Lookaside malloc is a set of fixed-size buffers that can be used
771 ** to satisfy small transient memory allocation requests for objects
772 ** associated with a particular database connection.  The use of
773 ** lookaside malloc provides a significant performance enhancement
774 ** (approx 10%) by avoiding numerous malloc/free requests while parsing
775 ** SQL statements.
776 **
777 ** The Lookaside structure holds configuration information about the
778 ** lookaside malloc subsystem.  Each available memory allocation in
779 ** the lookaside subsystem is stored on a linked list of LookasideSlot
780 ** objects.
781 **
782 ** Lookaside allocations are only allowed for objects that are associated
783 ** with a particular database connection.  Hence, schema information cannot
784 ** be stored in lookaside because in shared cache mode the schema information
785 ** is shared by multiple database connections.  Therefore, while parsing
786 ** schema information, the Lookaside.bEnabled flag is cleared so that
787 ** lookaside allocations are not used to construct the schema objects.
788 */
789 struct Lookaside {
790   u16 sz;                 /* Size of each buffer in bytes */
791   u8 bEnabled;            /* False to disable new lookaside allocations */
792   u8 bMalloced;           /* True if pStart obtained from sqlite3_malloc() */
793   int nOut;               /* Number of buffers currently checked out */
794   int mxOut;              /* Highwater mark for nOut */
795   int anStat[3];          /* 0: hits.  1: size misses.  2: full misses */
796   LookasideSlot *pFree;   /* List of available buffers */
797   void *pStart;           /* First byte of available memory space */
798   void *pEnd;             /* First byte past end of available space */
799 };
800 struct LookasideSlot {
801   LookasideSlot *pNext;    /* Next buffer in the list of free buffers */
802 };
803 
804 /*
805 ** A hash table for function definitions.
806 **
807 ** Hash each FuncDef structure into one of the FuncDefHash.a[] slots.
808 ** Collisions are on the FuncDef.pHash chain.
809 */
810 struct FuncDefHash {
811   FuncDef *a[23];       /* Hash table for functions */
812 };
813 
814 /*
815 ** Each database connection is an instance of the following structure.
816 */
817 struct sqlite3 {
818   sqlite3_vfs *pVfs;            /* OS Interface */
819   struct Vdbe *pVdbe;           /* List of active virtual machines */
820   CollSeq *pDfltColl;           /* The default collating sequence (BINARY) */
821   sqlite3_mutex *mutex;         /* Connection mutex */
822   Db *aDb;                      /* All backends */
823   int nDb;                      /* Number of backends currently in use */
824   int flags;                    /* Miscellaneous flags. See below */
825   i64 lastRowid;                /* ROWID of most recent insert (see above) */
826   unsigned int openFlags;       /* Flags passed to sqlite3_vfs.xOpen() */
827   int errCode;                  /* Most recent error code (SQLITE_*) */
828   int errMask;                  /* & result codes with this before returning */
829   u8 autoCommit;                /* The auto-commit flag. */
830   u8 temp_store;                /* 1: file 2: memory 0: default */
831   u8 mallocFailed;              /* True if we have seen a malloc failure */
832   u8 dfltLockMode;              /* Default locking-mode for attached dbs */
833   signed char nextAutovac;      /* Autovac setting after VACUUM if >=0 */
834   u8 suppressErr;               /* Do not issue error messages if true */
835   u8 vtabOnConflict;            /* Value to return for s3_vtab_on_conflict() */
836   u8 isTransactionSavepoint;    /* True if the outermost savepoint is a TS */
837   int nextPagesize;             /* Pagesize after VACUUM if >0 */
838   u32 magic;                    /* Magic number for detect library misuse */
839   int nChange;                  /* Value returned by sqlite3_changes() */
840   int nTotalChange;             /* Value returned by sqlite3_total_changes() */
841   int aLimit[SQLITE_N_LIMIT];   /* Limits */
842   struct sqlite3InitInfo {      /* Information used during initialization */
843     int newTnum;                /* Rootpage of table being initialized */
844     u8 iDb;                     /* Which db file is being initialized */
845     u8 busy;                    /* TRUE if currently initializing */
846     u8 orphanTrigger;           /* Last statement is orphaned TEMP trigger */
847   } init;
848   int activeVdbeCnt;            /* Number of VDBEs currently executing */
849   int writeVdbeCnt;             /* Number of active VDBEs that are writing */
850   int vdbeExecCnt;              /* Number of nested calls to VdbeExec() */
851   int nExtension;               /* Number of loaded extensions */
852   void **aExtension;            /* Array of shared library handles */
853   void (*xTrace)(void*,const char*);        /* Trace function */
854   void *pTraceArg;                          /* Argument to the trace function */
855   void (*xProfile)(void*,const char*,u64);  /* Profiling function */
856   void *pProfileArg;                        /* Argument to profile function */
857   void *pCommitArg;                 /* Argument to xCommitCallback() */
858   int (*xCommitCallback)(void*);    /* Invoked at every commit. */
859   void *pRollbackArg;               /* Argument to xRollbackCallback() */
860   void (*xRollbackCallback)(void*); /* Invoked at every commit. */
861   void *pUpdateArg;
862   void (*xUpdateCallback)(void*,int, const char*,const char*,sqlite_int64);
863 #ifndef SQLITE_OMIT_WAL
864   int (*xWalCallback)(void *, sqlite3 *, const char *, int);
865   void *pWalArg;
866 #endif
867   void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*);
868   void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*);
869   void *pCollNeededArg;
870   sqlite3_value *pErr;          /* Most recent error message */
871   char *zErrMsg;                /* Most recent error message (UTF-8 encoded) */
872   char *zErrMsg16;              /* Most recent error message (UTF-16 encoded) */
873   union {
874     volatile int isInterrupted; /* True if sqlite3_interrupt has been called */
875     double notUsed1;            /* Spacer */
876   } u1;
877   Lookaside lookaside;          /* Lookaside malloc configuration */
878 #ifndef SQLITE_OMIT_AUTHORIZATION
879   int (*xAuth)(void*,int,const char*,const char*,const char*,const char*);
880                                 /* Access authorization function */
881   void *pAuthArg;               /* 1st argument to the access auth function */
882 #endif
883 #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
884   int (*xProgress)(void *);     /* The progress callback */
885   void *pProgressArg;           /* Argument to the progress callback */
886   int nProgressOps;             /* Number of opcodes for progress callback */
887 #endif
888 #ifndef SQLITE_OMIT_VIRTUALTABLE
889   int nVTrans;                  /* Allocated size of aVTrans */
890   Hash aModule;                 /* populated by sqlite3_create_module() */
891   VtabCtx *pVtabCtx;            /* Context for active vtab connect/create */
892   VTable **aVTrans;             /* Virtual tables with open transactions */
893   VTable *pDisconnect;    /* Disconnect these in next sqlite3_prepare() */
894 #endif
895   FuncDefHash aFunc;            /* Hash table of connection functions */
896   Hash aCollSeq;                /* All collating sequences */
897   BusyHandler busyHandler;      /* Busy callback */
898   Db aDbStatic[2];              /* Static space for the 2 default backends */
899   Savepoint *pSavepoint;        /* List of active savepoints */
900   int busyTimeout;              /* Busy handler timeout, in msec */
901   int nSavepoint;               /* Number of non-transaction savepoints */
902   int nStatement;               /* Number of nested statement-transactions  */
903   i64 nDeferredCons;            /* Net deferred constraints this transaction. */
904   int *pnBytesFreed;            /* If not NULL, increment this in DbFree() */
905 
906 #ifdef SQLITE_ENABLE_UNLOCK_NOTIFY
907   /* The following variables are all protected by the STATIC_MASTER
908   ** mutex, not by sqlite3.mutex. They are used by code in notify.c.
909   **
910   ** When X.pUnlockConnection==Y, that means that X is waiting for Y to
911   ** unlock so that it can proceed.
912   **
913   ** When X.pBlockingConnection==Y, that means that something that X tried
914   ** tried to do recently failed with an SQLITE_LOCKED error due to locks
915   ** held by Y.
916   */
917   sqlite3 *pBlockingConnection; /* Connection that caused SQLITE_LOCKED */
918   sqlite3 *pUnlockConnection;           /* Connection to watch for unlock */
919   void *pUnlockArg;                     /* Argument to xUnlockNotify */
920   void (*xUnlockNotify)(void **, int);  /* Unlock notify callback */
921   sqlite3 *pNextBlocked;        /* Next in list of all blocked connections */
922 #endif
923 };
924 
925 /*
926 ** A macro to discover the encoding of a database.
927 */
928 #define ENC(db) ((db)->aDb[0].pSchema->enc)
929 
930 /*
931 ** Possible values for the sqlite3.flags.
932 */
933 #define SQLITE_VdbeTrace      0x00000100  /* True to trace VDBE execution */
934 #define SQLITE_InternChanges  0x00000200  /* Uncommitted Hash table changes */
935 #define SQLITE_FullColNames   0x00000400  /* Show full column names on SELECT */
936 #define SQLITE_ShortColNames  0x00000800  /* Show short columns names */
937 #define SQLITE_CountRows      0x00001000  /* Count rows changed by INSERT, */
938                                           /*   DELETE, or UPDATE and return */
939                                           /*   the count using a callback. */
940 #define SQLITE_NullCallback   0x00002000  /* Invoke the callback once if the */
941                                           /*   result set is empty */
942 #define SQLITE_SqlTrace       0x00004000  /* Debug print SQL as it executes */
943 #define SQLITE_VdbeListing    0x00008000  /* Debug listings of VDBE programs */
944 #define SQLITE_WriteSchema    0x00010000  /* OK to update SQLITE_MASTER */
945                          /*   0x00020000  Unused */
946 #define SQLITE_IgnoreChecks   0x00040000  /* Do not enforce check constraints */
947 #define SQLITE_ReadUncommitted 0x0080000  /* For shared-cache mode */
948 #define SQLITE_LegacyFileFmt  0x00100000  /* Create new databases in format 1 */
949 #define SQLITE_FullFSync      0x00200000  /* Use full fsync on the backend */
950 #define SQLITE_CkptFullFSync  0x00400000  /* Use full fsync for checkpoint */
951 #define SQLITE_RecoveryMode   0x00800000  /* Ignore schema errors */
952 #define SQLITE_ReverseOrder   0x01000000  /* Reverse unordered SELECTs */
953 #define SQLITE_RecTriggers    0x02000000  /* Enable recursive triggers */
954 #define SQLITE_ForeignKeys    0x04000000  /* Enforce foreign key constraints  */
955 #define SQLITE_AutoIndex      0x08000000  /* Enable automatic indexes */
956 #define SQLITE_PreferBuiltin  0x10000000  /* Preference to built-in funcs */
957 #define SQLITE_LoadExtension  0x20000000  /* Enable load_extension */
958 #define SQLITE_EnableTrigger  0x40000000  /* True to enable triggers */
959 
960 /*
961 ** Bits of the sqlite3.flags field that are used by the
962 ** sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS,...) interface.
963 ** These must be the low-order bits of the flags field.
964 */
965 #define SQLITE_QueryFlattener 0x01        /* Disable query flattening */
966 #define SQLITE_ColumnCache    0x02        /* Disable the column cache */
967 #define SQLITE_IndexSort      0x04        /* Disable indexes for sorting */
968 #define SQLITE_IndexSearch    0x08        /* Disable indexes for searching */
969 #define SQLITE_IndexCover     0x10        /* Disable index covering table */
970 #define SQLITE_GroupByOrder   0x20        /* Disable GROUPBY cover of ORDERBY */
971 #define SQLITE_FactorOutConst 0x40        /* Disable factoring out constants */
972 #define SQLITE_IdxRealAsInt   0x80        /* Store REAL as INT in indices */
973 #define SQLITE_DistinctOpt    0x80        /* DISTINCT using indexes */
974 #define SQLITE_OptMask        0xff        /* Mask of all disablable opts */
975 
976 /*
977 ** Possible values for the sqlite.magic field.
978 ** The numbers are obtained at random and have no special meaning, other
979 ** than being distinct from one another.
980 */
981 #define SQLITE_MAGIC_OPEN     0xa029a697  /* Database is open */
982 #define SQLITE_MAGIC_CLOSED   0x9f3c2d33  /* Database is closed */
983 #define SQLITE_MAGIC_SICK     0x4b771290  /* Error and awaiting close */
984 #define SQLITE_MAGIC_BUSY     0xf03b7906  /* Database currently in use */
985 #define SQLITE_MAGIC_ERROR    0xb5357930  /* An SQLITE_MISUSE error occurred */
986 #define SQLITE_MAGIC_ZOMBIE   0x64cffc7f  /* Close with last statement close */
987 
988 /*
989 ** Each SQL function is defined by an instance of the following
990 ** structure.  A pointer to this structure is stored in the sqlite.aFunc
991 ** hash table.  When multiple functions have the same name, the hash table
992 ** points to a linked list of these structures.
993 */
994 struct FuncDef {
995   i16 nArg;            /* Number of arguments.  -1 means unlimited */
996   u8 iPrefEnc;         /* Preferred text encoding (SQLITE_UTF8, 16LE, 16BE) */
997   u8 flags;            /* Some combination of SQLITE_FUNC_* */
998   void *pUserData;     /* User data parameter */
999   FuncDef *pNext;      /* Next function with same name */
1000   void (*xFunc)(sqlite3_context*,int,sqlite3_value**); /* Regular function */
1001   void (*xStep)(sqlite3_context*,int,sqlite3_value**); /* Aggregate step */
1002   void (*xFinalize)(sqlite3_context*);                /* Aggregate finalizer */
1003   char *zName;         /* SQL name of the function. */
1004   FuncDef *pHash;      /* Next with a different name but the same hash */
1005   FuncDestructor *pDestructor;   /* Reference counted destructor function */
1006 };
1007 
1008 /*
1009 ** This structure encapsulates a user-function destructor callback (as
1010 ** configured using create_function_v2()) and a reference counter. When
1011 ** create_function_v2() is called to create a function with a destructor,
1012 ** a single object of this type is allocated. FuncDestructor.nRef is set to
1013 ** the number of FuncDef objects created (either 1 or 3, depending on whether
1014 ** or not the specified encoding is SQLITE_ANY). The FuncDef.pDestructor
1015 ** member of each of the new FuncDef objects is set to point to the allocated
1016 ** FuncDestructor.
1017 **
1018 ** Thereafter, when one of the FuncDef objects is deleted, the reference
1019 ** count on this object is decremented. When it reaches 0, the destructor
1020 ** is invoked and the FuncDestructor structure freed.
1021 */
1022 struct FuncDestructor {
1023   int nRef;
1024   void (*xDestroy)(void *);
1025   void *pUserData;
1026 };
1027 
1028 /*
1029 ** Possible values for FuncDef.flags.  Note that the _LENGTH and _TYPEOF
1030 ** values must correspond to OPFLAG_LENGTHARG and OPFLAG_TYPEOFARG.  There
1031 ** are assert() statements in the code to verify this.
1032 */
1033 #define SQLITE_FUNC_LIKE     0x01 /* Candidate for the LIKE optimization */
1034 #define SQLITE_FUNC_CASE     0x02 /* Case-sensitive LIKE-type function */
1035 #define SQLITE_FUNC_EPHEM    0x04 /* Ephemeral.  Delete with VDBE */
1036 #define SQLITE_FUNC_NEEDCOLL 0x08 /* sqlite3GetFuncCollSeq() might be called */
1037 #define SQLITE_FUNC_COUNT    0x10 /* Built-in count(*) aggregate */
1038 #define SQLITE_FUNC_COALESCE 0x20 /* Built-in coalesce() or ifnull() function */
1039 #define SQLITE_FUNC_LENGTH   0x40 /* Built-in length() function */
1040 #define SQLITE_FUNC_TYPEOF   0x80 /* Built-in typeof() function */
1041 
1042 /*
1043 ** The following three macros, FUNCTION(), LIKEFUNC() and AGGREGATE() are
1044 ** used to create the initializers for the FuncDef structures.
1045 **
1046 **   FUNCTION(zName, nArg, iArg, bNC, xFunc)
1047 **     Used to create a scalar function definition of a function zName
1048 **     implemented by C function xFunc that accepts nArg arguments. The
1049 **     value passed as iArg is cast to a (void*) and made available
1050 **     as the user-data (sqlite3_user_data()) for the function. If
1051 **     argument bNC is true, then the SQLITE_FUNC_NEEDCOLL flag is set.
1052 **
1053 **   AGGREGATE(zName, nArg, iArg, bNC, xStep, xFinal)
1054 **     Used to create an aggregate function definition implemented by
1055 **     the C functions xStep and xFinal. The first four parameters
1056 **     are interpreted in the same way as the first 4 parameters to
1057 **     FUNCTION().
1058 **
1059 **   LIKEFUNC(zName, nArg, pArg, flags)
1060 **     Used to create a scalar function definition of a function zName
1061 **     that accepts nArg arguments and is implemented by a call to C
1062 **     function likeFunc. Argument pArg is cast to a (void *) and made
1063 **     available as the function user-data (sqlite3_user_data()). The
1064 **     FuncDef.flags variable is set to the value passed as the flags
1065 **     parameter.
1066 */
1067 #define FUNCTION(zName, nArg, iArg, bNC, xFunc) \
1068   {nArg, SQLITE_UTF8, (bNC*SQLITE_FUNC_NEEDCOLL), \
1069    SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, 0, #zName, 0, 0}
1070 #define FUNCTION2(zName, nArg, iArg, bNC, xFunc, extraFlags) \
1071   {nArg, SQLITE_UTF8, (bNC*SQLITE_FUNC_NEEDCOLL)|extraFlags, \
1072    SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, 0, #zName, 0, 0}
1073 #define STR_FUNCTION(zName, nArg, pArg, bNC, xFunc) \
1074   {nArg, SQLITE_UTF8, bNC*SQLITE_FUNC_NEEDCOLL, \
1075    pArg, 0, xFunc, 0, 0, #zName, 0, 0}
1076 #define LIKEFUNC(zName, nArg, arg, flags) \
1077   {nArg, SQLITE_UTF8, flags, (void *)arg, 0, likeFunc, 0, 0, #zName, 0, 0}
1078 #define AGGREGATE(zName, nArg, arg, nc, xStep, xFinal) \
1079   {nArg, SQLITE_UTF8, nc*SQLITE_FUNC_NEEDCOLL, \
1080    SQLITE_INT_TO_PTR(arg), 0, 0, xStep,xFinal,#zName,0,0}
1081 
1082 /*
1083 ** All current savepoints are stored in a linked list starting at
1084 ** sqlite3.pSavepoint. The first element in the list is the most recently
1085 ** opened savepoint. Savepoints are added to the list by the vdbe
1086 ** OP_Savepoint instruction.
1087 */
1088 struct Savepoint {
1089   char *zName;                        /* Savepoint name (nul-terminated) */
1090   i64 nDeferredCons;                  /* Number of deferred fk violations */
1091   Savepoint *pNext;                   /* Parent savepoint (if any) */
1092 };
1093 
1094 /*
1095 ** The following are used as the second parameter to sqlite3Savepoint(),
1096 ** and as the P1 argument to the OP_Savepoint instruction.
1097 */
1098 #define SAVEPOINT_BEGIN      0
1099 #define SAVEPOINT_RELEASE    1
1100 #define SAVEPOINT_ROLLBACK   2
1101 
1102 
1103 /*
1104 ** Each SQLite module (virtual table definition) is defined by an
1105 ** instance of the following structure, stored in the sqlite3.aModule
1106 ** hash table.
1107 */
1108 struct Module {
1109   const sqlite3_module *pModule;       /* Callback pointers */
1110   const char *zName;                   /* Name passed to create_module() */
1111   void *pAux;                          /* pAux passed to create_module() */
1112   void (*xDestroy)(void *);            /* Module destructor function */
1113 };
1114 
1115 /*
1116 ** information about each column of an SQL table is held in an instance
1117 ** of this structure.
1118 */
1119 struct Column {
1120   char *zName;     /* Name of this column */
1121   Expr *pDflt;     /* Default value of this column */
1122   char *zDflt;     /* Original text of the default value */
1123   char *zType;     /* Data type for this column */
1124   char *zColl;     /* Collating sequence.  If NULL, use the default */
1125   u8 notNull;      /* True if there is a NOT NULL constraint */
1126   u8 isPrimKey;    /* True if this column is part of the PRIMARY KEY */
1127   char affinity;   /* One of the SQLITE_AFF_... values */
1128 #ifndef SQLITE_OMIT_VIRTUALTABLE
1129   u8 isHidden;     /* True if this column is 'hidden' */
1130 #endif
1131 };
1132 
1133 /*
1134 ** A "Collating Sequence" is defined by an instance of the following
1135 ** structure. Conceptually, a collating sequence consists of a name and
1136 ** a comparison routine that defines the order of that sequence.
1137 **
1138 ** There may two separate implementations of the collation function, one
1139 ** that processes text in UTF-8 encoding (CollSeq.xCmp) and another that
1140 ** processes text encoded in UTF-16 (CollSeq.xCmp16), using the machine
1141 ** native byte order. When a collation sequence is invoked, SQLite selects
1142 ** the version that will require the least expensive encoding
1143 ** translations, if any.
1144 **
1145 ** The CollSeq.pUser member variable is an extra parameter that passed in
1146 ** as the first argument to the UTF-8 comparison function, xCmp.
1147 ** CollSeq.pUser16 is the equivalent for the UTF-16 comparison function,
1148 ** xCmp16.
1149 **
1150 ** If both CollSeq.xCmp and CollSeq.xCmp16 are NULL, it means that the
1151 ** collating sequence is undefined.  Indices built on an undefined
1152 ** collating sequence may not be read or written.
1153 */
1154 struct CollSeq {
1155   char *zName;          /* Name of the collating sequence, UTF-8 encoded */
1156   u8 enc;               /* Text encoding handled by xCmp() */
1157   void *pUser;          /* First argument to xCmp() */
1158   int (*xCmp)(void*,int, const void*, int, const void*);
1159   void (*xDel)(void*);  /* Destructor for pUser */
1160 };
1161 
1162 /*
1163 ** A sort order can be either ASC or DESC.
1164 */
1165 #define SQLITE_SO_ASC       0  /* Sort in ascending order */
1166 #define SQLITE_SO_DESC      1  /* Sort in ascending order */
1167 
1168 /*
1169 ** Column affinity types.
1170 **
1171 ** These used to have mnemonic name like 'i' for SQLITE_AFF_INTEGER and
1172 ** 't' for SQLITE_AFF_TEXT.  But we can save a little space and improve
1173 ** the speed a little by numbering the values consecutively.
1174 **
1175 ** But rather than start with 0 or 1, we begin with 'a'.  That way,
1176 ** when multiple affinity types are concatenated into a string and
1177 ** used as the P4 operand, they will be more readable.
1178 **
1179 ** Note also that the numeric types are grouped together so that testing
1180 ** for a numeric type is a single comparison.
1181 */
1182 #define SQLITE_AFF_TEXT     'a'
1183 #define SQLITE_AFF_NONE     'b'
1184 #define SQLITE_AFF_NUMERIC  'c'
1185 #define SQLITE_AFF_INTEGER  'd'
1186 #define SQLITE_AFF_REAL     'e'
1187 
1188 #define sqlite3IsNumericAffinity(X)  ((X)>=SQLITE_AFF_NUMERIC)
1189 
1190 /*
1191 ** The SQLITE_AFF_MASK values masks off the significant bits of an
1192 ** affinity value.
1193 */
1194 #define SQLITE_AFF_MASK     0x67
1195 
1196 /*
1197 ** Additional bit values that can be ORed with an affinity without
1198 ** changing the affinity.
1199 */
1200 #define SQLITE_JUMPIFNULL   0x08  /* jumps if either operand is NULL */
1201 #define SQLITE_STOREP2      0x10  /* Store result in reg[P2] rather than jump */
1202 #define SQLITE_NULLEQ       0x80  /* NULL=NULL */
1203 
1204 /*
1205 ** An object of this type is created for each virtual table present in
1206 ** the database schema.
1207 **
1208 ** If the database schema is shared, then there is one instance of this
1209 ** structure for each database connection (sqlite3*) that uses the shared
1210 ** schema. This is because each database connection requires its own unique
1211 ** instance of the sqlite3_vtab* handle used to access the virtual table
1212 ** implementation. sqlite3_vtab* handles can not be shared between
1213 ** database connections, even when the rest of the in-memory database
1214 ** schema is shared, as the implementation often stores the database
1215 ** connection handle passed to it via the xConnect() or xCreate() method
1216 ** during initialization internally. This database connection handle may
1217 ** then be used by the virtual table implementation to access real tables
1218 ** within the database. So that they appear as part of the callers
1219 ** transaction, these accesses need to be made via the same database
1220 ** connection as that used to execute SQL operations on the virtual table.
1221 **
1222 ** All VTable objects that correspond to a single table in a shared
1223 ** database schema are initially stored in a linked-list pointed to by
1224 ** the Table.pVTable member variable of the corresponding Table object.
1225 ** When an sqlite3_prepare() operation is required to access the virtual
1226 ** table, it searches the list for the VTable that corresponds to the
1227 ** database connection doing the preparing so as to use the correct
1228 ** sqlite3_vtab* handle in the compiled query.
1229 **
1230 ** When an in-memory Table object is deleted (for example when the
1231 ** schema is being reloaded for some reason), the VTable objects are not
1232 ** deleted and the sqlite3_vtab* handles are not xDisconnect()ed
1233 ** immediately. Instead, they are moved from the Table.pVTable list to
1234 ** another linked list headed by the sqlite3.pDisconnect member of the
1235 ** corresponding sqlite3 structure. They are then deleted/xDisconnected
1236 ** next time a statement is prepared using said sqlite3*. This is done
1237 ** to avoid deadlock issues involving multiple sqlite3.mutex mutexes.
1238 ** Refer to comments above function sqlite3VtabUnlockList() for an
1239 ** explanation as to why it is safe to add an entry to an sqlite3.pDisconnect
1240 ** list without holding the corresponding sqlite3.mutex mutex.
1241 **
1242 ** The memory for objects of this type is always allocated by
1243 ** sqlite3DbMalloc(), using the connection handle stored in VTable.db as
1244 ** the first argument.
1245 */
1246 struct VTable {
1247   sqlite3 *db;              /* Database connection associated with this table */
1248   Module *pMod;             /* Pointer to module implementation */
1249   sqlite3_vtab *pVtab;      /* Pointer to vtab instance */
1250   int nRef;                 /* Number of pointers to this structure */
1251   u8 bConstraint;           /* True if constraints are supported */
1252   int iSavepoint;           /* Depth of the SAVEPOINT stack */
1253   VTable *pNext;            /* Next in linked list (see above) */
1254 };
1255 
1256 /*
1257 ** Each SQL table is represented in memory by an instance of the
1258 ** following structure.
1259 **
1260 ** Table.zName is the name of the table.  The case of the original
1261 ** CREATE TABLE statement is stored, but case is not significant for
1262 ** comparisons.
1263 **
1264 ** Table.nCol is the number of columns in this table.  Table.aCol is a
1265 ** pointer to an array of Column structures, one for each column.
1266 **
1267 ** If the table has an INTEGER PRIMARY KEY, then Table.iPKey is the index of
1268 ** the column that is that key.   Otherwise Table.iPKey is negative.  Note
1269 ** that the datatype of the PRIMARY KEY must be INTEGER for this field to
1270 ** be set.  An INTEGER PRIMARY KEY is used as the rowid for each row of
1271 ** the table.  If a table has no INTEGER PRIMARY KEY, then a random rowid
1272 ** is generated for each row of the table.  TF_HasPrimaryKey is set if
1273 ** the table has any PRIMARY KEY, INTEGER or otherwise.
1274 **
1275 ** Table.tnum is the page number for the root BTree page of the table in the
1276 ** database file.  If Table.iDb is the index of the database table backend
1277 ** in sqlite.aDb[].  0 is for the main database and 1 is for the file that
1278 ** holds temporary tables and indices.  If TF_Ephemeral is set
1279 ** then the table is stored in a file that is automatically deleted
1280 ** when the VDBE cursor to the table is closed.  In this case Table.tnum
1281 ** refers VDBE cursor number that holds the table open, not to the root
1282 ** page number.  Transient tables are used to hold the results of a
1283 ** sub-query that appears instead of a real table name in the FROM clause
1284 ** of a SELECT statement.
1285 */
1286 struct Table {
1287   char *zName;         /* Name of the table or view */
1288   int iPKey;           /* If not negative, use aCol[iPKey] as the primary key */
1289   int nCol;            /* Number of columns in this table */
1290   Column *aCol;        /* Information about each column */
1291   Index *pIndex;       /* List of SQL indexes on this table. */
1292   int tnum;            /* Root BTree node for this table (see note above) */
1293   tRowcnt nRowEst;     /* Estimated rows in table - from sqlite_stat1 table */
1294   Select *pSelect;     /* NULL for tables.  Points to definition if a view. */
1295   u16 nRef;            /* Number of pointers to this Table */
1296   u8 tabFlags;         /* Mask of TF_* values */
1297   u8 keyConf;          /* What to do in case of uniqueness conflict on iPKey */
1298   FKey *pFKey;         /* Linked list of all foreign keys in this table */
1299   char *zColAff;       /* String defining the affinity of each column */
1300 #ifndef SQLITE_OMIT_CHECK
1301   ExprList *pCheck;    /* All CHECK constraints */
1302 #endif
1303 #ifndef SQLITE_OMIT_ALTERTABLE
1304   int addColOffset;    /* Offset in CREATE TABLE stmt to add a new column */
1305 #endif
1306 #ifndef SQLITE_OMIT_VIRTUALTABLE
1307   VTable *pVTable;     /* List of VTable objects. */
1308   int nModuleArg;      /* Number of arguments to the module */
1309   char **azModuleArg;  /* Text of all module args. [0] is module name */
1310 #endif
1311   Trigger *pTrigger;   /* List of triggers stored in pSchema */
1312   Schema *pSchema;     /* Schema that contains this table */
1313   Table *pNextZombie;  /* Next on the Parse.pZombieTab list */
1314 };
1315 
1316 /*
1317 ** Allowed values for Tabe.tabFlags.
1318 */
1319 #define TF_Readonly        0x01    /* Read-only system table */
1320 #define TF_Ephemeral       0x02    /* An ephemeral table */
1321 #define TF_HasPrimaryKey   0x04    /* Table has a primary key */
1322 #define TF_Autoincrement   0x08    /* Integer primary key is autoincrement */
1323 #define TF_Virtual         0x10    /* Is a virtual table */
1324 
1325 
1326 /*
1327 ** Test to see whether or not a table is a virtual table.  This is
1328 ** done as a macro so that it will be optimized out when virtual
1329 ** table support is omitted from the build.
1330 */
1331 #ifndef SQLITE_OMIT_VIRTUALTABLE
1332 #  define IsVirtual(X)      (((X)->tabFlags & TF_Virtual)!=0)
1333 #  define IsHiddenColumn(X) ((X)->isHidden)
1334 #else
1335 #  define IsVirtual(X)      0
1336 #  define IsHiddenColumn(X) 0
1337 #endif
1338 
1339 /*
1340 ** Each foreign key constraint is an instance of the following structure.
1341 **
1342 ** A foreign key is associated with two tables.  The "from" table is
1343 ** the table that contains the REFERENCES clause that creates the foreign
1344 ** key.  The "to" table is the table that is named in the REFERENCES clause.
1345 ** Consider this example:
1346 **
1347 **     CREATE TABLE ex1(
1348 **       a INTEGER PRIMARY KEY,
1349 **       b INTEGER CONSTRAINT fk1 REFERENCES ex2(x)
1350 **     );
1351 **
1352 ** For foreign key "fk1", the from-table is "ex1" and the to-table is "ex2".
1353 **
1354 ** Each REFERENCES clause generates an instance of the following structure
1355 ** which is attached to the from-table.  The to-table need not exist when
1356 ** the from-table is created.  The existence of the to-table is not checked.
1357 */
1358 struct FKey {
1359   Table *pFrom;     /* Table containing the REFERENCES clause (aka: Child) */
1360   FKey *pNextFrom;  /* Next foreign key in pFrom */
1361   char *zTo;        /* Name of table that the key points to (aka: Parent) */
1362   FKey *pNextTo;    /* Next foreign key on table named zTo */
1363   FKey *pPrevTo;    /* Previous foreign key on table named zTo */
1364   int nCol;         /* Number of columns in this key */
1365   /* EV: R-30323-21917 */
1366   u8 isDeferred;    /* True if constraint checking is deferred till COMMIT */
1367   u8 aAction[2];          /* ON DELETE and ON UPDATE actions, respectively */
1368   Trigger *apTrigger[2];  /* Triggers for aAction[] actions */
1369   struct sColMap {  /* Mapping of columns in pFrom to columns in zTo */
1370     int iFrom;         /* Index of column in pFrom */
1371     char *zCol;        /* Name of column in zTo.  If 0 use PRIMARY KEY */
1372   } aCol[1];        /* One entry for each of nCol column s */
1373 };
1374 
1375 /*
1376 ** SQLite supports many different ways to resolve a constraint
1377 ** error.  ROLLBACK processing means that a constraint violation
1378 ** causes the operation in process to fail and for the current transaction
1379 ** to be rolled back.  ABORT processing means the operation in process
1380 ** fails and any prior changes from that one operation are backed out,
1381 ** but the transaction is not rolled back.  FAIL processing means that
1382 ** the operation in progress stops and returns an error code.  But prior
1383 ** changes due to the same operation are not backed out and no rollback
1384 ** occurs.  IGNORE means that the particular row that caused the constraint
1385 ** error is not inserted or updated.  Processing continues and no error
1386 ** is returned.  REPLACE means that preexisting database rows that caused
1387 ** a UNIQUE constraint violation are removed so that the new insert or
1388 ** update can proceed.  Processing continues and no error is reported.
1389 **
1390 ** RESTRICT, SETNULL, and CASCADE actions apply only to foreign keys.
1391 ** RESTRICT is the same as ABORT for IMMEDIATE foreign keys and the
1392 ** same as ROLLBACK for DEFERRED keys.  SETNULL means that the foreign
1393 ** key is set to NULL.  CASCADE means that a DELETE or UPDATE of the
1394 ** referenced table row is propagated into the row that holds the
1395 ** foreign key.
1396 **
1397 ** The following symbolic values are used to record which type
1398 ** of action to take.
1399 */
1400 #define OE_None     0   /* There is no constraint to check */
1401 #define OE_Rollback 1   /* Fail the operation and rollback the transaction */
1402 #define OE_Abort    2   /* Back out changes but do no rollback transaction */
1403 #define OE_Fail     3   /* Stop the operation but leave all prior changes */
1404 #define OE_Ignore   4   /* Ignore the error. Do not do the INSERT or UPDATE */
1405 #define OE_Replace  5   /* Delete existing record, then do INSERT or UPDATE */
1406 
1407 #define OE_Restrict 6   /* OE_Abort for IMMEDIATE, OE_Rollback for DEFERRED */
1408 #define OE_SetNull  7   /* Set the foreign key value to NULL */
1409 #define OE_SetDflt  8   /* Set the foreign key value to its default */
1410 #define OE_Cascade  9   /* Cascade the changes */
1411 
1412 #define OE_Default  99  /* Do whatever the default action is */
1413 
1414 
1415 /*
1416 ** An instance of the following structure is passed as the first
1417 ** argument to sqlite3VdbeKeyCompare and is used to control the
1418 ** comparison of the two index keys.
1419 */
1420 struct KeyInfo {
1421   sqlite3 *db;        /* The database connection */
1422   u8 enc;             /* Text encoding - one of the SQLITE_UTF* values */
1423   u16 nField;         /* Number of entries in aColl[] */
1424   u8 *aSortOrder;     /* Sort order for each column.  May be NULL */
1425   CollSeq *aColl[1];  /* Collating sequence for each term of the key */
1426 };
1427 
1428 /*
1429 ** An instance of the following structure holds information about a
1430 ** single index record that has already been parsed out into individual
1431 ** values.
1432 **
1433 ** A record is an object that contains one or more fields of data.
1434 ** Records are used to store the content of a table row and to store
1435 ** the key of an index.  A blob encoding of a record is created by
1436 ** the OP_MakeRecord opcode of the VDBE and is disassembled by the
1437 ** OP_Column opcode.
1438 **
1439 ** This structure holds a record that has already been disassembled
1440 ** into its constituent fields.
1441 */
1442 struct UnpackedRecord {
1443   KeyInfo *pKeyInfo;  /* Collation and sort-order information */
1444   u16 nField;         /* Number of entries in apMem[] */
1445   u8 flags;           /* Boolean settings.  UNPACKED_... below */
1446   i64 rowid;          /* Used by UNPACKED_PREFIX_SEARCH */
1447   Mem *aMem;          /* Values */
1448 };
1449 
1450 /*
1451 ** Allowed values of UnpackedRecord.flags
1452 */
1453 #define UNPACKED_INCRKEY       0x01  /* Make this key an epsilon larger */
1454 #define UNPACKED_PREFIX_MATCH  0x02  /* A prefix match is considered OK */
1455 #define UNPACKED_PREFIX_SEARCH 0x04  /* Ignore final (rowid) field */
1456 
1457 /*
1458 ** Each SQL index is represented in memory by an
1459 ** instance of the following structure.
1460 **
1461 ** The columns of the table that are to be indexed are described
1462 ** by the aiColumn[] field of this structure.  For example, suppose
1463 ** we have the following table and index:
1464 **
1465 **     CREATE TABLE Ex1(c1 int, c2 int, c3 text);
1466 **     CREATE INDEX Ex2 ON Ex1(c3,c1);
1467 **
1468 ** In the Table structure describing Ex1, nCol==3 because there are
1469 ** three columns in the table.  In the Index structure describing
1470 ** Ex2, nColumn==2 since 2 of the 3 columns of Ex1 are indexed.
1471 ** The value of aiColumn is {2, 0}.  aiColumn[0]==2 because the
1472 ** first column to be indexed (c3) has an index of 2 in Ex1.aCol[].
1473 ** The second column to be indexed (c1) has an index of 0 in
1474 ** Ex1.aCol[], hence Ex2.aiColumn[1]==0.
1475 **
1476 ** The Index.onError field determines whether or not the indexed columns
1477 ** must be unique and what to do if they are not.  When Index.onError=OE_None,
1478 ** it means this is not a unique index.  Otherwise it is a unique index
1479 ** and the value of Index.onError indicate the which conflict resolution
1480 ** algorithm to employ whenever an attempt is made to insert a non-unique
1481 ** element.
1482 */
1483 struct Index {
1484   char *zName;     /* Name of this index */
1485   int *aiColumn;   /* Which columns are used by this index.  1st is 0 */
1486   tRowcnt *aiRowEst; /* Result of ANALYZE: Est. rows selected by each column */
1487   Table *pTable;   /* The SQL table being indexed */
1488   char *zColAff;   /* String defining the affinity of each column */
1489   Index *pNext;    /* The next index associated with the same table */
1490   Schema *pSchema; /* Schema containing this index */
1491   u8 *aSortOrder;  /* Array of size Index.nColumn. True==DESC, False==ASC */
1492   char **azColl;   /* Array of collation sequence names for index */
1493   int nColumn;     /* Number of columns in the table used by this index */
1494   int tnum;        /* Page containing root of this index in database file */
1495   u8 onError;      /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
1496   u8 autoIndex;    /* True if is automatically created (ex: by UNIQUE) */
1497   u8 bUnordered;   /* Use this index for == or IN queries only */
1498 #ifdef SQLITE_ENABLE_STAT3
1499   int nSample;             /* Number of elements in aSample[] */
1500   tRowcnt avgEq;           /* Average nEq value for key values not in aSample */
1501   IndexSample *aSample;    /* Samples of the left-most key */
1502 #endif
1503 };
1504 
1505 /*
1506 ** Each sample stored in the sqlite_stat3 table is represented in memory
1507 ** using a structure of this type.  See documentation at the top of the
1508 ** analyze.c source file for additional information.
1509 */
1510 struct IndexSample {
1511   union {
1512     char *z;        /* Value if eType is SQLITE_TEXT or SQLITE_BLOB */
1513     double r;       /* Value if eType is SQLITE_FLOAT */
1514     i64 i;          /* Value if eType is SQLITE_INTEGER */
1515   } u;
1516   u8 eType;         /* SQLITE_NULL, SQLITE_INTEGER ... etc. */
1517   int nByte;        /* Size in byte of text or blob. */
1518   tRowcnt nEq;      /* Est. number of rows where the key equals this sample */
1519   tRowcnt nLt;      /* Est. number of rows where key is less than this sample */
1520   tRowcnt nDLt;     /* Est. number of distinct keys less than this sample */
1521 };
1522 
1523 /*
1524 ** Each token coming out of the lexer is an instance of
1525 ** this structure.  Tokens are also used as part of an expression.
1526 **
1527 ** Note if Token.z==0 then Token.dyn and Token.n are undefined and
1528 ** may contain random values.  Do not make any assumptions about Token.dyn
1529 ** and Token.n when Token.z==0.
1530 */
1531 struct Token {
1532   const char *z;     /* Text of the token.  Not NULL-terminated! */
1533   unsigned int n;    /* Number of characters in this token */
1534 };
1535 
1536 /*
1537 ** An instance of this structure contains information needed to generate
1538 ** code for a SELECT that contains aggregate functions.
1539 **
1540 ** If Expr.op==TK_AGG_COLUMN or TK_AGG_FUNCTION then Expr.pAggInfo is a
1541 ** pointer to this structure.  The Expr.iColumn field is the index in
1542 ** AggInfo.aCol[] or AggInfo.aFunc[] of information needed to generate
1543 ** code for that node.
1544 **
1545 ** AggInfo.pGroupBy and AggInfo.aFunc.pExpr point to fields within the
1546 ** original Select structure that describes the SELECT statement.  These
1547 ** fields do not need to be freed when deallocating the AggInfo structure.
1548 */
1549 struct AggInfo {
1550   u8 directMode;          /* Direct rendering mode means take data directly
1551                           ** from source tables rather than from accumulators */
1552   u8 useSortingIdx;       /* In direct mode, reference the sorting index rather
1553                           ** than the source table */
1554   int sortingIdx;         /* Cursor number of the sorting index */
1555   int sortingIdxPTab;     /* Cursor number of pseudo-table */
1556   int nSortingColumn;     /* Number of columns in the sorting index */
1557   ExprList *pGroupBy;     /* The group by clause */
1558   struct AggInfo_col {    /* For each column used in source tables */
1559     Table *pTab;             /* Source table */
1560     int iTable;              /* Cursor number of the source table */
1561     int iColumn;             /* Column number within the source table */
1562     int iSorterColumn;       /* Column number in the sorting index */
1563     int iMem;                /* Memory location that acts as accumulator */
1564     Expr *pExpr;             /* The original expression */
1565   } *aCol;
1566   int nColumn;            /* Number of used entries in aCol[] */
1567   int nAccumulator;       /* Number of columns that show through to the output.
1568                           ** Additional columns are used only as parameters to
1569                           ** aggregate functions */
1570   struct AggInfo_func {   /* For each aggregate function */
1571     Expr *pExpr;             /* Expression encoding the function */
1572     FuncDef *pFunc;          /* The aggregate function implementation */
1573     int iMem;                /* Memory location that acts as accumulator */
1574     int iDistinct;           /* Ephemeral table used to enforce DISTINCT */
1575   } *aFunc;
1576   int nFunc;              /* Number of entries in aFunc[] */
1577 };
1578 
1579 /*
1580 ** The datatype ynVar is a signed integer, either 16-bit or 32-bit.
1581 ** Usually it is 16-bits.  But if SQLITE_MAX_VARIABLE_NUMBER is greater
1582 ** than 32767 we have to make it 32-bit.  16-bit is preferred because
1583 ** it uses less memory in the Expr object, which is a big memory user
1584 ** in systems with lots of prepared statements.  And few applications
1585 ** need more than about 10 or 20 variables.  But some extreme users want
1586 ** to have prepared statements with over 32767 variables, and for them
1587 ** the option is available (at compile-time).
1588 */
1589 #if SQLITE_MAX_VARIABLE_NUMBER<=32767
1590 typedef i16 ynVar;
1591 #else
1592 typedef int ynVar;
1593 #endif
1594 
1595 /*
1596 ** Each node of an expression in the parse tree is an instance
1597 ** of this structure.
1598 **
1599 ** Expr.op is the opcode. The integer parser token codes are reused
1600 ** as opcodes here. For example, the parser defines TK_GE to be an integer
1601 ** code representing the ">=" operator. This same integer code is reused
1602 ** to represent the greater-than-or-equal-to operator in the expression
1603 ** tree.
1604 **
1605 ** If the expression is an SQL literal (TK_INTEGER, TK_FLOAT, TK_BLOB,
1606 ** or TK_STRING), then Expr.token contains the text of the SQL literal. If
1607 ** the expression is a variable (TK_VARIABLE), then Expr.token contains the
1608 ** variable name. Finally, if the expression is an SQL function (TK_FUNCTION),
1609 ** then Expr.token contains the name of the function.
1610 **
1611 ** Expr.pRight and Expr.pLeft are the left and right subexpressions of a
1612 ** binary operator. Either or both may be NULL.
1613 **
1614 ** Expr.x.pList is a list of arguments if the expression is an SQL function,
1615 ** a CASE expression or an IN expression of the form "<lhs> IN (<y>, <z>...)".
1616 ** Expr.x.pSelect is used if the expression is a sub-select or an expression of
1617 ** the form "<lhs> IN (SELECT ...)". If the EP_xIsSelect bit is set in the
1618 ** Expr.flags mask, then Expr.x.pSelect is valid. Otherwise, Expr.x.pList is
1619 ** valid.
1620 **
1621 ** An expression of the form ID or ID.ID refers to a column in a table.
1622 ** For such expressions, Expr.op is set to TK_COLUMN and Expr.iTable is
1623 ** the integer cursor number of a VDBE cursor pointing to that table and
1624 ** Expr.iColumn is the column number for the specific column.  If the
1625 ** expression is used as a result in an aggregate SELECT, then the
1626 ** value is also stored in the Expr.iAgg column in the aggregate so that
1627 ** it can be accessed after all aggregates are computed.
1628 **
1629 ** If the expression is an unbound variable marker (a question mark
1630 ** character '?' in the original SQL) then the Expr.iTable holds the index
1631 ** number for that variable.
1632 **
1633 ** If the expression is a subquery then Expr.iColumn holds an integer
1634 ** register number containing the result of the subquery.  If the
1635 ** subquery gives a constant result, then iTable is -1.  If the subquery
1636 ** gives a different answer at different times during statement processing
1637 ** then iTable is the address of a subroutine that computes the subquery.
1638 **
1639 ** If the Expr is of type OP_Column, and the table it is selecting from
1640 ** is a disk table or the "old.*" pseudo-table, then pTab points to the
1641 ** corresponding table definition.
1642 **
1643 ** ALLOCATION NOTES:
1644 **
1645 ** Expr objects can use a lot of memory space in database schema.  To
1646 ** help reduce memory requirements, sometimes an Expr object will be
1647 ** truncated.  And to reduce the number of memory allocations, sometimes
1648 ** two or more Expr objects will be stored in a single memory allocation,
1649 ** together with Expr.zToken strings.
1650 **
1651 ** If the EP_Reduced and EP_TokenOnly flags are set when
1652 ** an Expr object is truncated.  When EP_Reduced is set, then all
1653 ** the child Expr objects in the Expr.pLeft and Expr.pRight subtrees
1654 ** are contained within the same memory allocation.  Note, however, that
1655 ** the subtrees in Expr.x.pList or Expr.x.pSelect are always separately
1656 ** allocated, regardless of whether or not EP_Reduced is set.
1657 */
1658 struct Expr {
1659   u8 op;                 /* Operation performed by this node */
1660   char affinity;         /* The affinity of the column or 0 if not a column */
1661   u16 flags;             /* Various flags.  EP_* See below */
1662   union {
1663     char *zToken;          /* Token value. Zero terminated and dequoted */
1664     int iValue;            /* Non-negative integer value if EP_IntValue */
1665   } u;
1666 
1667   /* If the EP_TokenOnly flag is set in the Expr.flags mask, then no
1668   ** space is allocated for the fields below this point. An attempt to
1669   ** access them will result in a segfault or malfunction.
1670   *********************************************************************/
1671 
1672   Expr *pLeft;           /* Left subnode */
1673   Expr *pRight;          /* Right subnode */
1674   union {
1675     ExprList *pList;     /* Function arguments or in "<expr> IN (<expr-list)" */
1676     Select *pSelect;     /* Used for sub-selects and "<expr> IN (<select>)" */
1677   } x;
1678   CollSeq *pColl;        /* The collation type of the column or 0 */
1679 
1680   /* If the EP_Reduced flag is set in the Expr.flags mask, then no
1681   ** space is allocated for the fields below this point. An attempt to
1682   ** access them will result in a segfault or malfunction.
1683   *********************************************************************/
1684 
1685   int iTable;            /* TK_COLUMN: cursor number of table holding column
1686                          ** TK_REGISTER: register number
1687                          ** TK_TRIGGER: 1 -> new, 0 -> old */
1688   ynVar iColumn;         /* TK_COLUMN: column index.  -1 for rowid.
1689                          ** TK_VARIABLE: variable number (always >= 1). */
1690   i16 iAgg;              /* Which entry in pAggInfo->aCol[] or ->aFunc[] */
1691   i16 iRightJoinTable;   /* If EP_FromJoin, the right table of the join */
1692   u8 flags2;             /* Second set of flags.  EP2_... */
1693   u8 op2;                /* If a TK_REGISTER, the original value of Expr.op */
1694                          /* If TK_COLUMN, the value of p5 for OP_Column */
1695   AggInfo *pAggInfo;     /* Used by TK_AGG_COLUMN and TK_AGG_FUNCTION */
1696   Table *pTab;           /* Table for TK_COLUMN expressions. */
1697 #if SQLITE_MAX_EXPR_DEPTH>0
1698   int nHeight;           /* Height of the tree headed by this node */
1699 #endif
1700 };
1701 
1702 /*
1703 ** The following are the meanings of bits in the Expr.flags field.
1704 */
1705 #define EP_FromJoin   0x0001  /* Originated in ON or USING clause of a join */
1706 #define EP_Agg        0x0002  /* Contains one or more aggregate functions */
1707 #define EP_Resolved   0x0004  /* IDs have been resolved to COLUMNs */
1708 #define EP_Error      0x0008  /* Expression contains one or more errors */
1709 #define EP_Distinct   0x0010  /* Aggregate function with DISTINCT keyword */
1710 #define EP_VarSelect  0x0020  /* pSelect is correlated, not constant */
1711 #define EP_DblQuoted  0x0040  /* token.z was originally in "..." */
1712 #define EP_InfixFunc  0x0080  /* True for an infix function: LIKE, GLOB, etc */
1713 #define EP_ExpCollate 0x0100  /* Collating sequence specified explicitly */
1714 #define EP_FixedDest  0x0200  /* Result needed in a specific register */
1715 #define EP_IntValue   0x0400  /* Integer value contained in u.iValue */
1716 #define EP_xIsSelect  0x0800  /* x.pSelect is valid (otherwise x.pList is) */
1717 #define EP_Hint       0x1000  /* Not used */
1718 #define EP_Reduced    0x2000  /* Expr struct is EXPR_REDUCEDSIZE bytes only */
1719 #define EP_TokenOnly  0x4000  /* Expr struct is EXPR_TOKENONLYSIZE bytes only */
1720 #define EP_Static     0x8000  /* Held in memory not obtained from malloc() */
1721 
1722 /*
1723 ** The following are the meanings of bits in the Expr.flags2 field.
1724 */
1725 #define EP2_MallocedToken  0x0001  /* Need to sqlite3DbFree() Expr.zToken */
1726 #define EP2_Irreducible    0x0002  /* Cannot EXPRDUP_REDUCE this Expr */
1727 
1728 /*
1729 ** The pseudo-routine sqlite3ExprSetIrreducible sets the EP2_Irreducible
1730 ** flag on an expression structure.  This flag is used for VV&A only.  The
1731 ** routine is implemented as a macro that only works when in debugging mode,
1732 ** so as not to burden production code.
1733 */
1734 #ifdef SQLITE_DEBUG
1735 # define ExprSetIrreducible(X)  (X)->flags2 |= EP2_Irreducible
1736 #else
1737 # define ExprSetIrreducible(X)
1738 #endif
1739 
1740 /*
1741 ** These macros can be used to test, set, or clear bits in the
1742 ** Expr.flags field.
1743 */
1744 #define ExprHasProperty(E,P)     (((E)->flags&(P))==(P))
1745 #define ExprHasAnyProperty(E,P)  (((E)->flags&(P))!=0)
1746 #define ExprSetProperty(E,P)     (E)->flags|=(P)
1747 #define ExprClearProperty(E,P)   (E)->flags&=~(P)
1748 
1749 /*
1750 ** Macros to determine the number of bytes required by a normal Expr
1751 ** struct, an Expr struct with the EP_Reduced flag set in Expr.flags
1752 ** and an Expr struct with the EP_TokenOnly flag set.
1753 */
1754 #define EXPR_FULLSIZE           sizeof(Expr)           /* Full size */
1755 #define EXPR_REDUCEDSIZE        offsetof(Expr,iTable)  /* Common features */
1756 #define EXPR_TOKENONLYSIZE      offsetof(Expr,pLeft)   /* Fewer features */
1757 
1758 /*
1759 ** Flags passed to the sqlite3ExprDup() function. See the header comment
1760 ** above sqlite3ExprDup() for details.
1761 */
1762 #define EXPRDUP_REDUCE         0x0001  /* Used reduced-size Expr nodes */
1763 
1764 /*
1765 ** A list of expressions.  Each expression may optionally have a
1766 ** name.  An expr/name combination can be used in several ways, such
1767 ** as the list of "expr AS ID" fields following a "SELECT" or in the
1768 ** list of "ID = expr" items in an UPDATE.  A list of expressions can
1769 ** also be used as the argument to a function, in which case the a.zName
1770 ** field is not used.
1771 */
1772 struct ExprList {
1773   int nExpr;             /* Number of expressions on the list */
1774   int iECursor;          /* VDBE Cursor associated with this ExprList */
1775   struct ExprList_item { /* For each expression in the list */
1776     Expr *pExpr;           /* The list of expressions */
1777     char *zName;           /* Token associated with this expression */
1778     char *zSpan;           /* Original text of the expression */
1779     u8 sortOrder;          /* 1 for DESC or 0 for ASC */
1780     u8 done;               /* A flag to indicate when processing is finished */
1781     u16 iOrderByCol;       /* For ORDER BY, column number in result set */
1782     u16 iAlias;            /* Index into Parse.aAlias[] for zName */
1783   } *a;                  /* Alloc a power of two greater or equal to nExpr */
1784 };
1785 
1786 /*
1787 ** An instance of this structure is used by the parser to record both
1788 ** the parse tree for an expression and the span of input text for an
1789 ** expression.
1790 */
1791 struct ExprSpan {
1792   Expr *pExpr;          /* The expression parse tree */
1793   const char *zStart;   /* First character of input text */
1794   const char *zEnd;     /* One character past the end of input text */
1795 };
1796 
1797 /*
1798 ** An instance of this structure can hold a simple list of identifiers,
1799 ** such as the list "a,b,c" in the following statements:
1800 **
1801 **      INSERT INTO t(a,b,c) VALUES ...;
1802 **      CREATE INDEX idx ON t(a,b,c);
1803 **      CREATE TRIGGER trig BEFORE UPDATE ON t(a,b,c) ...;
1804 **
1805 ** The IdList.a.idx field is used when the IdList represents the list of
1806 ** column names after a table name in an INSERT statement.  In the statement
1807 **
1808 **     INSERT INTO t(a,b,c) ...
1809 **
1810 ** If "a" is the k-th column of table "t", then IdList.a[0].idx==k.
1811 */
1812 struct IdList {
1813   struct IdList_item {
1814     char *zName;      /* Name of the identifier */
1815     int idx;          /* Index in some Table.aCol[] of a column named zName */
1816   } *a;
1817   int nId;         /* Number of identifiers on the list */
1818 };
1819 
1820 /*
1821 ** The bitmask datatype defined below is used for various optimizations.
1822 **
1823 ** Changing this from a 64-bit to a 32-bit type limits the number of
1824 ** tables in a join to 32 instead of 64.  But it also reduces the size
1825 ** of the library by 738 bytes on ix86.
1826 */
1827 typedef u64 Bitmask;
1828 
1829 /*
1830 ** The number of bits in a Bitmask.  "BMS" means "BitMask Size".
1831 */
1832 #define BMS  ((int)(sizeof(Bitmask)*8))
1833 
1834 /*
1835 ** The following structure describes the FROM clause of a SELECT statement.
1836 ** Each table or subquery in the FROM clause is a separate element of
1837 ** the SrcList.a[] array.
1838 **
1839 ** With the addition of multiple database support, the following structure
1840 ** can also be used to describe a particular table such as the table that
1841 ** is modified by an INSERT, DELETE, or UPDATE statement.  In standard SQL,
1842 ** such a table must be a simple name: ID.  But in SQLite, the table can
1843 ** now be identified by a database name, a dot, then the table name: ID.ID.
1844 **
1845 ** The jointype starts out showing the join type between the current table
1846 ** and the next table on the list.  The parser builds the list this way.
1847 ** But sqlite3SrcListShiftJoinType() later shifts the jointypes so that each
1848 ** jointype expresses the join between the table and the previous table.
1849 **
1850 ** In the colUsed field, the high-order bit (bit 63) is set if the table
1851 ** contains more than 63 columns and the 64-th or later column is used.
1852 */
1853 struct SrcList {
1854   i16 nSrc;        /* Number of tables or subqueries in the FROM clause */
1855   i16 nAlloc;      /* Number of entries allocated in a[] below */
1856   struct SrcList_item {
1857     char *zDatabase;  /* Name of database holding this table */
1858     char *zName;      /* Name of the table */
1859     char *zAlias;     /* The "B" part of a "A AS B" phrase.  zName is the "A" */
1860     Table *pTab;      /* An SQL table corresponding to zName */
1861     Select *pSelect;  /* A SELECT statement used in place of a table name */
1862     int addrFillSub;  /* Address of subroutine to manifest a subquery */
1863     int regReturn;    /* Register holding return address of addrFillSub */
1864     u8 jointype;      /* Type of join between this able and the previous */
1865     u8 notIndexed;    /* True if there is a NOT INDEXED clause */
1866     u8 isCorrelated;  /* True if sub-query is correlated */
1867 #ifndef SQLITE_OMIT_EXPLAIN
1868     u8 iSelectId;     /* If pSelect!=0, the id of the sub-select in EQP */
1869 #endif
1870     int iCursor;      /* The VDBE cursor number used to access this table */
1871     Expr *pOn;        /* The ON clause of a join */
1872     IdList *pUsing;   /* The USING clause of a join */
1873     Bitmask colUsed;  /* Bit N (1<<N) set if column N of pTab is used */
1874     char *zIndex;     /* Identifier from "INDEXED BY <zIndex>" clause */
1875     Index *pIndex;    /* Index structure corresponding to zIndex, if any */
1876   } a[1];             /* One entry for each identifier on the list */
1877 };
1878 
1879 /*
1880 ** Permitted values of the SrcList.a.jointype field
1881 */
1882 #define JT_INNER     0x0001    /* Any kind of inner or cross join */
1883 #define JT_CROSS     0x0002    /* Explicit use of the CROSS keyword */
1884 #define JT_NATURAL   0x0004    /* True for a "natural" join */
1885 #define JT_LEFT      0x0008    /* Left outer join */
1886 #define JT_RIGHT     0x0010    /* Right outer join */
1887 #define JT_OUTER     0x0020    /* The "OUTER" keyword is present */
1888 #define JT_ERROR     0x0040    /* unknown or unsupported join type */
1889 
1890 
1891 /*
1892 ** A WherePlan object holds information that describes a lookup
1893 ** strategy.
1894 **
1895 ** This object is intended to be opaque outside of the where.c module.
1896 ** It is included here only so that that compiler will know how big it
1897 ** is.  None of the fields in this object should be used outside of
1898 ** the where.c module.
1899 **
1900 ** Within the union, pIdx is only used when wsFlags&WHERE_INDEXED is true.
1901 ** pTerm is only used when wsFlags&WHERE_MULTI_OR is true.  And pVtabIdx
1902 ** is only used when wsFlags&WHERE_VIRTUALTABLE is true.  It is never the
1903 ** case that more than one of these conditions is true.
1904 */
1905 struct WherePlan {
1906   u32 wsFlags;                   /* WHERE_* flags that describe the strategy */
1907   u32 nEq;                       /* Number of == constraints */
1908   double nRow;                   /* Estimated number of rows (for EQP) */
1909   union {
1910     Index *pIdx;                   /* Index when WHERE_INDEXED is true */
1911     struct WhereTerm *pTerm;       /* WHERE clause term for OR-search */
1912     sqlite3_index_info *pVtabIdx;  /* Virtual table index to use */
1913   } u;
1914 };
1915 
1916 /*
1917 ** For each nested loop in a WHERE clause implementation, the WhereInfo
1918 ** structure contains a single instance of this structure.  This structure
1919 ** is intended to be private the the where.c module and should not be
1920 ** access or modified by other modules.
1921 **
1922 ** The pIdxInfo field is used to help pick the best index on a
1923 ** virtual table.  The pIdxInfo pointer contains indexing
1924 ** information for the i-th table in the FROM clause before reordering.
1925 ** All the pIdxInfo pointers are freed by whereInfoFree() in where.c.
1926 ** All other information in the i-th WhereLevel object for the i-th table
1927 ** after FROM clause ordering.
1928 */
1929 struct WhereLevel {
1930   WherePlan plan;       /* query plan for this element of the FROM clause */
1931   int iLeftJoin;        /* Memory cell used to implement LEFT OUTER JOIN */
1932   int iTabCur;          /* The VDBE cursor used to access the table */
1933   int iIdxCur;          /* The VDBE cursor used to access pIdx */
1934   int addrBrk;          /* Jump here to break out of the loop */
1935   int addrNxt;          /* Jump here to start the next IN combination */
1936   int addrCont;         /* Jump here to continue with the next loop cycle */
1937   int addrFirst;        /* First instruction of interior of the loop */
1938   u8 iFrom;             /* Which entry in the FROM clause */
1939   u8 op, p5;            /* Opcode and P5 of the opcode that ends the loop */
1940   int p1, p2;           /* Operands of the opcode used to ends the loop */
1941   union {               /* Information that depends on plan.wsFlags */
1942     struct {
1943       int nIn;              /* Number of entries in aInLoop[] */
1944       struct InLoop {
1945         int iCur;              /* The VDBE cursor used by this IN operator */
1946         int addrInTop;         /* Top of the IN loop */
1947       } *aInLoop;           /* Information about each nested IN operator */
1948     } in;                 /* Used when plan.wsFlags&WHERE_IN_ABLE */
1949   } u;
1950 
1951   /* The following field is really not part of the current level.  But
1952   ** we need a place to cache virtual table index information for each
1953   ** virtual table in the FROM clause and the WhereLevel structure is
1954   ** a convenient place since there is one WhereLevel for each FROM clause
1955   ** element.
1956   */
1957   sqlite3_index_info *pIdxInfo;  /* Index info for n-th source table */
1958 };
1959 
1960 /*
1961 ** Flags appropriate for the wctrlFlags parameter of sqlite3WhereBegin()
1962 ** and the WhereInfo.wctrlFlags member.
1963 */
1964 #define WHERE_ORDERBY_NORMAL   0x0000 /* No-op */
1965 #define WHERE_ORDERBY_MIN      0x0001 /* ORDER BY processing for min() func */
1966 #define WHERE_ORDERBY_MAX      0x0002 /* ORDER BY processing for max() func */
1967 #define WHERE_ONEPASS_DESIRED  0x0004 /* Want to do one-pass UPDATE/DELETE */
1968 #define WHERE_DUPLICATES_OK    0x0008 /* Ok to return a row more than once */
1969 #define WHERE_OMIT_OPEN_CLOSE  0x0010 /* Table cursors are already open */
1970 #define WHERE_FORCE_TABLE      0x0020 /* Do not use an index-only search */
1971 #define WHERE_ONETABLE_ONLY    0x0040 /* Only code the 1st table in pTabList */
1972 #define WHERE_AND_ONLY         0x0080 /* Don't use indices for OR terms */
1973 
1974 /*
1975 ** The WHERE clause processing routine has two halves.  The
1976 ** first part does the start of the WHERE loop and the second
1977 ** half does the tail of the WHERE loop.  An instance of
1978 ** this structure is returned by the first half and passed
1979 ** into the second half to give some continuity.
1980 */
1981 struct WhereInfo {
1982   Parse *pParse;       /* Parsing and code generating context */
1983   u16 wctrlFlags;      /* Flags originally passed to sqlite3WhereBegin() */
1984   u8 okOnePass;        /* Ok to use one-pass algorithm for UPDATE or DELETE */
1985   u8 untestedTerms;    /* Not all WHERE terms resolved by outer loop */
1986   u8 eDistinct;
1987   SrcList *pTabList;             /* List of tables in the join */
1988   int iTop;                      /* The very beginning of the WHERE loop */
1989   int iContinue;                 /* Jump here to continue with next record */
1990   int iBreak;                    /* Jump here to break out of the loop */
1991   int nLevel;                    /* Number of nested loop */
1992   struct WhereClause *pWC;       /* Decomposition of the WHERE clause */
1993   double savedNQueryLoop;        /* pParse->nQueryLoop outside the WHERE loop */
1994   double nRowOut;                /* Estimated number of output rows */
1995   WhereLevel a[1];               /* Information about each nest loop in WHERE */
1996 };
1997 
1998 #define WHERE_DISTINCT_UNIQUE 1
1999 #define WHERE_DISTINCT_ORDERED 2
2000 
2001 /*
2002 ** A NameContext defines a context in which to resolve table and column
2003 ** names.  The context consists of a list of tables (the pSrcList) field and
2004 ** a list of named expression (pEList).  The named expression list may
2005 ** be NULL.  The pSrc corresponds to the FROM clause of a SELECT or
2006 ** to the table being operated on by INSERT, UPDATE, or DELETE.  The
2007 ** pEList corresponds to the result set of a SELECT and is NULL for
2008 ** other statements.
2009 **
2010 ** NameContexts can be nested.  When resolving names, the inner-most
2011 ** context is searched first.  If no match is found, the next outer
2012 ** context is checked.  If there is still no match, the next context
2013 ** is checked.  This process continues until either a match is found
2014 ** or all contexts are check.  When a match is found, the nRef member of
2015 ** the context containing the match is incremented.
2016 **
2017 ** Each subquery gets a new NameContext.  The pNext field points to the
2018 ** NameContext in the parent query.  Thus the process of scanning the
2019 ** NameContext list corresponds to searching through successively outer
2020 ** subqueries looking for a match.
2021 */
2022 struct NameContext {
2023   Parse *pParse;       /* The parser */
2024   SrcList *pSrcList;   /* One or more tables used to resolve names */
2025   ExprList *pEList;    /* Optional list of named expressions */
2026   AggInfo *pAggInfo;   /* Information about aggregates at this level */
2027   NameContext *pNext;  /* Next outer name context.  NULL for outermost */
2028   int nRef;            /* Number of names resolved by this context */
2029   int nErr;            /* Number of errors encountered while resolving names */
2030   u8 ncFlags;          /* Zero or more NC_* flags defined below */
2031 };
2032 
2033 /*
2034 ** Allowed values for the NameContext, ncFlags field.
2035 */
2036 #define NC_AllowAgg  0x01    /* Aggregate functions are allowed here */
2037 #define NC_HasAgg    0x02    /* One or more aggregate functions seen */
2038 #define NC_IsCheck   0x04    /* True if resolving names in a CHECK constraint */
2039 #define NC_InAggFunc 0x08    /* True if analyzing arguments to an agg func */
2040 
2041 /*
2042 ** An instance of the following structure contains all information
2043 ** needed to generate code for a single SELECT statement.
2044 **
2045 ** nLimit is set to -1 if there is no LIMIT clause.  nOffset is set to 0.
2046 ** If there is a LIMIT clause, the parser sets nLimit to the value of the
2047 ** limit and nOffset to the value of the offset (or 0 if there is not
2048 ** offset).  But later on, nLimit and nOffset become the memory locations
2049 ** in the VDBE that record the limit and offset counters.
2050 **
2051 ** addrOpenEphm[] entries contain the address of OP_OpenEphemeral opcodes.
2052 ** These addresses must be stored so that we can go back and fill in
2053 ** the P4_KEYINFO and P2 parameters later.  Neither the KeyInfo nor
2054 ** the number of columns in P2 can be computed at the same time
2055 ** as the OP_OpenEphm instruction is coded because not
2056 ** enough information about the compound query is known at that point.
2057 ** The KeyInfo for addrOpenTran[0] and [1] contains collating sequences
2058 ** for the result set.  The KeyInfo for addrOpenTran[2] contains collating
2059 ** sequences for the ORDER BY clause.
2060 */
2061 struct Select {
2062   ExprList *pEList;      /* The fields of the result */
2063   u8 op;                 /* One of: TK_UNION TK_ALL TK_INTERSECT TK_EXCEPT */
2064   char affinity;         /* MakeRecord with this affinity for SRT_Set */
2065   u16 selFlags;          /* Various SF_* values */
2066   int iLimit, iOffset;   /* Memory registers holding LIMIT & OFFSET counters */
2067   int addrOpenEphm[3];   /* OP_OpenEphem opcodes related to this select */
2068   double nSelectRow;     /* Estimated number of result rows */
2069   SrcList *pSrc;         /* The FROM clause */
2070   Expr *pWhere;          /* The WHERE clause */
2071   ExprList *pGroupBy;    /* The GROUP BY clause */
2072   Expr *pHaving;         /* The HAVING clause */
2073   ExprList *pOrderBy;    /* The ORDER BY clause */
2074   Select *pPrior;        /* Prior select in a compound select statement */
2075   Select *pNext;         /* Next select to the left in a compound */
2076   Select *pRightmost;    /* Right-most select in a compound select statement */
2077   Expr *pLimit;          /* LIMIT expression. NULL means not used. */
2078   Expr *pOffset;         /* OFFSET expression. NULL means not used. */
2079 };
2080 
2081 /*
2082 ** Allowed values for Select.selFlags.  The "SF" prefix stands for
2083 ** "Select Flag".
2084 */
2085 #define SF_Distinct        0x01  /* Output should be DISTINCT */
2086 #define SF_Resolved        0x02  /* Identifiers have been resolved */
2087 #define SF_Aggregate       0x04  /* Contains aggregate functions */
2088 #define SF_UsesEphemeral   0x08  /* Uses the OpenEphemeral opcode */
2089 #define SF_Expanded        0x10  /* sqlite3SelectExpand() called on this */
2090 #define SF_HasTypeInfo     0x20  /* FROM subqueries have Table metadata */
2091 #define SF_UseSorter       0x40  /* Sort using a sorter */
2092 #define SF_Values          0x80  /* Synthesized from VALUES clause */
2093 
2094 
2095 /*
2096 ** The results of a select can be distributed in several ways.  The
2097 ** "SRT" prefix means "SELECT Result Type".
2098 */
2099 #define SRT_Union        1  /* Store result as keys in an index */
2100 #define SRT_Except       2  /* Remove result from a UNION index */
2101 #define SRT_Exists       3  /* Store 1 if the result is not empty */
2102 #define SRT_Discard      4  /* Do not save the results anywhere */
2103 
2104 /* The ORDER BY clause is ignored for all of the above */
2105 #define IgnorableOrderby(X) ((X->eDest)<=SRT_Discard)
2106 
2107 #define SRT_Output       5  /* Output each row of result */
2108 #define SRT_Mem          6  /* Store result in a memory cell */
2109 #define SRT_Set          7  /* Store results as keys in an index */
2110 #define SRT_Table        8  /* Store result as data with an automatic rowid */
2111 #define SRT_EphemTab     9  /* Create transient tab and store like SRT_Table */
2112 #define SRT_Coroutine   10  /* Generate a single row of result */
2113 
2114 /*
2115 ** A structure used to customize the behavior of sqlite3Select(). See
2116 ** comments above sqlite3Select() for details.
2117 */
2118 typedef struct SelectDest SelectDest;
2119 struct SelectDest {
2120   u8 eDest;         /* How to dispose of the results */
2121   u8 affSdst;       /* Affinity used when eDest==SRT_Set */
2122   int iSDParm;      /* A parameter used by the eDest disposal method */
2123   int iSdst;        /* Base register where results are written */
2124   int nSdst;        /* Number of registers allocated */
2125 };
2126 
2127 /*
2128 ** During code generation of statements that do inserts into AUTOINCREMENT
2129 ** tables, the following information is attached to the Table.u.autoInc.p
2130 ** pointer of each autoincrement table to record some side information that
2131 ** the code generator needs.  We have to keep per-table autoincrement
2132 ** information in case inserts are down within triggers.  Triggers do not
2133 ** normally coordinate their activities, but we do need to coordinate the
2134 ** loading and saving of autoincrement information.
2135 */
2136 struct AutoincInfo {
2137   AutoincInfo *pNext;   /* Next info block in a list of them all */
2138   Table *pTab;          /* Table this info block refers to */
2139   int iDb;              /* Index in sqlite3.aDb[] of database holding pTab */
2140   int regCtr;           /* Memory register holding the rowid counter */
2141 };
2142 
2143 /*
2144 ** Size of the column cache
2145 */
2146 #ifndef SQLITE_N_COLCACHE
2147 # define SQLITE_N_COLCACHE 10
2148 #endif
2149 
2150 /*
2151 ** At least one instance of the following structure is created for each
2152 ** trigger that may be fired while parsing an INSERT, UPDATE or DELETE
2153 ** statement. All such objects are stored in the linked list headed at
2154 ** Parse.pTriggerPrg and deleted once statement compilation has been
2155 ** completed.
2156 **
2157 ** A Vdbe sub-program that implements the body and WHEN clause of trigger
2158 ** TriggerPrg.pTrigger, assuming a default ON CONFLICT clause of
2159 ** TriggerPrg.orconf, is stored in the TriggerPrg.pProgram variable.
2160 ** The Parse.pTriggerPrg list never contains two entries with the same
2161 ** values for both pTrigger and orconf.
2162 **
2163 ** The TriggerPrg.aColmask[0] variable is set to a mask of old.* columns
2164 ** accessed (or set to 0 for triggers fired as a result of INSERT
2165 ** statements). Similarly, the TriggerPrg.aColmask[1] variable is set to
2166 ** a mask of new.* columns used by the program.
2167 */
2168 struct TriggerPrg {
2169   Trigger *pTrigger;      /* Trigger this program was coded from */
2170   TriggerPrg *pNext;      /* Next entry in Parse.pTriggerPrg list */
2171   SubProgram *pProgram;   /* Program implementing pTrigger/orconf */
2172   int orconf;             /* Default ON CONFLICT policy */
2173   u32 aColmask[2];        /* Masks of old.*, new.* columns accessed */
2174 };
2175 
2176 /*
2177 ** The yDbMask datatype for the bitmask of all attached databases.
2178 */
2179 #if SQLITE_MAX_ATTACHED>30
2180   typedef sqlite3_uint64 yDbMask;
2181 #else
2182   typedef unsigned int yDbMask;
2183 #endif
2184 
2185 /*
2186 ** An SQL parser context.  A copy of this structure is passed through
2187 ** the parser and down into all the parser action routine in order to
2188 ** carry around information that is global to the entire parse.
2189 **
2190 ** The structure is divided into two parts.  When the parser and code
2191 ** generate call themselves recursively, the first part of the structure
2192 ** is constant but the second part is reset at the beginning and end of
2193 ** each recursion.
2194 **
2195 ** The nTableLock and aTableLock variables are only used if the shared-cache
2196 ** feature is enabled (if sqlite3Tsd()->useSharedData is true). They are
2197 ** used to store the set of table-locks required by the statement being
2198 ** compiled. Function sqlite3TableLock() is used to add entries to the
2199 ** list.
2200 */
2201 struct Parse {
2202   sqlite3 *db;         /* The main database structure */
2203   char *zErrMsg;       /* An error message */
2204   Vdbe *pVdbe;         /* An engine for executing database bytecode */
2205   int rc;              /* Return code from execution */
2206   u8 colNamesSet;      /* TRUE after OP_ColumnName has been issued to pVdbe */
2207   u8 checkSchema;      /* Causes schema cookie check after an error */
2208   u8 nested;           /* Number of nested calls to the parser/code generator */
2209   u8 nTempReg;         /* Number of temporary registers in aTempReg[] */
2210   u8 nTempInUse;       /* Number of aTempReg[] currently checked out */
2211   u8 nColCache;        /* Number of entries in aColCache[] */
2212   u8 iColCache;        /* Next entry in aColCache[] to replace */
2213   u8 isMultiWrite;     /* True if statement may modify/insert multiple rows */
2214   u8 mayAbort;         /* True if statement may throw an ABORT exception */
2215   int aTempReg[8];     /* Holding area for temporary registers */
2216   int nRangeReg;       /* Size of the temporary register block */
2217   int iRangeReg;       /* First register in temporary register block */
2218   int nErr;            /* Number of errors seen */
2219   int nTab;            /* Number of previously allocated VDBE cursors */
2220   int nMem;            /* Number of memory cells used so far */
2221   int nSet;            /* Number of sets used so far */
2222   int nOnce;           /* Number of OP_Once instructions so far */
2223   int ckBase;          /* Base register of data during check constraints */
2224   int iCacheLevel;     /* ColCache valid when aColCache[].iLevel<=iCacheLevel */
2225   int iCacheCnt;       /* Counter used to generate aColCache[].lru values */
2226   struct yColCache {
2227     int iTable;           /* Table cursor number */
2228     int iColumn;          /* Table column number */
2229     u8 tempReg;           /* iReg is a temp register that needs to be freed */
2230     int iLevel;           /* Nesting level */
2231     int iReg;             /* Reg with value of this column. 0 means none. */
2232     int lru;              /* Least recently used entry has the smallest value */
2233   } aColCache[SQLITE_N_COLCACHE];  /* One for each column cache entry */
2234   yDbMask writeMask;   /* Start a write transaction on these databases */
2235   yDbMask cookieMask;  /* Bitmask of schema verified databases */
2236   int cookieGoto;      /* Address of OP_Goto to cookie verifier subroutine */
2237   int cookieValue[SQLITE_MAX_ATTACHED+2];  /* Values of cookies to verify */
2238   int regRowid;        /* Register holding rowid of CREATE TABLE entry */
2239   int regRoot;         /* Register holding root page number for new objects */
2240   int nMaxArg;         /* Max args passed to user function by sub-program */
2241   Token constraintName;/* Name of the constraint currently being parsed */
2242 #ifndef SQLITE_OMIT_SHARED_CACHE
2243   int nTableLock;        /* Number of locks in aTableLock */
2244   TableLock *aTableLock; /* Required table locks for shared-cache mode */
2245 #endif
2246   AutoincInfo *pAinc;  /* Information about AUTOINCREMENT counters */
2247 
2248   /* Information used while coding trigger programs. */
2249   Parse *pToplevel;    /* Parse structure for main program (or NULL) */
2250   Table *pTriggerTab;  /* Table triggers are being coded for */
2251   double nQueryLoop;   /* Estimated number of iterations of a query */
2252   u32 oldmask;         /* Mask of old.* columns referenced */
2253   u32 newmask;         /* Mask of new.* columns referenced */
2254   u8 eTriggerOp;       /* TK_UPDATE, TK_INSERT or TK_DELETE */
2255   u8 eOrconf;          /* Default ON CONFLICT policy for trigger steps */
2256   u8 disableTriggers;  /* True to disable triggers */
2257 
2258   /* Above is constant between recursions.  Below is reset before and after
2259   ** each recursion */
2260 
2261   int nVar;                 /* Number of '?' variables seen in the SQL so far */
2262   int nzVar;                /* Number of available slots in azVar[] */
2263   u8 explain;               /* True if the EXPLAIN flag is found on the query */
2264 #ifndef SQLITE_OMIT_VIRTUALTABLE
2265   u8 declareVtab;           /* True if inside sqlite3_declare_vtab() */
2266   int nVtabLock;            /* Number of virtual tables to lock */
2267 #endif
2268   int nAlias;               /* Number of aliased result set columns */
2269   int nHeight;              /* Expression tree height of current sub-select */
2270 #ifndef SQLITE_OMIT_EXPLAIN
2271   int iSelectId;            /* ID of current select for EXPLAIN output */
2272   int iNextSelectId;        /* Next available select ID for EXPLAIN output */
2273 #endif
2274   char **azVar;             /* Pointers to names of parameters */
2275   Vdbe *pReprepare;         /* VM being reprepared (sqlite3Reprepare()) */
2276   int *aAlias;              /* Register used to hold aliased result */
2277   const char *zTail;        /* All SQL text past the last semicolon parsed */
2278   Table *pNewTable;         /* A table being constructed by CREATE TABLE */
2279   Trigger *pNewTrigger;     /* Trigger under construct by a CREATE TRIGGER */
2280   const char *zAuthContext; /* The 6th parameter to db->xAuth callbacks */
2281   Token sNameToken;         /* Token with unqualified schema object name */
2282   Token sLastToken;         /* The last token parsed */
2283 #ifndef SQLITE_OMIT_VIRTUALTABLE
2284   Token sArg;               /* Complete text of a module argument */
2285   Table **apVtabLock;       /* Pointer to virtual tables needing locking */
2286 #endif
2287   Table *pZombieTab;        /* List of Table objects to delete after code gen */
2288   TriggerPrg *pTriggerPrg;  /* Linked list of coded triggers */
2289 };
2290 
2291 /*
2292 ** Return true if currently inside an sqlite3_declare_vtab() call.
2293 */
2294 #ifdef SQLITE_OMIT_VIRTUALTABLE
2295   #define IN_DECLARE_VTAB 0
2296 #else
2297   #define IN_DECLARE_VTAB (pParse->declareVtab)
2298 #endif
2299 
2300 /*
2301 ** An instance of the following structure can be declared on a stack and used
2302 ** to save the Parse.zAuthContext value so that it can be restored later.
2303 */
2304 struct AuthContext {
2305   const char *zAuthContext;   /* Put saved Parse.zAuthContext here */
2306   Parse *pParse;              /* The Parse structure */
2307 };
2308 
2309 /*
2310 ** Bitfield flags for P5 value in various opcodes.
2311 */
2312 #define OPFLAG_NCHANGE       0x01    /* Set to update db->nChange */
2313 #define OPFLAG_LASTROWID     0x02    /* Set to update db->lastRowid */
2314 #define OPFLAG_ISUPDATE      0x04    /* This OP_Insert is an sql UPDATE */
2315 #define OPFLAG_APPEND        0x08    /* This is likely to be an append */
2316 #define OPFLAG_USESEEKRESULT 0x10    /* Try to avoid a seek in BtreeInsert() */
2317 #define OPFLAG_CLEARCACHE    0x20    /* Clear pseudo-table cache in OP_Column */
2318 #define OPFLAG_LENGTHARG     0x40    /* OP_Column only used for length() */
2319 #define OPFLAG_TYPEOFARG     0x80    /* OP_Column only used for typeof() */
2320 
2321 /*
2322  * Each trigger present in the database schema is stored as an instance of
2323  * struct Trigger.
2324  *
2325  * Pointers to instances of struct Trigger are stored in two ways.
2326  * 1. In the "trigHash" hash table (part of the sqlite3* that represents the
2327  *    database). This allows Trigger structures to be retrieved by name.
2328  * 2. All triggers associated with a single table form a linked list, using the
2329  *    pNext member of struct Trigger. A pointer to the first element of the
2330  *    linked list is stored as the "pTrigger" member of the associated
2331  *    struct Table.
2332  *
2333  * The "step_list" member points to the first element of a linked list
2334  * containing the SQL statements specified as the trigger program.
2335  */
2336 struct Trigger {
2337   char *zName;            /* The name of the trigger                        */
2338   char *table;            /* The table or view to which the trigger applies */
2339   u8 op;                  /* One of TK_DELETE, TK_UPDATE, TK_INSERT         */
2340   u8 tr_tm;               /* One of TRIGGER_BEFORE, TRIGGER_AFTER */
2341   Expr *pWhen;            /* The WHEN clause of the expression (may be NULL) */
2342   IdList *pColumns;       /* If this is an UPDATE OF <column-list> trigger,
2343                              the <column-list> is stored here */
2344   Schema *pSchema;        /* Schema containing the trigger */
2345   Schema *pTabSchema;     /* Schema containing the table */
2346   TriggerStep *step_list; /* Link list of trigger program steps             */
2347   Trigger *pNext;         /* Next trigger associated with the table */
2348 };
2349 
2350 /*
2351 ** A trigger is either a BEFORE or an AFTER trigger.  The following constants
2352 ** determine which.
2353 **
2354 ** If there are multiple triggers, you might of some BEFORE and some AFTER.
2355 ** In that cases, the constants below can be ORed together.
2356 */
2357 #define TRIGGER_BEFORE  1
2358 #define TRIGGER_AFTER   2
2359 
2360 /*
2361  * An instance of struct TriggerStep is used to store a single SQL statement
2362  * that is a part of a trigger-program.
2363  *
2364  * Instances of struct TriggerStep are stored in a singly linked list (linked
2365  * using the "pNext" member) referenced by the "step_list" member of the
2366  * associated struct Trigger instance. The first element of the linked list is
2367  * the first step of the trigger-program.
2368  *
2369  * The "op" member indicates whether this is a "DELETE", "INSERT", "UPDATE" or
2370  * "SELECT" statement. The meanings of the other members is determined by the
2371  * value of "op" as follows:
2372  *
2373  * (op == TK_INSERT)
2374  * orconf    -> stores the ON CONFLICT algorithm
2375  * pSelect   -> If this is an INSERT INTO ... SELECT ... statement, then
2376  *              this stores a pointer to the SELECT statement. Otherwise NULL.
2377  * target    -> A token holding the quoted name of the table to insert into.
2378  * pExprList -> If this is an INSERT INTO ... VALUES ... statement, then
2379  *              this stores values to be inserted. Otherwise NULL.
2380  * pIdList   -> If this is an INSERT INTO ... (<column-names>) VALUES ...
2381  *              statement, then this stores the column-names to be
2382  *              inserted into.
2383  *
2384  * (op == TK_DELETE)
2385  * target    -> A token holding the quoted name of the table to delete from.
2386  * pWhere    -> The WHERE clause of the DELETE statement if one is specified.
2387  *              Otherwise NULL.
2388  *
2389  * (op == TK_UPDATE)
2390  * target    -> A token holding the quoted name of the table to update rows of.
2391  * pWhere    -> The WHERE clause of the UPDATE statement if one is specified.
2392  *              Otherwise NULL.
2393  * pExprList -> A list of the columns to update and the expressions to update
2394  *              them to. See sqlite3Update() documentation of "pChanges"
2395  *              argument.
2396  *
2397  */
2398 struct TriggerStep {
2399   u8 op;               /* One of TK_DELETE, TK_UPDATE, TK_INSERT, TK_SELECT */
2400   u8 orconf;           /* OE_Rollback etc. */
2401   Trigger *pTrig;      /* The trigger that this step is a part of */
2402   Select *pSelect;     /* SELECT statment or RHS of INSERT INTO .. SELECT ... */
2403   Token target;        /* Target table for DELETE, UPDATE, INSERT */
2404   Expr *pWhere;        /* The WHERE clause for DELETE or UPDATE steps */
2405   ExprList *pExprList; /* SET clause for UPDATE.  VALUES clause for INSERT */
2406   IdList *pIdList;     /* Column names for INSERT */
2407   TriggerStep *pNext;  /* Next in the link-list */
2408   TriggerStep *pLast;  /* Last element in link-list. Valid for 1st elem only */
2409 };
2410 
2411 /*
2412 ** The following structure contains information used by the sqliteFix...
2413 ** routines as they walk the parse tree to make database references
2414 ** explicit.
2415 */
2416 typedef struct DbFixer DbFixer;
2417 struct DbFixer {
2418   Parse *pParse;      /* The parsing context.  Error messages written here */
2419   const char *zDb;    /* Make sure all objects are contained in this database */
2420   const char *zType;  /* Type of the container - used for error messages */
2421   const Token *pName; /* Name of the container - used for error messages */
2422 };
2423 
2424 /*
2425 ** An objected used to accumulate the text of a string where we
2426 ** do not necessarily know how big the string will be in the end.
2427 */
2428 struct StrAccum {
2429   sqlite3 *db;         /* Optional database for lookaside.  Can be NULL */
2430   char *zBase;         /* A base allocation.  Not from malloc. */
2431   char *zText;         /* The string collected so far */
2432   int  nChar;          /* Length of the string so far */
2433   int  nAlloc;         /* Amount of space allocated in zText */
2434   int  mxAlloc;        /* Maximum allowed string length */
2435   u8   mallocFailed;   /* Becomes true if any memory allocation fails */
2436   u8   useMalloc;      /* 0: none,  1: sqlite3DbMalloc,  2: sqlite3_malloc */
2437   u8   tooBig;         /* Becomes true if string size exceeds limits */
2438 };
2439 
2440 /*
2441 ** A pointer to this structure is used to communicate information
2442 ** from sqlite3Init and OP_ParseSchema into the sqlite3InitCallback.
2443 */
2444 typedef struct {
2445   sqlite3 *db;        /* The database being initialized */
2446   char **pzErrMsg;    /* Error message stored here */
2447   int iDb;            /* 0 for main database.  1 for TEMP, 2.. for ATTACHed */
2448   int rc;             /* Result code stored here */
2449 } InitData;
2450 
2451 /*
2452 ** Structure containing global configuration data for the SQLite library.
2453 **
2454 ** This structure also contains some state information.
2455 */
2456 struct Sqlite3Config {
2457   int bMemstat;                     /* True to enable memory status */
2458   int bCoreMutex;                   /* True to enable core mutexing */
2459   int bFullMutex;                   /* True to enable full mutexing */
2460   int bOpenUri;                     /* True to interpret filenames as URIs */
2461   int mxStrlen;                     /* Maximum string length */
2462   int szLookaside;                  /* Default lookaside buffer size */
2463   int nLookaside;                   /* Default lookaside buffer count */
2464   sqlite3_mem_methods m;            /* Low-level memory allocation interface */
2465   sqlite3_mutex_methods mutex;      /* Low-level mutex interface */
2466   sqlite3_pcache_methods2 pcache2;  /* Low-level page-cache interface */
2467   void *pHeap;                      /* Heap storage space */
2468   int nHeap;                        /* Size of pHeap[] */
2469   int mnReq, mxReq;                 /* Min and max heap requests sizes */
2470   void *pScratch;                   /* Scratch memory */
2471   int szScratch;                    /* Size of each scratch buffer */
2472   int nScratch;                     /* Number of scratch buffers */
2473   void *pPage;                      /* Page cache memory */
2474   int szPage;                       /* Size of each page in pPage[] */
2475   int nPage;                        /* Number of pages in pPage[] */
2476   int mxParserStack;                /* maximum depth of the parser stack */
2477   int sharedCacheEnabled;           /* true if shared-cache mode enabled */
2478   /* The above might be initialized to non-zero.  The following need to always
2479   ** initially be zero, however. */
2480   int isInit;                       /* True after initialization has finished */
2481   int inProgress;                   /* True while initialization in progress */
2482   int isMutexInit;                  /* True after mutexes are initialized */
2483   int isMallocInit;                 /* True after malloc is initialized */
2484   int isPCacheInit;                 /* True after malloc is initialized */
2485   sqlite3_mutex *pInitMutex;        /* Mutex used by sqlite3_initialize() */
2486   int nRefInitMutex;                /* Number of users of pInitMutex */
2487   void (*xLog)(void*,int,const char*); /* Function for logging */
2488   void *pLogArg;                       /* First argument to xLog() */
2489   int bLocaltimeFault;              /* True to fail localtime() calls */
2490 };
2491 
2492 /*
2493 ** Context pointer passed down through the tree-walk.
2494 */
2495 struct Walker {
2496   int (*xExprCallback)(Walker*, Expr*);     /* Callback for expressions */
2497   int (*xSelectCallback)(Walker*,Select*);  /* Callback for SELECTs */
2498   Parse *pParse;                            /* Parser context.  */
2499   union {                                   /* Extra data for callback */
2500     NameContext *pNC;                          /* Naming context */
2501     int i;                                     /* Integer value */
2502     SrcList *pSrcList;                         /* FROM clause */
2503   } u;
2504 };
2505 
2506 /* Forward declarations */
2507 int sqlite3WalkExpr(Walker*, Expr*);
2508 int sqlite3WalkExprList(Walker*, ExprList*);
2509 int sqlite3WalkSelect(Walker*, Select*);
2510 int sqlite3WalkSelectExpr(Walker*, Select*);
2511 int sqlite3WalkSelectFrom(Walker*, Select*);
2512 
2513 /*
2514 ** Return code from the parse-tree walking primitives and their
2515 ** callbacks.
2516 */
2517 #define WRC_Continue    0   /* Continue down into children */
2518 #define WRC_Prune       1   /* Omit children but continue walking siblings */
2519 #define WRC_Abort       2   /* Abandon the tree walk */
2520 
2521 /*
2522 ** Assuming zIn points to the first byte of a UTF-8 character,
2523 ** advance zIn to point to the first byte of the next UTF-8 character.
2524 */
2525 #define SQLITE_SKIP_UTF8(zIn) {                        \
2526   if( (*(zIn++))>=0xc0 ){                              \
2527     while( (*zIn & 0xc0)==0x80 ){ zIn++; }             \
2528   }                                                    \
2529 }
2530 
2531 /*
2532 ** The SQLITE_*_BKPT macros are substitutes for the error codes with
2533 ** the same name but without the _BKPT suffix.  These macros invoke
2534 ** routines that report the line-number on which the error originated
2535 ** using sqlite3_log().  The routines also provide a convenient place
2536 ** to set a debugger breakpoint.
2537 */
2538 int sqlite3CorruptError(int);
2539 int sqlite3MisuseError(int);
2540 int sqlite3CantopenError(int);
2541 #define SQLITE_CORRUPT_BKPT sqlite3CorruptError(__LINE__)
2542 #define SQLITE_MISUSE_BKPT sqlite3MisuseError(__LINE__)
2543 #define SQLITE_CANTOPEN_BKPT sqlite3CantopenError(__LINE__)
2544 
2545 
2546 /*
2547 ** FTS4 is really an extension for FTS3.  It is enabled using the
2548 ** SQLITE_ENABLE_FTS3 macro.  But to avoid confusion we also all
2549 ** the SQLITE_ENABLE_FTS4 macro to serve as an alisse for SQLITE_ENABLE_FTS3.
2550 */
2551 #if defined(SQLITE_ENABLE_FTS4) && !defined(SQLITE_ENABLE_FTS3)
2552 # define SQLITE_ENABLE_FTS3
2553 #endif
2554 
2555 /*
2556 ** The ctype.h header is needed for non-ASCII systems.  It is also
2557 ** needed by FTS3 when FTS3 is included in the amalgamation.
2558 */
2559 #if !defined(SQLITE_ASCII) || \
2560     (defined(SQLITE_ENABLE_FTS3) && defined(SQLITE_AMALGAMATION))
2561 # include <ctype.h>
2562 #endif
2563 
2564 /*
2565 ** The following macros mimic the standard library functions toupper(),
2566 ** isspace(), isalnum(), isdigit() and isxdigit(), respectively. The
2567 ** sqlite versions only work for ASCII characters, regardless of locale.
2568 */
2569 #ifdef SQLITE_ASCII
2570 # define sqlite3Toupper(x)  ((x)&~(sqlite3CtypeMap[(unsigned char)(x)]&0x20))
2571 # define sqlite3Isspace(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x01)
2572 # define sqlite3Isalnum(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x06)
2573 # define sqlite3Isalpha(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x02)
2574 # define sqlite3Isdigit(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x04)
2575 # define sqlite3Isxdigit(x)  (sqlite3CtypeMap[(unsigned char)(x)]&0x08)
2576 # define sqlite3Tolower(x)   (sqlite3UpperToLower[(unsigned char)(x)])
2577 #else
2578 # define sqlite3Toupper(x)   toupper((unsigned char)(x))
2579 # define sqlite3Isspace(x)   isspace((unsigned char)(x))
2580 # define sqlite3Isalnum(x)   isalnum((unsigned char)(x))
2581 # define sqlite3Isalpha(x)   isalpha((unsigned char)(x))
2582 # define sqlite3Isdigit(x)   isdigit((unsigned char)(x))
2583 # define sqlite3Isxdigit(x)  isxdigit((unsigned char)(x))
2584 # define sqlite3Tolower(x)   tolower((unsigned char)(x))
2585 #endif
2586 
2587 /*
2588 ** Internal function prototypes
2589 */
2590 #define sqlite3StrICmp sqlite3_stricmp
2591 int sqlite3Strlen30(const char*);
2592 #define sqlite3StrNICmp sqlite3_strnicmp
2593 
2594 int sqlite3MallocInit(void);
2595 void sqlite3MallocEnd(void);
2596 void *sqlite3Malloc(int);
2597 void *sqlite3MallocZero(int);
2598 void *sqlite3DbMallocZero(sqlite3*, int);
2599 void *sqlite3DbMallocRaw(sqlite3*, int);
2600 char *sqlite3DbStrDup(sqlite3*,const char*);
2601 char *sqlite3DbStrNDup(sqlite3*,const char*, int);
2602 void *sqlite3Realloc(void*, int);
2603 void *sqlite3DbReallocOrFree(sqlite3 *, void *, int);
2604 void *sqlite3DbRealloc(sqlite3 *, void *, int);
2605 void sqlite3DbFree(sqlite3*, void*);
2606 int sqlite3MallocSize(void*);
2607 int sqlite3DbMallocSize(sqlite3*, void*);
2608 void *sqlite3ScratchMalloc(int);
2609 void sqlite3ScratchFree(void*);
2610 void *sqlite3PageMalloc(int);
2611 void sqlite3PageFree(void*);
2612 void sqlite3MemSetDefault(void);
2613 void sqlite3BenignMallocHooks(void (*)(void), void (*)(void));
2614 int sqlite3HeapNearlyFull(void);
2615 
2616 /*
2617 ** On systems with ample stack space and that support alloca(), make
2618 ** use of alloca() to obtain space for large automatic objects.  By default,
2619 ** obtain space from malloc().
2620 **
2621 ** The alloca() routine never returns NULL.  This will cause code paths
2622 ** that deal with sqlite3StackAlloc() failures to be unreachable.
2623 */
2624 #ifdef SQLITE_USE_ALLOCA
2625 # define sqlite3StackAllocRaw(D,N)   alloca(N)
2626 # define sqlite3StackAllocZero(D,N)  memset(alloca(N), 0, N)
2627 # define sqlite3StackFree(D,P)
2628 #else
2629 # define sqlite3StackAllocRaw(D,N)   sqlite3DbMallocRaw(D,N)
2630 # define sqlite3StackAllocZero(D,N)  sqlite3DbMallocZero(D,N)
2631 # define sqlite3StackFree(D,P)       sqlite3DbFree(D,P)
2632 #endif
2633 
2634 #ifdef SQLITE_ENABLE_MEMSYS3
2635 const sqlite3_mem_methods *sqlite3MemGetMemsys3(void);
2636 #endif
2637 #ifdef SQLITE_ENABLE_MEMSYS5
2638 const sqlite3_mem_methods *sqlite3MemGetMemsys5(void);
2639 #endif
2640 
2641 
2642 #ifndef SQLITE_MUTEX_OMIT
2643   sqlite3_mutex_methods const *sqlite3DefaultMutex(void);
2644   sqlite3_mutex_methods const *sqlite3NoopMutex(void);
2645   sqlite3_mutex *sqlite3MutexAlloc(int);
2646   int sqlite3MutexInit(void);
2647   int sqlite3MutexEnd(void);
2648 #endif
2649 
2650 int sqlite3StatusValue(int);
2651 void sqlite3StatusAdd(int, int);
2652 void sqlite3StatusSet(int, int);
2653 
2654 #ifndef SQLITE_OMIT_FLOATING_POINT
2655   int sqlite3IsNaN(double);
2656 #else
2657 # define sqlite3IsNaN(X)  0
2658 #endif
2659 
2660 void sqlite3VXPrintf(StrAccum*, int, const char*, va_list);
2661 #ifndef SQLITE_OMIT_TRACE
2662 void sqlite3XPrintf(StrAccum*, const char*, ...);
2663 #endif
2664 char *sqlite3MPrintf(sqlite3*,const char*, ...);
2665 char *sqlite3VMPrintf(sqlite3*,const char*, va_list);
2666 char *sqlite3MAppendf(sqlite3*,char*,const char*,...);
2667 #if defined(SQLITE_TEST) || defined(SQLITE_DEBUG)
2668   void sqlite3DebugPrintf(const char*, ...);
2669 #endif
2670 #if defined(SQLITE_TEST)
2671   void *sqlite3TestTextToPtr(const char*);
2672 #endif
2673 
2674 /* Output formatting for SQLITE_TESTCTRL_EXPLAIN */
2675 #if defined(SQLITE_ENABLE_TREE_EXPLAIN)
2676   void sqlite3ExplainBegin(Vdbe*);
2677   void sqlite3ExplainPrintf(Vdbe*, const char*, ...);
2678   void sqlite3ExplainNL(Vdbe*);
2679   void sqlite3ExplainPush(Vdbe*);
2680   void sqlite3ExplainPop(Vdbe*);
2681   void sqlite3ExplainFinish(Vdbe*);
2682   void sqlite3ExplainSelect(Vdbe*, Select*);
2683   void sqlite3ExplainExpr(Vdbe*, Expr*);
2684   void sqlite3ExplainExprList(Vdbe*, ExprList*);
2685   const char *sqlite3VdbeExplanation(Vdbe*);
2686 #else
2687 # define sqlite3ExplainBegin(X)
2688 # define sqlite3ExplainSelect(A,B)
2689 # define sqlite3ExplainExpr(A,B)
2690 # define sqlite3ExplainExprList(A,B)
2691 # define sqlite3ExplainFinish(X)
2692 # define sqlite3VdbeExplanation(X) 0
2693 #endif
2694 
2695 
2696 void sqlite3SetString(char **, sqlite3*, const char*, ...);
2697 void sqlite3ErrorMsg(Parse*, const char*, ...);
2698 int sqlite3Dequote(char*);
2699 int sqlite3KeywordCode(const unsigned char*, int);
2700 int sqlite3RunParser(Parse*, const char*, char **);
2701 void sqlite3FinishCoding(Parse*);
2702 int sqlite3GetTempReg(Parse*);
2703 void sqlite3ReleaseTempReg(Parse*,int);
2704 int sqlite3GetTempRange(Parse*,int);
2705 void sqlite3ReleaseTempRange(Parse*,int,int);
2706 void sqlite3ClearTempRegCache(Parse*);
2707 Expr *sqlite3ExprAlloc(sqlite3*,int,const Token*,int);
2708 Expr *sqlite3Expr(sqlite3*,int,const char*);
2709 void sqlite3ExprAttachSubtrees(sqlite3*,Expr*,Expr*,Expr*);
2710 Expr *sqlite3PExpr(Parse*, int, Expr*, Expr*, const Token*);
2711 Expr *sqlite3ExprAnd(sqlite3*,Expr*, Expr*);
2712 Expr *sqlite3ExprFunction(Parse*,ExprList*, Token*);
2713 void sqlite3ExprAssignVarNumber(Parse*, Expr*);
2714 void sqlite3ExprDelete(sqlite3*, Expr*);
2715 ExprList *sqlite3ExprListAppend(Parse*,ExprList*,Expr*);
2716 void sqlite3ExprListSetName(Parse*,ExprList*,Token*,int);
2717 void sqlite3ExprListSetSpan(Parse*,ExprList*,ExprSpan*);
2718 void sqlite3ExprListDelete(sqlite3*, ExprList*);
2719 int sqlite3Init(sqlite3*, char**);
2720 int sqlite3InitCallback(void*, int, char**, char**);
2721 void sqlite3Pragma(Parse*,Token*,Token*,Token*,int);
2722 void sqlite3ResetAllSchemasOfConnection(sqlite3*);
2723 void sqlite3ResetOneSchema(sqlite3*,int);
2724 void sqlite3CollapseDatabaseArray(sqlite3*);
2725 void sqlite3BeginParse(Parse*,int);
2726 void sqlite3CommitInternalChanges(sqlite3*);
2727 Table *sqlite3ResultSetOfSelect(Parse*,Select*);
2728 void sqlite3OpenMasterTable(Parse *, int);
2729 void sqlite3StartTable(Parse*,Token*,Token*,int,int,int,int);
2730 void sqlite3AddColumn(Parse*,Token*);
2731 void sqlite3AddNotNull(Parse*, int);
2732 void sqlite3AddPrimaryKey(Parse*, ExprList*, int, int, int);
2733 void sqlite3AddCheckConstraint(Parse*, Expr*);
2734 void sqlite3AddColumnType(Parse*,Token*);
2735 void sqlite3AddDefaultValue(Parse*,ExprSpan*);
2736 void sqlite3AddCollateType(Parse*, Token*);
2737 void sqlite3EndTable(Parse*,Token*,Token*,Select*);
2738 int sqlite3ParseUri(const char*,const char*,unsigned int*,
2739                     sqlite3_vfs**,char**,char **);
2740 Btree *sqlite3DbNameToBtree(sqlite3*,const char*);
2741 int sqlite3CodeOnce(Parse *);
2742 
2743 Bitvec *sqlite3BitvecCreate(u32);
2744 int sqlite3BitvecTest(Bitvec*, u32);
2745 int sqlite3BitvecSet(Bitvec*, u32);
2746 void sqlite3BitvecClear(Bitvec*, u32, void*);
2747 void sqlite3BitvecDestroy(Bitvec*);
2748 u32 sqlite3BitvecSize(Bitvec*);
2749 int sqlite3BitvecBuiltinTest(int,int*);
2750 
2751 RowSet *sqlite3RowSetInit(sqlite3*, void*, unsigned int);
2752 void sqlite3RowSetClear(RowSet*);
2753 void sqlite3RowSetInsert(RowSet*, i64);
2754 int sqlite3RowSetTest(RowSet*, u8 iBatch, i64);
2755 int sqlite3RowSetNext(RowSet*, i64*);
2756 
2757 void sqlite3CreateView(Parse*,Token*,Token*,Token*,Select*,int,int);
2758 
2759 #if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE)
2760   int sqlite3ViewGetColumnNames(Parse*,Table*);
2761 #else
2762 # define sqlite3ViewGetColumnNames(A,B) 0
2763 #endif
2764 
2765 void sqlite3DropTable(Parse*, SrcList*, int, int);
2766 void sqlite3CodeDropTable(Parse*, Table*, int, int);
2767 void sqlite3DeleteTable(sqlite3*, Table*);
2768 #ifndef SQLITE_OMIT_AUTOINCREMENT
2769   void sqlite3AutoincrementBegin(Parse *pParse);
2770   void sqlite3AutoincrementEnd(Parse *pParse);
2771 #else
2772 # define sqlite3AutoincrementBegin(X)
2773 # define sqlite3AutoincrementEnd(X)
2774 #endif
2775 void sqlite3Insert(Parse*, SrcList*, ExprList*, Select*, IdList*, int);
2776 void *sqlite3ArrayAllocate(sqlite3*,void*,int,int*,int*);
2777 IdList *sqlite3IdListAppend(sqlite3*, IdList*, Token*);
2778 int sqlite3IdListIndex(IdList*,const char*);
2779 SrcList *sqlite3SrcListEnlarge(sqlite3*, SrcList*, int, int);
2780 SrcList *sqlite3SrcListAppend(sqlite3*, SrcList*, Token*, Token*);
2781 SrcList *sqlite3SrcListAppendFromTerm(Parse*, SrcList*, Token*, Token*,
2782                                       Token*, Select*, Expr*, IdList*);
2783 void sqlite3SrcListIndexedBy(Parse *, SrcList *, Token *);
2784 int sqlite3IndexedByLookup(Parse *, struct SrcList_item *);
2785 void sqlite3SrcListShiftJoinType(SrcList*);
2786 void sqlite3SrcListAssignCursors(Parse*, SrcList*);
2787 void sqlite3IdListDelete(sqlite3*, IdList*);
2788 void sqlite3SrcListDelete(sqlite3*, SrcList*);
2789 Index *sqlite3CreateIndex(Parse*,Token*,Token*,SrcList*,ExprList*,int,Token*,
2790                         Token*, int, int);
2791 void sqlite3DropIndex(Parse*, SrcList*, int);
2792 int sqlite3Select(Parse*, Select*, SelectDest*);
2793 Select *sqlite3SelectNew(Parse*,ExprList*,SrcList*,Expr*,ExprList*,
2794                          Expr*,ExprList*,int,Expr*,Expr*);
2795 void sqlite3SelectDelete(sqlite3*, Select*);
2796 Table *sqlite3SrcListLookup(Parse*, SrcList*);
2797 int sqlite3IsReadOnly(Parse*, Table*, int);
2798 void sqlite3OpenTable(Parse*, int iCur, int iDb, Table*, int);
2799 #if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY)
2800 Expr *sqlite3LimitWhere(Parse *, SrcList *, Expr *, ExprList *, Expr *, Expr *, char *);
2801 #endif
2802 void sqlite3DeleteFrom(Parse*, SrcList*, Expr*);
2803 void sqlite3Update(Parse*, SrcList*, ExprList*, Expr*, int);
2804 WhereInfo *sqlite3WhereBegin(Parse*, SrcList*, Expr*, ExprList**,ExprList*,u16);
2805 void sqlite3WhereEnd(WhereInfo*);
2806 int sqlite3ExprCodeGetColumn(Parse*, Table*, int, int, int, u8);
2807 void sqlite3ExprCodeGetColumnOfTable(Vdbe*, Table*, int, int, int);
2808 void sqlite3ExprCodeMove(Parse*, int, int, int);
2809 void sqlite3ExprCodeCopy(Parse*, int, int, int);
2810 void sqlite3ExprCacheStore(Parse*, int, int, int);
2811 void sqlite3ExprCachePush(Parse*);
2812 void sqlite3ExprCachePop(Parse*, int);
2813 void sqlite3ExprCacheRemove(Parse*, int, int);
2814 void sqlite3ExprCacheClear(Parse*);
2815 void sqlite3ExprCacheAffinityChange(Parse*, int, int);
2816 int sqlite3ExprCode(Parse*, Expr*, int);
2817 int sqlite3ExprCodeTemp(Parse*, Expr*, int*);
2818 int sqlite3ExprCodeTarget(Parse*, Expr*, int);
2819 int sqlite3ExprCodeAndCache(Parse*, Expr*, int);
2820 void sqlite3ExprCodeConstants(Parse*, Expr*);
2821 int sqlite3ExprCodeExprList(Parse*, ExprList*, int, int);
2822 void sqlite3ExprIfTrue(Parse*, Expr*, int, int);
2823 void sqlite3ExprIfFalse(Parse*, Expr*, int, int);
2824 Table *sqlite3FindTable(sqlite3*,const char*, const char*);
2825 Table *sqlite3LocateTable(Parse*,int isView,const char*, const char*);
2826 Index *sqlite3FindIndex(sqlite3*,const char*, const char*);
2827 void sqlite3UnlinkAndDeleteTable(sqlite3*,int,const char*);
2828 void sqlite3UnlinkAndDeleteIndex(sqlite3*,int,const char*);
2829 void sqlite3Vacuum(Parse*);
2830 int sqlite3RunVacuum(char**, sqlite3*);
2831 char *sqlite3NameFromToken(sqlite3*, Token*);
2832 int sqlite3ExprCompare(Expr*, Expr*);
2833 int sqlite3ExprListCompare(ExprList*, ExprList*);
2834 void sqlite3ExprAnalyzeAggregates(NameContext*, Expr*);
2835 void sqlite3ExprAnalyzeAggList(NameContext*,ExprList*);
2836 Vdbe *sqlite3GetVdbe(Parse*);
2837 void sqlite3PrngSaveState(void);
2838 void sqlite3PrngRestoreState(void);
2839 void sqlite3PrngResetState(void);
2840 void sqlite3RollbackAll(sqlite3*,int);
2841 void sqlite3CodeVerifySchema(Parse*, int);
2842 void sqlite3CodeVerifyNamedSchema(Parse*, const char *zDb);
2843 void sqlite3BeginTransaction(Parse*, int);
2844 void sqlite3CommitTransaction(Parse*);
2845 void sqlite3RollbackTransaction(Parse*);
2846 void sqlite3Savepoint(Parse*, int, Token*);
2847 void sqlite3CloseSavepoints(sqlite3 *);
2848 void sqlite3LeaveMutexAndCloseZombie(sqlite3*);
2849 int sqlite3ExprIsConstant(Expr*);
2850 int sqlite3ExprIsConstantNotJoin(Expr*);
2851 int sqlite3ExprIsConstantOrFunction(Expr*);
2852 int sqlite3ExprIsInteger(Expr*, int*);
2853 int sqlite3ExprCanBeNull(const Expr*);
2854 void sqlite3ExprCodeIsNullJump(Vdbe*, const Expr*, int, int);
2855 int sqlite3ExprNeedsNoAffinityChange(const Expr*, char);
2856 int sqlite3IsRowid(const char*);
2857 void sqlite3GenerateRowDelete(Parse*, Table*, int, int, int, Trigger *, int);
2858 void sqlite3GenerateRowIndexDelete(Parse*, Table*, int, int*);
2859 int sqlite3GenerateIndexKey(Parse*, Index*, int, int, int);
2860 void sqlite3GenerateConstraintChecks(Parse*,Table*,int,int,
2861                                      int*,int,int,int,int,int*);
2862 void sqlite3CompleteInsertion(Parse*, Table*, int, int, int*, int, int, int);
2863 int sqlite3OpenTableAndIndices(Parse*, Table*, int, int);
2864 void sqlite3BeginWriteOperation(Parse*, int, int);
2865 void sqlite3MultiWrite(Parse*);
2866 void sqlite3MayAbort(Parse*);
2867 void sqlite3HaltConstraint(Parse*, int, char*, int);
2868 Expr *sqlite3ExprDup(sqlite3*,Expr*,int);
2869 ExprList *sqlite3ExprListDup(sqlite3*,ExprList*,int);
2870 SrcList *sqlite3SrcListDup(sqlite3*,SrcList*,int);
2871 IdList *sqlite3IdListDup(sqlite3*,IdList*);
2872 Select *sqlite3SelectDup(sqlite3*,Select*,int);
2873 void sqlite3FuncDefInsert(FuncDefHash*, FuncDef*);
2874 FuncDef *sqlite3FindFunction(sqlite3*,const char*,int,int,u8,u8);
2875 void sqlite3RegisterBuiltinFunctions(sqlite3*);
2876 void sqlite3RegisterDateTimeFunctions(void);
2877 void sqlite3RegisterGlobalFunctions(void);
2878 int sqlite3SafetyCheckOk(sqlite3*);
2879 int sqlite3SafetyCheckSickOrOk(sqlite3*);
2880 void sqlite3ChangeCookie(Parse*, int);
2881 
2882 #if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
2883 void sqlite3MaterializeView(Parse*, Table*, Expr*, int);
2884 #endif
2885 
2886 #ifndef SQLITE_OMIT_TRIGGER
2887   void sqlite3BeginTrigger(Parse*, Token*,Token*,int,int,IdList*,SrcList*,
2888                            Expr*,int, int);
2889   void sqlite3FinishTrigger(Parse*, TriggerStep*, Token*);
2890   void sqlite3DropTrigger(Parse*, SrcList*, int);
2891   void sqlite3DropTriggerPtr(Parse*, Trigger*);
2892   Trigger *sqlite3TriggersExist(Parse *, Table*, int, ExprList*, int *pMask);
2893   Trigger *sqlite3TriggerList(Parse *, Table *);
2894   void sqlite3CodeRowTrigger(Parse*, Trigger *, int, ExprList*, int, Table *,
2895                             int, int, int);
2896   void sqlite3CodeRowTriggerDirect(Parse *, Trigger *, Table *, int, int, int);
2897   void sqliteViewTriggers(Parse*, Table*, Expr*, int, ExprList*);
2898   void sqlite3DeleteTriggerStep(sqlite3*, TriggerStep*);
2899   TriggerStep *sqlite3TriggerSelectStep(sqlite3*,Select*);
2900   TriggerStep *sqlite3TriggerInsertStep(sqlite3*,Token*, IdList*,
2901                                         ExprList*,Select*,u8);
2902   TriggerStep *sqlite3TriggerUpdateStep(sqlite3*,Token*,ExprList*, Expr*, u8);
2903   TriggerStep *sqlite3TriggerDeleteStep(sqlite3*,Token*, Expr*);
2904   void sqlite3DeleteTrigger(sqlite3*, Trigger*);
2905   void sqlite3UnlinkAndDeleteTrigger(sqlite3*,int,const char*);
2906   u32 sqlite3TriggerColmask(Parse*,Trigger*,ExprList*,int,int,Table*,int);
2907 # define sqlite3ParseToplevel(p) ((p)->pToplevel ? (p)->pToplevel : (p))
2908 #else
2909 # define sqlite3TriggersExist(B,C,D,E,F) 0
2910 # define sqlite3DeleteTrigger(A,B)
2911 # define sqlite3DropTriggerPtr(A,B)
2912 # define sqlite3UnlinkAndDeleteTrigger(A,B,C)
2913 # define sqlite3CodeRowTrigger(A,B,C,D,E,F,G,H,I)
2914 # define sqlite3CodeRowTriggerDirect(A,B,C,D,E,F)
2915 # define sqlite3TriggerList(X, Y) 0
2916 # define sqlite3ParseToplevel(p) p
2917 # define sqlite3TriggerColmask(A,B,C,D,E,F,G) 0
2918 #endif
2919 
2920 int sqlite3JoinType(Parse*, Token*, Token*, Token*);
2921 void sqlite3CreateForeignKey(Parse*, ExprList*, Token*, ExprList*, int);
2922 void sqlite3DeferForeignKey(Parse*, int);
2923 #ifndef SQLITE_OMIT_AUTHORIZATION
2924   void sqlite3AuthRead(Parse*,Expr*,Schema*,SrcList*);
2925   int sqlite3AuthCheck(Parse*,int, const char*, const char*, const char*);
2926   void sqlite3AuthContextPush(Parse*, AuthContext*, const char*);
2927   void sqlite3AuthContextPop(AuthContext*);
2928   int sqlite3AuthReadCol(Parse*, const char *, const char *, int);
2929 #else
2930 # define sqlite3AuthRead(a,b,c,d)
2931 # define sqlite3AuthCheck(a,b,c,d,e)    SQLITE_OK
2932 # define sqlite3AuthContextPush(a,b,c)
2933 # define sqlite3AuthContextPop(a)  ((void)(a))
2934 #endif
2935 void sqlite3Attach(Parse*, Expr*, Expr*, Expr*);
2936 void sqlite3Detach(Parse*, Expr*);
2937 int sqlite3FixInit(DbFixer*, Parse*, int, const char*, const Token*);
2938 int sqlite3FixSrcList(DbFixer*, SrcList*);
2939 int sqlite3FixSelect(DbFixer*, Select*);
2940 int sqlite3FixExpr(DbFixer*, Expr*);
2941 int sqlite3FixExprList(DbFixer*, ExprList*);
2942 int sqlite3FixTriggerStep(DbFixer*, TriggerStep*);
2943 int sqlite3AtoF(const char *z, double*, int, u8);
2944 int sqlite3GetInt32(const char *, int*);
2945 int sqlite3Atoi(const char*);
2946 int sqlite3Utf16ByteLen(const void *pData, int nChar);
2947 int sqlite3Utf8CharLen(const char *pData, int nByte);
2948 u32 sqlite3Utf8Read(const u8*, const u8**);
2949 
2950 /*
2951 ** Routines to read and write variable-length integers.  These used to
2952 ** be defined locally, but now we use the varint routines in the util.c
2953 ** file.  Code should use the MACRO forms below, as the Varint32 versions
2954 ** are coded to assume the single byte case is already handled (which
2955 ** the MACRO form does).
2956 */
2957 int sqlite3PutVarint(unsigned char*, u64);
2958 int sqlite3PutVarint32(unsigned char*, u32);
2959 u8 sqlite3GetVarint(const unsigned char *, u64 *);
2960 u8 sqlite3GetVarint32(const unsigned char *, u32 *);
2961 int sqlite3VarintLen(u64 v);
2962 
2963 /*
2964 ** The header of a record consists of a sequence variable-length integers.
2965 ** These integers are almost always small and are encoded as a single byte.
2966 ** The following macros take advantage this fact to provide a fast encode
2967 ** and decode of the integers in a record header.  It is faster for the common
2968 ** case where the integer is a single byte.  It is a little slower when the
2969 ** integer is two or more bytes.  But overall it is faster.
2970 **
2971 ** The following expressions are equivalent:
2972 **
2973 **     x = sqlite3GetVarint32( A, &B );
2974 **     x = sqlite3PutVarint32( A, B );
2975 **
2976 **     x = getVarint32( A, B );
2977 **     x = putVarint32( A, B );
2978 **
2979 */
2980 #define getVarint32(A,B)  (u8)((*(A)<(u8)0x80) ? ((B) = (u32)*(A)),1 : sqlite3GetVarint32((A), (u32 *)&(B)))
2981 #define putVarint32(A,B)  (u8)(((u32)(B)<(u32)0x80) ? (*(A) = (unsigned char)(B)),1 : sqlite3PutVarint32((A), (B)))
2982 #define getVarint    sqlite3GetVarint
2983 #define putVarint    sqlite3PutVarint
2984 
2985 
2986 const char *sqlite3IndexAffinityStr(Vdbe *, Index *);
2987 void sqlite3TableAffinityStr(Vdbe *, Table *);
2988 char sqlite3CompareAffinity(Expr *pExpr, char aff2);
2989 int sqlite3IndexAffinityOk(Expr *pExpr, char idx_affinity);
2990 char sqlite3ExprAffinity(Expr *pExpr);
2991 int sqlite3Atoi64(const char*, i64*, int, u8);
2992 void sqlite3Error(sqlite3*, int, const char*,...);
2993 void *sqlite3HexToBlob(sqlite3*, const char *z, int n);
2994 u8 sqlite3HexToInt(int h);
2995 int sqlite3TwoPartName(Parse *, Token *, Token *, Token **);
2996 const char *sqlite3ErrStr(int);
2997 int sqlite3ReadSchema(Parse *pParse);
2998 CollSeq *sqlite3FindCollSeq(sqlite3*,u8 enc, const char*,int);
2999 CollSeq *sqlite3LocateCollSeq(Parse *pParse, const char*zName);
3000 CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr);
3001 Expr *sqlite3ExprSetColl(Expr*, CollSeq*);
3002 Expr *sqlite3ExprSetCollByToken(Parse *pParse, Expr*, Token*);
3003 int sqlite3CheckCollSeq(Parse *, CollSeq *);
3004 int sqlite3CheckObjectName(Parse *, const char *);
3005 void sqlite3VdbeSetChanges(sqlite3 *, int);
3006 int sqlite3AddInt64(i64*,i64);
3007 int sqlite3SubInt64(i64*,i64);
3008 int sqlite3MulInt64(i64*,i64);
3009 int sqlite3AbsInt32(int);
3010 #ifdef SQLITE_ENABLE_8_3_NAMES
3011 void sqlite3FileSuffix3(const char*, char*);
3012 #else
3013 # define sqlite3FileSuffix3(X,Y)
3014 #endif
3015 u8 sqlite3GetBoolean(const char *z,int);
3016 
3017 const void *sqlite3ValueText(sqlite3_value*, u8);
3018 int sqlite3ValueBytes(sqlite3_value*, u8);
3019 void sqlite3ValueSetStr(sqlite3_value*, int, const void *,u8,
3020                         void(*)(void*));
3021 void sqlite3ValueFree(sqlite3_value*);
3022 sqlite3_value *sqlite3ValueNew(sqlite3 *);
3023 char *sqlite3Utf16to8(sqlite3 *, const void*, int, u8);
3024 #ifdef SQLITE_ENABLE_STAT3
3025 char *sqlite3Utf8to16(sqlite3 *, u8, char *, int, int *);
3026 #endif
3027 int sqlite3ValueFromExpr(sqlite3 *, Expr *, u8, u8, sqlite3_value **);
3028 void sqlite3ValueApplyAffinity(sqlite3_value *, u8, u8);
3029 #ifndef SQLITE_AMALGAMATION
3030 extern const unsigned char sqlite3OpcodeProperty[];
3031 extern const unsigned char sqlite3UpperToLower[];
3032 extern const unsigned char sqlite3CtypeMap[];
3033 extern const Token sqlite3IntTokens[];
3034 extern SQLITE_WSD struct Sqlite3Config sqlite3Config;
3035 extern SQLITE_WSD FuncDefHash sqlite3GlobalFunctions;
3036 #ifndef SQLITE_OMIT_WSD
3037 extern int sqlite3PendingByte;
3038 #endif
3039 #endif
3040 void sqlite3RootPageMoved(sqlite3*, int, int, int);
3041 void sqlite3Reindex(Parse*, Token*, Token*);
3042 void sqlite3AlterFunctions(void);
3043 void sqlite3AlterRenameTable(Parse*, SrcList*, Token*);
3044 int sqlite3GetToken(const unsigned char *, int *);
3045 void sqlite3NestedParse(Parse*, const char*, ...);
3046 void sqlite3ExpirePreparedStatements(sqlite3*);
3047 int sqlite3CodeSubselect(Parse *, Expr *, int, int);
3048 void sqlite3SelectPrep(Parse*, Select*, NameContext*);
3049 int sqlite3ResolveExprNames(NameContext*, Expr*);
3050 void sqlite3ResolveSelectNames(Parse*, Select*, NameContext*);
3051 int sqlite3ResolveOrderGroupBy(Parse*, Select*, ExprList*, const char*);
3052 void sqlite3ColumnDefault(Vdbe *, Table *, int, int);
3053 void sqlite3AlterFinishAddColumn(Parse *, Token *);
3054 void sqlite3AlterBeginAddColumn(Parse *, SrcList *);
3055 CollSeq *sqlite3GetCollSeq(sqlite3*, u8, CollSeq *, const char*);
3056 char sqlite3AffinityType(const char*);
3057 void sqlite3Analyze(Parse*, Token*, Token*);
3058 int sqlite3InvokeBusyHandler(BusyHandler*);
3059 int sqlite3FindDb(sqlite3*, Token*);
3060 int sqlite3FindDbName(sqlite3 *, const char *);
3061 int sqlite3AnalysisLoad(sqlite3*,int iDB);
3062 void sqlite3DeleteIndexSamples(sqlite3*,Index*);
3063 void sqlite3DefaultRowEst(Index*);
3064 void sqlite3RegisterLikeFunctions(sqlite3*, int);
3065 int sqlite3IsLikeFunction(sqlite3*,Expr*,int*,char*);
3066 void sqlite3MinimumFileFormat(Parse*, int, int);
3067 void sqlite3SchemaClear(void *);
3068 Schema *sqlite3SchemaGet(sqlite3 *, Btree *);
3069 int sqlite3SchemaToIndex(sqlite3 *db, Schema *);
3070 KeyInfo *sqlite3IndexKeyinfo(Parse *, Index *);
3071 int sqlite3CreateFunc(sqlite3 *, const char *, int, int, void *,
3072   void (*)(sqlite3_context*,int,sqlite3_value **),
3073   void (*)(sqlite3_context*,int,sqlite3_value **), void (*)(sqlite3_context*),
3074   FuncDestructor *pDestructor
3075 );
3076 int sqlite3ApiExit(sqlite3 *db, int);
3077 int sqlite3OpenTempDatabase(Parse *);
3078 
3079 void sqlite3StrAccumInit(StrAccum*, char*, int, int);
3080 void sqlite3StrAccumAppend(StrAccum*,const char*,int);
3081 void sqlite3AppendSpace(StrAccum*,int);
3082 char *sqlite3StrAccumFinish(StrAccum*);
3083 void sqlite3StrAccumReset(StrAccum*);
3084 void sqlite3SelectDestInit(SelectDest*,int,int);
3085 Expr *sqlite3CreateColumnExpr(sqlite3 *, SrcList *, int, int);
3086 
3087 void sqlite3BackupRestart(sqlite3_backup *);
3088 void sqlite3BackupUpdate(sqlite3_backup *, Pgno, const u8 *);
3089 
3090 /*
3091 ** The interface to the LEMON-generated parser
3092 */
3093 void *sqlite3ParserAlloc(void*(*)(size_t));
3094 void sqlite3ParserFree(void*, void(*)(void*));
3095 void sqlite3Parser(void*, int, Token, Parse*);
3096 #ifdef YYTRACKMAXSTACKDEPTH
3097   int sqlite3ParserStackPeak(void*);
3098 #endif
3099 
3100 void sqlite3AutoLoadExtensions(sqlite3*);
3101 #ifndef SQLITE_OMIT_LOAD_EXTENSION
3102   void sqlite3CloseExtensions(sqlite3*);
3103 #else
3104 # define sqlite3CloseExtensions(X)
3105 #endif
3106 
3107 #ifndef SQLITE_OMIT_SHARED_CACHE
3108   void sqlite3TableLock(Parse *, int, int, u8, const char *);
3109 #else
3110   #define sqlite3TableLock(v,w,x,y,z)
3111 #endif
3112 
3113 #ifdef SQLITE_TEST
3114   int sqlite3Utf8To8(unsigned char*);
3115 #endif
3116 
3117 #ifdef SQLITE_OMIT_VIRTUALTABLE
3118 #  define sqlite3VtabClear(Y)
3119 #  define sqlite3VtabSync(X,Y) SQLITE_OK
3120 #  define sqlite3VtabRollback(X)
3121 #  define sqlite3VtabCommit(X)
3122 #  define sqlite3VtabInSync(db) 0
3123 #  define sqlite3VtabLock(X)
3124 #  define sqlite3VtabUnlock(X)
3125 #  define sqlite3VtabUnlockList(X)
3126 #  define sqlite3VtabSavepoint(X, Y, Z) SQLITE_OK
3127 #  define sqlite3GetVTable(X,Y)  ((VTable*)0)
3128 #else
3129    void sqlite3VtabClear(sqlite3 *db, Table*);
3130    void sqlite3VtabDisconnect(sqlite3 *db, Table *p);
3131    int sqlite3VtabSync(sqlite3 *db, char **);
3132    int sqlite3VtabRollback(sqlite3 *db);
3133    int sqlite3VtabCommit(sqlite3 *db);
3134    void sqlite3VtabLock(VTable *);
3135    void sqlite3VtabUnlock(VTable *);
3136    void sqlite3VtabUnlockList(sqlite3*);
3137    int sqlite3VtabSavepoint(sqlite3 *, int, int);
3138    VTable *sqlite3GetVTable(sqlite3*, Table*);
3139 #  define sqlite3VtabInSync(db) ((db)->nVTrans>0 && (db)->aVTrans==0)
3140 #endif
3141 void sqlite3VtabMakeWritable(Parse*,Table*);
3142 void sqlite3VtabBeginParse(Parse*, Token*, Token*, Token*, int);
3143 void sqlite3VtabFinishParse(Parse*, Token*);
3144 void sqlite3VtabArgInit(Parse*);
3145 void sqlite3VtabArgExtend(Parse*, Token*);
3146 int sqlite3VtabCallCreate(sqlite3*, int, const char *, char **);
3147 int sqlite3VtabCallConnect(Parse*, Table*);
3148 int sqlite3VtabCallDestroy(sqlite3*, int, const char *);
3149 int sqlite3VtabBegin(sqlite3 *, VTable *);
3150 FuncDef *sqlite3VtabOverloadFunction(sqlite3 *,FuncDef*, int nArg, Expr*);
3151 void sqlite3InvalidFunction(sqlite3_context*,int,sqlite3_value**);
3152 int sqlite3VdbeParameterIndex(Vdbe*, const char*, int);
3153 int sqlite3TransferBindings(sqlite3_stmt *, sqlite3_stmt *);
3154 int sqlite3Reprepare(Vdbe*);
3155 void sqlite3ExprListCheckLength(Parse*, ExprList*, const char*);
3156 CollSeq *sqlite3BinaryCompareCollSeq(Parse *, Expr *, Expr *);
3157 int sqlite3TempInMemory(const sqlite3*);
3158 const char *sqlite3JournalModename(int);
3159 int sqlite3Checkpoint(sqlite3*, int, int, int*, int*);
3160 int sqlite3WalDefaultHook(void*,sqlite3*,const char*,int);
3161 
3162 /* Declarations for functions in fkey.c. All of these are replaced by
3163 ** no-op macros if OMIT_FOREIGN_KEY is defined. In this case no foreign
3164 ** key functionality is available. If OMIT_TRIGGER is defined but
3165 ** OMIT_FOREIGN_KEY is not, only some of the functions are no-oped. In
3166 ** this case foreign keys are parsed, but no other functionality is
3167 ** provided (enforcement of FK constraints requires the triggers sub-system).
3168 */
3169 #if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)
3170   void sqlite3FkCheck(Parse*, Table*, int, int);
3171   void sqlite3FkDropTable(Parse*, SrcList *, Table*);
3172   void sqlite3FkActions(Parse*, Table*, ExprList*, int);
3173   int sqlite3FkRequired(Parse*, Table*, int*, int);
3174   u32 sqlite3FkOldmask(Parse*, Table*);
3175   FKey *sqlite3FkReferences(Table *);
3176 #else
3177   #define sqlite3FkActions(a,b,c,d)
3178   #define sqlite3FkCheck(a,b,c,d)
3179   #define sqlite3FkDropTable(a,b,c)
3180   #define sqlite3FkOldmask(a,b)      0
3181   #define sqlite3FkRequired(a,b,c,d) 0
3182 #endif
3183 #ifndef SQLITE_OMIT_FOREIGN_KEY
3184   void sqlite3FkDelete(sqlite3 *, Table*);
3185 #else
3186   #define sqlite3FkDelete(a,b)
3187 #endif
3188 
3189 
3190 /*
3191 ** Available fault injectors.  Should be numbered beginning with 0.
3192 */
3193 #define SQLITE_FAULTINJECTOR_MALLOC     0
3194 #define SQLITE_FAULTINJECTOR_COUNT      1
3195 
3196 /*
3197 ** The interface to the code in fault.c used for identifying "benign"
3198 ** malloc failures. This is only present if SQLITE_OMIT_BUILTIN_TEST
3199 ** is not defined.
3200 */
3201 #ifndef SQLITE_OMIT_BUILTIN_TEST
3202   void sqlite3BeginBenignMalloc(void);
3203   void sqlite3EndBenignMalloc(void);
3204 #else
3205   #define sqlite3BeginBenignMalloc()
3206   #define sqlite3EndBenignMalloc()
3207 #endif
3208 
3209 #define IN_INDEX_ROWID           1
3210 #define IN_INDEX_EPH             2
3211 #define IN_INDEX_INDEX           3
3212 int sqlite3FindInIndex(Parse *, Expr *, int*);
3213 
3214 #ifdef SQLITE_ENABLE_ATOMIC_WRITE
3215   int sqlite3JournalOpen(sqlite3_vfs *, const char *, sqlite3_file *, int, int);
3216   int sqlite3JournalSize(sqlite3_vfs *);
3217   int sqlite3JournalCreate(sqlite3_file *);
3218 #else
3219   #define sqlite3JournalSize(pVfs) ((pVfs)->szOsFile)
3220 #endif
3221 
3222 void sqlite3MemJournalOpen(sqlite3_file *);
3223 int sqlite3MemJournalSize(void);
3224 int sqlite3IsMemJournal(sqlite3_file *);
3225 
3226 #if SQLITE_MAX_EXPR_DEPTH>0
3227   void sqlite3ExprSetHeight(Parse *pParse, Expr *p);
3228   int sqlite3SelectExprHeight(Select *);
3229   int sqlite3ExprCheckHeight(Parse*, int);
3230 #else
3231   #define sqlite3ExprSetHeight(x,y)
3232   #define sqlite3SelectExprHeight(x) 0
3233   #define sqlite3ExprCheckHeight(x,y)
3234 #endif
3235 
3236 u32 sqlite3Get4byte(const u8*);
3237 void sqlite3Put4byte(u8*, u32);
3238 
3239 #ifdef SQLITE_ENABLE_UNLOCK_NOTIFY
3240   void sqlite3ConnectionBlocked(sqlite3 *, sqlite3 *);
3241   void sqlite3ConnectionUnlocked(sqlite3 *db);
3242   void sqlite3ConnectionClosed(sqlite3 *db);
3243 #else
3244   #define sqlite3ConnectionBlocked(x,y)
3245   #define sqlite3ConnectionUnlocked(x)
3246   #define sqlite3ConnectionClosed(x)
3247 #endif
3248 
3249 #ifdef SQLITE_DEBUG
3250   void sqlite3ParserTrace(FILE*, char *);
3251 #endif
3252 
3253 /*
3254 ** If the SQLITE_ENABLE IOTRACE exists then the global variable
3255 ** sqlite3IoTrace is a pointer to a printf-like routine used to
3256 ** print I/O tracing messages.
3257 */
3258 #ifdef SQLITE_ENABLE_IOTRACE
3259 # define IOTRACE(A)  if( sqlite3IoTrace ){ sqlite3IoTrace A; }
3260   void sqlite3VdbeIOTraceSql(Vdbe*);
3261 SQLITE_EXTERN void (*sqlite3IoTrace)(const char*,...);
3262 #else
3263 # define IOTRACE(A)
3264 # define sqlite3VdbeIOTraceSql(X)
3265 #endif
3266 
3267 /*
3268 ** These routines are available for the mem2.c debugging memory allocator
3269 ** only.  They are used to verify that different "types" of memory
3270 ** allocations are properly tracked by the system.
3271 **
3272 ** sqlite3MemdebugSetType() sets the "type" of an allocation to one of
3273 ** the MEMTYPE_* macros defined below.  The type must be a bitmask with
3274 ** a single bit set.
3275 **
3276 ** sqlite3MemdebugHasType() returns true if any of the bits in its second
3277 ** argument match the type set by the previous sqlite3MemdebugSetType().
3278 ** sqlite3MemdebugHasType() is intended for use inside assert() statements.
3279 **
3280 ** sqlite3MemdebugNoType() returns true if none of the bits in its second
3281 ** argument match the type set by the previous sqlite3MemdebugSetType().
3282 **
3283 ** Perhaps the most important point is the difference between MEMTYPE_HEAP
3284 ** and MEMTYPE_LOOKASIDE.  If an allocation is MEMTYPE_LOOKASIDE, that means
3285 ** it might have been allocated by lookaside, except the allocation was
3286 ** too large or lookaside was already full.  It is important to verify
3287 ** that allocations that might have been satisfied by lookaside are not
3288 ** passed back to non-lookaside free() routines.  Asserts such as the
3289 ** example above are placed on the non-lookaside free() routines to verify
3290 ** this constraint.
3291 **
3292 ** All of this is no-op for a production build.  It only comes into
3293 ** play when the SQLITE_MEMDEBUG compile-time option is used.
3294 */
3295 #ifdef SQLITE_MEMDEBUG
3296   void sqlite3MemdebugSetType(void*,u8);
3297   int sqlite3MemdebugHasType(void*,u8);
3298   int sqlite3MemdebugNoType(void*,u8);
3299 #else
3300 # define sqlite3MemdebugSetType(X,Y)  /* no-op */
3301 # define sqlite3MemdebugHasType(X,Y)  1
3302 # define sqlite3MemdebugNoType(X,Y)   1
3303 #endif
3304 #define MEMTYPE_HEAP       0x01  /* General heap allocations */
3305 #define MEMTYPE_LOOKASIDE  0x02  /* Might have been lookaside memory */
3306 #define MEMTYPE_SCRATCH    0x04  /* Scratch allocations */
3307 #define MEMTYPE_PCACHE     0x08  /* Page cache allocations */
3308 #define MEMTYPE_DB         0x10  /* Uses sqlite3DbMalloc, not sqlite_malloc */
3309 
3310 #endif /* _SQLITEINT_H_ */
3311