xref: /sqlite-3.40.0/src/sqliteInt.h (revision 36f6b891)
1 /*
2 ** 2001 September 15
3 **
4 ** The author disclaims copyright to this source code.  In place of
5 ** a legal notice, here is a blessing:
6 **
7 **    May you do good and not evil.
8 **    May you find forgiveness for yourself and forgive others.
9 **    May you share freely, never taking more than you give.
10 **
11 *************************************************************************
12 ** Internal interface definitions for SQLite.
13 **
14 */
15 #ifndef _SQLITEINT_H_
16 #define _SQLITEINT_H_
17 
18 /*
19 ** These #defines should enable >2GB file support on POSIX if the
20 ** underlying operating system supports it.  If the OS lacks
21 ** large file support, or if the OS is windows, these should be no-ops.
22 **
23 ** Ticket #2739:  The _LARGEFILE_SOURCE macro must appear before any
24 ** system #includes.  Hence, this block of code must be the very first
25 ** code in all source files.
26 **
27 ** Large file support can be disabled using the -DSQLITE_DISABLE_LFS switch
28 ** on the compiler command line.  This is necessary if you are compiling
29 ** on a recent machine (ex: Red Hat 7.2) but you want your code to work
30 ** on an older machine (ex: Red Hat 6.0).  If you compile on Red Hat 7.2
31 ** without this option, LFS is enable.  But LFS does not exist in the kernel
32 ** in Red Hat 6.0, so the code won't work.  Hence, for maximum binary
33 ** portability you should omit LFS.
34 **
35 ** Similar is true for Mac OS X.  LFS is only supported on Mac OS X 9 and later.
36 */
37 #ifndef SQLITE_DISABLE_LFS
38 # define _LARGE_FILE       1
39 # ifndef _FILE_OFFSET_BITS
40 #   define _FILE_OFFSET_BITS 64
41 # endif
42 # define _LARGEFILE_SOURCE 1
43 #endif
44 
45 /*
46 ** Include the configuration header output by 'configure' if we're using the
47 ** autoconf-based build
48 */
49 #ifdef _HAVE_SQLITE_CONFIG_H
50 #include "config.h"
51 #endif
52 
53 #include "sqliteLimit.h"
54 
55 /* Disable nuisance warnings on Borland compilers */
56 #if defined(__BORLANDC__)
57 #pragma warn -rch /* unreachable code */
58 #pragma warn -ccc /* Condition is always true or false */
59 #pragma warn -aus /* Assigned value is never used */
60 #pragma warn -csu /* Comparing signed and unsigned */
61 #pragma warn -spa /* Suspicious pointer arithmetic */
62 #endif
63 
64 /* Needed for various definitions... */
65 #ifndef _GNU_SOURCE
66 # define _GNU_SOURCE
67 #endif
68 
69 /*
70 ** Include standard header files as necessary
71 */
72 #ifdef HAVE_STDINT_H
73 #include <stdint.h>
74 #endif
75 #ifdef HAVE_INTTYPES_H
76 #include <inttypes.h>
77 #endif
78 
79 /*
80 ** The following macros are used to cast pointers to integers and
81 ** integers to pointers.  The way you do this varies from one compiler
82 ** to the next, so we have developed the following set of #if statements
83 ** to generate appropriate macros for a wide range of compilers.
84 **
85 ** The correct "ANSI" way to do this is to use the intptr_t type.
86 ** Unfortunately, that typedef is not available on all compilers, or
87 ** if it is available, it requires an #include of specific headers
88 ** that vary from one machine to the next.
89 **
90 ** Ticket #3860:  The llvm-gcc-4.2 compiler from Apple chokes on
91 ** the ((void*)&((char*)0)[X]) construct.  But MSVC chokes on ((void*)(X)).
92 ** So we have to define the macros in different ways depending on the
93 ** compiler.
94 */
95 #if defined(__PTRDIFF_TYPE__)  /* This case should work for GCC */
96 # define SQLITE_INT_TO_PTR(X)  ((void*)(__PTRDIFF_TYPE__)(X))
97 # define SQLITE_PTR_TO_INT(X)  ((int)(__PTRDIFF_TYPE__)(X))
98 #elif !defined(__GNUC__)       /* Works for compilers other than LLVM */
99 # define SQLITE_INT_TO_PTR(X)  ((void*)&((char*)0)[X])
100 # define SQLITE_PTR_TO_INT(X)  ((int)(((char*)X)-(char*)0))
101 #elif defined(HAVE_STDINT_H)   /* Use this case if we have ANSI headers */
102 # define SQLITE_INT_TO_PTR(X)  ((void*)(intptr_t)(X))
103 # define SQLITE_PTR_TO_INT(X)  ((int)(intptr_t)(X))
104 #else                          /* Generates a warning - but it always works */
105 # define SQLITE_INT_TO_PTR(X)  ((void*)(X))
106 # define SQLITE_PTR_TO_INT(X)  ((int)(X))
107 #endif
108 
109 /*
110 ** The SQLITE_THREADSAFE macro must be defined as 0, 1, or 2.
111 ** 0 means mutexes are permanently disable and the library is never
112 ** threadsafe.  1 means the library is serialized which is the highest
113 ** level of threadsafety.  2 means the libary is multithreaded - multiple
114 ** threads can use SQLite as long as no two threads try to use the same
115 ** database connection at the same time.
116 **
117 ** Older versions of SQLite used an optional THREADSAFE macro.
118 ** We support that for legacy.
119 */
120 #if !defined(SQLITE_THREADSAFE)
121 #if defined(THREADSAFE)
122 # define SQLITE_THREADSAFE THREADSAFE
123 #else
124 # define SQLITE_THREADSAFE 1 /* IMP: R-07272-22309 */
125 #endif
126 #endif
127 
128 /*
129 ** Powersafe overwrite is on by default.  But can be turned off using
130 ** the -DSQLITE_POWERSAFE_OVERWRITE=0 command-line option.
131 */
132 #ifndef SQLITE_POWERSAFE_OVERWRITE
133 # define SQLITE_POWERSAFE_OVERWRITE 1
134 #endif
135 
136 /*
137 ** The SQLITE_DEFAULT_MEMSTATUS macro must be defined as either 0 or 1.
138 ** It determines whether or not the features related to
139 ** SQLITE_CONFIG_MEMSTATUS are available by default or not. This value can
140 ** be overridden at runtime using the sqlite3_config() API.
141 */
142 #if !defined(SQLITE_DEFAULT_MEMSTATUS)
143 # define SQLITE_DEFAULT_MEMSTATUS 1
144 #endif
145 
146 /*
147 ** Exactly one of the following macros must be defined in order to
148 ** specify which memory allocation subsystem to use.
149 **
150 **     SQLITE_SYSTEM_MALLOC          // Use normal system malloc()
151 **     SQLITE_WIN32_MALLOC           // Use Win32 native heap API
152 **     SQLITE_MEMDEBUG               // Debugging version of system malloc()
153 **
154 ** On Windows, if the SQLITE_WIN32_MALLOC_VALIDATE macro is defined and the
155 ** assert() macro is enabled, each call into the Win32 native heap subsystem
156 ** will cause HeapValidate to be called.  If heap validation should fail, an
157 ** assertion will be triggered.
158 **
159 ** (Historical note:  There used to be several other options, but we've
160 ** pared it down to just these three.)
161 **
162 ** If none of the above are defined, then set SQLITE_SYSTEM_MALLOC as
163 ** the default.
164 */
165 #if defined(SQLITE_SYSTEM_MALLOC)+defined(SQLITE_WIN32_MALLOC)+defined(SQLITE_MEMDEBUG)>1
166 # error "At most one of the following compile-time configuration options\
167  is allows: SQLITE_SYSTEM_MALLOC, SQLITE_WIN32_MALLOC, SQLITE_MEMDEBUG"
168 #endif
169 #if defined(SQLITE_SYSTEM_MALLOC)+defined(SQLITE_WIN32_MALLOC)+defined(SQLITE_MEMDEBUG)==0
170 # define SQLITE_SYSTEM_MALLOC 1
171 #endif
172 
173 /*
174 ** If SQLITE_MALLOC_SOFT_LIMIT is not zero, then try to keep the
175 ** sizes of memory allocations below this value where possible.
176 */
177 #if !defined(SQLITE_MALLOC_SOFT_LIMIT)
178 # define SQLITE_MALLOC_SOFT_LIMIT 1024
179 #endif
180 
181 /*
182 ** We need to define _XOPEN_SOURCE as follows in order to enable
183 ** recursive mutexes on most Unix systems.  But Mac OS X is different.
184 ** The _XOPEN_SOURCE define causes problems for Mac OS X we are told,
185 ** so it is omitted there.  See ticket #2673.
186 **
187 ** Later we learn that _XOPEN_SOURCE is poorly or incorrectly
188 ** implemented on some systems.  So we avoid defining it at all
189 ** if it is already defined or if it is unneeded because we are
190 ** not doing a threadsafe build.  Ticket #2681.
191 **
192 ** See also ticket #2741.
193 */
194 #if !defined(_XOPEN_SOURCE) && !defined(__DARWIN__) && !defined(__APPLE__) && SQLITE_THREADSAFE
195 #  define _XOPEN_SOURCE 500  /* Needed to enable pthread recursive mutexes */
196 #endif
197 
198 /*
199 ** The TCL headers are only needed when compiling the TCL bindings.
200 */
201 #if defined(SQLITE_TCL) || defined(TCLSH)
202 # include <tcl.h>
203 #endif
204 
205 /*
206 ** Many people are failing to set -DNDEBUG=1 when compiling SQLite.
207 ** Setting NDEBUG makes the code smaller and run faster.  So the following
208 ** lines are added to automatically set NDEBUG unless the -DSQLITE_DEBUG=1
209 ** option is set.  Thus NDEBUG becomes an opt-in rather than an opt-out
210 ** feature.
211 */
212 #if !defined(NDEBUG) && !defined(SQLITE_DEBUG)
213 # define NDEBUG 1
214 #endif
215 
216 /*
217 ** The testcase() macro is used to aid in coverage testing.  When
218 ** doing coverage testing, the condition inside the argument to
219 ** testcase() must be evaluated both true and false in order to
220 ** get full branch coverage.  The testcase() macro is inserted
221 ** to help ensure adequate test coverage in places where simple
222 ** condition/decision coverage is inadequate.  For example, testcase()
223 ** can be used to make sure boundary values are tested.  For
224 ** bitmask tests, testcase() can be used to make sure each bit
225 ** is significant and used at least once.  On switch statements
226 ** where multiple cases go to the same block of code, testcase()
227 ** can insure that all cases are evaluated.
228 **
229 */
230 #ifdef SQLITE_COVERAGE_TEST
231   void sqlite3Coverage(int);
232 # define testcase(X)  if( X ){ sqlite3Coverage(__LINE__); }
233 #else
234 # define testcase(X)
235 #endif
236 
237 /*
238 ** The TESTONLY macro is used to enclose variable declarations or
239 ** other bits of code that are needed to support the arguments
240 ** within testcase() and assert() macros.
241 */
242 #if !defined(NDEBUG) || defined(SQLITE_COVERAGE_TEST)
243 # define TESTONLY(X)  X
244 #else
245 # define TESTONLY(X)
246 #endif
247 
248 /*
249 ** Sometimes we need a small amount of code such as a variable initialization
250 ** to setup for a later assert() statement.  We do not want this code to
251 ** appear when assert() is disabled.  The following macro is therefore
252 ** used to contain that setup code.  The "VVA" acronym stands for
253 ** "Verification, Validation, and Accreditation".  In other words, the
254 ** code within VVA_ONLY() will only run during verification processes.
255 */
256 #ifndef NDEBUG
257 # define VVA_ONLY(X)  X
258 #else
259 # define VVA_ONLY(X)
260 #endif
261 
262 /*
263 ** The ALWAYS and NEVER macros surround boolean expressions which
264 ** are intended to always be true or false, respectively.  Such
265 ** expressions could be omitted from the code completely.  But they
266 ** are included in a few cases in order to enhance the resilience
267 ** of SQLite to unexpected behavior - to make the code "self-healing"
268 ** or "ductile" rather than being "brittle" and crashing at the first
269 ** hint of unplanned behavior.
270 **
271 ** In other words, ALWAYS and NEVER are added for defensive code.
272 **
273 ** When doing coverage testing ALWAYS and NEVER are hard-coded to
274 ** be true and false so that the unreachable code then specify will
275 ** not be counted as untested code.
276 */
277 #if defined(SQLITE_COVERAGE_TEST)
278 # define ALWAYS(X)      (1)
279 # define NEVER(X)       (0)
280 #elif !defined(NDEBUG)
281 # define ALWAYS(X)      ((X)?1:(assert(0),0))
282 # define NEVER(X)       ((X)?(assert(0),1):0)
283 #else
284 # define ALWAYS(X)      (X)
285 # define NEVER(X)       (X)
286 #endif
287 
288 /*
289 ** Return true (non-zero) if the input is a integer that is too large
290 ** to fit in 32-bits.  This macro is used inside of various testcase()
291 ** macros to verify that we have tested SQLite for large-file support.
292 */
293 #define IS_BIG_INT(X)  (((X)&~(i64)0xffffffff)!=0)
294 
295 /*
296 ** The macro unlikely() is a hint that surrounds a boolean
297 ** expression that is usually false.  Macro likely() surrounds
298 ** a boolean expression that is usually true.  GCC is able to
299 ** use these hints to generate better code, sometimes.
300 */
301 #if defined(__GNUC__) && 0
302 # define likely(X)    __builtin_expect((X),1)
303 # define unlikely(X)  __builtin_expect((X),0)
304 #else
305 # define likely(X)    !!(X)
306 # define unlikely(X)  !!(X)
307 #endif
308 
309 #include "sqlite3.h"
310 #include "hash.h"
311 #include "parse.h"
312 #include <stdio.h>
313 #include <stdlib.h>
314 #include <string.h>
315 #include <assert.h>
316 #include <stddef.h>
317 
318 /*
319 ** If compiling for a processor that lacks floating point support,
320 ** substitute integer for floating-point
321 */
322 #ifdef SQLITE_OMIT_FLOATING_POINT
323 # define double sqlite_int64
324 # define float sqlite_int64
325 # define LONGDOUBLE_TYPE sqlite_int64
326 # ifndef SQLITE_BIG_DBL
327 #   define SQLITE_BIG_DBL (((sqlite3_int64)1)<<50)
328 # endif
329 # define SQLITE_OMIT_DATETIME_FUNCS 1
330 # define SQLITE_OMIT_TRACE 1
331 # undef SQLITE_MIXED_ENDIAN_64BIT_FLOAT
332 # undef SQLITE_HAVE_ISNAN
333 #endif
334 #ifndef SQLITE_BIG_DBL
335 # define SQLITE_BIG_DBL (1e99)
336 #endif
337 
338 /*
339 ** OMIT_TEMPDB is set to 1 if SQLITE_OMIT_TEMPDB is defined, or 0
340 ** afterward. Having this macro allows us to cause the C compiler
341 ** to omit code used by TEMP tables without messy #ifndef statements.
342 */
343 #ifdef SQLITE_OMIT_TEMPDB
344 #define OMIT_TEMPDB 1
345 #else
346 #define OMIT_TEMPDB 0
347 #endif
348 
349 /*
350 ** The "file format" number is an integer that is incremented whenever
351 ** the VDBE-level file format changes.  The following macros define the
352 ** the default file format for new databases and the maximum file format
353 ** that the library can read.
354 */
355 #define SQLITE_MAX_FILE_FORMAT 4
356 #ifndef SQLITE_DEFAULT_FILE_FORMAT
357 # define SQLITE_DEFAULT_FILE_FORMAT 4
358 #endif
359 
360 /*
361 ** Determine whether triggers are recursive by default.  This can be
362 ** changed at run-time using a pragma.
363 */
364 #ifndef SQLITE_DEFAULT_RECURSIVE_TRIGGERS
365 # define SQLITE_DEFAULT_RECURSIVE_TRIGGERS 0
366 #endif
367 
368 /*
369 ** Provide a default value for SQLITE_TEMP_STORE in case it is not specified
370 ** on the command-line
371 */
372 #ifndef SQLITE_TEMP_STORE
373 # define SQLITE_TEMP_STORE 1
374 #endif
375 
376 /*
377 ** GCC does not define the offsetof() macro so we'll have to do it
378 ** ourselves.
379 */
380 #ifndef offsetof
381 #define offsetof(STRUCTURE,FIELD) ((int)((char*)&((STRUCTURE*)0)->FIELD))
382 #endif
383 
384 /*
385 ** Check to see if this machine uses EBCDIC.  (Yes, believe it or
386 ** not, there are still machines out there that use EBCDIC.)
387 */
388 #if 'A' == '\301'
389 # define SQLITE_EBCDIC 1
390 #else
391 # define SQLITE_ASCII 1
392 #endif
393 
394 /*
395 ** Integers of known sizes.  These typedefs might change for architectures
396 ** where the sizes very.  Preprocessor macros are available so that the
397 ** types can be conveniently redefined at compile-type.  Like this:
398 **
399 **         cc '-DUINTPTR_TYPE=long long int' ...
400 */
401 #ifndef UINT32_TYPE
402 # ifdef HAVE_UINT32_T
403 #  define UINT32_TYPE uint32_t
404 # else
405 #  define UINT32_TYPE unsigned int
406 # endif
407 #endif
408 #ifndef UINT16_TYPE
409 # ifdef HAVE_UINT16_T
410 #  define UINT16_TYPE uint16_t
411 # else
412 #  define UINT16_TYPE unsigned short int
413 # endif
414 #endif
415 #ifndef INT16_TYPE
416 # ifdef HAVE_INT16_T
417 #  define INT16_TYPE int16_t
418 # else
419 #  define INT16_TYPE short int
420 # endif
421 #endif
422 #ifndef UINT8_TYPE
423 # ifdef HAVE_UINT8_T
424 #  define UINT8_TYPE uint8_t
425 # else
426 #  define UINT8_TYPE unsigned char
427 # endif
428 #endif
429 #ifndef INT8_TYPE
430 # ifdef HAVE_INT8_T
431 #  define INT8_TYPE int8_t
432 # else
433 #  define INT8_TYPE signed char
434 # endif
435 #endif
436 #ifndef LONGDOUBLE_TYPE
437 # define LONGDOUBLE_TYPE long double
438 #endif
439 typedef sqlite_int64 i64;          /* 8-byte signed integer */
440 typedef sqlite_uint64 u64;         /* 8-byte unsigned integer */
441 typedef UINT32_TYPE u32;           /* 4-byte unsigned integer */
442 typedef UINT16_TYPE u16;           /* 2-byte unsigned integer */
443 typedef INT16_TYPE i16;            /* 2-byte signed integer */
444 typedef UINT8_TYPE u8;             /* 1-byte unsigned integer */
445 typedef INT8_TYPE i8;              /* 1-byte signed integer */
446 
447 /*
448 ** SQLITE_MAX_U32 is a u64 constant that is the maximum u64 value
449 ** that can be stored in a u32 without loss of data.  The value
450 ** is 0x00000000ffffffff.  But because of quirks of some compilers, we
451 ** have to specify the value in the less intuitive manner shown:
452 */
453 #define SQLITE_MAX_U32  ((((u64)1)<<32)-1)
454 
455 /*
456 ** The datatype used to store estimates of the number of rows in a
457 ** table or index.  This is an unsigned integer type.  For 99.9% of
458 ** the world, a 32-bit integer is sufficient.  But a 64-bit integer
459 ** can be used at compile-time if desired.
460 */
461 #ifdef SQLITE_64BIT_STATS
462  typedef u64 tRowcnt;    /* 64-bit only if requested at compile-time */
463 #else
464  typedef u32 tRowcnt;    /* 32-bit is the default */
465 #endif
466 
467 /*
468 ** Macros to determine whether the machine is big or little endian,
469 ** evaluated at runtime.
470 */
471 #ifdef SQLITE_AMALGAMATION
472 const int sqlite3one = 1;
473 #else
474 extern const int sqlite3one;
475 #endif
476 #if defined(i386) || defined(__i386__) || defined(_M_IX86)\
477                              || defined(__x86_64) || defined(__x86_64__)
478 # define SQLITE_BIGENDIAN    0
479 # define SQLITE_LITTLEENDIAN 1
480 # define SQLITE_UTF16NATIVE  SQLITE_UTF16LE
481 #else
482 # define SQLITE_BIGENDIAN    (*(char *)(&sqlite3one)==0)
483 # define SQLITE_LITTLEENDIAN (*(char *)(&sqlite3one)==1)
484 # define SQLITE_UTF16NATIVE (SQLITE_BIGENDIAN?SQLITE_UTF16BE:SQLITE_UTF16LE)
485 #endif
486 
487 /*
488 ** Constants for the largest and smallest possible 64-bit signed integers.
489 ** These macros are designed to work correctly on both 32-bit and 64-bit
490 ** compilers.
491 */
492 #define LARGEST_INT64  (0xffffffff|(((i64)0x7fffffff)<<32))
493 #define SMALLEST_INT64 (((i64)-1) - LARGEST_INT64)
494 
495 /*
496 ** Round up a number to the next larger multiple of 8.  This is used
497 ** to force 8-byte alignment on 64-bit architectures.
498 */
499 #define ROUND8(x)     (((x)+7)&~7)
500 
501 /*
502 ** Round down to the nearest multiple of 8
503 */
504 #define ROUNDDOWN8(x) ((x)&~7)
505 
506 /*
507 ** Assert that the pointer X is aligned to an 8-byte boundary.  This
508 ** macro is used only within assert() to verify that the code gets
509 ** all alignment restrictions correct.
510 **
511 ** Except, if SQLITE_4_BYTE_ALIGNED_MALLOC is defined, then the
512 ** underlying malloc() implemention might return us 4-byte aligned
513 ** pointers.  In that case, only verify 4-byte alignment.
514 */
515 #ifdef SQLITE_4_BYTE_ALIGNED_MALLOC
516 # define EIGHT_BYTE_ALIGNMENT(X)   ((((char*)(X) - (char*)0)&3)==0)
517 #else
518 # define EIGHT_BYTE_ALIGNMENT(X)   ((((char*)(X) - (char*)0)&7)==0)
519 #endif
520 
521 
522 /*
523 ** An instance of the following structure is used to store the busy-handler
524 ** callback for a given sqlite handle.
525 **
526 ** The sqlite.busyHandler member of the sqlite struct contains the busy
527 ** callback for the database handle. Each pager opened via the sqlite
528 ** handle is passed a pointer to sqlite.busyHandler. The busy-handler
529 ** callback is currently invoked only from within pager.c.
530 */
531 typedef struct BusyHandler BusyHandler;
532 struct BusyHandler {
533   int (*xFunc)(void *,int);  /* The busy callback */
534   void *pArg;                /* First arg to busy callback */
535   int nBusy;                 /* Incremented with each busy call */
536 };
537 
538 /*
539 ** Name of the master database table.  The master database table
540 ** is a special table that holds the names and attributes of all
541 ** user tables and indices.
542 */
543 #define MASTER_NAME       "sqlite_master"
544 #define TEMP_MASTER_NAME  "sqlite_temp_master"
545 
546 /*
547 ** The root-page of the master database table.
548 */
549 #define MASTER_ROOT       1
550 
551 /*
552 ** The name of the schema table.
553 */
554 #define SCHEMA_TABLE(x)  ((!OMIT_TEMPDB)&&(x==1)?TEMP_MASTER_NAME:MASTER_NAME)
555 
556 /*
557 ** A convenience macro that returns the number of elements in
558 ** an array.
559 */
560 #define ArraySize(X)    ((int)(sizeof(X)/sizeof(X[0])))
561 
562 /*
563 ** The following value as a destructor means to use sqlite3DbFree().
564 ** The sqlite3DbFree() routine requires two parameters instead of the
565 ** one parameter that destructors normally want.  So we have to introduce
566 ** this magic value that the code knows to handle differently.  Any
567 ** pointer will work here as long as it is distinct from SQLITE_STATIC
568 ** and SQLITE_TRANSIENT.
569 */
570 #define SQLITE_DYNAMIC   ((sqlite3_destructor_type)sqlite3MallocSize)
571 
572 /*
573 ** When SQLITE_OMIT_WSD is defined, it means that the target platform does
574 ** not support Writable Static Data (WSD) such as global and static variables.
575 ** All variables must either be on the stack or dynamically allocated from
576 ** the heap.  When WSD is unsupported, the variable declarations scattered
577 ** throughout the SQLite code must become constants instead.  The SQLITE_WSD
578 ** macro is used for this purpose.  And instead of referencing the variable
579 ** directly, we use its constant as a key to lookup the run-time allocated
580 ** buffer that holds real variable.  The constant is also the initializer
581 ** for the run-time allocated buffer.
582 **
583 ** In the usual case where WSD is supported, the SQLITE_WSD and GLOBAL
584 ** macros become no-ops and have zero performance impact.
585 */
586 #ifdef SQLITE_OMIT_WSD
587   #define SQLITE_WSD const
588   #define GLOBAL(t,v) (*(t*)sqlite3_wsd_find((void*)&(v), sizeof(v)))
589   #define sqlite3GlobalConfig GLOBAL(struct Sqlite3Config, sqlite3Config)
590   int sqlite3_wsd_init(int N, int J);
591   void *sqlite3_wsd_find(void *K, int L);
592 #else
593   #define SQLITE_WSD
594   #define GLOBAL(t,v) v
595   #define sqlite3GlobalConfig sqlite3Config
596 #endif
597 
598 /*
599 ** The following macros are used to suppress compiler warnings and to
600 ** make it clear to human readers when a function parameter is deliberately
601 ** left unused within the body of a function. This usually happens when
602 ** a function is called via a function pointer. For example the
603 ** implementation of an SQL aggregate step callback may not use the
604 ** parameter indicating the number of arguments passed to the aggregate,
605 ** if it knows that this is enforced elsewhere.
606 **
607 ** When a function parameter is not used at all within the body of a function,
608 ** it is generally named "NotUsed" or "NotUsed2" to make things even clearer.
609 ** However, these macros may also be used to suppress warnings related to
610 ** parameters that may or may not be used depending on compilation options.
611 ** For example those parameters only used in assert() statements. In these
612 ** cases the parameters are named as per the usual conventions.
613 */
614 #define UNUSED_PARAMETER(x) (void)(x)
615 #define UNUSED_PARAMETER2(x,y) UNUSED_PARAMETER(x),UNUSED_PARAMETER(y)
616 
617 /*
618 ** Forward references to structures
619 */
620 typedef struct AggInfo AggInfo;
621 typedef struct AuthContext AuthContext;
622 typedef struct AutoincInfo AutoincInfo;
623 typedef struct Bitvec Bitvec;
624 typedef struct CollSeq CollSeq;
625 typedef struct Column Column;
626 typedef struct Db Db;
627 typedef struct Schema Schema;
628 typedef struct Expr Expr;
629 typedef struct ExprList ExprList;
630 typedef struct ExprSpan ExprSpan;
631 typedef struct FKey FKey;
632 typedef struct FuncDestructor FuncDestructor;
633 typedef struct FuncDef FuncDef;
634 typedef struct FuncDefHash FuncDefHash;
635 typedef struct IdList IdList;
636 typedef struct Index Index;
637 typedef struct IndexSample IndexSample;
638 typedef struct KeyClass KeyClass;
639 typedef struct KeyInfo KeyInfo;
640 typedef struct Lookaside Lookaside;
641 typedef struct LookasideSlot LookasideSlot;
642 typedef struct Module Module;
643 typedef struct NameContext NameContext;
644 typedef struct Parse Parse;
645 typedef struct RowSet RowSet;
646 typedef struct Savepoint Savepoint;
647 typedef struct Select Select;
648 typedef struct SrcList SrcList;
649 typedef struct StrAccum StrAccum;
650 typedef struct Table Table;
651 typedef struct TableLock TableLock;
652 typedef struct Token Token;
653 typedef struct Trigger Trigger;
654 typedef struct TriggerPrg TriggerPrg;
655 typedef struct TriggerStep TriggerStep;
656 typedef struct UnpackedRecord UnpackedRecord;
657 typedef struct VTable VTable;
658 typedef struct VtabCtx VtabCtx;
659 typedef struct Walker Walker;
660 typedef struct WherePlan WherePlan;
661 typedef struct WhereInfo WhereInfo;
662 typedef struct WhereLevel WhereLevel;
663 
664 /*
665 ** Defer sourcing vdbe.h and btree.h until after the "u8" and
666 ** "BusyHandler" typedefs. vdbe.h also requires a few of the opaque
667 ** pointer types (i.e. FuncDef) defined above.
668 */
669 #include "btree.h"
670 #include "vdbe.h"
671 #include "pager.h"
672 #include "pcache.h"
673 
674 #include "os.h"
675 #include "mutex.h"
676 
677 
678 /*
679 ** Each database file to be accessed by the system is an instance
680 ** of the following structure.  There are normally two of these structures
681 ** in the sqlite.aDb[] array.  aDb[0] is the main database file and
682 ** aDb[1] is the database file used to hold temporary tables.  Additional
683 ** databases may be attached.
684 */
685 struct Db {
686   char *zName;         /* Name of this database */
687   Btree *pBt;          /* The B*Tree structure for this database file */
688   u8 inTrans;          /* 0: not writable.  1: Transaction.  2: Checkpoint */
689   u8 safety_level;     /* How aggressive at syncing data to disk */
690   Schema *pSchema;     /* Pointer to database schema (possibly shared) */
691 };
692 
693 /*
694 ** An instance of the following structure stores a database schema.
695 **
696 ** Most Schema objects are associated with a Btree.  The exception is
697 ** the Schema for the TEMP databaes (sqlite3.aDb[1]) which is free-standing.
698 ** In shared cache mode, a single Schema object can be shared by multiple
699 ** Btrees that refer to the same underlying BtShared object.
700 **
701 ** Schema objects are automatically deallocated when the last Btree that
702 ** references them is destroyed.   The TEMP Schema is manually freed by
703 ** sqlite3_close().
704 *
705 ** A thread must be holding a mutex on the corresponding Btree in order
706 ** to access Schema content.  This implies that the thread must also be
707 ** holding a mutex on the sqlite3 connection pointer that owns the Btree.
708 ** For a TEMP Schema, only the connection mutex is required.
709 */
710 struct Schema {
711   int schema_cookie;   /* Database schema version number for this file */
712   int iGeneration;     /* Generation counter.  Incremented with each change */
713   Hash tblHash;        /* All tables indexed by name */
714   Hash idxHash;        /* All (named) indices indexed by name */
715   Hash trigHash;       /* All triggers indexed by name */
716   Hash fkeyHash;       /* All foreign keys by referenced table name */
717   Table *pSeqTab;      /* The sqlite_sequence table used by AUTOINCREMENT */
718   u8 file_format;      /* Schema format version for this file */
719   u8 enc;              /* Text encoding used by this database */
720   u16 flags;           /* Flags associated with this schema */
721   int cache_size;      /* Number of pages to use in the cache */
722 };
723 
724 /*
725 ** These macros can be used to test, set, or clear bits in the
726 ** Db.pSchema->flags field.
727 */
728 #define DbHasProperty(D,I,P)     (((D)->aDb[I].pSchema->flags&(P))==(P))
729 #define DbHasAnyProperty(D,I,P)  (((D)->aDb[I].pSchema->flags&(P))!=0)
730 #define DbSetProperty(D,I,P)     (D)->aDb[I].pSchema->flags|=(P)
731 #define DbClearProperty(D,I,P)   (D)->aDb[I].pSchema->flags&=~(P)
732 
733 /*
734 ** Allowed values for the DB.pSchema->flags field.
735 **
736 ** The DB_SchemaLoaded flag is set after the database schema has been
737 ** read into internal hash tables.
738 **
739 ** DB_UnresetViews means that one or more views have column names that
740 ** have been filled out.  If the schema changes, these column names might
741 ** changes and so the view will need to be reset.
742 */
743 #define DB_SchemaLoaded    0x0001  /* The schema has been loaded */
744 #define DB_UnresetViews    0x0002  /* Some views have defined column names */
745 #define DB_Empty           0x0004  /* The file is empty (length 0 bytes) */
746 
747 /*
748 ** The number of different kinds of things that can be limited
749 ** using the sqlite3_limit() interface.
750 */
751 #define SQLITE_N_LIMIT (SQLITE_LIMIT_TRIGGER_DEPTH+1)
752 
753 /*
754 ** Lookaside malloc is a set of fixed-size buffers that can be used
755 ** to satisfy small transient memory allocation requests for objects
756 ** associated with a particular database connection.  The use of
757 ** lookaside malloc provides a significant performance enhancement
758 ** (approx 10%) by avoiding numerous malloc/free requests while parsing
759 ** SQL statements.
760 **
761 ** The Lookaside structure holds configuration information about the
762 ** lookaside malloc subsystem.  Each available memory allocation in
763 ** the lookaside subsystem is stored on a linked list of LookasideSlot
764 ** objects.
765 **
766 ** Lookaside allocations are only allowed for objects that are associated
767 ** with a particular database connection.  Hence, schema information cannot
768 ** be stored in lookaside because in shared cache mode the schema information
769 ** is shared by multiple database connections.  Therefore, while parsing
770 ** schema information, the Lookaside.bEnabled flag is cleared so that
771 ** lookaside allocations are not used to construct the schema objects.
772 */
773 struct Lookaside {
774   u16 sz;                 /* Size of each buffer in bytes */
775   u8 bEnabled;            /* False to disable new lookaside allocations */
776   u8 bMalloced;           /* True if pStart obtained from sqlite3_malloc() */
777   int nOut;               /* Number of buffers currently checked out */
778   int mxOut;              /* Highwater mark for nOut */
779   int anStat[3];          /* 0: hits.  1: size misses.  2: full misses */
780   LookasideSlot *pFree;   /* List of available buffers */
781   void *pStart;           /* First byte of available memory space */
782   void *pEnd;             /* First byte past end of available space */
783 };
784 struct LookasideSlot {
785   LookasideSlot *pNext;    /* Next buffer in the list of free buffers */
786 };
787 
788 /*
789 ** A hash table for function definitions.
790 **
791 ** Hash each FuncDef structure into one of the FuncDefHash.a[] slots.
792 ** Collisions are on the FuncDef.pHash chain.
793 */
794 struct FuncDefHash {
795   FuncDef *a[23];       /* Hash table for functions */
796 };
797 
798 /*
799 ** Each database connection is an instance of the following structure.
800 */
801 struct sqlite3 {
802   sqlite3_vfs *pVfs;            /* OS Interface */
803   struct Vdbe *pVdbe;           /* List of active virtual machines */
804   CollSeq *pDfltColl;           /* The default collating sequence (BINARY) */
805   sqlite3_mutex *mutex;         /* Connection mutex */
806   Db *aDb;                      /* All backends */
807   int nDb;                      /* Number of backends currently in use */
808   int flags;                    /* Miscellaneous flags. See below */
809   i64 lastRowid;                /* ROWID of most recent insert (see above) */
810   unsigned int openFlags;       /* Flags passed to sqlite3_vfs.xOpen() */
811   int errCode;                  /* Most recent error code (SQLITE_*) */
812   int errMask;                  /* & result codes with this before returning */
813   u8 autoCommit;                /* The auto-commit flag. */
814   u8 temp_store;                /* 1: file 2: memory 0: default */
815   u8 mallocFailed;              /* True if we have seen a malloc failure */
816   u8 dfltLockMode;              /* Default locking-mode for attached dbs */
817   signed char nextAutovac;      /* Autovac setting after VACUUM if >=0 */
818   u8 suppressErr;               /* Do not issue error messages if true */
819   u8 vtabOnConflict;            /* Value to return for s3_vtab_on_conflict() */
820   u8 isTransactionSavepoint;    /* True if the outermost savepoint is a TS */
821   int nextPagesize;             /* Pagesize after VACUUM if >0 */
822   u32 magic;                    /* Magic number for detect library misuse */
823   int nChange;                  /* Value returned by sqlite3_changes() */
824   int nTotalChange;             /* Value returned by sqlite3_total_changes() */
825   int aLimit[SQLITE_N_LIMIT];   /* Limits */
826   struct sqlite3InitInfo {      /* Information used during initialization */
827     int newTnum;                /* Rootpage of table being initialized */
828     u8 iDb;                     /* Which db file is being initialized */
829     u8 busy;                    /* TRUE if currently initializing */
830     u8 orphanTrigger;           /* Last statement is orphaned TEMP trigger */
831   } init;
832   int activeVdbeCnt;            /* Number of VDBEs currently executing */
833   int writeVdbeCnt;             /* Number of active VDBEs that are writing */
834   int vdbeExecCnt;              /* Number of nested calls to VdbeExec() */
835   int nExtension;               /* Number of loaded extensions */
836   void **aExtension;            /* Array of shared library handles */
837   void (*xTrace)(void*,const char*);        /* Trace function */
838   void *pTraceArg;                          /* Argument to the trace function */
839   void (*xProfile)(void*,const char*,u64);  /* Profiling function */
840   void *pProfileArg;                        /* Argument to profile function */
841   void *pCommitArg;                 /* Argument to xCommitCallback() */
842   int (*xCommitCallback)(void*);    /* Invoked at every commit. */
843   void *pRollbackArg;               /* Argument to xRollbackCallback() */
844   void (*xRollbackCallback)(void*); /* Invoked at every commit. */
845   void *pUpdateArg;
846   void (*xUpdateCallback)(void*,int, const char*,const char*,sqlite_int64);
847 #ifndef SQLITE_OMIT_WAL
848   int (*xWalCallback)(void *, sqlite3 *, const char *, int);
849   void *pWalArg;
850 #endif
851   void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*);
852   void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*);
853   void *pCollNeededArg;
854   sqlite3_value *pErr;          /* Most recent error message */
855   char *zErrMsg;                /* Most recent error message (UTF-8 encoded) */
856   char *zErrMsg16;              /* Most recent error message (UTF-16 encoded) */
857   union {
858     volatile int isInterrupted; /* True if sqlite3_interrupt has been called */
859     double notUsed1;            /* Spacer */
860   } u1;
861   Lookaside lookaside;          /* Lookaside malloc configuration */
862 #ifndef SQLITE_OMIT_AUTHORIZATION
863   int (*xAuth)(void*,int,const char*,const char*,const char*,const char*);
864                                 /* Access authorization function */
865   void *pAuthArg;               /* 1st argument to the access auth function */
866 #endif
867 #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
868   int (*xProgress)(void *);     /* The progress callback */
869   void *pProgressArg;           /* Argument to the progress callback */
870   int nProgressOps;             /* Number of opcodes for progress callback */
871 #endif
872 #ifndef SQLITE_OMIT_VIRTUALTABLE
873   int nVTrans;                  /* Allocated size of aVTrans */
874   Hash aModule;                 /* populated by sqlite3_create_module() */
875   VtabCtx *pVtabCtx;            /* Context for active vtab connect/create */
876   VTable **aVTrans;             /* Virtual tables with open transactions */
877   VTable *pDisconnect;    /* Disconnect these in next sqlite3_prepare() */
878 #endif
879   FuncDefHash aFunc;            /* Hash table of connection functions */
880   Hash aCollSeq;                /* All collating sequences */
881   BusyHandler busyHandler;      /* Busy callback */
882   Db aDbStatic[2];              /* Static space for the 2 default backends */
883   Savepoint *pSavepoint;        /* List of active savepoints */
884   int busyTimeout;              /* Busy handler timeout, in msec */
885   int nSavepoint;               /* Number of non-transaction savepoints */
886   int nStatement;               /* Number of nested statement-transactions  */
887   i64 nDeferredCons;            /* Net deferred constraints this transaction. */
888   int *pnBytesFreed;            /* If not NULL, increment this in DbFree() */
889 
890 #ifdef SQLITE_ENABLE_UNLOCK_NOTIFY
891   /* The following variables are all protected by the STATIC_MASTER
892   ** mutex, not by sqlite3.mutex. They are used by code in notify.c.
893   **
894   ** When X.pUnlockConnection==Y, that means that X is waiting for Y to
895   ** unlock so that it can proceed.
896   **
897   ** When X.pBlockingConnection==Y, that means that something that X tried
898   ** tried to do recently failed with an SQLITE_LOCKED error due to locks
899   ** held by Y.
900   */
901   sqlite3 *pBlockingConnection; /* Connection that caused SQLITE_LOCKED */
902   sqlite3 *pUnlockConnection;           /* Connection to watch for unlock */
903   void *pUnlockArg;                     /* Argument to xUnlockNotify */
904   void (*xUnlockNotify)(void **, int);  /* Unlock notify callback */
905   sqlite3 *pNextBlocked;        /* Next in list of all blocked connections */
906 #endif
907 };
908 
909 /*
910 ** A macro to discover the encoding of a database.
911 */
912 #define ENC(db) ((db)->aDb[0].pSchema->enc)
913 
914 /*
915 ** Possible values for the sqlite3.flags.
916 */
917 #define SQLITE_VdbeTrace      0x00000100  /* True to trace VDBE execution */
918 #define SQLITE_InternChanges  0x00000200  /* Uncommitted Hash table changes */
919 #define SQLITE_FullColNames   0x00000400  /* Show full column names on SELECT */
920 #define SQLITE_ShortColNames  0x00000800  /* Show short columns names */
921 #define SQLITE_CountRows      0x00001000  /* Count rows changed by INSERT, */
922                                           /*   DELETE, or UPDATE and return */
923                                           /*   the count using a callback. */
924 #define SQLITE_NullCallback   0x00002000  /* Invoke the callback once if the */
925                                           /*   result set is empty */
926 #define SQLITE_SqlTrace       0x00004000  /* Debug print SQL as it executes */
927 #define SQLITE_VdbeListing    0x00008000  /* Debug listings of VDBE programs */
928 #define SQLITE_WriteSchema    0x00010000  /* OK to update SQLITE_MASTER */
929                          /*   0x00020000  Unused */
930 #define SQLITE_IgnoreChecks   0x00040000  /* Do not enforce check constraints */
931 #define SQLITE_ReadUncommitted 0x0080000  /* For shared-cache mode */
932 #define SQLITE_LegacyFileFmt  0x00100000  /* Create new databases in format 1 */
933 #define SQLITE_FullFSync      0x00200000  /* Use full fsync on the backend */
934 #define SQLITE_CkptFullFSync  0x00400000  /* Use full fsync for checkpoint */
935 #define SQLITE_RecoveryMode   0x00800000  /* Ignore schema errors */
936 #define SQLITE_ReverseOrder   0x01000000  /* Reverse unordered SELECTs */
937 #define SQLITE_RecTriggers    0x02000000  /* Enable recursive triggers */
938 #define SQLITE_ForeignKeys    0x04000000  /* Enforce foreign key constraints  */
939 #define SQLITE_AutoIndex      0x08000000  /* Enable automatic indexes */
940 #define SQLITE_PreferBuiltin  0x10000000  /* Preference to built-in funcs */
941 #define SQLITE_LoadExtension  0x20000000  /* Enable load_extension */
942 #define SQLITE_EnableTrigger  0x40000000  /* True to enable triggers */
943 
944 /*
945 ** Bits of the sqlite3.flags field that are used by the
946 ** sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS,...) interface.
947 ** These must be the low-order bits of the flags field.
948 */
949 #define SQLITE_QueryFlattener 0x01        /* Disable query flattening */
950 #define SQLITE_ColumnCache    0x02        /* Disable the column cache */
951 #define SQLITE_IndexSort      0x04        /* Disable indexes for sorting */
952 #define SQLITE_IndexSearch    0x08        /* Disable indexes for searching */
953 #define SQLITE_IndexCover     0x10        /* Disable index covering table */
954 #define SQLITE_GroupByOrder   0x20        /* Disable GROUPBY cover of ORDERBY */
955 #define SQLITE_FactorOutConst 0x40        /* Disable factoring out constants */
956 #define SQLITE_IdxRealAsInt   0x80        /* Store REAL as INT in indices */
957 #define SQLITE_DistinctOpt    0x80        /* DISTINCT using indexes */
958 #define SQLITE_OptMask        0xff        /* Mask of all disablable opts */
959 
960 /*
961 ** Possible values for the sqlite.magic field.
962 ** The numbers are obtained at random and have no special meaning, other
963 ** than being distinct from one another.
964 */
965 #define SQLITE_MAGIC_OPEN     0xa029a697  /* Database is open */
966 #define SQLITE_MAGIC_CLOSED   0x9f3c2d33  /* Database is closed */
967 #define SQLITE_MAGIC_SICK     0x4b771290  /* Error and awaiting close */
968 #define SQLITE_MAGIC_BUSY     0xf03b7906  /* Database currently in use */
969 #define SQLITE_MAGIC_ERROR    0xb5357930  /* An SQLITE_MISUSE error occurred */
970 
971 /*
972 ** Each SQL function is defined by an instance of the following
973 ** structure.  A pointer to this structure is stored in the sqlite.aFunc
974 ** hash table.  When multiple functions have the same name, the hash table
975 ** points to a linked list of these structures.
976 */
977 struct FuncDef {
978   i16 nArg;            /* Number of arguments.  -1 means unlimited */
979   u8 iPrefEnc;         /* Preferred text encoding (SQLITE_UTF8, 16LE, 16BE) */
980   u8 flags;            /* Some combination of SQLITE_FUNC_* */
981   void *pUserData;     /* User data parameter */
982   FuncDef *pNext;      /* Next function with same name */
983   void (*xFunc)(sqlite3_context*,int,sqlite3_value**); /* Regular function */
984   void (*xStep)(sqlite3_context*,int,sqlite3_value**); /* Aggregate step */
985   void (*xFinalize)(sqlite3_context*);                /* Aggregate finalizer */
986   char *zName;         /* SQL name of the function. */
987   FuncDef *pHash;      /* Next with a different name but the same hash */
988   FuncDestructor *pDestructor;   /* Reference counted destructor function */
989 };
990 
991 /*
992 ** This structure encapsulates a user-function destructor callback (as
993 ** configured using create_function_v2()) and a reference counter. When
994 ** create_function_v2() is called to create a function with a destructor,
995 ** a single object of this type is allocated. FuncDestructor.nRef is set to
996 ** the number of FuncDef objects created (either 1 or 3, depending on whether
997 ** or not the specified encoding is SQLITE_ANY). The FuncDef.pDestructor
998 ** member of each of the new FuncDef objects is set to point to the allocated
999 ** FuncDestructor.
1000 **
1001 ** Thereafter, when one of the FuncDef objects is deleted, the reference
1002 ** count on this object is decremented. When it reaches 0, the destructor
1003 ** is invoked and the FuncDestructor structure freed.
1004 */
1005 struct FuncDestructor {
1006   int nRef;
1007   void (*xDestroy)(void *);
1008   void *pUserData;
1009 };
1010 
1011 /*
1012 ** Possible values for FuncDef.flags
1013 */
1014 #define SQLITE_FUNC_LIKE     0x01 /* Candidate for the LIKE optimization */
1015 #define SQLITE_FUNC_CASE     0x02 /* Case-sensitive LIKE-type function */
1016 #define SQLITE_FUNC_EPHEM    0x04 /* Ephemeral.  Delete with VDBE */
1017 #define SQLITE_FUNC_NEEDCOLL 0x08 /* sqlite3GetFuncCollSeq() might be called */
1018 #define SQLITE_FUNC_COUNT    0x20 /* Built-in count(*) aggregate */
1019 #define SQLITE_FUNC_COALESCE 0x40 /* Built-in coalesce() or ifnull() function */
1020 
1021 /*
1022 ** The following three macros, FUNCTION(), LIKEFUNC() and AGGREGATE() are
1023 ** used to create the initializers for the FuncDef structures.
1024 **
1025 **   FUNCTION(zName, nArg, iArg, bNC, xFunc)
1026 **     Used to create a scalar function definition of a function zName
1027 **     implemented by C function xFunc that accepts nArg arguments. The
1028 **     value passed as iArg is cast to a (void*) and made available
1029 **     as the user-data (sqlite3_user_data()) for the function. If
1030 **     argument bNC is true, then the SQLITE_FUNC_NEEDCOLL flag is set.
1031 **
1032 **   AGGREGATE(zName, nArg, iArg, bNC, xStep, xFinal)
1033 **     Used to create an aggregate function definition implemented by
1034 **     the C functions xStep and xFinal. The first four parameters
1035 **     are interpreted in the same way as the first 4 parameters to
1036 **     FUNCTION().
1037 **
1038 **   LIKEFUNC(zName, nArg, pArg, flags)
1039 **     Used to create a scalar function definition of a function zName
1040 **     that accepts nArg arguments and is implemented by a call to C
1041 **     function likeFunc. Argument pArg is cast to a (void *) and made
1042 **     available as the function user-data (sqlite3_user_data()). The
1043 **     FuncDef.flags variable is set to the value passed as the flags
1044 **     parameter.
1045 */
1046 #define FUNCTION(zName, nArg, iArg, bNC, xFunc) \
1047   {nArg, SQLITE_UTF8, bNC*SQLITE_FUNC_NEEDCOLL, \
1048    SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, 0, #zName, 0, 0}
1049 #define STR_FUNCTION(zName, nArg, pArg, bNC, xFunc) \
1050   {nArg, SQLITE_UTF8, bNC*SQLITE_FUNC_NEEDCOLL, \
1051    pArg, 0, xFunc, 0, 0, #zName, 0, 0}
1052 #define LIKEFUNC(zName, nArg, arg, flags) \
1053   {nArg, SQLITE_UTF8, flags, (void *)arg, 0, likeFunc, 0, 0, #zName, 0, 0}
1054 #define AGGREGATE(zName, nArg, arg, nc, xStep, xFinal) \
1055   {nArg, SQLITE_UTF8, nc*SQLITE_FUNC_NEEDCOLL, \
1056    SQLITE_INT_TO_PTR(arg), 0, 0, xStep,xFinal,#zName,0,0}
1057 
1058 /*
1059 ** All current savepoints are stored in a linked list starting at
1060 ** sqlite3.pSavepoint. The first element in the list is the most recently
1061 ** opened savepoint. Savepoints are added to the list by the vdbe
1062 ** OP_Savepoint instruction.
1063 */
1064 struct Savepoint {
1065   char *zName;                        /* Savepoint name (nul-terminated) */
1066   i64 nDeferredCons;                  /* Number of deferred fk violations */
1067   Savepoint *pNext;                   /* Parent savepoint (if any) */
1068 };
1069 
1070 /*
1071 ** The following are used as the second parameter to sqlite3Savepoint(),
1072 ** and as the P1 argument to the OP_Savepoint instruction.
1073 */
1074 #define SAVEPOINT_BEGIN      0
1075 #define SAVEPOINT_RELEASE    1
1076 #define SAVEPOINT_ROLLBACK   2
1077 
1078 
1079 /*
1080 ** Each SQLite module (virtual table definition) is defined by an
1081 ** instance of the following structure, stored in the sqlite3.aModule
1082 ** hash table.
1083 */
1084 struct Module {
1085   const sqlite3_module *pModule;       /* Callback pointers */
1086   const char *zName;                   /* Name passed to create_module() */
1087   void *pAux;                          /* pAux passed to create_module() */
1088   void (*xDestroy)(void *);            /* Module destructor function */
1089 };
1090 
1091 /*
1092 ** information about each column of an SQL table is held in an instance
1093 ** of this structure.
1094 */
1095 struct Column {
1096   char *zName;     /* Name of this column */
1097   Expr *pDflt;     /* Default value of this column */
1098   char *zDflt;     /* Original text of the default value */
1099   char *zType;     /* Data type for this column */
1100   char *zColl;     /* Collating sequence.  If NULL, use the default */
1101   u8 notNull;      /* True if there is a NOT NULL constraint */
1102   u8 isPrimKey;    /* True if this column is part of the PRIMARY KEY */
1103   char affinity;   /* One of the SQLITE_AFF_... values */
1104 #ifndef SQLITE_OMIT_VIRTUALTABLE
1105   u8 isHidden;     /* True if this column is 'hidden' */
1106 #endif
1107 };
1108 
1109 /*
1110 ** A "Collating Sequence" is defined by an instance of the following
1111 ** structure. Conceptually, a collating sequence consists of a name and
1112 ** a comparison routine that defines the order of that sequence.
1113 **
1114 ** There may two separate implementations of the collation function, one
1115 ** that processes text in UTF-8 encoding (CollSeq.xCmp) and another that
1116 ** processes text encoded in UTF-16 (CollSeq.xCmp16), using the machine
1117 ** native byte order. When a collation sequence is invoked, SQLite selects
1118 ** the version that will require the least expensive encoding
1119 ** translations, if any.
1120 **
1121 ** The CollSeq.pUser member variable is an extra parameter that passed in
1122 ** as the first argument to the UTF-8 comparison function, xCmp.
1123 ** CollSeq.pUser16 is the equivalent for the UTF-16 comparison function,
1124 ** xCmp16.
1125 **
1126 ** If both CollSeq.xCmp and CollSeq.xCmp16 are NULL, it means that the
1127 ** collating sequence is undefined.  Indices built on an undefined
1128 ** collating sequence may not be read or written.
1129 */
1130 struct CollSeq {
1131   char *zName;          /* Name of the collating sequence, UTF-8 encoded */
1132   u8 enc;               /* Text encoding handled by xCmp() */
1133   void *pUser;          /* First argument to xCmp() */
1134   int (*xCmp)(void*,int, const void*, int, const void*);
1135   void (*xDel)(void*);  /* Destructor for pUser */
1136 };
1137 
1138 /*
1139 ** A sort order can be either ASC or DESC.
1140 */
1141 #define SQLITE_SO_ASC       0  /* Sort in ascending order */
1142 #define SQLITE_SO_DESC      1  /* Sort in ascending order */
1143 
1144 /*
1145 ** Column affinity types.
1146 **
1147 ** These used to have mnemonic name like 'i' for SQLITE_AFF_INTEGER and
1148 ** 't' for SQLITE_AFF_TEXT.  But we can save a little space and improve
1149 ** the speed a little by numbering the values consecutively.
1150 **
1151 ** But rather than start with 0 or 1, we begin with 'a'.  That way,
1152 ** when multiple affinity types are concatenated into a string and
1153 ** used as the P4 operand, they will be more readable.
1154 **
1155 ** Note also that the numeric types are grouped together so that testing
1156 ** for a numeric type is a single comparison.
1157 */
1158 #define SQLITE_AFF_TEXT     'a'
1159 #define SQLITE_AFF_NONE     'b'
1160 #define SQLITE_AFF_NUMERIC  'c'
1161 #define SQLITE_AFF_INTEGER  'd'
1162 #define SQLITE_AFF_REAL     'e'
1163 
1164 #define sqlite3IsNumericAffinity(X)  ((X)>=SQLITE_AFF_NUMERIC)
1165 
1166 /*
1167 ** The SQLITE_AFF_MASK values masks off the significant bits of an
1168 ** affinity value.
1169 */
1170 #define SQLITE_AFF_MASK     0x67
1171 
1172 /*
1173 ** Additional bit values that can be ORed with an affinity without
1174 ** changing the affinity.
1175 */
1176 #define SQLITE_JUMPIFNULL   0x08  /* jumps if either operand is NULL */
1177 #define SQLITE_STOREP2      0x10  /* Store result in reg[P2] rather than jump */
1178 #define SQLITE_NULLEQ       0x80  /* NULL=NULL */
1179 
1180 /*
1181 ** An object of this type is created for each virtual table present in
1182 ** the database schema.
1183 **
1184 ** If the database schema is shared, then there is one instance of this
1185 ** structure for each database connection (sqlite3*) that uses the shared
1186 ** schema. This is because each database connection requires its own unique
1187 ** instance of the sqlite3_vtab* handle used to access the virtual table
1188 ** implementation. sqlite3_vtab* handles can not be shared between
1189 ** database connections, even when the rest of the in-memory database
1190 ** schema is shared, as the implementation often stores the database
1191 ** connection handle passed to it via the xConnect() or xCreate() method
1192 ** during initialization internally. This database connection handle may
1193 ** then be used by the virtual table implementation to access real tables
1194 ** within the database. So that they appear as part of the callers
1195 ** transaction, these accesses need to be made via the same database
1196 ** connection as that used to execute SQL operations on the virtual table.
1197 **
1198 ** All VTable objects that correspond to a single table in a shared
1199 ** database schema are initially stored in a linked-list pointed to by
1200 ** the Table.pVTable member variable of the corresponding Table object.
1201 ** When an sqlite3_prepare() operation is required to access the virtual
1202 ** table, it searches the list for the VTable that corresponds to the
1203 ** database connection doing the preparing so as to use the correct
1204 ** sqlite3_vtab* handle in the compiled query.
1205 **
1206 ** When an in-memory Table object is deleted (for example when the
1207 ** schema is being reloaded for some reason), the VTable objects are not
1208 ** deleted and the sqlite3_vtab* handles are not xDisconnect()ed
1209 ** immediately. Instead, they are moved from the Table.pVTable list to
1210 ** another linked list headed by the sqlite3.pDisconnect member of the
1211 ** corresponding sqlite3 structure. They are then deleted/xDisconnected
1212 ** next time a statement is prepared using said sqlite3*. This is done
1213 ** to avoid deadlock issues involving multiple sqlite3.mutex mutexes.
1214 ** Refer to comments above function sqlite3VtabUnlockList() for an
1215 ** explanation as to why it is safe to add an entry to an sqlite3.pDisconnect
1216 ** list without holding the corresponding sqlite3.mutex mutex.
1217 **
1218 ** The memory for objects of this type is always allocated by
1219 ** sqlite3DbMalloc(), using the connection handle stored in VTable.db as
1220 ** the first argument.
1221 */
1222 struct VTable {
1223   sqlite3 *db;              /* Database connection associated with this table */
1224   Module *pMod;             /* Pointer to module implementation */
1225   sqlite3_vtab *pVtab;      /* Pointer to vtab instance */
1226   int nRef;                 /* Number of pointers to this structure */
1227   u8 bConstraint;           /* True if constraints are supported */
1228   int iSavepoint;           /* Depth of the SAVEPOINT stack */
1229   VTable *pNext;            /* Next in linked list (see above) */
1230 };
1231 
1232 /*
1233 ** Each SQL table is represented in memory by an instance of the
1234 ** following structure.
1235 **
1236 ** Table.zName is the name of the table.  The case of the original
1237 ** CREATE TABLE statement is stored, but case is not significant for
1238 ** comparisons.
1239 **
1240 ** Table.nCol is the number of columns in this table.  Table.aCol is a
1241 ** pointer to an array of Column structures, one for each column.
1242 **
1243 ** If the table has an INTEGER PRIMARY KEY, then Table.iPKey is the index of
1244 ** the column that is that key.   Otherwise Table.iPKey is negative.  Note
1245 ** that the datatype of the PRIMARY KEY must be INTEGER for this field to
1246 ** be set.  An INTEGER PRIMARY KEY is used as the rowid for each row of
1247 ** the table.  If a table has no INTEGER PRIMARY KEY, then a random rowid
1248 ** is generated for each row of the table.  TF_HasPrimaryKey is set if
1249 ** the table has any PRIMARY KEY, INTEGER or otherwise.
1250 **
1251 ** Table.tnum is the page number for the root BTree page of the table in the
1252 ** database file.  If Table.iDb is the index of the database table backend
1253 ** in sqlite.aDb[].  0 is for the main database and 1 is for the file that
1254 ** holds temporary tables and indices.  If TF_Ephemeral is set
1255 ** then the table is stored in a file that is automatically deleted
1256 ** when the VDBE cursor to the table is closed.  In this case Table.tnum
1257 ** refers VDBE cursor number that holds the table open, not to the root
1258 ** page number.  Transient tables are used to hold the results of a
1259 ** sub-query that appears instead of a real table name in the FROM clause
1260 ** of a SELECT statement.
1261 */
1262 struct Table {
1263   char *zName;         /* Name of the table or view */
1264   int iPKey;           /* If not negative, use aCol[iPKey] as the primary key */
1265   int nCol;            /* Number of columns in this table */
1266   Column *aCol;        /* Information about each column */
1267   Index *pIndex;       /* List of SQL indexes on this table. */
1268   int tnum;            /* Root BTree node for this table (see note above) */
1269   tRowcnt nRowEst;     /* Estimated rows in table - from sqlite_stat1 table */
1270   Select *pSelect;     /* NULL for tables.  Points to definition if a view. */
1271   u16 nRef;            /* Number of pointers to this Table */
1272   u8 tabFlags;         /* Mask of TF_* values */
1273   u8 keyConf;          /* What to do in case of uniqueness conflict on iPKey */
1274   FKey *pFKey;         /* Linked list of all foreign keys in this table */
1275   char *zColAff;       /* String defining the affinity of each column */
1276 #ifndef SQLITE_OMIT_CHECK
1277   Expr *pCheck;        /* The AND of all CHECK constraints */
1278 #endif
1279 #ifndef SQLITE_OMIT_ALTERTABLE
1280   int addColOffset;    /* Offset in CREATE TABLE stmt to add a new column */
1281 #endif
1282 #ifndef SQLITE_OMIT_VIRTUALTABLE
1283   VTable *pVTable;     /* List of VTable objects. */
1284   int nModuleArg;      /* Number of arguments to the module */
1285   char **azModuleArg;  /* Text of all module args. [0] is module name */
1286 #endif
1287   Trigger *pTrigger;   /* List of triggers stored in pSchema */
1288   Schema *pSchema;     /* Schema that contains this table */
1289   Table *pNextZombie;  /* Next on the Parse.pZombieTab list */
1290 };
1291 
1292 /*
1293 ** Allowed values for Tabe.tabFlags.
1294 */
1295 #define TF_Readonly        0x01    /* Read-only system table */
1296 #define TF_Ephemeral       0x02    /* An ephemeral table */
1297 #define TF_HasPrimaryKey   0x04    /* Table has a primary key */
1298 #define TF_Autoincrement   0x08    /* Integer primary key is autoincrement */
1299 #define TF_Virtual         0x10    /* Is a virtual table */
1300 
1301 
1302 /*
1303 ** Test to see whether or not a table is a virtual table.  This is
1304 ** done as a macro so that it will be optimized out when virtual
1305 ** table support is omitted from the build.
1306 */
1307 #ifndef SQLITE_OMIT_VIRTUALTABLE
1308 #  define IsVirtual(X)      (((X)->tabFlags & TF_Virtual)!=0)
1309 #  define IsHiddenColumn(X) ((X)->isHidden)
1310 #else
1311 #  define IsVirtual(X)      0
1312 #  define IsHiddenColumn(X) 0
1313 #endif
1314 
1315 /*
1316 ** Each foreign key constraint is an instance of the following structure.
1317 **
1318 ** A foreign key is associated with two tables.  The "from" table is
1319 ** the table that contains the REFERENCES clause that creates the foreign
1320 ** key.  The "to" table is the table that is named in the REFERENCES clause.
1321 ** Consider this example:
1322 **
1323 **     CREATE TABLE ex1(
1324 **       a INTEGER PRIMARY KEY,
1325 **       b INTEGER CONSTRAINT fk1 REFERENCES ex2(x)
1326 **     );
1327 **
1328 ** For foreign key "fk1", the from-table is "ex1" and the to-table is "ex2".
1329 **
1330 ** Each REFERENCES clause generates an instance of the following structure
1331 ** which is attached to the from-table.  The to-table need not exist when
1332 ** the from-table is created.  The existence of the to-table is not checked.
1333 */
1334 struct FKey {
1335   Table *pFrom;     /* Table containing the REFERENCES clause (aka: Child) */
1336   FKey *pNextFrom;  /* Next foreign key in pFrom */
1337   char *zTo;        /* Name of table that the key points to (aka: Parent) */
1338   FKey *pNextTo;    /* Next foreign key on table named zTo */
1339   FKey *pPrevTo;    /* Previous foreign key on table named zTo */
1340   int nCol;         /* Number of columns in this key */
1341   /* EV: R-30323-21917 */
1342   u8 isDeferred;    /* True if constraint checking is deferred till COMMIT */
1343   u8 aAction[2];          /* ON DELETE and ON UPDATE actions, respectively */
1344   Trigger *apTrigger[2];  /* Triggers for aAction[] actions */
1345   struct sColMap {  /* Mapping of columns in pFrom to columns in zTo */
1346     int iFrom;         /* Index of column in pFrom */
1347     char *zCol;        /* Name of column in zTo.  If 0 use PRIMARY KEY */
1348   } aCol[1];        /* One entry for each of nCol column s */
1349 };
1350 
1351 /*
1352 ** SQLite supports many different ways to resolve a constraint
1353 ** error.  ROLLBACK processing means that a constraint violation
1354 ** causes the operation in process to fail and for the current transaction
1355 ** to be rolled back.  ABORT processing means the operation in process
1356 ** fails and any prior changes from that one operation are backed out,
1357 ** but the transaction is not rolled back.  FAIL processing means that
1358 ** the operation in progress stops and returns an error code.  But prior
1359 ** changes due to the same operation are not backed out and no rollback
1360 ** occurs.  IGNORE means that the particular row that caused the constraint
1361 ** error is not inserted or updated.  Processing continues and no error
1362 ** is returned.  REPLACE means that preexisting database rows that caused
1363 ** a UNIQUE constraint violation are removed so that the new insert or
1364 ** update can proceed.  Processing continues and no error is reported.
1365 **
1366 ** RESTRICT, SETNULL, and CASCADE actions apply only to foreign keys.
1367 ** RESTRICT is the same as ABORT for IMMEDIATE foreign keys and the
1368 ** same as ROLLBACK for DEFERRED keys.  SETNULL means that the foreign
1369 ** key is set to NULL.  CASCADE means that a DELETE or UPDATE of the
1370 ** referenced table row is propagated into the row that holds the
1371 ** foreign key.
1372 **
1373 ** The following symbolic values are used to record which type
1374 ** of action to take.
1375 */
1376 #define OE_None     0   /* There is no constraint to check */
1377 #define OE_Rollback 1   /* Fail the operation and rollback the transaction */
1378 #define OE_Abort    2   /* Back out changes but do no rollback transaction */
1379 #define OE_Fail     3   /* Stop the operation but leave all prior changes */
1380 #define OE_Ignore   4   /* Ignore the error. Do not do the INSERT or UPDATE */
1381 #define OE_Replace  5   /* Delete existing record, then do INSERT or UPDATE */
1382 
1383 #define OE_Restrict 6   /* OE_Abort for IMMEDIATE, OE_Rollback for DEFERRED */
1384 #define OE_SetNull  7   /* Set the foreign key value to NULL */
1385 #define OE_SetDflt  8   /* Set the foreign key value to its default */
1386 #define OE_Cascade  9   /* Cascade the changes */
1387 
1388 #define OE_Default  99  /* Do whatever the default action is */
1389 
1390 
1391 /*
1392 ** An instance of the following structure is passed as the first
1393 ** argument to sqlite3VdbeKeyCompare and is used to control the
1394 ** comparison of the two index keys.
1395 */
1396 struct KeyInfo {
1397   sqlite3 *db;        /* The database connection */
1398   u8 enc;             /* Text encoding - one of the SQLITE_UTF* values */
1399   u16 nField;         /* Number of entries in aColl[] */
1400   u8 *aSortOrder;     /* Sort order for each column.  May be NULL */
1401   CollSeq *aColl[1];  /* Collating sequence for each term of the key */
1402 };
1403 
1404 /*
1405 ** An instance of the following structure holds information about a
1406 ** single index record that has already been parsed out into individual
1407 ** values.
1408 **
1409 ** A record is an object that contains one or more fields of data.
1410 ** Records are used to store the content of a table row and to store
1411 ** the key of an index.  A blob encoding of a record is created by
1412 ** the OP_MakeRecord opcode of the VDBE and is disassembled by the
1413 ** OP_Column opcode.
1414 **
1415 ** This structure holds a record that has already been disassembled
1416 ** into its constituent fields.
1417 */
1418 struct UnpackedRecord {
1419   KeyInfo *pKeyInfo;  /* Collation and sort-order information */
1420   u16 nField;         /* Number of entries in apMem[] */
1421   u8 flags;           /* Boolean settings.  UNPACKED_... below */
1422   i64 rowid;          /* Used by UNPACKED_PREFIX_SEARCH */
1423   Mem *aMem;          /* Values */
1424 };
1425 
1426 /*
1427 ** Allowed values of UnpackedRecord.flags
1428 */
1429 #define UNPACKED_INCRKEY       0x01  /* Make this key an epsilon larger */
1430 #define UNPACKED_PREFIX_MATCH  0x02  /* A prefix match is considered OK */
1431 #define UNPACKED_PREFIX_SEARCH 0x04  /* Ignore final (rowid) field */
1432 
1433 /*
1434 ** Each SQL index is represented in memory by an
1435 ** instance of the following structure.
1436 **
1437 ** The columns of the table that are to be indexed are described
1438 ** by the aiColumn[] field of this structure.  For example, suppose
1439 ** we have the following table and index:
1440 **
1441 **     CREATE TABLE Ex1(c1 int, c2 int, c3 text);
1442 **     CREATE INDEX Ex2 ON Ex1(c3,c1);
1443 **
1444 ** In the Table structure describing Ex1, nCol==3 because there are
1445 ** three columns in the table.  In the Index structure describing
1446 ** Ex2, nColumn==2 since 2 of the 3 columns of Ex1 are indexed.
1447 ** The value of aiColumn is {2, 0}.  aiColumn[0]==2 because the
1448 ** first column to be indexed (c3) has an index of 2 in Ex1.aCol[].
1449 ** The second column to be indexed (c1) has an index of 0 in
1450 ** Ex1.aCol[], hence Ex2.aiColumn[1]==0.
1451 **
1452 ** The Index.onError field determines whether or not the indexed columns
1453 ** must be unique and what to do if they are not.  When Index.onError=OE_None,
1454 ** it means this is not a unique index.  Otherwise it is a unique index
1455 ** and the value of Index.onError indicate the which conflict resolution
1456 ** algorithm to employ whenever an attempt is made to insert a non-unique
1457 ** element.
1458 */
1459 struct Index {
1460   char *zName;     /* Name of this index */
1461   int *aiColumn;   /* Which columns are used by this index.  1st is 0 */
1462   tRowcnt *aiRowEst; /* Result of ANALYZE: Est. rows selected by each column */
1463   Table *pTable;   /* The SQL table being indexed */
1464   char *zColAff;   /* String defining the affinity of each column */
1465   Index *pNext;    /* The next index associated with the same table */
1466   Schema *pSchema; /* Schema containing this index */
1467   u8 *aSortOrder;  /* Array of size Index.nColumn. True==DESC, False==ASC */
1468   char **azColl;   /* Array of collation sequence names for index */
1469   int nColumn;     /* Number of columns in the table used by this index */
1470   int tnum;        /* Page containing root of this index in database file */
1471   u8 onError;      /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
1472   u8 autoIndex;    /* True if is automatically created (ex: by UNIQUE) */
1473   u8 bUnordered;   /* Use this index for == or IN queries only */
1474 #ifdef SQLITE_ENABLE_STAT3
1475   int nSample;             /* Number of elements in aSample[] */
1476   tRowcnt avgEq;           /* Average nEq value for key values not in aSample */
1477   IndexSample *aSample;    /* Samples of the left-most key */
1478 #endif
1479 };
1480 
1481 /*
1482 ** Each sample stored in the sqlite_stat3 table is represented in memory
1483 ** using a structure of this type.  See documentation at the top of the
1484 ** analyze.c source file for additional information.
1485 */
1486 struct IndexSample {
1487   union {
1488     char *z;        /* Value if eType is SQLITE_TEXT or SQLITE_BLOB */
1489     double r;       /* Value if eType is SQLITE_FLOAT */
1490     i64 i;          /* Value if eType is SQLITE_INTEGER */
1491   } u;
1492   u8 eType;         /* SQLITE_NULL, SQLITE_INTEGER ... etc. */
1493   int nByte;        /* Size in byte of text or blob. */
1494   tRowcnt nEq;      /* Est. number of rows where the key equals this sample */
1495   tRowcnt nLt;      /* Est. number of rows where key is less than this sample */
1496   tRowcnt nDLt;     /* Est. number of distinct keys less than this sample */
1497 };
1498 
1499 /*
1500 ** Each token coming out of the lexer is an instance of
1501 ** this structure.  Tokens are also used as part of an expression.
1502 **
1503 ** Note if Token.z==0 then Token.dyn and Token.n are undefined and
1504 ** may contain random values.  Do not make any assumptions about Token.dyn
1505 ** and Token.n when Token.z==0.
1506 */
1507 struct Token {
1508   const char *z;     /* Text of the token.  Not NULL-terminated! */
1509   unsigned int n;    /* Number of characters in this token */
1510 };
1511 
1512 /*
1513 ** An instance of this structure contains information needed to generate
1514 ** code for a SELECT that contains aggregate functions.
1515 **
1516 ** If Expr.op==TK_AGG_COLUMN or TK_AGG_FUNCTION then Expr.pAggInfo is a
1517 ** pointer to this structure.  The Expr.iColumn field is the index in
1518 ** AggInfo.aCol[] or AggInfo.aFunc[] of information needed to generate
1519 ** code for that node.
1520 **
1521 ** AggInfo.pGroupBy and AggInfo.aFunc.pExpr point to fields within the
1522 ** original Select structure that describes the SELECT statement.  These
1523 ** fields do not need to be freed when deallocating the AggInfo structure.
1524 */
1525 struct AggInfo {
1526   u8 directMode;          /* Direct rendering mode means take data directly
1527                           ** from source tables rather than from accumulators */
1528   u8 useSortingIdx;       /* In direct mode, reference the sorting index rather
1529                           ** than the source table */
1530   int sortingIdx;         /* Cursor number of the sorting index */
1531   int sortingIdxPTab;     /* Cursor number of pseudo-table */
1532   int nSortingColumn;     /* Number of columns in the sorting index */
1533   ExprList *pGroupBy;     /* The group by clause */
1534   struct AggInfo_col {    /* For each column used in source tables */
1535     Table *pTab;             /* Source table */
1536     int iTable;              /* Cursor number of the source table */
1537     int iColumn;             /* Column number within the source table */
1538     int iSorterColumn;       /* Column number in the sorting index */
1539     int iMem;                /* Memory location that acts as accumulator */
1540     Expr *pExpr;             /* The original expression */
1541   } *aCol;
1542   int nColumn;            /* Number of used entries in aCol[] */
1543   int nAccumulator;       /* Number of columns that show through to the output.
1544                           ** Additional columns are used only as parameters to
1545                           ** aggregate functions */
1546   struct AggInfo_func {   /* For each aggregate function */
1547     Expr *pExpr;             /* Expression encoding the function */
1548     FuncDef *pFunc;          /* The aggregate function implementation */
1549     int iMem;                /* Memory location that acts as accumulator */
1550     int iDistinct;           /* Ephemeral table used to enforce DISTINCT */
1551   } *aFunc;
1552   int nFunc;              /* Number of entries in aFunc[] */
1553 };
1554 
1555 /*
1556 ** The datatype ynVar is a signed integer, either 16-bit or 32-bit.
1557 ** Usually it is 16-bits.  But if SQLITE_MAX_VARIABLE_NUMBER is greater
1558 ** than 32767 we have to make it 32-bit.  16-bit is preferred because
1559 ** it uses less memory in the Expr object, which is a big memory user
1560 ** in systems with lots of prepared statements.  And few applications
1561 ** need more than about 10 or 20 variables.  But some extreme users want
1562 ** to have prepared statements with over 32767 variables, and for them
1563 ** the option is available (at compile-time).
1564 */
1565 #if SQLITE_MAX_VARIABLE_NUMBER<=32767
1566 typedef i16 ynVar;
1567 #else
1568 typedef int ynVar;
1569 #endif
1570 
1571 /*
1572 ** Each node of an expression in the parse tree is an instance
1573 ** of this structure.
1574 **
1575 ** Expr.op is the opcode. The integer parser token codes are reused
1576 ** as opcodes here. For example, the parser defines TK_GE to be an integer
1577 ** code representing the ">=" operator. This same integer code is reused
1578 ** to represent the greater-than-or-equal-to operator in the expression
1579 ** tree.
1580 **
1581 ** If the expression is an SQL literal (TK_INTEGER, TK_FLOAT, TK_BLOB,
1582 ** or TK_STRING), then Expr.token contains the text of the SQL literal. If
1583 ** the expression is a variable (TK_VARIABLE), then Expr.token contains the
1584 ** variable name. Finally, if the expression is an SQL function (TK_FUNCTION),
1585 ** then Expr.token contains the name of the function.
1586 **
1587 ** Expr.pRight and Expr.pLeft are the left and right subexpressions of a
1588 ** binary operator. Either or both may be NULL.
1589 **
1590 ** Expr.x.pList is a list of arguments if the expression is an SQL function,
1591 ** a CASE expression or an IN expression of the form "<lhs> IN (<y>, <z>...)".
1592 ** Expr.x.pSelect is used if the expression is a sub-select or an expression of
1593 ** the form "<lhs> IN (SELECT ...)". If the EP_xIsSelect bit is set in the
1594 ** Expr.flags mask, then Expr.x.pSelect is valid. Otherwise, Expr.x.pList is
1595 ** valid.
1596 **
1597 ** An expression of the form ID or ID.ID refers to a column in a table.
1598 ** For such expressions, Expr.op is set to TK_COLUMN and Expr.iTable is
1599 ** the integer cursor number of a VDBE cursor pointing to that table and
1600 ** Expr.iColumn is the column number for the specific column.  If the
1601 ** expression is used as a result in an aggregate SELECT, then the
1602 ** value is also stored in the Expr.iAgg column in the aggregate so that
1603 ** it can be accessed after all aggregates are computed.
1604 **
1605 ** If the expression is an unbound variable marker (a question mark
1606 ** character '?' in the original SQL) then the Expr.iTable holds the index
1607 ** number for that variable.
1608 **
1609 ** If the expression is a subquery then Expr.iColumn holds an integer
1610 ** register number containing the result of the subquery.  If the
1611 ** subquery gives a constant result, then iTable is -1.  If the subquery
1612 ** gives a different answer at different times during statement processing
1613 ** then iTable is the address of a subroutine that computes the subquery.
1614 **
1615 ** If the Expr is of type OP_Column, and the table it is selecting from
1616 ** is a disk table or the "old.*" pseudo-table, then pTab points to the
1617 ** corresponding table definition.
1618 **
1619 ** ALLOCATION NOTES:
1620 **
1621 ** Expr objects can use a lot of memory space in database schema.  To
1622 ** help reduce memory requirements, sometimes an Expr object will be
1623 ** truncated.  And to reduce the number of memory allocations, sometimes
1624 ** two or more Expr objects will be stored in a single memory allocation,
1625 ** together with Expr.zToken strings.
1626 **
1627 ** If the EP_Reduced and EP_TokenOnly flags are set when
1628 ** an Expr object is truncated.  When EP_Reduced is set, then all
1629 ** the child Expr objects in the Expr.pLeft and Expr.pRight subtrees
1630 ** are contained within the same memory allocation.  Note, however, that
1631 ** the subtrees in Expr.x.pList or Expr.x.pSelect are always separately
1632 ** allocated, regardless of whether or not EP_Reduced is set.
1633 */
1634 struct Expr {
1635   u8 op;                 /* Operation performed by this node */
1636   char affinity;         /* The affinity of the column or 0 if not a column */
1637   u16 flags;             /* Various flags.  EP_* See below */
1638   union {
1639     char *zToken;          /* Token value. Zero terminated and dequoted */
1640     int iValue;            /* Non-negative integer value if EP_IntValue */
1641   } u;
1642 
1643   /* If the EP_TokenOnly flag is set in the Expr.flags mask, then no
1644   ** space is allocated for the fields below this point. An attempt to
1645   ** access them will result in a segfault or malfunction.
1646   *********************************************************************/
1647 
1648   Expr *pLeft;           /* Left subnode */
1649   Expr *pRight;          /* Right subnode */
1650   union {
1651     ExprList *pList;     /* Function arguments or in "<expr> IN (<expr-list)" */
1652     Select *pSelect;     /* Used for sub-selects and "<expr> IN (<select>)" */
1653   } x;
1654   CollSeq *pColl;        /* The collation type of the column or 0 */
1655 
1656   /* If the EP_Reduced flag is set in the Expr.flags mask, then no
1657   ** space is allocated for the fields below this point. An attempt to
1658   ** access them will result in a segfault or malfunction.
1659   *********************************************************************/
1660 
1661   int iTable;            /* TK_COLUMN: cursor number of table holding column
1662                          ** TK_REGISTER: register number
1663                          ** TK_TRIGGER: 1 -> new, 0 -> old */
1664   ynVar iColumn;         /* TK_COLUMN: column index.  -1 for rowid.
1665                          ** TK_VARIABLE: variable number (always >= 1). */
1666   i16 iAgg;              /* Which entry in pAggInfo->aCol[] or ->aFunc[] */
1667   i16 iRightJoinTable;   /* If EP_FromJoin, the right table of the join */
1668   u8 flags2;             /* Second set of flags.  EP2_... */
1669   u8 op2;                /* If a TK_REGISTER, the original value of Expr.op */
1670   AggInfo *pAggInfo;     /* Used by TK_AGG_COLUMN and TK_AGG_FUNCTION */
1671   Table *pTab;           /* Table for TK_COLUMN expressions. */
1672 #if SQLITE_MAX_EXPR_DEPTH>0
1673   int nHeight;           /* Height of the tree headed by this node */
1674 #endif
1675 };
1676 
1677 /*
1678 ** The following are the meanings of bits in the Expr.flags field.
1679 */
1680 #define EP_FromJoin   0x0001  /* Originated in ON or USING clause of a join */
1681 #define EP_Agg        0x0002  /* Contains one or more aggregate functions */
1682 #define EP_Resolved   0x0004  /* IDs have been resolved to COLUMNs */
1683 #define EP_Error      0x0008  /* Expression contains one or more errors */
1684 #define EP_Distinct   0x0010  /* Aggregate function with DISTINCT keyword */
1685 #define EP_VarSelect  0x0020  /* pSelect is correlated, not constant */
1686 #define EP_DblQuoted  0x0040  /* token.z was originally in "..." */
1687 #define EP_InfixFunc  0x0080  /* True for an infix function: LIKE, GLOB, etc */
1688 #define EP_ExpCollate 0x0100  /* Collating sequence specified explicitly */
1689 #define EP_FixedDest  0x0200  /* Result needed in a specific register */
1690 #define EP_IntValue   0x0400  /* Integer value contained in u.iValue */
1691 #define EP_xIsSelect  0x0800  /* x.pSelect is valid (otherwise x.pList is) */
1692 #define EP_Hint       0x1000  /* Optimizer hint. Not required for correctness */
1693 #define EP_Reduced    0x2000  /* Expr struct is EXPR_REDUCEDSIZE bytes only */
1694 #define EP_TokenOnly  0x4000  /* Expr struct is EXPR_TOKENONLYSIZE bytes only */
1695 #define EP_Static     0x8000  /* Held in memory not obtained from malloc() */
1696 
1697 /*
1698 ** The following are the meanings of bits in the Expr.flags2 field.
1699 */
1700 #define EP2_MallocedToken  0x0001  /* Need to sqlite3DbFree() Expr.zToken */
1701 #define EP2_Irreducible    0x0002  /* Cannot EXPRDUP_REDUCE this Expr */
1702 
1703 /*
1704 ** The pseudo-routine sqlite3ExprSetIrreducible sets the EP2_Irreducible
1705 ** flag on an expression structure.  This flag is used for VV&A only.  The
1706 ** routine is implemented as a macro that only works when in debugging mode,
1707 ** so as not to burden production code.
1708 */
1709 #ifdef SQLITE_DEBUG
1710 # define ExprSetIrreducible(X)  (X)->flags2 |= EP2_Irreducible
1711 #else
1712 # define ExprSetIrreducible(X)
1713 #endif
1714 
1715 /*
1716 ** These macros can be used to test, set, or clear bits in the
1717 ** Expr.flags field.
1718 */
1719 #define ExprHasProperty(E,P)     (((E)->flags&(P))==(P))
1720 #define ExprHasAnyProperty(E,P)  (((E)->flags&(P))!=0)
1721 #define ExprSetProperty(E,P)     (E)->flags|=(P)
1722 #define ExprClearProperty(E,P)   (E)->flags&=~(P)
1723 
1724 /*
1725 ** Macros to determine the number of bytes required by a normal Expr
1726 ** struct, an Expr struct with the EP_Reduced flag set in Expr.flags
1727 ** and an Expr struct with the EP_TokenOnly flag set.
1728 */
1729 #define EXPR_FULLSIZE           sizeof(Expr)           /* Full size */
1730 #define EXPR_REDUCEDSIZE        offsetof(Expr,iTable)  /* Common features */
1731 #define EXPR_TOKENONLYSIZE      offsetof(Expr,pLeft)   /* Fewer features */
1732 
1733 /*
1734 ** Flags passed to the sqlite3ExprDup() function. See the header comment
1735 ** above sqlite3ExprDup() for details.
1736 */
1737 #define EXPRDUP_REDUCE         0x0001  /* Used reduced-size Expr nodes */
1738 
1739 /*
1740 ** A list of expressions.  Each expression may optionally have a
1741 ** name.  An expr/name combination can be used in several ways, such
1742 ** as the list of "expr AS ID" fields following a "SELECT" or in the
1743 ** list of "ID = expr" items in an UPDATE.  A list of expressions can
1744 ** also be used as the argument to a function, in which case the a.zName
1745 ** field is not used.
1746 */
1747 struct ExprList {
1748   int nExpr;             /* Number of expressions on the list */
1749   int iECursor;          /* VDBE Cursor associated with this ExprList */
1750   struct ExprList_item { /* For each expression in the list */
1751     Expr *pExpr;           /* The list of expressions */
1752     char *zName;           /* Token associated with this expression */
1753     char *zSpan;           /* Original text of the expression */
1754     u8 sortOrder;          /* 1 for DESC or 0 for ASC */
1755     u8 done;               /* A flag to indicate when processing is finished */
1756     u16 iOrderByCol;       /* For ORDER BY, column number in result set */
1757     u16 iAlias;            /* Index into Parse.aAlias[] for zName */
1758   } *a;                  /* Alloc a power of two greater or equal to nExpr */
1759 };
1760 
1761 /*
1762 ** An instance of this structure is used by the parser to record both
1763 ** the parse tree for an expression and the span of input text for an
1764 ** expression.
1765 */
1766 struct ExprSpan {
1767   Expr *pExpr;          /* The expression parse tree */
1768   const char *zStart;   /* First character of input text */
1769   const char *zEnd;     /* One character past the end of input text */
1770 };
1771 
1772 /*
1773 ** An instance of this structure can hold a simple list of identifiers,
1774 ** such as the list "a,b,c" in the following statements:
1775 **
1776 **      INSERT INTO t(a,b,c) VALUES ...;
1777 **      CREATE INDEX idx ON t(a,b,c);
1778 **      CREATE TRIGGER trig BEFORE UPDATE ON t(a,b,c) ...;
1779 **
1780 ** The IdList.a.idx field is used when the IdList represents the list of
1781 ** column names after a table name in an INSERT statement.  In the statement
1782 **
1783 **     INSERT INTO t(a,b,c) ...
1784 **
1785 ** If "a" is the k-th column of table "t", then IdList.a[0].idx==k.
1786 */
1787 struct IdList {
1788   struct IdList_item {
1789     char *zName;      /* Name of the identifier */
1790     int idx;          /* Index in some Table.aCol[] of a column named zName */
1791   } *a;
1792   int nId;         /* Number of identifiers on the list */
1793 };
1794 
1795 /*
1796 ** The bitmask datatype defined below is used for various optimizations.
1797 **
1798 ** Changing this from a 64-bit to a 32-bit type limits the number of
1799 ** tables in a join to 32 instead of 64.  But it also reduces the size
1800 ** of the library by 738 bytes on ix86.
1801 */
1802 typedef u64 Bitmask;
1803 
1804 /*
1805 ** The number of bits in a Bitmask.  "BMS" means "BitMask Size".
1806 */
1807 #define BMS  ((int)(sizeof(Bitmask)*8))
1808 
1809 /*
1810 ** The following structure describes the FROM clause of a SELECT statement.
1811 ** Each table or subquery in the FROM clause is a separate element of
1812 ** the SrcList.a[] array.
1813 **
1814 ** With the addition of multiple database support, the following structure
1815 ** can also be used to describe a particular table such as the table that
1816 ** is modified by an INSERT, DELETE, or UPDATE statement.  In standard SQL,
1817 ** such a table must be a simple name: ID.  But in SQLite, the table can
1818 ** now be identified by a database name, a dot, then the table name: ID.ID.
1819 **
1820 ** The jointype starts out showing the join type between the current table
1821 ** and the next table on the list.  The parser builds the list this way.
1822 ** But sqlite3SrcListShiftJoinType() later shifts the jointypes so that each
1823 ** jointype expresses the join between the table and the previous table.
1824 **
1825 ** In the colUsed field, the high-order bit (bit 63) is set if the table
1826 ** contains more than 63 columns and the 64-th or later column is used.
1827 */
1828 struct SrcList {
1829   i16 nSrc;        /* Number of tables or subqueries in the FROM clause */
1830   i16 nAlloc;      /* Number of entries allocated in a[] below */
1831   struct SrcList_item {
1832     char *zDatabase;  /* Name of database holding this table */
1833     char *zName;      /* Name of the table */
1834     char *zAlias;     /* The "B" part of a "A AS B" phrase.  zName is the "A" */
1835     Table *pTab;      /* An SQL table corresponding to zName */
1836     Select *pSelect;  /* A SELECT statement used in place of a table name */
1837     int addrFillSub;  /* Address of subroutine to manifest a subquery */
1838     int regReturn;    /* Register holding return address of addrFillSub */
1839     u8 jointype;      /* Type of join between this able and the previous */
1840     u8 notIndexed;    /* True if there is a NOT INDEXED clause */
1841     u8 isCorrelated;  /* True if sub-query is correlated */
1842 #ifndef SQLITE_OMIT_EXPLAIN
1843     u8 iSelectId;     /* If pSelect!=0, the id of the sub-select in EQP */
1844 #endif
1845     int iCursor;      /* The VDBE cursor number used to access this table */
1846     Expr *pOn;        /* The ON clause of a join */
1847     IdList *pUsing;   /* The USING clause of a join */
1848     Bitmask colUsed;  /* Bit N (1<<N) set if column N of pTab is used */
1849     char *zIndex;     /* Identifier from "INDEXED BY <zIndex>" clause */
1850     Index *pIndex;    /* Index structure corresponding to zIndex, if any */
1851   } a[1];             /* One entry for each identifier on the list */
1852 };
1853 
1854 /*
1855 ** Permitted values of the SrcList.a.jointype field
1856 */
1857 #define JT_INNER     0x0001    /* Any kind of inner or cross join */
1858 #define JT_CROSS     0x0002    /* Explicit use of the CROSS keyword */
1859 #define JT_NATURAL   0x0004    /* True for a "natural" join */
1860 #define JT_LEFT      0x0008    /* Left outer join */
1861 #define JT_RIGHT     0x0010    /* Right outer join */
1862 #define JT_OUTER     0x0020    /* The "OUTER" keyword is present */
1863 #define JT_ERROR     0x0040    /* unknown or unsupported join type */
1864 
1865 
1866 /*
1867 ** A WherePlan object holds information that describes a lookup
1868 ** strategy.
1869 **
1870 ** This object is intended to be opaque outside of the where.c module.
1871 ** It is included here only so that that compiler will know how big it
1872 ** is.  None of the fields in this object should be used outside of
1873 ** the where.c module.
1874 **
1875 ** Within the union, pIdx is only used when wsFlags&WHERE_INDEXED is true.
1876 ** pTerm is only used when wsFlags&WHERE_MULTI_OR is true.  And pVtabIdx
1877 ** is only used when wsFlags&WHERE_VIRTUALTABLE is true.  It is never the
1878 ** case that more than one of these conditions is true.
1879 */
1880 struct WherePlan {
1881   u32 wsFlags;                   /* WHERE_* flags that describe the strategy */
1882   u32 nEq;                       /* Number of == constraints */
1883   double nRow;                   /* Estimated number of rows (for EQP) */
1884   union {
1885     Index *pIdx;                   /* Index when WHERE_INDEXED is true */
1886     struct WhereTerm *pTerm;       /* WHERE clause term for OR-search */
1887     sqlite3_index_info *pVtabIdx;  /* Virtual table index to use */
1888   } u;
1889 };
1890 
1891 /*
1892 ** For each nested loop in a WHERE clause implementation, the WhereInfo
1893 ** structure contains a single instance of this structure.  This structure
1894 ** is intended to be private the the where.c module and should not be
1895 ** access or modified by other modules.
1896 **
1897 ** The pIdxInfo field is used to help pick the best index on a
1898 ** virtual table.  The pIdxInfo pointer contains indexing
1899 ** information for the i-th table in the FROM clause before reordering.
1900 ** All the pIdxInfo pointers are freed by whereInfoFree() in where.c.
1901 ** All other information in the i-th WhereLevel object for the i-th table
1902 ** after FROM clause ordering.
1903 */
1904 struct WhereLevel {
1905   WherePlan plan;       /* query plan for this element of the FROM clause */
1906   int iLeftJoin;        /* Memory cell used to implement LEFT OUTER JOIN */
1907   int iTabCur;          /* The VDBE cursor used to access the table */
1908   int iIdxCur;          /* The VDBE cursor used to access pIdx */
1909   int addrBrk;          /* Jump here to break out of the loop */
1910   int addrNxt;          /* Jump here to start the next IN combination */
1911   int addrCont;         /* Jump here to continue with the next loop cycle */
1912   int addrFirst;        /* First instruction of interior of the loop */
1913   u8 iFrom;             /* Which entry in the FROM clause */
1914   u8 op, p5;            /* Opcode and P5 of the opcode that ends the loop */
1915   int p1, p2;           /* Operands of the opcode used to ends the loop */
1916   union {               /* Information that depends on plan.wsFlags */
1917     struct {
1918       int nIn;              /* Number of entries in aInLoop[] */
1919       struct InLoop {
1920         int iCur;              /* The VDBE cursor used by this IN operator */
1921         int addrInTop;         /* Top of the IN loop */
1922       } *aInLoop;           /* Information about each nested IN operator */
1923     } in;                 /* Used when plan.wsFlags&WHERE_IN_ABLE */
1924   } u;
1925 
1926   /* The following field is really not part of the current level.  But
1927   ** we need a place to cache virtual table index information for each
1928   ** virtual table in the FROM clause and the WhereLevel structure is
1929   ** a convenient place since there is one WhereLevel for each FROM clause
1930   ** element.
1931   */
1932   sqlite3_index_info *pIdxInfo;  /* Index info for n-th source table */
1933 };
1934 
1935 /*
1936 ** Flags appropriate for the wctrlFlags parameter of sqlite3WhereBegin()
1937 ** and the WhereInfo.wctrlFlags member.
1938 */
1939 #define WHERE_ORDERBY_NORMAL   0x0000 /* No-op */
1940 #define WHERE_ORDERBY_MIN      0x0001 /* ORDER BY processing for min() func */
1941 #define WHERE_ORDERBY_MAX      0x0002 /* ORDER BY processing for max() func */
1942 #define WHERE_ONEPASS_DESIRED  0x0004 /* Want to do one-pass UPDATE/DELETE */
1943 #define WHERE_DUPLICATES_OK    0x0008 /* Ok to return a row more than once */
1944 #define WHERE_OMIT_OPEN_CLOSE  0x0010 /* Table cursors are already open */
1945 #define WHERE_FORCE_TABLE      0x0020 /* Do not use an index-only search */
1946 #define WHERE_ONETABLE_ONLY    0x0040 /* Only code the 1st table in pTabList */
1947 #define WHERE_AND_ONLY         0x0080 /* Don't use indices for OR terms */
1948 
1949 /*
1950 ** The WHERE clause processing routine has two halves.  The
1951 ** first part does the start of the WHERE loop and the second
1952 ** half does the tail of the WHERE loop.  An instance of
1953 ** this structure is returned by the first half and passed
1954 ** into the second half to give some continuity.
1955 */
1956 struct WhereInfo {
1957   Parse *pParse;       /* Parsing and code generating context */
1958   u16 wctrlFlags;      /* Flags originally passed to sqlite3WhereBegin() */
1959   u8 okOnePass;        /* Ok to use one-pass algorithm for UPDATE or DELETE */
1960   u8 untestedTerms;    /* Not all WHERE terms resolved by outer loop */
1961   u8 eDistinct;
1962   SrcList *pTabList;             /* List of tables in the join */
1963   int iTop;                      /* The very beginning of the WHERE loop */
1964   int iContinue;                 /* Jump here to continue with next record */
1965   int iBreak;                    /* Jump here to break out of the loop */
1966   int nLevel;                    /* Number of nested loop */
1967   struct WhereClause *pWC;       /* Decomposition of the WHERE clause */
1968   double savedNQueryLoop;        /* pParse->nQueryLoop outside the WHERE loop */
1969   double nRowOut;                /* Estimated number of output rows */
1970   WhereLevel a[1];               /* Information about each nest loop in WHERE */
1971 };
1972 
1973 #define WHERE_DISTINCT_UNIQUE 1
1974 #define WHERE_DISTINCT_ORDERED 2
1975 
1976 /*
1977 ** A NameContext defines a context in which to resolve table and column
1978 ** names.  The context consists of a list of tables (the pSrcList) field and
1979 ** a list of named expression (pEList).  The named expression list may
1980 ** be NULL.  The pSrc corresponds to the FROM clause of a SELECT or
1981 ** to the table being operated on by INSERT, UPDATE, or DELETE.  The
1982 ** pEList corresponds to the result set of a SELECT and is NULL for
1983 ** other statements.
1984 **
1985 ** NameContexts can be nested.  When resolving names, the inner-most
1986 ** context is searched first.  If no match is found, the next outer
1987 ** context is checked.  If there is still no match, the next context
1988 ** is checked.  This process continues until either a match is found
1989 ** or all contexts are check.  When a match is found, the nRef member of
1990 ** the context containing the match is incremented.
1991 **
1992 ** Each subquery gets a new NameContext.  The pNext field points to the
1993 ** NameContext in the parent query.  Thus the process of scanning the
1994 ** NameContext list corresponds to searching through successively outer
1995 ** subqueries looking for a match.
1996 */
1997 struct NameContext {
1998   Parse *pParse;       /* The parser */
1999   SrcList *pSrcList;   /* One or more tables used to resolve names */
2000   ExprList *pEList;    /* Optional list of named expressions */
2001   int nRef;            /* Number of names resolved by this context */
2002   int nErr;            /* Number of errors encountered while resolving names */
2003   u8 allowAgg;         /* Aggregate functions allowed here */
2004   u8 hasAgg;           /* True if aggregates are seen */
2005   u8 isCheck;          /* True if resolving names in a CHECK constraint */
2006   int nDepth;          /* Depth of subquery recursion. 1 for no recursion */
2007   AggInfo *pAggInfo;   /* Information about aggregates at this level */
2008   NameContext *pNext;  /* Next outer name context.  NULL for outermost */
2009 };
2010 
2011 /*
2012 ** An instance of the following structure contains all information
2013 ** needed to generate code for a single SELECT statement.
2014 **
2015 ** nLimit is set to -1 if there is no LIMIT clause.  nOffset is set to 0.
2016 ** If there is a LIMIT clause, the parser sets nLimit to the value of the
2017 ** limit and nOffset to the value of the offset (or 0 if there is not
2018 ** offset).  But later on, nLimit and nOffset become the memory locations
2019 ** in the VDBE that record the limit and offset counters.
2020 **
2021 ** addrOpenEphm[] entries contain the address of OP_OpenEphemeral opcodes.
2022 ** These addresses must be stored so that we can go back and fill in
2023 ** the P4_KEYINFO and P2 parameters later.  Neither the KeyInfo nor
2024 ** the number of columns in P2 can be computed at the same time
2025 ** as the OP_OpenEphm instruction is coded because not
2026 ** enough information about the compound query is known at that point.
2027 ** The KeyInfo for addrOpenTran[0] and [1] contains collating sequences
2028 ** for the result set.  The KeyInfo for addrOpenTran[2] contains collating
2029 ** sequences for the ORDER BY clause.
2030 */
2031 struct Select {
2032   ExprList *pEList;      /* The fields of the result */
2033   u8 op;                 /* One of: TK_UNION TK_ALL TK_INTERSECT TK_EXCEPT */
2034   char affinity;         /* MakeRecord with this affinity for SRT_Set */
2035   u16 selFlags;          /* Various SF_* values */
2036   int iLimit, iOffset;   /* Memory registers holding LIMIT & OFFSET counters */
2037   int addrOpenEphm[3];   /* OP_OpenEphem opcodes related to this select */
2038   double nSelectRow;     /* Estimated number of result rows */
2039   SrcList *pSrc;         /* The FROM clause */
2040   Expr *pWhere;          /* The WHERE clause */
2041   ExprList *pGroupBy;    /* The GROUP BY clause */
2042   Expr *pHaving;         /* The HAVING clause */
2043   ExprList *pOrderBy;    /* The ORDER BY clause */
2044   Select *pPrior;        /* Prior select in a compound select statement */
2045   Select *pNext;         /* Next select to the left in a compound */
2046   Select *pRightmost;    /* Right-most select in a compound select statement */
2047   Expr *pLimit;          /* LIMIT expression. NULL means not used. */
2048   Expr *pOffset;         /* OFFSET expression. NULL means not used. */
2049 };
2050 
2051 /*
2052 ** Allowed values for Select.selFlags.  The "SF" prefix stands for
2053 ** "Select Flag".
2054 */
2055 #define SF_Distinct        0x01  /* Output should be DISTINCT */
2056 #define SF_Resolved        0x02  /* Identifiers have been resolved */
2057 #define SF_Aggregate       0x04  /* Contains aggregate functions */
2058 #define SF_UsesEphemeral   0x08  /* Uses the OpenEphemeral opcode */
2059 #define SF_Expanded        0x10  /* sqlite3SelectExpand() called on this */
2060 #define SF_HasTypeInfo     0x20  /* FROM subqueries have Table metadata */
2061 #define SF_UseSorter       0x40  /* Sort using a sorter */
2062 #define SF_Values          0x80  /* Synthesized from VALUES clause */
2063 
2064 
2065 /*
2066 ** The results of a select can be distributed in several ways.  The
2067 ** "SRT" prefix means "SELECT Result Type".
2068 */
2069 #define SRT_Union        1  /* Store result as keys in an index */
2070 #define SRT_Except       2  /* Remove result from a UNION index */
2071 #define SRT_Exists       3  /* Store 1 if the result is not empty */
2072 #define SRT_Discard      4  /* Do not save the results anywhere */
2073 
2074 /* The ORDER BY clause is ignored for all of the above */
2075 #define IgnorableOrderby(X) ((X->eDest)<=SRT_Discard)
2076 
2077 #define SRT_Output       5  /* Output each row of result */
2078 #define SRT_Mem          6  /* Store result in a memory cell */
2079 #define SRT_Set          7  /* Store results as keys in an index */
2080 #define SRT_Table        8  /* Store result as data with an automatic rowid */
2081 #define SRT_EphemTab     9  /* Create transient tab and store like SRT_Table */
2082 #define SRT_Coroutine   10  /* Generate a single row of result */
2083 
2084 /*
2085 ** A structure used to customize the behavior of sqlite3Select(). See
2086 ** comments above sqlite3Select() for details.
2087 */
2088 typedef struct SelectDest SelectDest;
2089 struct SelectDest {
2090   u8 eDest;         /* How to dispose of the results */
2091   u8 affinity;      /* Affinity used when eDest==SRT_Set */
2092   int iParm;        /* A parameter used by the eDest disposal method */
2093   int iMem;         /* Base register where results are written */
2094   int nMem;         /* Number of registers allocated */
2095 };
2096 
2097 /*
2098 ** During code generation of statements that do inserts into AUTOINCREMENT
2099 ** tables, the following information is attached to the Table.u.autoInc.p
2100 ** pointer of each autoincrement table to record some side information that
2101 ** the code generator needs.  We have to keep per-table autoincrement
2102 ** information in case inserts are down within triggers.  Triggers do not
2103 ** normally coordinate their activities, but we do need to coordinate the
2104 ** loading and saving of autoincrement information.
2105 */
2106 struct AutoincInfo {
2107   AutoincInfo *pNext;   /* Next info block in a list of them all */
2108   Table *pTab;          /* Table this info block refers to */
2109   int iDb;              /* Index in sqlite3.aDb[] of database holding pTab */
2110   int regCtr;           /* Memory register holding the rowid counter */
2111 };
2112 
2113 /*
2114 ** Size of the column cache
2115 */
2116 #ifndef SQLITE_N_COLCACHE
2117 # define SQLITE_N_COLCACHE 10
2118 #endif
2119 
2120 /*
2121 ** At least one instance of the following structure is created for each
2122 ** trigger that may be fired while parsing an INSERT, UPDATE or DELETE
2123 ** statement. All such objects are stored in the linked list headed at
2124 ** Parse.pTriggerPrg and deleted once statement compilation has been
2125 ** completed.
2126 **
2127 ** A Vdbe sub-program that implements the body and WHEN clause of trigger
2128 ** TriggerPrg.pTrigger, assuming a default ON CONFLICT clause of
2129 ** TriggerPrg.orconf, is stored in the TriggerPrg.pProgram variable.
2130 ** The Parse.pTriggerPrg list never contains two entries with the same
2131 ** values for both pTrigger and orconf.
2132 **
2133 ** The TriggerPrg.aColmask[0] variable is set to a mask of old.* columns
2134 ** accessed (or set to 0 for triggers fired as a result of INSERT
2135 ** statements). Similarly, the TriggerPrg.aColmask[1] variable is set to
2136 ** a mask of new.* columns used by the program.
2137 */
2138 struct TriggerPrg {
2139   Trigger *pTrigger;      /* Trigger this program was coded from */
2140   TriggerPrg *pNext;      /* Next entry in Parse.pTriggerPrg list */
2141   SubProgram *pProgram;   /* Program implementing pTrigger/orconf */
2142   int orconf;             /* Default ON CONFLICT policy */
2143   u32 aColmask[2];        /* Masks of old.*, new.* columns accessed */
2144 };
2145 
2146 /*
2147 ** The yDbMask datatype for the bitmask of all attached databases.
2148 */
2149 #if SQLITE_MAX_ATTACHED>30
2150   typedef sqlite3_uint64 yDbMask;
2151 #else
2152   typedef unsigned int yDbMask;
2153 #endif
2154 
2155 /*
2156 ** An SQL parser context.  A copy of this structure is passed through
2157 ** the parser and down into all the parser action routine in order to
2158 ** carry around information that is global to the entire parse.
2159 **
2160 ** The structure is divided into two parts.  When the parser and code
2161 ** generate call themselves recursively, the first part of the structure
2162 ** is constant but the second part is reset at the beginning and end of
2163 ** each recursion.
2164 **
2165 ** The nTableLock and aTableLock variables are only used if the shared-cache
2166 ** feature is enabled (if sqlite3Tsd()->useSharedData is true). They are
2167 ** used to store the set of table-locks required by the statement being
2168 ** compiled. Function sqlite3TableLock() is used to add entries to the
2169 ** list.
2170 */
2171 struct Parse {
2172   sqlite3 *db;         /* The main database structure */
2173   char *zErrMsg;       /* An error message */
2174   Vdbe *pVdbe;         /* An engine for executing database bytecode */
2175   int rc;              /* Return code from execution */
2176   u8 colNamesSet;      /* TRUE after OP_ColumnName has been issued to pVdbe */
2177   u8 checkSchema;      /* Causes schema cookie check after an error */
2178   u8 nested;           /* Number of nested calls to the parser/code generator */
2179   u8 nTempReg;         /* Number of temporary registers in aTempReg[] */
2180   u8 nTempInUse;       /* Number of aTempReg[] currently checked out */
2181   u8 nColCache;        /* Number of entries in aColCache[] */
2182   u8 iColCache;        /* Next entry in aColCache[] to replace */
2183   u8 isMultiWrite;     /* True if statement may modify/insert multiple rows */
2184   u8 mayAbort;         /* True if statement may throw an ABORT exception */
2185   int aTempReg[8];     /* Holding area for temporary registers */
2186   int nRangeReg;       /* Size of the temporary register block */
2187   int iRangeReg;       /* First register in temporary register block */
2188   int nErr;            /* Number of errors seen */
2189   int nTab;            /* Number of previously allocated VDBE cursors */
2190   int nMem;            /* Number of memory cells used so far */
2191   int nSet;            /* Number of sets used so far */
2192   int nOnce;           /* Number of OP_Once instructions so far */
2193   int ckBase;          /* Base register of data during check constraints */
2194   int iCacheLevel;     /* ColCache valid when aColCache[].iLevel<=iCacheLevel */
2195   int iCacheCnt;       /* Counter used to generate aColCache[].lru values */
2196   struct yColCache {
2197     int iTable;           /* Table cursor number */
2198     int iColumn;          /* Table column number */
2199     u8 tempReg;           /* iReg is a temp register that needs to be freed */
2200     int iLevel;           /* Nesting level */
2201     int iReg;             /* Reg with value of this column. 0 means none. */
2202     int lru;              /* Least recently used entry has the smallest value */
2203   } aColCache[SQLITE_N_COLCACHE];  /* One for each column cache entry */
2204   yDbMask writeMask;   /* Start a write transaction on these databases */
2205   yDbMask cookieMask;  /* Bitmask of schema verified databases */
2206   int cookieGoto;      /* Address of OP_Goto to cookie verifier subroutine */
2207   int cookieValue[SQLITE_MAX_ATTACHED+2];  /* Values of cookies to verify */
2208   int regRowid;        /* Register holding rowid of CREATE TABLE entry */
2209   int regRoot;         /* Register holding root page number for new objects */
2210   int nMaxArg;         /* Max args passed to user function by sub-program */
2211 #ifndef SQLITE_OMIT_SHARED_CACHE
2212   int nTableLock;        /* Number of locks in aTableLock */
2213   TableLock *aTableLock; /* Required table locks for shared-cache mode */
2214 #endif
2215   AutoincInfo *pAinc;  /* Information about AUTOINCREMENT counters */
2216 
2217   /* Information used while coding trigger programs. */
2218   Parse *pToplevel;    /* Parse structure for main program (or NULL) */
2219   Table *pTriggerTab;  /* Table triggers are being coded for */
2220   double nQueryLoop;   /* Estimated number of iterations of a query */
2221   u32 oldmask;         /* Mask of old.* columns referenced */
2222   u32 newmask;         /* Mask of new.* columns referenced */
2223   u8 eTriggerOp;       /* TK_UPDATE, TK_INSERT or TK_DELETE */
2224   u8 eOrconf;          /* Default ON CONFLICT policy for trigger steps */
2225   u8 disableTriggers;  /* True to disable triggers */
2226 
2227   /* Above is constant between recursions.  Below is reset before and after
2228   ** each recursion */
2229 
2230   int nVar;                 /* Number of '?' variables seen in the SQL so far */
2231   int nzVar;                /* Number of available slots in azVar[] */
2232   u8 explain;               /* True if the EXPLAIN flag is found on the query */
2233 #ifndef SQLITE_OMIT_VIRTUALTABLE
2234   u8 declareVtab;           /* True if inside sqlite3_declare_vtab() */
2235   int nVtabLock;            /* Number of virtual tables to lock */
2236 #endif
2237   int nAlias;               /* Number of aliased result set columns */
2238   int nHeight;              /* Expression tree height of current sub-select */
2239 #ifndef SQLITE_OMIT_EXPLAIN
2240   int iSelectId;            /* ID of current select for EXPLAIN output */
2241   int iNextSelectId;        /* Next available select ID for EXPLAIN output */
2242 #endif
2243   char **azVar;             /* Pointers to names of parameters */
2244   Vdbe *pReprepare;         /* VM being reprepared (sqlite3Reprepare()) */
2245   int *aAlias;              /* Register used to hold aliased result */
2246   const char *zTail;        /* All SQL text past the last semicolon parsed */
2247   Table *pNewTable;         /* A table being constructed by CREATE TABLE */
2248   Trigger *pNewTrigger;     /* Trigger under construct by a CREATE TRIGGER */
2249   const char *zAuthContext; /* The 6th parameter to db->xAuth callbacks */
2250   Token sNameToken;         /* Token with unqualified schema object name */
2251   Token sLastToken;         /* The last token parsed */
2252 #ifndef SQLITE_OMIT_VIRTUALTABLE
2253   Token sArg;               /* Complete text of a module argument */
2254   Table **apVtabLock;       /* Pointer to virtual tables needing locking */
2255 #endif
2256   Table *pZombieTab;        /* List of Table objects to delete after code gen */
2257   TriggerPrg *pTriggerPrg;  /* Linked list of coded triggers */
2258 };
2259 
2260 /*
2261 ** Return true if currently inside an sqlite3_declare_vtab() call.
2262 */
2263 #ifdef SQLITE_OMIT_VIRTUALTABLE
2264   #define IN_DECLARE_VTAB 0
2265 #else
2266   #define IN_DECLARE_VTAB (pParse->declareVtab)
2267 #endif
2268 
2269 /*
2270 ** An instance of the following structure can be declared on a stack and used
2271 ** to save the Parse.zAuthContext value so that it can be restored later.
2272 */
2273 struct AuthContext {
2274   const char *zAuthContext;   /* Put saved Parse.zAuthContext here */
2275   Parse *pParse;              /* The Parse structure */
2276 };
2277 
2278 /*
2279 ** Bitfield flags for P5 value in OP_Insert and OP_Delete
2280 */
2281 #define OPFLAG_NCHANGE       0x01    /* Set to update db->nChange */
2282 #define OPFLAG_LASTROWID     0x02    /* Set to update db->lastRowid */
2283 #define OPFLAG_ISUPDATE      0x04    /* This OP_Insert is an sql UPDATE */
2284 #define OPFLAG_APPEND        0x08    /* This is likely to be an append */
2285 #define OPFLAG_USESEEKRESULT 0x10    /* Try to avoid a seek in BtreeInsert() */
2286 #define OPFLAG_CLEARCACHE    0x20    /* Clear pseudo-table cache in OP_Column */
2287 
2288 /*
2289  * Each trigger present in the database schema is stored as an instance of
2290  * struct Trigger.
2291  *
2292  * Pointers to instances of struct Trigger are stored in two ways.
2293  * 1. In the "trigHash" hash table (part of the sqlite3* that represents the
2294  *    database). This allows Trigger structures to be retrieved by name.
2295  * 2. All triggers associated with a single table form a linked list, using the
2296  *    pNext member of struct Trigger. A pointer to the first element of the
2297  *    linked list is stored as the "pTrigger" member of the associated
2298  *    struct Table.
2299  *
2300  * The "step_list" member points to the first element of a linked list
2301  * containing the SQL statements specified as the trigger program.
2302  */
2303 struct Trigger {
2304   char *zName;            /* The name of the trigger                        */
2305   char *table;            /* The table or view to which the trigger applies */
2306   u8 op;                  /* One of TK_DELETE, TK_UPDATE, TK_INSERT         */
2307   u8 tr_tm;               /* One of TRIGGER_BEFORE, TRIGGER_AFTER */
2308   Expr *pWhen;            /* The WHEN clause of the expression (may be NULL) */
2309   IdList *pColumns;       /* If this is an UPDATE OF <column-list> trigger,
2310                              the <column-list> is stored here */
2311   Schema *pSchema;        /* Schema containing the trigger */
2312   Schema *pTabSchema;     /* Schema containing the table */
2313   TriggerStep *step_list; /* Link list of trigger program steps             */
2314   Trigger *pNext;         /* Next trigger associated with the table */
2315 };
2316 
2317 /*
2318 ** A trigger is either a BEFORE or an AFTER trigger.  The following constants
2319 ** determine which.
2320 **
2321 ** If there are multiple triggers, you might of some BEFORE and some AFTER.
2322 ** In that cases, the constants below can be ORed together.
2323 */
2324 #define TRIGGER_BEFORE  1
2325 #define TRIGGER_AFTER   2
2326 
2327 /*
2328  * An instance of struct TriggerStep is used to store a single SQL statement
2329  * that is a part of a trigger-program.
2330  *
2331  * Instances of struct TriggerStep are stored in a singly linked list (linked
2332  * using the "pNext" member) referenced by the "step_list" member of the
2333  * associated struct Trigger instance. The first element of the linked list is
2334  * the first step of the trigger-program.
2335  *
2336  * The "op" member indicates whether this is a "DELETE", "INSERT", "UPDATE" or
2337  * "SELECT" statement. The meanings of the other members is determined by the
2338  * value of "op" as follows:
2339  *
2340  * (op == TK_INSERT)
2341  * orconf    -> stores the ON CONFLICT algorithm
2342  * pSelect   -> If this is an INSERT INTO ... SELECT ... statement, then
2343  *              this stores a pointer to the SELECT statement. Otherwise NULL.
2344  * target    -> A token holding the quoted name of the table to insert into.
2345  * pExprList -> If this is an INSERT INTO ... VALUES ... statement, then
2346  *              this stores values to be inserted. Otherwise NULL.
2347  * pIdList   -> If this is an INSERT INTO ... (<column-names>) VALUES ...
2348  *              statement, then this stores the column-names to be
2349  *              inserted into.
2350  *
2351  * (op == TK_DELETE)
2352  * target    -> A token holding the quoted name of the table to delete from.
2353  * pWhere    -> The WHERE clause of the DELETE statement if one is specified.
2354  *              Otherwise NULL.
2355  *
2356  * (op == TK_UPDATE)
2357  * target    -> A token holding the quoted name of the table to update rows of.
2358  * pWhere    -> The WHERE clause of the UPDATE statement if one is specified.
2359  *              Otherwise NULL.
2360  * pExprList -> A list of the columns to update and the expressions to update
2361  *              them to. See sqlite3Update() documentation of "pChanges"
2362  *              argument.
2363  *
2364  */
2365 struct TriggerStep {
2366   u8 op;               /* One of TK_DELETE, TK_UPDATE, TK_INSERT, TK_SELECT */
2367   u8 orconf;           /* OE_Rollback etc. */
2368   Trigger *pTrig;      /* The trigger that this step is a part of */
2369   Select *pSelect;     /* SELECT statment or RHS of INSERT INTO .. SELECT ... */
2370   Token target;        /* Target table for DELETE, UPDATE, INSERT */
2371   Expr *pWhere;        /* The WHERE clause for DELETE or UPDATE steps */
2372   ExprList *pExprList; /* SET clause for UPDATE.  VALUES clause for INSERT */
2373   IdList *pIdList;     /* Column names for INSERT */
2374   TriggerStep *pNext;  /* Next in the link-list */
2375   TriggerStep *pLast;  /* Last element in link-list. Valid for 1st elem only */
2376 };
2377 
2378 /*
2379 ** The following structure contains information used by the sqliteFix...
2380 ** routines as they walk the parse tree to make database references
2381 ** explicit.
2382 */
2383 typedef struct DbFixer DbFixer;
2384 struct DbFixer {
2385   Parse *pParse;      /* The parsing context.  Error messages written here */
2386   const char *zDb;    /* Make sure all objects are contained in this database */
2387   const char *zType;  /* Type of the container - used for error messages */
2388   const Token *pName; /* Name of the container - used for error messages */
2389 };
2390 
2391 /*
2392 ** An objected used to accumulate the text of a string where we
2393 ** do not necessarily know how big the string will be in the end.
2394 */
2395 struct StrAccum {
2396   sqlite3 *db;         /* Optional database for lookaside.  Can be NULL */
2397   char *zBase;         /* A base allocation.  Not from malloc. */
2398   char *zText;         /* The string collected so far */
2399   int  nChar;          /* Length of the string so far */
2400   int  nAlloc;         /* Amount of space allocated in zText */
2401   int  mxAlloc;        /* Maximum allowed string length */
2402   u8   mallocFailed;   /* Becomes true if any memory allocation fails */
2403   u8   useMalloc;      /* 0: none,  1: sqlite3DbMalloc,  2: sqlite3_malloc */
2404   u8   tooBig;         /* Becomes true if string size exceeds limits */
2405 };
2406 
2407 /*
2408 ** A pointer to this structure is used to communicate information
2409 ** from sqlite3Init and OP_ParseSchema into the sqlite3InitCallback.
2410 */
2411 typedef struct {
2412   sqlite3 *db;        /* The database being initialized */
2413   char **pzErrMsg;    /* Error message stored here */
2414   int iDb;            /* 0 for main database.  1 for TEMP, 2.. for ATTACHed */
2415   int rc;             /* Result code stored here */
2416 } InitData;
2417 
2418 /*
2419 ** Structure containing global configuration data for the SQLite library.
2420 **
2421 ** This structure also contains some state information.
2422 */
2423 struct Sqlite3Config {
2424   int bMemstat;                     /* True to enable memory status */
2425   int bCoreMutex;                   /* True to enable core mutexing */
2426   int bFullMutex;                   /* True to enable full mutexing */
2427   int bOpenUri;                     /* True to interpret filenames as URIs */
2428   int mxStrlen;                     /* Maximum string length */
2429   int szLookaside;                  /* Default lookaside buffer size */
2430   int nLookaside;                   /* Default lookaside buffer count */
2431   sqlite3_mem_methods m;            /* Low-level memory allocation interface */
2432   sqlite3_mutex_methods mutex;      /* Low-level mutex interface */
2433   sqlite3_pcache_methods2 pcache2;  /* Low-level page-cache interface */
2434   void *pHeap;                      /* Heap storage space */
2435   int nHeap;                        /* Size of pHeap[] */
2436   int mnReq, mxReq;                 /* Min and max heap requests sizes */
2437   void *pScratch;                   /* Scratch memory */
2438   int szScratch;                    /* Size of each scratch buffer */
2439   int nScratch;                     /* Number of scratch buffers */
2440   void *pPage;                      /* Page cache memory */
2441   int szPage;                       /* Size of each page in pPage[] */
2442   int nPage;                        /* Number of pages in pPage[] */
2443   int mxParserStack;                /* maximum depth of the parser stack */
2444   int sharedCacheEnabled;           /* true if shared-cache mode enabled */
2445   /* The above might be initialized to non-zero.  The following need to always
2446   ** initially be zero, however. */
2447   int isInit;                       /* True after initialization has finished */
2448   int inProgress;                   /* True while initialization in progress */
2449   int isMutexInit;                  /* True after mutexes are initialized */
2450   int isMallocInit;                 /* True after malloc is initialized */
2451   int isPCacheInit;                 /* True after malloc is initialized */
2452   sqlite3_mutex *pInitMutex;        /* Mutex used by sqlite3_initialize() */
2453   int nRefInitMutex;                /* Number of users of pInitMutex */
2454   void (*xLog)(void*,int,const char*); /* Function for logging */
2455   void *pLogArg;                       /* First argument to xLog() */
2456   int bLocaltimeFault;              /* True to fail localtime() calls */
2457 };
2458 
2459 /*
2460 ** Context pointer passed down through the tree-walk.
2461 */
2462 struct Walker {
2463   int (*xExprCallback)(Walker*, Expr*);     /* Callback for expressions */
2464   int (*xSelectCallback)(Walker*,Select*);  /* Callback for SELECTs */
2465   Parse *pParse;                            /* Parser context.  */
2466   union {                                   /* Extra data for callback */
2467     NameContext *pNC;                          /* Naming context */
2468     int i;                                     /* Integer value */
2469   } u;
2470 };
2471 
2472 /* Forward declarations */
2473 int sqlite3WalkExpr(Walker*, Expr*);
2474 int sqlite3WalkExprList(Walker*, ExprList*);
2475 int sqlite3WalkSelect(Walker*, Select*);
2476 int sqlite3WalkSelectExpr(Walker*, Select*);
2477 int sqlite3WalkSelectFrom(Walker*, Select*);
2478 
2479 /*
2480 ** Return code from the parse-tree walking primitives and their
2481 ** callbacks.
2482 */
2483 #define WRC_Continue    0   /* Continue down into children */
2484 #define WRC_Prune       1   /* Omit children but continue walking siblings */
2485 #define WRC_Abort       2   /* Abandon the tree walk */
2486 
2487 /*
2488 ** Assuming zIn points to the first byte of a UTF-8 character,
2489 ** advance zIn to point to the first byte of the next UTF-8 character.
2490 */
2491 #define SQLITE_SKIP_UTF8(zIn) {                        \
2492   if( (*(zIn++))>=0xc0 ){                              \
2493     while( (*zIn & 0xc0)==0x80 ){ zIn++; }             \
2494   }                                                    \
2495 }
2496 
2497 /*
2498 ** The SQLITE_*_BKPT macros are substitutes for the error codes with
2499 ** the same name but without the _BKPT suffix.  These macros invoke
2500 ** routines that report the line-number on which the error originated
2501 ** using sqlite3_log().  The routines also provide a convenient place
2502 ** to set a debugger breakpoint.
2503 */
2504 int sqlite3CorruptError(int);
2505 int sqlite3MisuseError(int);
2506 int sqlite3CantopenError(int);
2507 #define SQLITE_CORRUPT_BKPT sqlite3CorruptError(__LINE__)
2508 #define SQLITE_MISUSE_BKPT sqlite3MisuseError(__LINE__)
2509 #define SQLITE_CANTOPEN_BKPT sqlite3CantopenError(__LINE__)
2510 
2511 
2512 /*
2513 ** FTS4 is really an extension for FTS3.  It is enabled using the
2514 ** SQLITE_ENABLE_FTS3 macro.  But to avoid confusion we also all
2515 ** the SQLITE_ENABLE_FTS4 macro to serve as an alisse for SQLITE_ENABLE_FTS3.
2516 */
2517 #if defined(SQLITE_ENABLE_FTS4) && !defined(SQLITE_ENABLE_FTS3)
2518 # define SQLITE_ENABLE_FTS3
2519 #endif
2520 
2521 /*
2522 ** The ctype.h header is needed for non-ASCII systems.  It is also
2523 ** needed by FTS3 when FTS3 is included in the amalgamation.
2524 */
2525 #if !defined(SQLITE_ASCII) || \
2526     (defined(SQLITE_ENABLE_FTS3) && defined(SQLITE_AMALGAMATION))
2527 # include <ctype.h>
2528 #endif
2529 
2530 /*
2531 ** The following macros mimic the standard library functions toupper(),
2532 ** isspace(), isalnum(), isdigit() and isxdigit(), respectively. The
2533 ** sqlite versions only work for ASCII characters, regardless of locale.
2534 */
2535 #ifdef SQLITE_ASCII
2536 # define sqlite3Toupper(x)  ((x)&~(sqlite3CtypeMap[(unsigned char)(x)]&0x20))
2537 # define sqlite3Isspace(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x01)
2538 # define sqlite3Isalnum(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x06)
2539 # define sqlite3Isalpha(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x02)
2540 # define sqlite3Isdigit(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x04)
2541 # define sqlite3Isxdigit(x)  (sqlite3CtypeMap[(unsigned char)(x)]&0x08)
2542 # define sqlite3Tolower(x)   (sqlite3UpperToLower[(unsigned char)(x)])
2543 #else
2544 # define sqlite3Toupper(x)   toupper((unsigned char)(x))
2545 # define sqlite3Isspace(x)   isspace((unsigned char)(x))
2546 # define sqlite3Isalnum(x)   isalnum((unsigned char)(x))
2547 # define sqlite3Isalpha(x)   isalpha((unsigned char)(x))
2548 # define sqlite3Isdigit(x)   isdigit((unsigned char)(x))
2549 # define sqlite3Isxdigit(x)  isxdigit((unsigned char)(x))
2550 # define sqlite3Tolower(x)   tolower((unsigned char)(x))
2551 #endif
2552 
2553 /*
2554 ** Internal function prototypes
2555 */
2556 #define sqlite3StrICmp sqlite3_stricmp
2557 int sqlite3Strlen30(const char*);
2558 #define sqlite3StrNICmp sqlite3_strnicmp
2559 
2560 int sqlite3MallocInit(void);
2561 void sqlite3MallocEnd(void);
2562 void *sqlite3Malloc(int);
2563 void *sqlite3MallocZero(int);
2564 void *sqlite3DbMallocZero(sqlite3*, int);
2565 void *sqlite3DbMallocRaw(sqlite3*, int);
2566 char *sqlite3DbStrDup(sqlite3*,const char*);
2567 char *sqlite3DbStrNDup(sqlite3*,const char*, int);
2568 void *sqlite3Realloc(void*, int);
2569 void *sqlite3DbReallocOrFree(sqlite3 *, void *, int);
2570 void *sqlite3DbRealloc(sqlite3 *, void *, int);
2571 void sqlite3DbFree(sqlite3*, void*);
2572 int sqlite3MallocSize(void*);
2573 int sqlite3DbMallocSize(sqlite3*, void*);
2574 void *sqlite3ScratchMalloc(int);
2575 void sqlite3ScratchFree(void*);
2576 void *sqlite3PageMalloc(int);
2577 void sqlite3PageFree(void*);
2578 void sqlite3MemSetDefault(void);
2579 void sqlite3BenignMallocHooks(void (*)(void), void (*)(void));
2580 int sqlite3HeapNearlyFull(void);
2581 
2582 /*
2583 ** On systems with ample stack space and that support alloca(), make
2584 ** use of alloca() to obtain space for large automatic objects.  By default,
2585 ** obtain space from malloc().
2586 **
2587 ** The alloca() routine never returns NULL.  This will cause code paths
2588 ** that deal with sqlite3StackAlloc() failures to be unreachable.
2589 */
2590 #ifdef SQLITE_USE_ALLOCA
2591 # define sqlite3StackAllocRaw(D,N)   alloca(N)
2592 # define sqlite3StackAllocZero(D,N)  memset(alloca(N), 0, N)
2593 # define sqlite3StackFree(D,P)
2594 #else
2595 # define sqlite3StackAllocRaw(D,N)   sqlite3DbMallocRaw(D,N)
2596 # define sqlite3StackAllocZero(D,N)  sqlite3DbMallocZero(D,N)
2597 # define sqlite3StackFree(D,P)       sqlite3DbFree(D,P)
2598 #endif
2599 
2600 #ifdef SQLITE_ENABLE_MEMSYS3
2601 const sqlite3_mem_methods *sqlite3MemGetMemsys3(void);
2602 #endif
2603 #ifdef SQLITE_ENABLE_MEMSYS5
2604 const sqlite3_mem_methods *sqlite3MemGetMemsys5(void);
2605 #endif
2606 
2607 
2608 #ifndef SQLITE_MUTEX_OMIT
2609   sqlite3_mutex_methods const *sqlite3DefaultMutex(void);
2610   sqlite3_mutex_methods const *sqlite3NoopMutex(void);
2611   sqlite3_mutex *sqlite3MutexAlloc(int);
2612   int sqlite3MutexInit(void);
2613   int sqlite3MutexEnd(void);
2614 #endif
2615 
2616 int sqlite3StatusValue(int);
2617 void sqlite3StatusAdd(int, int);
2618 void sqlite3StatusSet(int, int);
2619 
2620 #ifndef SQLITE_OMIT_FLOATING_POINT
2621   int sqlite3IsNaN(double);
2622 #else
2623 # define sqlite3IsNaN(X)  0
2624 #endif
2625 
2626 void sqlite3VXPrintf(StrAccum*, int, const char*, va_list);
2627 #ifndef SQLITE_OMIT_TRACE
2628 void sqlite3XPrintf(StrAccum*, const char*, ...);
2629 #endif
2630 char *sqlite3MPrintf(sqlite3*,const char*, ...);
2631 char *sqlite3VMPrintf(sqlite3*,const char*, va_list);
2632 char *sqlite3MAppendf(sqlite3*,char*,const char*,...);
2633 #if defined(SQLITE_TEST) || defined(SQLITE_DEBUG)
2634   void sqlite3DebugPrintf(const char*, ...);
2635 #endif
2636 #if defined(SQLITE_TEST)
2637   void *sqlite3TestTextToPtr(const char*);
2638 #endif
2639 
2640 /* Output formatting for SQLITE_TESTCTRL_EXPLAIN */
2641 #if defined(SQLITE_ENABLE_TREE_EXPLAIN)
2642   void sqlite3ExplainBegin(Vdbe*);
2643   void sqlite3ExplainPrintf(Vdbe*, const char*, ...);
2644   void sqlite3ExplainNL(Vdbe*);
2645   void sqlite3ExplainPush(Vdbe*);
2646   void sqlite3ExplainPop(Vdbe*);
2647   void sqlite3ExplainFinish(Vdbe*);
2648   void sqlite3ExplainSelect(Vdbe*, Select*);
2649   void sqlite3ExplainExpr(Vdbe*, Expr*);
2650   void sqlite3ExplainExprList(Vdbe*, ExprList*);
2651   const char *sqlite3VdbeExplanation(Vdbe*);
2652 #else
2653 # define sqlite3ExplainBegin(X)
2654 # define sqlite3ExplainSelect(A,B)
2655 # define sqlite3ExplainExpr(A,B)
2656 # define sqlite3ExplainExprList(A,B)
2657 # define sqlite3ExplainFinish(X)
2658 # define sqlite3VdbeExplanation(X) 0
2659 #endif
2660 
2661 
2662 void sqlite3SetString(char **, sqlite3*, const char*, ...);
2663 void sqlite3ErrorMsg(Parse*, const char*, ...);
2664 int sqlite3Dequote(char*);
2665 int sqlite3KeywordCode(const unsigned char*, int);
2666 int sqlite3RunParser(Parse*, const char*, char **);
2667 void sqlite3FinishCoding(Parse*);
2668 int sqlite3GetTempReg(Parse*);
2669 void sqlite3ReleaseTempReg(Parse*,int);
2670 int sqlite3GetTempRange(Parse*,int);
2671 void sqlite3ReleaseTempRange(Parse*,int,int);
2672 void sqlite3ClearTempRegCache(Parse*);
2673 Expr *sqlite3ExprAlloc(sqlite3*,int,const Token*,int);
2674 Expr *sqlite3Expr(sqlite3*,int,const char*);
2675 void sqlite3ExprAttachSubtrees(sqlite3*,Expr*,Expr*,Expr*);
2676 Expr *sqlite3PExpr(Parse*, int, Expr*, Expr*, const Token*);
2677 Expr *sqlite3ExprAnd(sqlite3*,Expr*, Expr*);
2678 Expr *sqlite3ExprFunction(Parse*,ExprList*, Token*);
2679 void sqlite3ExprAssignVarNumber(Parse*, Expr*);
2680 void sqlite3ExprDelete(sqlite3*, Expr*);
2681 ExprList *sqlite3ExprListAppend(Parse*,ExprList*,Expr*);
2682 void sqlite3ExprListSetName(Parse*,ExprList*,Token*,int);
2683 void sqlite3ExprListSetSpan(Parse*,ExprList*,ExprSpan*);
2684 void sqlite3ExprListDelete(sqlite3*, ExprList*);
2685 int sqlite3Init(sqlite3*, char**);
2686 int sqlite3InitCallback(void*, int, char**, char**);
2687 void sqlite3Pragma(Parse*,Token*,Token*,Token*,int);
2688 void sqlite3ResetInternalSchema(sqlite3*, int);
2689 void sqlite3BeginParse(Parse*,int);
2690 void sqlite3CommitInternalChanges(sqlite3*);
2691 Table *sqlite3ResultSetOfSelect(Parse*,Select*);
2692 void sqlite3OpenMasterTable(Parse *, int);
2693 void sqlite3StartTable(Parse*,Token*,Token*,int,int,int,int);
2694 void sqlite3AddColumn(Parse*,Token*);
2695 void sqlite3AddNotNull(Parse*, int);
2696 void sqlite3AddPrimaryKey(Parse*, ExprList*, int, int, int);
2697 void sqlite3AddCheckConstraint(Parse*, Expr*);
2698 void sqlite3AddColumnType(Parse*,Token*);
2699 void sqlite3AddDefaultValue(Parse*,ExprSpan*);
2700 void sqlite3AddCollateType(Parse*, Token*);
2701 void sqlite3EndTable(Parse*,Token*,Token*,Select*);
2702 int sqlite3ParseUri(const char*,const char*,unsigned int*,
2703                     sqlite3_vfs**,char**,char **);
2704 Btree *sqlite3DbNameToBtree(sqlite3*,const char*);
2705 int sqlite3CodeOnce(Parse *);
2706 
2707 Bitvec *sqlite3BitvecCreate(u32);
2708 int sqlite3BitvecTest(Bitvec*, u32);
2709 int sqlite3BitvecSet(Bitvec*, u32);
2710 void sqlite3BitvecClear(Bitvec*, u32, void*);
2711 void sqlite3BitvecDestroy(Bitvec*);
2712 u32 sqlite3BitvecSize(Bitvec*);
2713 int sqlite3BitvecBuiltinTest(int,int*);
2714 
2715 RowSet *sqlite3RowSetInit(sqlite3*, void*, unsigned int);
2716 void sqlite3RowSetClear(RowSet*);
2717 void sqlite3RowSetInsert(RowSet*, i64);
2718 int sqlite3RowSetTest(RowSet*, u8 iBatch, i64);
2719 int sqlite3RowSetNext(RowSet*, i64*);
2720 
2721 void sqlite3CreateView(Parse*,Token*,Token*,Token*,Select*,int,int);
2722 
2723 #if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE)
2724   int sqlite3ViewGetColumnNames(Parse*,Table*);
2725 #else
2726 # define sqlite3ViewGetColumnNames(A,B) 0
2727 #endif
2728 
2729 void sqlite3DropTable(Parse*, SrcList*, int, int);
2730 void sqlite3CodeDropTable(Parse*, Table*, int, int);
2731 void sqlite3DeleteTable(sqlite3*, Table*);
2732 #ifndef SQLITE_OMIT_AUTOINCREMENT
2733   void sqlite3AutoincrementBegin(Parse *pParse);
2734   void sqlite3AutoincrementEnd(Parse *pParse);
2735 #else
2736 # define sqlite3AutoincrementBegin(X)
2737 # define sqlite3AutoincrementEnd(X)
2738 #endif
2739 void sqlite3Insert(Parse*, SrcList*, ExprList*, Select*, IdList*, int);
2740 void *sqlite3ArrayAllocate(sqlite3*,void*,int,int*,int*);
2741 IdList *sqlite3IdListAppend(sqlite3*, IdList*, Token*);
2742 int sqlite3IdListIndex(IdList*,const char*);
2743 SrcList *sqlite3SrcListEnlarge(sqlite3*, SrcList*, int, int);
2744 SrcList *sqlite3SrcListAppend(sqlite3*, SrcList*, Token*, Token*);
2745 SrcList *sqlite3SrcListAppendFromTerm(Parse*, SrcList*, Token*, Token*,
2746                                       Token*, Select*, Expr*, IdList*);
2747 void sqlite3SrcListIndexedBy(Parse *, SrcList *, Token *);
2748 int sqlite3IndexedByLookup(Parse *, struct SrcList_item *);
2749 void sqlite3SrcListShiftJoinType(SrcList*);
2750 void sqlite3SrcListAssignCursors(Parse*, SrcList*);
2751 void sqlite3IdListDelete(sqlite3*, IdList*);
2752 void sqlite3SrcListDelete(sqlite3*, SrcList*);
2753 Index *sqlite3CreateIndex(Parse*,Token*,Token*,SrcList*,ExprList*,int,Token*,
2754                         Token*, int, int);
2755 void sqlite3DropIndex(Parse*, SrcList*, int);
2756 int sqlite3Select(Parse*, Select*, SelectDest*);
2757 Select *sqlite3SelectNew(Parse*,ExprList*,SrcList*,Expr*,ExprList*,
2758                          Expr*,ExprList*,int,Expr*,Expr*);
2759 void sqlite3SelectDelete(sqlite3*, Select*);
2760 Table *sqlite3SrcListLookup(Parse*, SrcList*);
2761 int sqlite3IsReadOnly(Parse*, Table*, int);
2762 void sqlite3OpenTable(Parse*, int iCur, int iDb, Table*, int);
2763 #if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY)
2764 Expr *sqlite3LimitWhere(Parse *, SrcList *, Expr *, ExprList *, Expr *, Expr *, char *);
2765 #endif
2766 void sqlite3DeleteFrom(Parse*, SrcList*, Expr*);
2767 void sqlite3Update(Parse*, SrcList*, ExprList*, Expr*, int);
2768 WhereInfo *sqlite3WhereBegin(Parse*, SrcList*, Expr*, ExprList**,ExprList*,u16);
2769 void sqlite3WhereEnd(WhereInfo*);
2770 int sqlite3ExprCodeGetColumn(Parse*, Table*, int, int, int);
2771 void sqlite3ExprCodeGetColumnOfTable(Vdbe*, Table*, int, int, int);
2772 void sqlite3ExprCodeMove(Parse*, int, int, int);
2773 void sqlite3ExprCodeCopy(Parse*, int, int, int);
2774 void sqlite3ExprCacheStore(Parse*, int, int, int);
2775 void sqlite3ExprCachePush(Parse*);
2776 void sqlite3ExprCachePop(Parse*, int);
2777 void sqlite3ExprCacheRemove(Parse*, int, int);
2778 void sqlite3ExprCacheClear(Parse*);
2779 void sqlite3ExprCacheAffinityChange(Parse*, int, int);
2780 int sqlite3ExprCode(Parse*, Expr*, int);
2781 int sqlite3ExprCodeTemp(Parse*, Expr*, int*);
2782 int sqlite3ExprCodeTarget(Parse*, Expr*, int);
2783 int sqlite3ExprCodeAndCache(Parse*, Expr*, int);
2784 void sqlite3ExprCodeConstants(Parse*, Expr*);
2785 int sqlite3ExprCodeExprList(Parse*, ExprList*, int, int);
2786 void sqlite3ExprIfTrue(Parse*, Expr*, int, int);
2787 void sqlite3ExprIfFalse(Parse*, Expr*, int, int);
2788 Table *sqlite3FindTable(sqlite3*,const char*, const char*);
2789 Table *sqlite3LocateTable(Parse*,int isView,const char*, const char*);
2790 Index *sqlite3FindIndex(sqlite3*,const char*, const char*);
2791 void sqlite3UnlinkAndDeleteTable(sqlite3*,int,const char*);
2792 void sqlite3UnlinkAndDeleteIndex(sqlite3*,int,const char*);
2793 void sqlite3Vacuum(Parse*);
2794 int sqlite3RunVacuum(char**, sqlite3*);
2795 char *sqlite3NameFromToken(sqlite3*, Token*);
2796 int sqlite3ExprCompare(Expr*, Expr*);
2797 int sqlite3ExprListCompare(ExprList*, ExprList*);
2798 void sqlite3ExprAnalyzeAggregates(NameContext*, Expr*);
2799 void sqlite3ExprAnalyzeAggList(NameContext*,ExprList*);
2800 Vdbe *sqlite3GetVdbe(Parse*);
2801 void sqlite3PrngSaveState(void);
2802 void sqlite3PrngRestoreState(void);
2803 void sqlite3PrngResetState(void);
2804 void sqlite3RollbackAll(sqlite3*,int);
2805 void sqlite3CodeVerifySchema(Parse*, int);
2806 void sqlite3CodeVerifyNamedSchema(Parse*, const char *zDb);
2807 void sqlite3BeginTransaction(Parse*, int);
2808 void sqlite3CommitTransaction(Parse*);
2809 void sqlite3RollbackTransaction(Parse*);
2810 void sqlite3Savepoint(Parse*, int, Token*);
2811 void sqlite3CloseSavepoints(sqlite3 *);
2812 int sqlite3ExprIsConstant(Expr*);
2813 int sqlite3ExprIsConstantNotJoin(Expr*);
2814 int sqlite3ExprIsConstantOrFunction(Expr*);
2815 int sqlite3ExprIsInteger(Expr*, int*);
2816 int sqlite3ExprCanBeNull(const Expr*);
2817 void sqlite3ExprCodeIsNullJump(Vdbe*, const Expr*, int, int);
2818 int sqlite3ExprNeedsNoAffinityChange(const Expr*, char);
2819 int sqlite3IsRowid(const char*);
2820 void sqlite3GenerateRowDelete(Parse*, Table*, int, int, int, Trigger *, int);
2821 void sqlite3GenerateRowIndexDelete(Parse*, Table*, int, int*);
2822 int sqlite3GenerateIndexKey(Parse*, Index*, int, int, int);
2823 void sqlite3GenerateConstraintChecks(Parse*,Table*,int,int,
2824                                      int*,int,int,int,int,int*);
2825 void sqlite3CompleteInsertion(Parse*, Table*, int, int, int*, int, int, int);
2826 int sqlite3OpenTableAndIndices(Parse*, Table*, int, int);
2827 void sqlite3BeginWriteOperation(Parse*, int, int);
2828 void sqlite3MultiWrite(Parse*);
2829 void sqlite3MayAbort(Parse*);
2830 void sqlite3HaltConstraint(Parse*, int, char*, int);
2831 Expr *sqlite3ExprDup(sqlite3*,Expr*,int);
2832 ExprList *sqlite3ExprListDup(sqlite3*,ExprList*,int);
2833 SrcList *sqlite3SrcListDup(sqlite3*,SrcList*,int);
2834 IdList *sqlite3IdListDup(sqlite3*,IdList*);
2835 Select *sqlite3SelectDup(sqlite3*,Select*,int);
2836 void sqlite3FuncDefInsert(FuncDefHash*, FuncDef*);
2837 FuncDef *sqlite3FindFunction(sqlite3*,const char*,int,int,u8,int);
2838 void sqlite3RegisterBuiltinFunctions(sqlite3*);
2839 void sqlite3RegisterDateTimeFunctions(void);
2840 void sqlite3RegisterGlobalFunctions(void);
2841 int sqlite3SafetyCheckOk(sqlite3*);
2842 int sqlite3SafetyCheckSickOrOk(sqlite3*);
2843 void sqlite3ChangeCookie(Parse*, int);
2844 
2845 #if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
2846 void sqlite3MaterializeView(Parse*, Table*, Expr*, int);
2847 #endif
2848 
2849 #ifndef SQLITE_OMIT_TRIGGER
2850   void sqlite3BeginTrigger(Parse*, Token*,Token*,int,int,IdList*,SrcList*,
2851                            Expr*,int, int);
2852   void sqlite3FinishTrigger(Parse*, TriggerStep*, Token*);
2853   void sqlite3DropTrigger(Parse*, SrcList*, int);
2854   void sqlite3DropTriggerPtr(Parse*, Trigger*);
2855   Trigger *sqlite3TriggersExist(Parse *, Table*, int, ExprList*, int *pMask);
2856   Trigger *sqlite3TriggerList(Parse *, Table *);
2857   void sqlite3CodeRowTrigger(Parse*, Trigger *, int, ExprList*, int, Table *,
2858                             int, int, int);
2859   void sqlite3CodeRowTriggerDirect(Parse *, Trigger *, Table *, int, int, int);
2860   void sqliteViewTriggers(Parse*, Table*, Expr*, int, ExprList*);
2861   void sqlite3DeleteTriggerStep(sqlite3*, TriggerStep*);
2862   TriggerStep *sqlite3TriggerSelectStep(sqlite3*,Select*);
2863   TriggerStep *sqlite3TriggerInsertStep(sqlite3*,Token*, IdList*,
2864                                         ExprList*,Select*,u8);
2865   TriggerStep *sqlite3TriggerUpdateStep(sqlite3*,Token*,ExprList*, Expr*, u8);
2866   TriggerStep *sqlite3TriggerDeleteStep(sqlite3*,Token*, Expr*);
2867   void sqlite3DeleteTrigger(sqlite3*, Trigger*);
2868   void sqlite3UnlinkAndDeleteTrigger(sqlite3*,int,const char*);
2869   u32 sqlite3TriggerColmask(Parse*,Trigger*,ExprList*,int,int,Table*,int);
2870 # define sqlite3ParseToplevel(p) ((p)->pToplevel ? (p)->pToplevel : (p))
2871 #else
2872 # define sqlite3TriggersExist(B,C,D,E,F) 0
2873 # define sqlite3DeleteTrigger(A,B)
2874 # define sqlite3DropTriggerPtr(A,B)
2875 # define sqlite3UnlinkAndDeleteTrigger(A,B,C)
2876 # define sqlite3CodeRowTrigger(A,B,C,D,E,F,G,H,I)
2877 # define sqlite3CodeRowTriggerDirect(A,B,C,D,E,F)
2878 # define sqlite3TriggerList(X, Y) 0
2879 # define sqlite3ParseToplevel(p) p
2880 # define sqlite3TriggerColmask(A,B,C,D,E,F,G) 0
2881 #endif
2882 
2883 int sqlite3JoinType(Parse*, Token*, Token*, Token*);
2884 void sqlite3CreateForeignKey(Parse*, ExprList*, Token*, ExprList*, int);
2885 void sqlite3DeferForeignKey(Parse*, int);
2886 #ifndef SQLITE_OMIT_AUTHORIZATION
2887   void sqlite3AuthRead(Parse*,Expr*,Schema*,SrcList*);
2888   int sqlite3AuthCheck(Parse*,int, const char*, const char*, const char*);
2889   void sqlite3AuthContextPush(Parse*, AuthContext*, const char*);
2890   void sqlite3AuthContextPop(AuthContext*);
2891   int sqlite3AuthReadCol(Parse*, const char *, const char *, int);
2892 #else
2893 # define sqlite3AuthRead(a,b,c,d)
2894 # define sqlite3AuthCheck(a,b,c,d,e)    SQLITE_OK
2895 # define sqlite3AuthContextPush(a,b,c)
2896 # define sqlite3AuthContextPop(a)  ((void)(a))
2897 #endif
2898 void sqlite3Attach(Parse*, Expr*, Expr*, Expr*);
2899 void sqlite3Detach(Parse*, Expr*);
2900 int sqlite3FixInit(DbFixer*, Parse*, int, const char*, const Token*);
2901 int sqlite3FixSrcList(DbFixer*, SrcList*);
2902 int sqlite3FixSelect(DbFixer*, Select*);
2903 int sqlite3FixExpr(DbFixer*, Expr*);
2904 int sqlite3FixExprList(DbFixer*, ExprList*);
2905 int sqlite3FixTriggerStep(DbFixer*, TriggerStep*);
2906 int sqlite3AtoF(const char *z, double*, int, u8);
2907 int sqlite3GetInt32(const char *, int*);
2908 int sqlite3Atoi(const char*);
2909 int sqlite3Utf16ByteLen(const void *pData, int nChar);
2910 int sqlite3Utf8CharLen(const char *pData, int nByte);
2911 u32 sqlite3Utf8Read(const u8*, const u8**);
2912 
2913 /*
2914 ** Routines to read and write variable-length integers.  These used to
2915 ** be defined locally, but now we use the varint routines in the util.c
2916 ** file.  Code should use the MACRO forms below, as the Varint32 versions
2917 ** are coded to assume the single byte case is already handled (which
2918 ** the MACRO form does).
2919 */
2920 int sqlite3PutVarint(unsigned char*, u64);
2921 int sqlite3PutVarint32(unsigned char*, u32);
2922 u8 sqlite3GetVarint(const unsigned char *, u64 *);
2923 u8 sqlite3GetVarint32(const unsigned char *, u32 *);
2924 int sqlite3VarintLen(u64 v);
2925 
2926 /*
2927 ** The header of a record consists of a sequence variable-length integers.
2928 ** These integers are almost always small and are encoded as a single byte.
2929 ** The following macros take advantage this fact to provide a fast encode
2930 ** and decode of the integers in a record header.  It is faster for the common
2931 ** case where the integer is a single byte.  It is a little slower when the
2932 ** integer is two or more bytes.  But overall it is faster.
2933 **
2934 ** The following expressions are equivalent:
2935 **
2936 **     x = sqlite3GetVarint32( A, &B );
2937 **     x = sqlite3PutVarint32( A, B );
2938 **
2939 **     x = getVarint32( A, B );
2940 **     x = putVarint32( A, B );
2941 **
2942 */
2943 #define getVarint32(A,B)  (u8)((*(A)<(u8)0x80) ? ((B) = (u32)*(A)),1 : sqlite3GetVarint32((A), (u32 *)&(B)))
2944 #define putVarint32(A,B)  (u8)(((u32)(B)<(u32)0x80) ? (*(A) = (unsigned char)(B)),1 : sqlite3PutVarint32((A), (B)))
2945 #define getVarint    sqlite3GetVarint
2946 #define putVarint    sqlite3PutVarint
2947 
2948 
2949 const char *sqlite3IndexAffinityStr(Vdbe *, Index *);
2950 void sqlite3TableAffinityStr(Vdbe *, Table *);
2951 char sqlite3CompareAffinity(Expr *pExpr, char aff2);
2952 int sqlite3IndexAffinityOk(Expr *pExpr, char idx_affinity);
2953 char sqlite3ExprAffinity(Expr *pExpr);
2954 int sqlite3Atoi64(const char*, i64*, int, u8);
2955 void sqlite3Error(sqlite3*, int, const char*,...);
2956 void *sqlite3HexToBlob(sqlite3*, const char *z, int n);
2957 u8 sqlite3HexToInt(int h);
2958 int sqlite3TwoPartName(Parse *, Token *, Token *, Token **);
2959 const char *sqlite3ErrStr(int);
2960 int sqlite3ReadSchema(Parse *pParse);
2961 CollSeq *sqlite3FindCollSeq(sqlite3*,u8 enc, const char*,int);
2962 CollSeq *sqlite3LocateCollSeq(Parse *pParse, const char*zName);
2963 CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr);
2964 Expr *sqlite3ExprSetColl(Expr*, CollSeq*);
2965 Expr *sqlite3ExprSetCollByToken(Parse *pParse, Expr*, Token*);
2966 int sqlite3CheckCollSeq(Parse *, CollSeq *);
2967 int sqlite3CheckObjectName(Parse *, const char *);
2968 void sqlite3VdbeSetChanges(sqlite3 *, int);
2969 int sqlite3AddInt64(i64*,i64);
2970 int sqlite3SubInt64(i64*,i64);
2971 int sqlite3MulInt64(i64*,i64);
2972 int sqlite3AbsInt32(int);
2973 #ifdef SQLITE_ENABLE_8_3_NAMES
2974 void sqlite3FileSuffix3(const char*, char*);
2975 #else
2976 # define sqlite3FileSuffix3(X,Y)
2977 #endif
2978 u8 sqlite3GetBoolean(const char *z,int);
2979 
2980 const void *sqlite3ValueText(sqlite3_value*, u8);
2981 int sqlite3ValueBytes(sqlite3_value*, u8);
2982 void sqlite3ValueSetStr(sqlite3_value*, int, const void *,u8,
2983                         void(*)(void*));
2984 void sqlite3ValueFree(sqlite3_value*);
2985 sqlite3_value *sqlite3ValueNew(sqlite3 *);
2986 char *sqlite3Utf16to8(sqlite3 *, const void*, int, u8);
2987 #ifdef SQLITE_ENABLE_STAT3
2988 char *sqlite3Utf8to16(sqlite3 *, u8, char *, int, int *);
2989 #endif
2990 int sqlite3ValueFromExpr(sqlite3 *, Expr *, u8, u8, sqlite3_value **);
2991 void sqlite3ValueApplyAffinity(sqlite3_value *, u8, u8);
2992 #ifndef SQLITE_AMALGAMATION
2993 extern const unsigned char sqlite3OpcodeProperty[];
2994 extern const unsigned char sqlite3UpperToLower[];
2995 extern const unsigned char sqlite3CtypeMap[];
2996 extern const Token sqlite3IntTokens[];
2997 extern SQLITE_WSD struct Sqlite3Config sqlite3Config;
2998 extern SQLITE_WSD FuncDefHash sqlite3GlobalFunctions;
2999 #ifndef SQLITE_OMIT_WSD
3000 extern int sqlite3PendingByte;
3001 #endif
3002 #endif
3003 void sqlite3RootPageMoved(sqlite3*, int, int, int);
3004 void sqlite3Reindex(Parse*, Token*, Token*);
3005 void sqlite3AlterFunctions(void);
3006 void sqlite3AlterRenameTable(Parse*, SrcList*, Token*);
3007 int sqlite3GetToken(const unsigned char *, int *);
3008 void sqlite3NestedParse(Parse*, const char*, ...);
3009 void sqlite3ExpirePreparedStatements(sqlite3*);
3010 int sqlite3CodeSubselect(Parse *, Expr *, int, int);
3011 void sqlite3SelectPrep(Parse*, Select*, NameContext*);
3012 int sqlite3ResolveExprNames(NameContext*, Expr*);
3013 void sqlite3ResolveSelectNames(Parse*, Select*, NameContext*);
3014 int sqlite3ResolveOrderGroupBy(Parse*, Select*, ExprList*, const char*);
3015 void sqlite3ColumnDefault(Vdbe *, Table *, int, int);
3016 void sqlite3AlterFinishAddColumn(Parse *, Token *);
3017 void sqlite3AlterBeginAddColumn(Parse *, SrcList *);
3018 CollSeq *sqlite3GetCollSeq(sqlite3*, u8, CollSeq *, const char*);
3019 char sqlite3AffinityType(const char*);
3020 void sqlite3Analyze(Parse*, Token*, Token*);
3021 int sqlite3InvokeBusyHandler(BusyHandler*);
3022 int sqlite3FindDb(sqlite3*, Token*);
3023 int sqlite3FindDbName(sqlite3 *, const char *);
3024 int sqlite3AnalysisLoad(sqlite3*,int iDB);
3025 void sqlite3DeleteIndexSamples(sqlite3*,Index*);
3026 void sqlite3DefaultRowEst(Index*);
3027 void sqlite3RegisterLikeFunctions(sqlite3*, int);
3028 int sqlite3IsLikeFunction(sqlite3*,Expr*,int*,char*);
3029 void sqlite3MinimumFileFormat(Parse*, int, int);
3030 void sqlite3SchemaClear(void *);
3031 Schema *sqlite3SchemaGet(sqlite3 *, Btree *);
3032 int sqlite3SchemaToIndex(sqlite3 *db, Schema *);
3033 KeyInfo *sqlite3IndexKeyinfo(Parse *, Index *);
3034 int sqlite3CreateFunc(sqlite3 *, const char *, int, int, void *,
3035   void (*)(sqlite3_context*,int,sqlite3_value **),
3036   void (*)(sqlite3_context*,int,sqlite3_value **), void (*)(sqlite3_context*),
3037   FuncDestructor *pDestructor
3038 );
3039 int sqlite3ApiExit(sqlite3 *db, int);
3040 int sqlite3OpenTempDatabase(Parse *);
3041 
3042 void sqlite3StrAccumInit(StrAccum*, char*, int, int);
3043 void sqlite3StrAccumAppend(StrAccum*,const char*,int);
3044 void sqlite3AppendSpace(StrAccum*,int);
3045 char *sqlite3StrAccumFinish(StrAccum*);
3046 void sqlite3StrAccumReset(StrAccum*);
3047 void sqlite3SelectDestInit(SelectDest*,int,int);
3048 Expr *sqlite3CreateColumnExpr(sqlite3 *, SrcList *, int, int);
3049 
3050 void sqlite3BackupRestart(sqlite3_backup *);
3051 void sqlite3BackupUpdate(sqlite3_backup *, Pgno, const u8 *);
3052 
3053 /*
3054 ** The interface to the LEMON-generated parser
3055 */
3056 void *sqlite3ParserAlloc(void*(*)(size_t));
3057 void sqlite3ParserFree(void*, void(*)(void*));
3058 void sqlite3Parser(void*, int, Token, Parse*);
3059 #ifdef YYTRACKMAXSTACKDEPTH
3060   int sqlite3ParserStackPeak(void*);
3061 #endif
3062 
3063 void sqlite3AutoLoadExtensions(sqlite3*);
3064 #ifndef SQLITE_OMIT_LOAD_EXTENSION
3065   void sqlite3CloseExtensions(sqlite3*);
3066 #else
3067 # define sqlite3CloseExtensions(X)
3068 #endif
3069 
3070 #ifndef SQLITE_OMIT_SHARED_CACHE
3071   void sqlite3TableLock(Parse *, int, int, u8, const char *);
3072 #else
3073   #define sqlite3TableLock(v,w,x,y,z)
3074 #endif
3075 
3076 #ifdef SQLITE_TEST
3077   int sqlite3Utf8To8(unsigned char*);
3078 #endif
3079 
3080 #ifdef SQLITE_OMIT_VIRTUALTABLE
3081 #  define sqlite3VtabClear(Y)
3082 #  define sqlite3VtabSync(X,Y) SQLITE_OK
3083 #  define sqlite3VtabRollback(X)
3084 #  define sqlite3VtabCommit(X)
3085 #  define sqlite3VtabInSync(db) 0
3086 #  define sqlite3VtabLock(X)
3087 #  define sqlite3VtabUnlock(X)
3088 #  define sqlite3VtabUnlockList(X)
3089 #  define sqlite3VtabSavepoint(X, Y, Z) SQLITE_OK
3090 #  define sqlite3GetVTable(X,Y)  ((VTable*)0)
3091 #else
3092    void sqlite3VtabClear(sqlite3 *db, Table*);
3093    int sqlite3VtabSync(sqlite3 *db, char **);
3094    int sqlite3VtabRollback(sqlite3 *db);
3095    int sqlite3VtabCommit(sqlite3 *db);
3096    void sqlite3VtabLock(VTable *);
3097    void sqlite3VtabUnlock(VTable *);
3098    void sqlite3VtabUnlockList(sqlite3*);
3099    int sqlite3VtabSavepoint(sqlite3 *, int, int);
3100    VTable *sqlite3GetVTable(sqlite3*, Table*);
3101 #  define sqlite3VtabInSync(db) ((db)->nVTrans>0 && (db)->aVTrans==0)
3102 #endif
3103 void sqlite3VtabMakeWritable(Parse*,Table*);
3104 void sqlite3VtabBeginParse(Parse*, Token*, Token*, Token*, int);
3105 void sqlite3VtabFinishParse(Parse*, Token*);
3106 void sqlite3VtabArgInit(Parse*);
3107 void sqlite3VtabArgExtend(Parse*, Token*);
3108 int sqlite3VtabCallCreate(sqlite3*, int, const char *, char **);
3109 int sqlite3VtabCallConnect(Parse*, Table*);
3110 int sqlite3VtabCallDestroy(sqlite3*, int, const char *);
3111 int sqlite3VtabBegin(sqlite3 *, VTable *);
3112 FuncDef *sqlite3VtabOverloadFunction(sqlite3 *,FuncDef*, int nArg, Expr*);
3113 void sqlite3InvalidFunction(sqlite3_context*,int,sqlite3_value**);
3114 int sqlite3VdbeParameterIndex(Vdbe*, const char*, int);
3115 int sqlite3TransferBindings(sqlite3_stmt *, sqlite3_stmt *);
3116 int sqlite3Reprepare(Vdbe*);
3117 void sqlite3ExprListCheckLength(Parse*, ExprList*, const char*);
3118 CollSeq *sqlite3BinaryCompareCollSeq(Parse *, Expr *, Expr *);
3119 int sqlite3TempInMemory(const sqlite3*);
3120 const char *sqlite3JournalModename(int);
3121 int sqlite3Checkpoint(sqlite3*, int, int, int*, int*);
3122 int sqlite3WalDefaultHook(void*,sqlite3*,const char*,int);
3123 
3124 /* Declarations for functions in fkey.c. All of these are replaced by
3125 ** no-op macros if OMIT_FOREIGN_KEY is defined. In this case no foreign
3126 ** key functionality is available. If OMIT_TRIGGER is defined but
3127 ** OMIT_FOREIGN_KEY is not, only some of the functions are no-oped. In
3128 ** this case foreign keys are parsed, but no other functionality is
3129 ** provided (enforcement of FK constraints requires the triggers sub-system).
3130 */
3131 #if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)
3132   void sqlite3FkCheck(Parse*, Table*, int, int);
3133   void sqlite3FkDropTable(Parse*, SrcList *, Table*);
3134   void sqlite3FkActions(Parse*, Table*, ExprList*, int);
3135   int sqlite3FkRequired(Parse*, Table*, int*, int);
3136   u32 sqlite3FkOldmask(Parse*, Table*);
3137   FKey *sqlite3FkReferences(Table *);
3138 #else
3139   #define sqlite3FkActions(a,b,c,d)
3140   #define sqlite3FkCheck(a,b,c,d)
3141   #define sqlite3FkDropTable(a,b,c)
3142   #define sqlite3FkOldmask(a,b)      0
3143   #define sqlite3FkRequired(a,b,c,d) 0
3144 #endif
3145 #ifndef SQLITE_OMIT_FOREIGN_KEY
3146   void sqlite3FkDelete(sqlite3 *, Table*);
3147 #else
3148   #define sqlite3FkDelete(a,b)
3149 #endif
3150 
3151 
3152 /*
3153 ** Available fault injectors.  Should be numbered beginning with 0.
3154 */
3155 #define SQLITE_FAULTINJECTOR_MALLOC     0
3156 #define SQLITE_FAULTINJECTOR_COUNT      1
3157 
3158 /*
3159 ** The interface to the code in fault.c used for identifying "benign"
3160 ** malloc failures. This is only present if SQLITE_OMIT_BUILTIN_TEST
3161 ** is not defined.
3162 */
3163 #ifndef SQLITE_OMIT_BUILTIN_TEST
3164   void sqlite3BeginBenignMalloc(void);
3165   void sqlite3EndBenignMalloc(void);
3166 #else
3167   #define sqlite3BeginBenignMalloc()
3168   #define sqlite3EndBenignMalloc()
3169 #endif
3170 
3171 #define IN_INDEX_ROWID           1
3172 #define IN_INDEX_EPH             2
3173 #define IN_INDEX_INDEX           3
3174 int sqlite3FindInIndex(Parse *, Expr *, int*);
3175 
3176 #ifdef SQLITE_ENABLE_ATOMIC_WRITE
3177   int sqlite3JournalOpen(sqlite3_vfs *, const char *, sqlite3_file *, int, int);
3178   int sqlite3JournalSize(sqlite3_vfs *);
3179   int sqlite3JournalCreate(sqlite3_file *);
3180 #else
3181   #define sqlite3JournalSize(pVfs) ((pVfs)->szOsFile)
3182 #endif
3183 
3184 void sqlite3MemJournalOpen(sqlite3_file *);
3185 int sqlite3MemJournalSize(void);
3186 int sqlite3IsMemJournal(sqlite3_file *);
3187 
3188 #if SQLITE_MAX_EXPR_DEPTH>0
3189   void sqlite3ExprSetHeight(Parse *pParse, Expr *p);
3190   int sqlite3SelectExprHeight(Select *);
3191   int sqlite3ExprCheckHeight(Parse*, int);
3192 #else
3193   #define sqlite3ExprSetHeight(x,y)
3194   #define sqlite3SelectExprHeight(x) 0
3195   #define sqlite3ExprCheckHeight(x,y)
3196 #endif
3197 
3198 u32 sqlite3Get4byte(const u8*);
3199 void sqlite3Put4byte(u8*, u32);
3200 
3201 #ifdef SQLITE_ENABLE_UNLOCK_NOTIFY
3202   void sqlite3ConnectionBlocked(sqlite3 *, sqlite3 *);
3203   void sqlite3ConnectionUnlocked(sqlite3 *db);
3204   void sqlite3ConnectionClosed(sqlite3 *db);
3205 #else
3206   #define sqlite3ConnectionBlocked(x,y)
3207   #define sqlite3ConnectionUnlocked(x)
3208   #define sqlite3ConnectionClosed(x)
3209 #endif
3210 
3211 #ifdef SQLITE_DEBUG
3212   void sqlite3ParserTrace(FILE*, char *);
3213 #endif
3214 
3215 /*
3216 ** If the SQLITE_ENABLE IOTRACE exists then the global variable
3217 ** sqlite3IoTrace is a pointer to a printf-like routine used to
3218 ** print I/O tracing messages.
3219 */
3220 #ifdef SQLITE_ENABLE_IOTRACE
3221 # define IOTRACE(A)  if( sqlite3IoTrace ){ sqlite3IoTrace A; }
3222   void sqlite3VdbeIOTraceSql(Vdbe*);
3223 SQLITE_EXTERN void (*sqlite3IoTrace)(const char*,...);
3224 #else
3225 # define IOTRACE(A)
3226 # define sqlite3VdbeIOTraceSql(X)
3227 #endif
3228 
3229 /*
3230 ** These routines are available for the mem2.c debugging memory allocator
3231 ** only.  They are used to verify that different "types" of memory
3232 ** allocations are properly tracked by the system.
3233 **
3234 ** sqlite3MemdebugSetType() sets the "type" of an allocation to one of
3235 ** the MEMTYPE_* macros defined below.  The type must be a bitmask with
3236 ** a single bit set.
3237 **
3238 ** sqlite3MemdebugHasType() returns true if any of the bits in its second
3239 ** argument match the type set by the previous sqlite3MemdebugSetType().
3240 ** sqlite3MemdebugHasType() is intended for use inside assert() statements.
3241 **
3242 ** sqlite3MemdebugNoType() returns true if none of the bits in its second
3243 ** argument match the type set by the previous sqlite3MemdebugSetType().
3244 **
3245 ** Perhaps the most important point is the difference between MEMTYPE_HEAP
3246 ** and MEMTYPE_LOOKASIDE.  If an allocation is MEMTYPE_LOOKASIDE, that means
3247 ** it might have been allocated by lookaside, except the allocation was
3248 ** too large or lookaside was already full.  It is important to verify
3249 ** that allocations that might have been satisfied by lookaside are not
3250 ** passed back to non-lookaside free() routines.  Asserts such as the
3251 ** example above are placed on the non-lookaside free() routines to verify
3252 ** this constraint.
3253 **
3254 ** All of this is no-op for a production build.  It only comes into
3255 ** play when the SQLITE_MEMDEBUG compile-time option is used.
3256 */
3257 #ifdef SQLITE_MEMDEBUG
3258   void sqlite3MemdebugSetType(void*,u8);
3259   int sqlite3MemdebugHasType(void*,u8);
3260   int sqlite3MemdebugNoType(void*,u8);
3261 #else
3262 # define sqlite3MemdebugSetType(X,Y)  /* no-op */
3263 # define sqlite3MemdebugHasType(X,Y)  1
3264 # define sqlite3MemdebugNoType(X,Y)   1
3265 #endif
3266 #define MEMTYPE_HEAP       0x01  /* General heap allocations */
3267 #define MEMTYPE_LOOKASIDE  0x02  /* Might have been lookaside memory */
3268 #define MEMTYPE_SCRATCH    0x04  /* Scratch allocations */
3269 #define MEMTYPE_PCACHE     0x08  /* Page cache allocations */
3270 #define MEMTYPE_DB         0x10  /* Uses sqlite3DbMalloc, not sqlite_malloc */
3271 
3272 #endif /* _SQLITEINT_H_ */
3273