xref: /sqlite-3.40.0/src/func.c (revision 2e27d28f)
1 /*
2 ** 2002 February 23
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 ** This file contains the C-language implementations for many of the SQL
13 ** functions of SQLite.  (Some function, and in particular the date and
14 ** time functions, are implemented separately.)
15 */
16 #include "sqliteInt.h"
17 #include <stdlib.h>
18 #include <assert.h>
19 #include "vdbeInt.h"
20 
21 /*
22 ** Return the collating function associated with a function.
23 */
24 static CollSeq *sqlite3GetFuncCollSeq(sqlite3_context *context){
25   VdbeOp *pOp;
26   assert( context->pVdbe!=0 );
27   pOp = &context->pVdbe->aOp[context->iOp-1];
28   assert( pOp->opcode==OP_CollSeq );
29   assert( pOp->p4type==P4_COLLSEQ );
30   return pOp->p4.pColl;
31 }
32 
33 /*
34 ** Indicate that the accumulator load should be skipped on this
35 ** iteration of the aggregate loop.
36 */
37 static void sqlite3SkipAccumulatorLoad(sqlite3_context *context){
38   context->skipFlag = 1;
39 }
40 
41 /*
42 ** Implementation of the non-aggregate min() and max() functions
43 */
44 static void minmaxFunc(
45   sqlite3_context *context,
46   int argc,
47   sqlite3_value **argv
48 ){
49   int i;
50   int mask;    /* 0 for min() or 0xffffffff for max() */
51   int iBest;
52   CollSeq *pColl;
53 
54   assert( argc>1 );
55   mask = sqlite3_user_data(context)==0 ? 0 : -1;
56   pColl = sqlite3GetFuncCollSeq(context);
57   assert( pColl );
58   assert( mask==-1 || mask==0 );
59   iBest = 0;
60   if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
61   for(i=1; i<argc; i++){
62     if( sqlite3_value_type(argv[i])==SQLITE_NULL ) return;
63     if( (sqlite3MemCompare(argv[iBest], argv[i], pColl)^mask)>=0 ){
64       testcase( mask==0 );
65       iBest = i;
66     }
67   }
68   sqlite3_result_value(context, argv[iBest]);
69 }
70 
71 /*
72 ** Return the type of the argument.
73 */
74 static void typeofFunc(
75   sqlite3_context *context,
76   int NotUsed,
77   sqlite3_value **argv
78 ){
79   static const char *azType[] = { "integer", "real", "text", "blob", "null" };
80   int i = sqlite3_value_type(argv[0]) - 1;
81   UNUSED_PARAMETER(NotUsed);
82   assert( i>=0 && i<ArraySize(azType) );
83   assert( SQLITE_INTEGER==1 );
84   assert( SQLITE_FLOAT==2 );
85   assert( SQLITE_TEXT==3 );
86   assert( SQLITE_BLOB==4 );
87   assert( SQLITE_NULL==5 );
88   /* EVIDENCE-OF: R-01470-60482 The sqlite3_value_type(V) interface returns
89   ** the datatype code for the initial datatype of the sqlite3_value object
90   ** V. The returned value is one of SQLITE_INTEGER, SQLITE_FLOAT,
91   ** SQLITE_TEXT, SQLITE_BLOB, or SQLITE_NULL. */
92   sqlite3_result_text(context, azType[i], -1, SQLITE_STATIC);
93 }
94 
95 
96 /*
97 ** Implementation of the length() function
98 */
99 static void lengthFunc(
100   sqlite3_context *context,
101   int argc,
102   sqlite3_value **argv
103 ){
104   int len;
105 
106   assert( argc==1 );
107   UNUSED_PARAMETER(argc);
108   switch( sqlite3_value_type(argv[0]) ){
109     case SQLITE_BLOB:
110     case SQLITE_INTEGER:
111     case SQLITE_FLOAT: {
112       sqlite3_result_int(context, sqlite3_value_bytes(argv[0]));
113       break;
114     }
115     case SQLITE_TEXT: {
116       const unsigned char *z = sqlite3_value_text(argv[0]);
117       if( z==0 ) return;
118       len = 0;
119       while( *z ){
120         len++;
121         SQLITE_SKIP_UTF8(z);
122       }
123       sqlite3_result_int(context, len);
124       break;
125     }
126     default: {
127       sqlite3_result_null(context);
128       break;
129     }
130   }
131 }
132 
133 /*
134 ** Implementation of the abs() function.
135 **
136 ** IMP: R-23979-26855 The abs(X) function returns the absolute value of
137 ** the numeric argument X.
138 */
139 static void absFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
140   assert( argc==1 );
141   UNUSED_PARAMETER(argc);
142   switch( sqlite3_value_type(argv[0]) ){
143     case SQLITE_INTEGER: {
144       i64 iVal = sqlite3_value_int64(argv[0]);
145       if( iVal<0 ){
146         if( iVal==SMALLEST_INT64 ){
147           /* IMP: R-31676-45509 If X is the integer -9223372036854775808
148           ** then abs(X) throws an integer overflow error since there is no
149           ** equivalent positive 64-bit two complement value. */
150           sqlite3_result_error(context, "integer overflow", -1);
151           return;
152         }
153         iVal = -iVal;
154       }
155       sqlite3_result_int64(context, iVal);
156       break;
157     }
158     case SQLITE_NULL: {
159       /* IMP: R-37434-19929 Abs(X) returns NULL if X is NULL. */
160       sqlite3_result_null(context);
161       break;
162     }
163     default: {
164       /* Because sqlite3_value_double() returns 0.0 if the argument is not
165       ** something that can be converted into a number, we have:
166       ** IMP: R-01992-00519 Abs(X) returns 0.0 if X is a string or blob
167       ** that cannot be converted to a numeric value.
168       */
169       double rVal = sqlite3_value_double(argv[0]);
170       if( rVal<0 ) rVal = -rVal;
171       sqlite3_result_double(context, rVal);
172       break;
173     }
174   }
175 }
176 
177 /*
178 ** Implementation of the instr() function.
179 **
180 ** instr(haystack,needle) finds the first occurrence of needle
181 ** in haystack and returns the number of previous characters plus 1,
182 ** or 0 if needle does not occur within haystack.
183 **
184 ** If both haystack and needle are BLOBs, then the result is one more than
185 ** the number of bytes in haystack prior to the first occurrence of needle,
186 ** or 0 if needle never occurs in haystack.
187 */
188 static void instrFunc(
189   sqlite3_context *context,
190   int argc,
191   sqlite3_value **argv
192 ){
193   const unsigned char *zHaystack;
194   const unsigned char *zNeedle;
195   int nHaystack;
196   int nNeedle;
197   int typeHaystack, typeNeedle;
198   int N = 1;
199   int isText;
200 
201   UNUSED_PARAMETER(argc);
202   typeHaystack = sqlite3_value_type(argv[0]);
203   typeNeedle = sqlite3_value_type(argv[1]);
204   if( typeHaystack==SQLITE_NULL || typeNeedle==SQLITE_NULL ) return;
205   nHaystack = sqlite3_value_bytes(argv[0]);
206   nNeedle = sqlite3_value_bytes(argv[1]);
207   if( nNeedle>0 ){
208     if( typeHaystack==SQLITE_BLOB && typeNeedle==SQLITE_BLOB ){
209       zHaystack = sqlite3_value_blob(argv[0]);
210       zNeedle = sqlite3_value_blob(argv[1]);
211       isText = 0;
212     }else{
213       zHaystack = sqlite3_value_text(argv[0]);
214       zNeedle = sqlite3_value_text(argv[1]);
215       isText = 1;
216     }
217     if( zNeedle==0 || (nHaystack && zHaystack==0) ) return;
218     while( nNeedle<=nHaystack && memcmp(zHaystack, zNeedle, nNeedle)!=0 ){
219       N++;
220       do{
221         nHaystack--;
222         zHaystack++;
223       }while( isText && (zHaystack[0]&0xc0)==0x80 );
224     }
225     if( nNeedle>nHaystack ) N = 0;
226   }
227   sqlite3_result_int(context, N);
228 }
229 
230 /*
231 ** Implementation of the printf() function.
232 */
233 static void printfFunc(
234   sqlite3_context *context,
235   int argc,
236   sqlite3_value **argv
237 ){
238   PrintfArguments x;
239   StrAccum str;
240   const char *zFormat;
241   int n;
242   sqlite3 *db = sqlite3_context_db_handle(context);
243 
244   if( argc>=1 && (zFormat = (const char*)sqlite3_value_text(argv[0]))!=0 ){
245     x.nArg = argc-1;
246     x.nUsed = 0;
247     x.apArg = argv+1;
248     sqlite3StrAccumInit(&str, db, 0, 0, db->aLimit[SQLITE_LIMIT_LENGTH]);
249     str.printfFlags = SQLITE_PRINTF_SQLFUNC;
250     sqlite3XPrintf(&str, zFormat, &x);
251     n = str.nChar;
252     sqlite3_result_text(context, sqlite3StrAccumFinish(&str), n,
253                         SQLITE_DYNAMIC);
254   }
255 }
256 
257 /*
258 ** Implementation of the substr() function.
259 **
260 ** substr(x,p1,p2)  returns p2 characters of x[] beginning with p1.
261 ** p1 is 1-indexed.  So substr(x,1,1) returns the first character
262 ** of x.  If x is text, then we actually count UTF-8 characters.
263 ** If x is a blob, then we count bytes.
264 **
265 ** If p1 is negative, then we begin abs(p1) from the end of x[].
266 **
267 ** If p2 is negative, return the p2 characters preceding p1.
268 */
269 static void substrFunc(
270   sqlite3_context *context,
271   int argc,
272   sqlite3_value **argv
273 ){
274   const unsigned char *z;
275   const unsigned char *z2;
276   int len;
277   int p0type;
278   i64 p1, p2;
279   int negP2 = 0;
280 
281   assert( argc==3 || argc==2 );
282   if( sqlite3_value_type(argv[1])==SQLITE_NULL
283    || (argc==3 && sqlite3_value_type(argv[2])==SQLITE_NULL)
284   ){
285     return;
286   }
287   p0type = sqlite3_value_type(argv[0]);
288   p1 = sqlite3_value_int(argv[1]);
289   if( p0type==SQLITE_BLOB ){
290     len = sqlite3_value_bytes(argv[0]);
291     z = sqlite3_value_blob(argv[0]);
292     if( z==0 ) return;
293     assert( len==sqlite3_value_bytes(argv[0]) );
294   }else{
295     z = sqlite3_value_text(argv[0]);
296     if( z==0 ) return;
297     len = 0;
298     if( p1<0 ){
299       for(z2=z; *z2; len++){
300         SQLITE_SKIP_UTF8(z2);
301       }
302     }
303   }
304 #ifdef SQLITE_SUBSTR_COMPATIBILITY
305   /* If SUBSTR_COMPATIBILITY is defined then substr(X,0,N) work the same as
306   ** as substr(X,1,N) - it returns the first N characters of X.  This
307   ** is essentially a back-out of the bug-fix in check-in [5fc125d362df4b8]
308   ** from 2009-02-02 for compatibility of applications that exploited the
309   ** old buggy behavior. */
310   if( p1==0 ) p1 = 1; /* <rdar://problem/6778339> */
311 #endif
312   if( argc==3 ){
313     p2 = sqlite3_value_int(argv[2]);
314     if( p2<0 ){
315       p2 = -p2;
316       negP2 = 1;
317     }
318   }else{
319     p2 = sqlite3_context_db_handle(context)->aLimit[SQLITE_LIMIT_LENGTH];
320   }
321   if( p1<0 ){
322     p1 += len;
323     if( p1<0 ){
324       p2 += p1;
325       if( p2<0 ) p2 = 0;
326       p1 = 0;
327     }
328   }else if( p1>0 ){
329     p1--;
330   }else if( p2>0 ){
331     p2--;
332   }
333   if( negP2 ){
334     p1 -= p2;
335     if( p1<0 ){
336       p2 += p1;
337       p1 = 0;
338     }
339   }
340   assert( p1>=0 && p2>=0 );
341   if( p0type!=SQLITE_BLOB ){
342     while( *z && p1 ){
343       SQLITE_SKIP_UTF8(z);
344       p1--;
345     }
346     for(z2=z; *z2 && p2; p2--){
347       SQLITE_SKIP_UTF8(z2);
348     }
349     sqlite3_result_text64(context, (char*)z, z2-z, SQLITE_TRANSIENT,
350                           SQLITE_UTF8);
351   }else{
352     if( p1+p2>len ){
353       p2 = len-p1;
354       if( p2<0 ) p2 = 0;
355     }
356     sqlite3_result_blob64(context, (char*)&z[p1], (u64)p2, SQLITE_TRANSIENT);
357   }
358 }
359 
360 /*
361 ** Implementation of the round() function
362 */
363 #ifndef SQLITE_OMIT_FLOATING_POINT
364 static void roundFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
365   int n = 0;
366   double r;
367   char *zBuf;
368   assert( argc==1 || argc==2 );
369   if( argc==2 ){
370     if( SQLITE_NULL==sqlite3_value_type(argv[1]) ) return;
371     n = sqlite3_value_int(argv[1]);
372     if( n>30 ) n = 30;
373     if( n<0 ) n = 0;
374   }
375   if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
376   r = sqlite3_value_double(argv[0]);
377   /* If Y==0 and X will fit in a 64-bit int,
378   ** handle the rounding directly,
379   ** otherwise use printf.
380   */
381   if( n==0 && r>=0 && r<LARGEST_INT64-1 ){
382     r = (double)((sqlite_int64)(r+0.5));
383   }else if( n==0 && r<0 && (-r)<LARGEST_INT64-1 ){
384     r = -(double)((sqlite_int64)((-r)+0.5));
385   }else{
386     zBuf = sqlite3_mprintf("%.*f",n,r);
387     if( zBuf==0 ){
388       sqlite3_result_error_nomem(context);
389       return;
390     }
391     sqlite3AtoF(zBuf, &r, sqlite3Strlen30(zBuf), SQLITE_UTF8);
392     sqlite3_free(zBuf);
393   }
394   sqlite3_result_double(context, r);
395 }
396 #endif
397 
398 /*
399 ** Allocate nByte bytes of space using sqlite3Malloc(). If the
400 ** allocation fails, call sqlite3_result_error_nomem() to notify
401 ** the database handle that malloc() has failed and return NULL.
402 ** If nByte is larger than the maximum string or blob length, then
403 ** raise an SQLITE_TOOBIG exception and return NULL.
404 */
405 static void *contextMalloc(sqlite3_context *context, i64 nByte){
406   char *z;
407   sqlite3 *db = sqlite3_context_db_handle(context);
408   assert( nByte>0 );
409   testcase( nByte==db->aLimit[SQLITE_LIMIT_LENGTH] );
410   testcase( nByte==db->aLimit[SQLITE_LIMIT_LENGTH]+1 );
411   if( nByte>db->aLimit[SQLITE_LIMIT_LENGTH] ){
412     sqlite3_result_error_toobig(context);
413     z = 0;
414   }else{
415     z = sqlite3Malloc(nByte);
416     if( !z ){
417       sqlite3_result_error_nomem(context);
418     }
419   }
420   return z;
421 }
422 
423 /*
424 ** Implementation of the upper() and lower() SQL functions.
425 */
426 static void upperFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
427   char *z1;
428   const char *z2;
429   int i, n;
430   UNUSED_PARAMETER(argc);
431   z2 = (char*)sqlite3_value_text(argv[0]);
432   n = sqlite3_value_bytes(argv[0]);
433   /* Verify that the call to _bytes() does not invalidate the _text() pointer */
434   assert( z2==(char*)sqlite3_value_text(argv[0]) );
435   if( z2 ){
436     z1 = contextMalloc(context, ((i64)n)+1);
437     if( z1 ){
438       for(i=0; i<n; i++){
439         z1[i] = (char)sqlite3Toupper(z2[i]);
440       }
441       sqlite3_result_text(context, z1, n, sqlite3_free);
442     }
443   }
444 }
445 static void lowerFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
446   char *z1;
447   const char *z2;
448   int i, n;
449   UNUSED_PARAMETER(argc);
450   z2 = (char*)sqlite3_value_text(argv[0]);
451   n = sqlite3_value_bytes(argv[0]);
452   /* Verify that the call to _bytes() does not invalidate the _text() pointer */
453   assert( z2==(char*)sqlite3_value_text(argv[0]) );
454   if( z2 ){
455     z1 = contextMalloc(context, ((i64)n)+1);
456     if( z1 ){
457       for(i=0; i<n; i++){
458         z1[i] = sqlite3Tolower(z2[i]);
459       }
460       sqlite3_result_text(context, z1, n, sqlite3_free);
461     }
462   }
463 }
464 
465 /*
466 ** Some functions like COALESCE() and IFNULL() and UNLIKELY() are implemented
467 ** as VDBE code so that unused argument values do not have to be computed.
468 ** However, we still need some kind of function implementation for this
469 ** routines in the function table.  The noopFunc macro provides this.
470 ** noopFunc will never be called so it doesn't matter what the implementation
471 ** is.  We might as well use the "version()" function as a substitute.
472 */
473 #define noopFunc versionFunc   /* Substitute function - never called */
474 
475 /*
476 ** Implementation of random().  Return a random integer.
477 */
478 static void randomFunc(
479   sqlite3_context *context,
480   int NotUsed,
481   sqlite3_value **NotUsed2
482 ){
483   sqlite_int64 r;
484   UNUSED_PARAMETER2(NotUsed, NotUsed2);
485   sqlite3_randomness(sizeof(r), &r);
486   if( r<0 ){
487     /* We need to prevent a random number of 0x8000000000000000
488     ** (or -9223372036854775808) since when you do abs() of that
489     ** number of you get the same value back again.  To do this
490     ** in a way that is testable, mask the sign bit off of negative
491     ** values, resulting in a positive value.  Then take the
492     ** 2s complement of that positive value.  The end result can
493     ** therefore be no less than -9223372036854775807.
494     */
495     r = -(r & LARGEST_INT64);
496   }
497   sqlite3_result_int64(context, r);
498 }
499 
500 /*
501 ** Implementation of randomblob(N).  Return a random blob
502 ** that is N bytes long.
503 */
504 static void randomBlob(
505   sqlite3_context *context,
506   int argc,
507   sqlite3_value **argv
508 ){
509   int n;
510   unsigned char *p;
511   assert( argc==1 );
512   UNUSED_PARAMETER(argc);
513   n = sqlite3_value_int(argv[0]);
514   if( n<1 ){
515     n = 1;
516   }
517   p = contextMalloc(context, n);
518   if( p ){
519     sqlite3_randomness(n, p);
520     sqlite3_result_blob(context, (char*)p, n, sqlite3_free);
521   }
522 }
523 
524 /*
525 ** Implementation of the last_insert_rowid() SQL function.  The return
526 ** value is the same as the sqlite3_last_insert_rowid() API function.
527 */
528 static void last_insert_rowid(
529   sqlite3_context *context,
530   int NotUsed,
531   sqlite3_value **NotUsed2
532 ){
533   sqlite3 *db = sqlite3_context_db_handle(context);
534   UNUSED_PARAMETER2(NotUsed, NotUsed2);
535   /* IMP: R-51513-12026 The last_insert_rowid() SQL function is a
536   ** wrapper around the sqlite3_last_insert_rowid() C/C++ interface
537   ** function. */
538   sqlite3_result_int64(context, sqlite3_last_insert_rowid(db));
539 }
540 
541 /*
542 ** Implementation of the changes() SQL function.
543 **
544 ** IMP: R-62073-11209 The changes() SQL function is a wrapper
545 ** around the sqlite3_changes() C/C++ function and hence follows the same
546 ** rules for counting changes.
547 */
548 static void changes(
549   sqlite3_context *context,
550   int NotUsed,
551   sqlite3_value **NotUsed2
552 ){
553   sqlite3 *db = sqlite3_context_db_handle(context);
554   UNUSED_PARAMETER2(NotUsed, NotUsed2);
555   sqlite3_result_int(context, sqlite3_changes(db));
556 }
557 
558 /*
559 ** Implementation of the total_changes() SQL function.  The return value is
560 ** the same as the sqlite3_total_changes() API function.
561 */
562 static void total_changes(
563   sqlite3_context *context,
564   int NotUsed,
565   sqlite3_value **NotUsed2
566 ){
567   sqlite3 *db = sqlite3_context_db_handle(context);
568   UNUSED_PARAMETER2(NotUsed, NotUsed2);
569   /* IMP: R-52756-41993 This function is a wrapper around the
570   ** sqlite3_total_changes() C/C++ interface. */
571   sqlite3_result_int(context, sqlite3_total_changes(db));
572 }
573 
574 /*
575 ** A structure defining how to do GLOB-style comparisons.
576 */
577 struct compareInfo {
578   u8 matchAll;          /* "*" or "%" */
579   u8 matchOne;          /* "?" or "_" */
580   u8 matchSet;          /* "[" or 0 */
581   u8 noCase;            /* true to ignore case differences */
582 };
583 
584 /*
585 ** For LIKE and GLOB matching on EBCDIC machines, assume that every
586 ** character is exactly one byte in size.  Also, provde the Utf8Read()
587 ** macro for fast reading of the next character in the common case where
588 ** the next character is ASCII.
589 */
590 #if defined(SQLITE_EBCDIC)
591 # define sqlite3Utf8Read(A)        (*((*A)++))
592 # define Utf8Read(A)               (*(A++))
593 #else
594 # define Utf8Read(A)               (A[0]<0x80?*(A++):sqlite3Utf8Read(&A))
595 #endif
596 
597 static const struct compareInfo globInfo = { '*', '?', '[', 0 };
598 /* The correct SQL-92 behavior is for the LIKE operator to ignore
599 ** case.  Thus  'a' LIKE 'A' would be true. */
600 static const struct compareInfo likeInfoNorm = { '%', '_',   0, 1 };
601 /* If SQLITE_CASE_SENSITIVE_LIKE is defined, then the LIKE operator
602 ** is case sensitive causing 'a' LIKE 'A' to be false */
603 static const struct compareInfo likeInfoAlt = { '%', '_',   0, 0 };
604 
605 /*
606 ** Possible error returns from patternMatch()
607 */
608 #define SQLITE_MATCH             0
609 #define SQLITE_NOMATCH           1
610 #define SQLITE_NOWILDCARDMATCH   2
611 
612 /*
613 ** Compare two UTF-8 strings for equality where the first string is
614 ** a GLOB or LIKE expression.  Return values:
615 **
616 **    SQLITE_MATCH:            Match
617 **    SQLITE_NOMATCH:          No match
618 **    SQLITE_NOWILDCARDMATCH:  No match in spite of having * or % wildcards.
619 **
620 ** Globbing rules:
621 **
622 **      '*'       Matches any sequence of zero or more characters.
623 **
624 **      '?'       Matches exactly one character.
625 **
626 **     [...]      Matches one character from the enclosed list of
627 **                characters.
628 **
629 **     [^...]     Matches one character not in the enclosed list.
630 **
631 ** With the [...] and [^...] matching, a ']' character can be included
632 ** in the list by making it the first character after '[' or '^'.  A
633 ** range of characters can be specified using '-'.  Example:
634 ** "[a-z]" matches any single lower-case letter.  To match a '-', make
635 ** it the last character in the list.
636 **
637 ** Like matching rules:
638 **
639 **      '%'       Matches any sequence of zero or more characters
640 **
641 ***     '_'       Matches any one character
642 **
643 **      Ec        Where E is the "esc" character and c is any other
644 **                character, including '%', '_', and esc, match exactly c.
645 **
646 ** The comments within this routine usually assume glob matching.
647 **
648 ** This routine is usually quick, but can be N**2 in the worst case.
649 */
650 static int patternCompare(
651   const u8 *zPattern,              /* The glob pattern */
652   const u8 *zString,               /* The string to compare against the glob */
653   const struct compareInfo *pInfo, /* Information about how to do the compare */
654   u32 matchOther                   /* The escape char (LIKE) or '[' (GLOB) */
655 ){
656   u32 c, c2;                       /* Next pattern and input string chars */
657   u32 matchOne = pInfo->matchOne;  /* "?" or "_" */
658   u32 matchAll = pInfo->matchAll;  /* "*" or "%" */
659   u8 noCase = pInfo->noCase;       /* True if uppercase==lowercase */
660   const u8 *zEscaped = 0;          /* One past the last escaped input char */
661 
662   while( (c = Utf8Read(zPattern))!=0 ){
663     if( c==matchAll ){  /* Match "*" */
664       /* Skip over multiple "*" characters in the pattern.  If there
665       ** are also "?" characters, skip those as well, but consume a
666       ** single character of the input string for each "?" skipped */
667       while( (c=Utf8Read(zPattern)) == matchAll || c == matchOne ){
668         if( c==matchOne && sqlite3Utf8Read(&zString)==0 ){
669           return SQLITE_NOWILDCARDMATCH;
670         }
671       }
672       if( c==0 ){
673         return SQLITE_MATCH;   /* "*" at the end of the pattern matches */
674       }else if( c==matchOther ){
675         if( pInfo->matchSet==0 ){
676           c = sqlite3Utf8Read(&zPattern);
677           if( c==0 ) return SQLITE_NOWILDCARDMATCH;
678         }else{
679           /* "[...]" immediately follows the "*".  We have to do a slow
680           ** recursive search in this case, but it is an unusual case. */
681           assert( matchOther<0x80 );  /* '[' is a single-byte character */
682           while( *zString ){
683             int bMatch = patternCompare(&zPattern[-1],zString,pInfo,matchOther);
684             if( bMatch!=SQLITE_NOMATCH ) return bMatch;
685             SQLITE_SKIP_UTF8(zString);
686           }
687           return SQLITE_NOWILDCARDMATCH;
688         }
689       }
690 
691       /* At this point variable c contains the first character of the
692       ** pattern string past the "*".  Search in the input string for the
693       ** first matching character and recursively continue the match from
694       ** that point.
695       **
696       ** For a case-insensitive search, set variable cx to be the same as
697       ** c but in the other case and search the input string for either
698       ** c or cx.
699       */
700       if( c<=0x80 ){
701         u32 cx;
702         int bMatch;
703         if( noCase ){
704           cx = sqlite3Toupper(c);
705           c = sqlite3Tolower(c);
706         }else{
707           cx = c;
708         }
709         while( (c2 = *(zString++))!=0 ){
710           if( c2!=c && c2!=cx ) continue;
711           bMatch = patternCompare(zPattern,zString,pInfo,matchOther);
712           if( bMatch!=SQLITE_NOMATCH ) return bMatch;
713         }
714       }else{
715         int bMatch;
716         while( (c2 = Utf8Read(zString))!=0 ){
717           if( c2!=c ) continue;
718           bMatch = patternCompare(zPattern,zString,pInfo,matchOther);
719           if( bMatch!=SQLITE_NOMATCH ) return bMatch;
720         }
721       }
722       return SQLITE_NOWILDCARDMATCH;
723     }
724     if( c==matchOther ){
725       if( pInfo->matchSet==0 ){
726         c = sqlite3Utf8Read(&zPattern);
727         if( c==0 ) return SQLITE_NOMATCH;
728         zEscaped = zPattern;
729       }else{
730         u32 prior_c = 0;
731         int seen = 0;
732         int invert = 0;
733         c = sqlite3Utf8Read(&zString);
734         if( c==0 ) return SQLITE_NOMATCH;
735         c2 = sqlite3Utf8Read(&zPattern);
736         if( c2=='^' ){
737           invert = 1;
738           c2 = sqlite3Utf8Read(&zPattern);
739         }
740         if( c2==']' ){
741           if( c==']' ) seen = 1;
742           c2 = sqlite3Utf8Read(&zPattern);
743         }
744         while( c2 && c2!=']' ){
745           if( c2=='-' && zPattern[0]!=']' && zPattern[0]!=0 && prior_c>0 ){
746             c2 = sqlite3Utf8Read(&zPattern);
747             if( c>=prior_c && c<=c2 ) seen = 1;
748             prior_c = 0;
749           }else{
750             if( c==c2 ){
751               seen = 1;
752             }
753             prior_c = c2;
754           }
755           c2 = sqlite3Utf8Read(&zPattern);
756         }
757         if( c2==0 || (seen ^ invert)==0 ){
758           return SQLITE_NOMATCH;
759         }
760         continue;
761       }
762     }
763     c2 = Utf8Read(zString);
764     if( c==c2 ) continue;
765     if( noCase  && sqlite3Tolower(c)==sqlite3Tolower(c2) && c<0x80 && c2<0x80 ){
766       continue;
767     }
768     if( c==matchOne && zPattern!=zEscaped && c2!=0 ) continue;
769     return SQLITE_NOMATCH;
770   }
771   return *zString==0 ? SQLITE_MATCH : SQLITE_NOMATCH;
772 }
773 
774 /*
775 ** The sqlite3_strglob() interface.  Return 0 on a match (like strcmp()) and
776 ** non-zero if there is no match.
777 */
778 int sqlite3_strglob(const char *zGlobPattern, const char *zString){
779   return patternCompare((u8*)zGlobPattern, (u8*)zString, &globInfo, '[');
780 }
781 
782 /*
783 ** The sqlite3_strlike() interface.  Return 0 on a match and non-zero for
784 ** a miss - like strcmp().
785 */
786 int sqlite3_strlike(const char *zPattern, const char *zStr, unsigned int esc){
787   return patternCompare((u8*)zPattern, (u8*)zStr, &likeInfoNorm, esc);
788 }
789 
790 /*
791 ** Count the number of times that the LIKE operator (or GLOB which is
792 ** just a variation of LIKE) gets called.  This is used for testing
793 ** only.
794 */
795 #ifdef SQLITE_TEST
796 int sqlite3_like_count = 0;
797 #endif
798 
799 
800 /*
801 ** Implementation of the like() SQL function.  This function implements
802 ** the build-in LIKE operator.  The first argument to the function is the
803 ** pattern and the second argument is the string.  So, the SQL statements:
804 **
805 **       A LIKE B
806 **
807 ** is implemented as like(B,A).
808 **
809 ** This same function (with a different compareInfo structure) computes
810 ** the GLOB operator.
811 */
812 static void likeFunc(
813   sqlite3_context *context,
814   int argc,
815   sqlite3_value **argv
816 ){
817   const unsigned char *zA, *zB;
818   u32 escape;
819   int nPat;
820   sqlite3 *db = sqlite3_context_db_handle(context);
821   struct compareInfo *pInfo = sqlite3_user_data(context);
822 
823 #ifdef SQLITE_LIKE_DOESNT_MATCH_BLOBS
824   if( sqlite3_value_type(argv[0])==SQLITE_BLOB
825    || sqlite3_value_type(argv[1])==SQLITE_BLOB
826   ){
827 #ifdef SQLITE_TEST
828     sqlite3_like_count++;
829 #endif
830     sqlite3_result_int(context, 0);
831     return;
832   }
833 #endif
834   zB = sqlite3_value_text(argv[0]);
835   zA = sqlite3_value_text(argv[1]);
836 
837   /* Limit the length of the LIKE or GLOB pattern to avoid problems
838   ** of deep recursion and N*N behavior in patternCompare().
839   */
840   nPat = sqlite3_value_bytes(argv[0]);
841   testcase( nPat==db->aLimit[SQLITE_LIMIT_LIKE_PATTERN_LENGTH] );
842   testcase( nPat==db->aLimit[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]+1 );
843   if( nPat > db->aLimit[SQLITE_LIMIT_LIKE_PATTERN_LENGTH] ){
844     sqlite3_result_error(context, "LIKE or GLOB pattern too complex", -1);
845     return;
846   }
847   assert( zB==sqlite3_value_text(argv[0]) );  /* Encoding did not change */
848 
849   if( argc==3 ){
850     /* The escape character string must consist of a single UTF-8 character.
851     ** Otherwise, return an error.
852     */
853     const unsigned char *zEsc = sqlite3_value_text(argv[2]);
854     if( zEsc==0 ) return;
855     if( sqlite3Utf8CharLen((char*)zEsc, -1)!=1 ){
856       sqlite3_result_error(context,
857           "ESCAPE expression must be a single character", -1);
858       return;
859     }
860     escape = sqlite3Utf8Read(&zEsc);
861   }else{
862     escape = pInfo->matchSet;
863   }
864   if( zA && zB ){
865 #ifdef SQLITE_TEST
866     sqlite3_like_count++;
867 #endif
868     sqlite3_result_int(context, patternCompare(zB, zA, pInfo, escape)==SQLITE_MATCH);
869   }
870 }
871 
872 /*
873 ** Implementation of the NULLIF(x,y) function.  The result is the first
874 ** argument if the arguments are different.  The result is NULL if the
875 ** arguments are equal to each other.
876 */
877 static void nullifFunc(
878   sqlite3_context *context,
879   int NotUsed,
880   sqlite3_value **argv
881 ){
882   CollSeq *pColl = sqlite3GetFuncCollSeq(context);
883   UNUSED_PARAMETER(NotUsed);
884   if( sqlite3MemCompare(argv[0], argv[1], pColl)!=0 ){
885     sqlite3_result_value(context, argv[0]);
886   }
887 }
888 
889 /*
890 ** Implementation of the sqlite_version() function.  The result is the version
891 ** of the SQLite library that is running.
892 */
893 static void versionFunc(
894   sqlite3_context *context,
895   int NotUsed,
896   sqlite3_value **NotUsed2
897 ){
898   UNUSED_PARAMETER2(NotUsed, NotUsed2);
899   /* IMP: R-48699-48617 This function is an SQL wrapper around the
900   ** sqlite3_libversion() C-interface. */
901   sqlite3_result_text(context, sqlite3_libversion(), -1, SQLITE_STATIC);
902 }
903 
904 /*
905 ** Implementation of the sqlite_source_id() function. The result is a string
906 ** that identifies the particular version of the source code used to build
907 ** SQLite.
908 */
909 static void sourceidFunc(
910   sqlite3_context *context,
911   int NotUsed,
912   sqlite3_value **NotUsed2
913 ){
914   UNUSED_PARAMETER2(NotUsed, NotUsed2);
915   /* IMP: R-24470-31136 This function is an SQL wrapper around the
916   ** sqlite3_sourceid() C interface. */
917   sqlite3_result_text(context, sqlite3_sourceid(), -1, SQLITE_STATIC);
918 }
919 
920 /*
921 ** Implementation of the sqlite_log() function.  This is a wrapper around
922 ** sqlite3_log().  The return value is NULL.  The function exists purely for
923 ** its side-effects.
924 */
925 static void errlogFunc(
926   sqlite3_context *context,
927   int argc,
928   sqlite3_value **argv
929 ){
930   UNUSED_PARAMETER(argc);
931   UNUSED_PARAMETER(context);
932   sqlite3_log(sqlite3_value_int(argv[0]), "%s", sqlite3_value_text(argv[1]));
933 }
934 
935 /*
936 ** Implementation of the sqlite_compileoption_used() function.
937 ** The result is an integer that identifies if the compiler option
938 ** was used to build SQLite.
939 */
940 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
941 static void compileoptionusedFunc(
942   sqlite3_context *context,
943   int argc,
944   sqlite3_value **argv
945 ){
946   const char *zOptName;
947   assert( argc==1 );
948   UNUSED_PARAMETER(argc);
949   /* IMP: R-39564-36305 The sqlite_compileoption_used() SQL
950   ** function is a wrapper around the sqlite3_compileoption_used() C/C++
951   ** function.
952   */
953   if( (zOptName = (const char*)sqlite3_value_text(argv[0]))!=0 ){
954     sqlite3_result_int(context, sqlite3_compileoption_used(zOptName));
955   }
956 }
957 #endif /* SQLITE_OMIT_COMPILEOPTION_DIAGS */
958 
959 /*
960 ** Implementation of the sqlite_compileoption_get() function.
961 ** The result is a string that identifies the compiler options
962 ** used to build SQLite.
963 */
964 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
965 static void compileoptiongetFunc(
966   sqlite3_context *context,
967   int argc,
968   sqlite3_value **argv
969 ){
970   int n;
971   assert( argc==1 );
972   UNUSED_PARAMETER(argc);
973   /* IMP: R-04922-24076 The sqlite_compileoption_get() SQL function
974   ** is a wrapper around the sqlite3_compileoption_get() C/C++ function.
975   */
976   n = sqlite3_value_int(argv[0]);
977   sqlite3_result_text(context, sqlite3_compileoption_get(n), -1, SQLITE_STATIC);
978 }
979 #endif /* SQLITE_OMIT_COMPILEOPTION_DIAGS */
980 
981 /* Array for converting from half-bytes (nybbles) into ASCII hex
982 ** digits. */
983 static const char hexdigits[] = {
984   '0', '1', '2', '3', '4', '5', '6', '7',
985   '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'
986 };
987 
988 /*
989 ** Implementation of the QUOTE() function.  This function takes a single
990 ** argument.  If the argument is numeric, the return value is the same as
991 ** the argument.  If the argument is NULL, the return value is the string
992 ** "NULL".  Otherwise, the argument is enclosed in single quotes with
993 ** single-quote escapes.
994 */
995 static void quoteFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
996   assert( argc==1 );
997   UNUSED_PARAMETER(argc);
998   switch( sqlite3_value_type(argv[0]) ){
999     case SQLITE_FLOAT: {
1000       double r1, r2;
1001       char zBuf[50];
1002       r1 = sqlite3_value_double(argv[0]);
1003       sqlite3_snprintf(sizeof(zBuf), zBuf, "%!.15g", r1);
1004       sqlite3AtoF(zBuf, &r2, 20, SQLITE_UTF8);
1005       if( r1!=r2 ){
1006         sqlite3_snprintf(sizeof(zBuf), zBuf, "%!.20e", r1);
1007       }
1008       sqlite3_result_text(context, zBuf, -1, SQLITE_TRANSIENT);
1009       break;
1010     }
1011     case SQLITE_INTEGER: {
1012       sqlite3_result_value(context, argv[0]);
1013       break;
1014     }
1015     case SQLITE_BLOB: {
1016       char *zText = 0;
1017       char const *zBlob = sqlite3_value_blob(argv[0]);
1018       int nBlob = sqlite3_value_bytes(argv[0]);
1019       assert( zBlob==sqlite3_value_blob(argv[0]) ); /* No encoding change */
1020       zText = (char *)contextMalloc(context, (2*(i64)nBlob)+4);
1021       if( zText ){
1022         int i;
1023         for(i=0; i<nBlob; i++){
1024           zText[(i*2)+2] = hexdigits[(zBlob[i]>>4)&0x0F];
1025           zText[(i*2)+3] = hexdigits[(zBlob[i])&0x0F];
1026         }
1027         zText[(nBlob*2)+2] = '\'';
1028         zText[(nBlob*2)+3] = '\0';
1029         zText[0] = 'X';
1030         zText[1] = '\'';
1031         sqlite3_result_text(context, zText, -1, SQLITE_TRANSIENT);
1032         sqlite3_free(zText);
1033       }
1034       break;
1035     }
1036     case SQLITE_TEXT: {
1037       int i,j;
1038       u64 n;
1039       const unsigned char *zArg = sqlite3_value_text(argv[0]);
1040       char *z;
1041 
1042       if( zArg==0 ) return;
1043       for(i=0, n=0; zArg[i]; i++){ if( zArg[i]=='\'' ) n++; }
1044       z = contextMalloc(context, ((i64)i)+((i64)n)+3);
1045       if( z ){
1046         z[0] = '\'';
1047         for(i=0, j=1; zArg[i]; i++){
1048           z[j++] = zArg[i];
1049           if( zArg[i]=='\'' ){
1050             z[j++] = '\'';
1051           }
1052         }
1053         z[j++] = '\'';
1054         z[j] = 0;
1055         sqlite3_result_text(context, z, j, sqlite3_free);
1056       }
1057       break;
1058     }
1059     default: {
1060       assert( sqlite3_value_type(argv[0])==SQLITE_NULL );
1061       sqlite3_result_text(context, "NULL", 4, SQLITE_STATIC);
1062       break;
1063     }
1064   }
1065 }
1066 
1067 /*
1068 ** The unicode() function.  Return the integer unicode code-point value
1069 ** for the first character of the input string.
1070 */
1071 static void unicodeFunc(
1072   sqlite3_context *context,
1073   int argc,
1074   sqlite3_value **argv
1075 ){
1076   const unsigned char *z = sqlite3_value_text(argv[0]);
1077   (void)argc;
1078   if( z && z[0] ) sqlite3_result_int(context, sqlite3Utf8Read(&z));
1079 }
1080 
1081 /*
1082 ** The char() function takes zero or more arguments, each of which is
1083 ** an integer.  It constructs a string where each character of the string
1084 ** is the unicode character for the corresponding integer argument.
1085 */
1086 static void charFunc(
1087   sqlite3_context *context,
1088   int argc,
1089   sqlite3_value **argv
1090 ){
1091   unsigned char *z, *zOut;
1092   int i;
1093   zOut = z = sqlite3_malloc64( argc*4+1 );
1094   if( z==0 ){
1095     sqlite3_result_error_nomem(context);
1096     return;
1097   }
1098   for(i=0; i<argc; i++){
1099     sqlite3_int64 x;
1100     unsigned c;
1101     x = sqlite3_value_int64(argv[i]);
1102     if( x<0 || x>0x10ffff ) x = 0xfffd;
1103     c = (unsigned)(x & 0x1fffff);
1104     if( c<0x00080 ){
1105       *zOut++ = (u8)(c&0xFF);
1106     }else if( c<0x00800 ){
1107       *zOut++ = 0xC0 + (u8)((c>>6)&0x1F);
1108       *zOut++ = 0x80 + (u8)(c & 0x3F);
1109     }else if( c<0x10000 ){
1110       *zOut++ = 0xE0 + (u8)((c>>12)&0x0F);
1111       *zOut++ = 0x80 + (u8)((c>>6) & 0x3F);
1112       *zOut++ = 0x80 + (u8)(c & 0x3F);
1113     }else{
1114       *zOut++ = 0xF0 + (u8)((c>>18) & 0x07);
1115       *zOut++ = 0x80 + (u8)((c>>12) & 0x3F);
1116       *zOut++ = 0x80 + (u8)((c>>6) & 0x3F);
1117       *zOut++ = 0x80 + (u8)(c & 0x3F);
1118     }                                                    \
1119   }
1120   sqlite3_result_text64(context, (char*)z, zOut-z, sqlite3_free, SQLITE_UTF8);
1121 }
1122 
1123 /*
1124 ** The hex() function.  Interpret the argument as a blob.  Return
1125 ** a hexadecimal rendering as text.
1126 */
1127 static void hexFunc(
1128   sqlite3_context *context,
1129   int argc,
1130   sqlite3_value **argv
1131 ){
1132   int i, n;
1133   const unsigned char *pBlob;
1134   char *zHex, *z;
1135   assert( argc==1 );
1136   UNUSED_PARAMETER(argc);
1137   pBlob = sqlite3_value_blob(argv[0]);
1138   n = sqlite3_value_bytes(argv[0]);
1139   assert( pBlob==sqlite3_value_blob(argv[0]) );  /* No encoding change */
1140   z = zHex = contextMalloc(context, ((i64)n)*2 + 1);
1141   if( zHex ){
1142     for(i=0; i<n; i++, pBlob++){
1143       unsigned char c = *pBlob;
1144       *(z++) = hexdigits[(c>>4)&0xf];
1145       *(z++) = hexdigits[c&0xf];
1146     }
1147     *z = 0;
1148     sqlite3_result_text(context, zHex, n*2, sqlite3_free);
1149   }
1150 }
1151 
1152 /*
1153 ** The zeroblob(N) function returns a zero-filled blob of size N bytes.
1154 */
1155 static void zeroblobFunc(
1156   sqlite3_context *context,
1157   int argc,
1158   sqlite3_value **argv
1159 ){
1160   i64 n;
1161   int rc;
1162   assert( argc==1 );
1163   UNUSED_PARAMETER(argc);
1164   n = sqlite3_value_int64(argv[0]);
1165   if( n<0 ) n = 0;
1166   rc = sqlite3_result_zeroblob64(context, n); /* IMP: R-00293-64994 */
1167   if( rc ){
1168     sqlite3_result_error_code(context, rc);
1169   }
1170 }
1171 
1172 /*
1173 ** The replace() function.  Three arguments are all strings: call
1174 ** them A, B, and C. The result is also a string which is derived
1175 ** from A by replacing every occurrence of B with C.  The match
1176 ** must be exact.  Collating sequences are not used.
1177 */
1178 static void replaceFunc(
1179   sqlite3_context *context,
1180   int argc,
1181   sqlite3_value **argv
1182 ){
1183   const unsigned char *zStr;        /* The input string A */
1184   const unsigned char *zPattern;    /* The pattern string B */
1185   const unsigned char *zRep;        /* The replacement string C */
1186   unsigned char *zOut;              /* The output */
1187   int nStr;                /* Size of zStr */
1188   int nPattern;            /* Size of zPattern */
1189   int nRep;                /* Size of zRep */
1190   i64 nOut;                /* Maximum size of zOut */
1191   int loopLimit;           /* Last zStr[] that might match zPattern[] */
1192   int i, j;                /* Loop counters */
1193 
1194   assert( argc==3 );
1195   UNUSED_PARAMETER(argc);
1196   zStr = sqlite3_value_text(argv[0]);
1197   if( zStr==0 ) return;
1198   nStr = sqlite3_value_bytes(argv[0]);
1199   assert( zStr==sqlite3_value_text(argv[0]) );  /* No encoding change */
1200   zPattern = sqlite3_value_text(argv[1]);
1201   if( zPattern==0 ){
1202     assert( sqlite3_value_type(argv[1])==SQLITE_NULL
1203             || sqlite3_context_db_handle(context)->mallocFailed );
1204     return;
1205   }
1206   if( zPattern[0]==0 ){
1207     assert( sqlite3_value_type(argv[1])!=SQLITE_NULL );
1208     sqlite3_result_value(context, argv[0]);
1209     return;
1210   }
1211   nPattern = sqlite3_value_bytes(argv[1]);
1212   assert( zPattern==sqlite3_value_text(argv[1]) );  /* No encoding change */
1213   zRep = sqlite3_value_text(argv[2]);
1214   if( zRep==0 ) return;
1215   nRep = sqlite3_value_bytes(argv[2]);
1216   assert( zRep==sqlite3_value_text(argv[2]) );
1217   nOut = nStr + 1;
1218   assert( nOut<SQLITE_MAX_LENGTH );
1219   zOut = contextMalloc(context, (i64)nOut);
1220   if( zOut==0 ){
1221     return;
1222   }
1223   loopLimit = nStr - nPattern;
1224   for(i=j=0; i<=loopLimit; i++){
1225     if( zStr[i]!=zPattern[0] || memcmp(&zStr[i], zPattern, nPattern) ){
1226       zOut[j++] = zStr[i];
1227     }else{
1228       u8 *zOld;
1229       sqlite3 *db = sqlite3_context_db_handle(context);
1230       nOut += nRep - nPattern;
1231       testcase( nOut-1==db->aLimit[SQLITE_LIMIT_LENGTH] );
1232       testcase( nOut-2==db->aLimit[SQLITE_LIMIT_LENGTH] );
1233       if( nOut-1>db->aLimit[SQLITE_LIMIT_LENGTH] ){
1234         sqlite3_result_error_toobig(context);
1235         sqlite3_free(zOut);
1236         return;
1237       }
1238       zOld = zOut;
1239       zOut = sqlite3_realloc64(zOut, (int)nOut);
1240       if( zOut==0 ){
1241         sqlite3_result_error_nomem(context);
1242         sqlite3_free(zOld);
1243         return;
1244       }
1245       memcpy(&zOut[j], zRep, nRep);
1246       j += nRep;
1247       i += nPattern-1;
1248     }
1249   }
1250   assert( j+nStr-i+1==nOut );
1251   memcpy(&zOut[j], &zStr[i], nStr-i);
1252   j += nStr - i;
1253   assert( j<=nOut );
1254   zOut[j] = 0;
1255   sqlite3_result_text(context, (char*)zOut, j, sqlite3_free);
1256 }
1257 
1258 /*
1259 ** Implementation of the TRIM(), LTRIM(), and RTRIM() functions.
1260 ** The userdata is 0x1 for left trim, 0x2 for right trim, 0x3 for both.
1261 */
1262 static void trimFunc(
1263   sqlite3_context *context,
1264   int argc,
1265   sqlite3_value **argv
1266 ){
1267   const unsigned char *zIn;         /* Input string */
1268   const unsigned char *zCharSet;    /* Set of characters to trim */
1269   int nIn;                          /* Number of bytes in input */
1270   int flags;                        /* 1: trimleft  2: trimright  3: trim */
1271   int i;                            /* Loop counter */
1272   unsigned char *aLen = 0;          /* Length of each character in zCharSet */
1273   unsigned char **azChar = 0;       /* Individual characters in zCharSet */
1274   int nChar;                        /* Number of characters in zCharSet */
1275 
1276   if( sqlite3_value_type(argv[0])==SQLITE_NULL ){
1277     return;
1278   }
1279   zIn = sqlite3_value_text(argv[0]);
1280   if( zIn==0 ) return;
1281   nIn = sqlite3_value_bytes(argv[0]);
1282   assert( zIn==sqlite3_value_text(argv[0]) );
1283   if( argc==1 ){
1284     static const unsigned char lenOne[] = { 1 };
1285     static unsigned char * const azOne[] = { (u8*)" " };
1286     nChar = 1;
1287     aLen = (u8*)lenOne;
1288     azChar = (unsigned char **)azOne;
1289     zCharSet = 0;
1290   }else if( (zCharSet = sqlite3_value_text(argv[1]))==0 ){
1291     return;
1292   }else{
1293     const unsigned char *z;
1294     for(z=zCharSet, nChar=0; *z; nChar++){
1295       SQLITE_SKIP_UTF8(z);
1296     }
1297     if( nChar>0 ){
1298       azChar = contextMalloc(context, ((i64)nChar)*(sizeof(char*)+1));
1299       if( azChar==0 ){
1300         return;
1301       }
1302       aLen = (unsigned char*)&azChar[nChar];
1303       for(z=zCharSet, nChar=0; *z; nChar++){
1304         azChar[nChar] = (unsigned char *)z;
1305         SQLITE_SKIP_UTF8(z);
1306         aLen[nChar] = (u8)(z - azChar[nChar]);
1307       }
1308     }
1309   }
1310   if( nChar>0 ){
1311     flags = SQLITE_PTR_TO_INT(sqlite3_user_data(context));
1312     if( flags & 1 ){
1313       while( nIn>0 ){
1314         int len = 0;
1315         for(i=0; i<nChar; i++){
1316           len = aLen[i];
1317           if( len<=nIn && memcmp(zIn, azChar[i], len)==0 ) break;
1318         }
1319         if( i>=nChar ) break;
1320         zIn += len;
1321         nIn -= len;
1322       }
1323     }
1324     if( flags & 2 ){
1325       while( nIn>0 ){
1326         int len = 0;
1327         for(i=0; i<nChar; i++){
1328           len = aLen[i];
1329           if( len<=nIn && memcmp(&zIn[nIn-len],azChar[i],len)==0 ) break;
1330         }
1331         if( i>=nChar ) break;
1332         nIn -= len;
1333       }
1334     }
1335     if( zCharSet ){
1336       sqlite3_free(azChar);
1337     }
1338   }
1339   sqlite3_result_text(context, (char*)zIn, nIn, SQLITE_TRANSIENT);
1340 }
1341 
1342 
1343 #ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION
1344 /*
1345 ** The "unknown" function is automatically substituted in place of
1346 ** any unrecognized function name when doing an EXPLAIN or EXPLAIN QUERY PLAN
1347 ** when the SQLITE_ENABLE_UNKNOWN_FUNCTION compile-time option is used.
1348 ** When the "sqlite3" command-line shell is built using this functionality,
1349 ** that allows an EXPLAIN or EXPLAIN QUERY PLAN for complex queries
1350 ** involving application-defined functions to be examined in a generic
1351 ** sqlite3 shell.
1352 */
1353 static void unknownFunc(
1354   sqlite3_context *context,
1355   int argc,
1356   sqlite3_value **argv
1357 ){
1358   /* no-op */
1359 }
1360 #endif /*SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION*/
1361 
1362 
1363 /* IMP: R-25361-16150 This function is omitted from SQLite by default. It
1364 ** is only available if the SQLITE_SOUNDEX compile-time option is used
1365 ** when SQLite is built.
1366 */
1367 #ifdef SQLITE_SOUNDEX
1368 /*
1369 ** Compute the soundex encoding of a word.
1370 **
1371 ** IMP: R-59782-00072 The soundex(X) function returns a string that is the
1372 ** soundex encoding of the string X.
1373 */
1374 static void soundexFunc(
1375   sqlite3_context *context,
1376   int argc,
1377   sqlite3_value **argv
1378 ){
1379   char zResult[8];
1380   const u8 *zIn;
1381   int i, j;
1382   static const unsigned char iCode[] = {
1383     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
1384     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
1385     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
1386     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
1387     0, 0, 1, 2, 3, 0, 1, 2, 0, 0, 2, 2, 4, 5, 5, 0,
1388     1, 2, 6, 2, 3, 0, 1, 0, 2, 0, 2, 0, 0, 0, 0, 0,
1389     0, 0, 1, 2, 3, 0, 1, 2, 0, 0, 2, 2, 4, 5, 5, 0,
1390     1, 2, 6, 2, 3, 0, 1, 0, 2, 0, 2, 0, 0, 0, 0, 0,
1391   };
1392   assert( argc==1 );
1393   zIn = (u8*)sqlite3_value_text(argv[0]);
1394   if( zIn==0 ) zIn = (u8*)"";
1395   for(i=0; zIn[i] && !sqlite3Isalpha(zIn[i]); i++){}
1396   if( zIn[i] ){
1397     u8 prevcode = iCode[zIn[i]&0x7f];
1398     zResult[0] = sqlite3Toupper(zIn[i]);
1399     for(j=1; j<4 && zIn[i]; i++){
1400       int code = iCode[zIn[i]&0x7f];
1401       if( code>0 ){
1402         if( code!=prevcode ){
1403           prevcode = code;
1404           zResult[j++] = code + '0';
1405         }
1406       }else{
1407         prevcode = 0;
1408       }
1409     }
1410     while( j<4 ){
1411       zResult[j++] = '0';
1412     }
1413     zResult[j] = 0;
1414     sqlite3_result_text(context, zResult, 4, SQLITE_TRANSIENT);
1415   }else{
1416     /* IMP: R-64894-50321 The string "?000" is returned if the argument
1417     ** is NULL or contains no ASCII alphabetic characters. */
1418     sqlite3_result_text(context, "?000", 4, SQLITE_STATIC);
1419   }
1420 }
1421 #endif /* SQLITE_SOUNDEX */
1422 
1423 #ifndef SQLITE_OMIT_LOAD_EXTENSION
1424 /*
1425 ** A function that loads a shared-library extension then returns NULL.
1426 */
1427 static void loadExt(sqlite3_context *context, int argc, sqlite3_value **argv){
1428   const char *zFile = (const char *)sqlite3_value_text(argv[0]);
1429   const char *zProc;
1430   sqlite3 *db = sqlite3_context_db_handle(context);
1431   char *zErrMsg = 0;
1432 
1433   /* Disallow the load_extension() SQL function unless the SQLITE_LoadExtFunc
1434   ** flag is set.  See the sqlite3_enable_load_extension() API.
1435   */
1436   if( (db->flags & SQLITE_LoadExtFunc)==0 ){
1437     sqlite3_result_error(context, "not authorized", -1);
1438     return;
1439   }
1440 
1441   if( argc==2 ){
1442     zProc = (const char *)sqlite3_value_text(argv[1]);
1443   }else{
1444     zProc = 0;
1445   }
1446   if( zFile && sqlite3_load_extension(db, zFile, zProc, &zErrMsg) ){
1447     sqlite3_result_error(context, zErrMsg, -1);
1448     sqlite3_free(zErrMsg);
1449   }
1450 }
1451 #endif
1452 
1453 
1454 /*
1455 ** An instance of the following structure holds the context of a
1456 ** sum() or avg() aggregate computation.
1457 */
1458 typedef struct SumCtx SumCtx;
1459 struct SumCtx {
1460   double rSum;      /* Floating point sum */
1461   i64 iSum;         /* Integer sum */
1462   i64 cnt;          /* Number of elements summed */
1463   u8 overflow;      /* True if integer overflow seen */
1464   u8 approx;        /* True if non-integer value was input to the sum */
1465 };
1466 
1467 /*
1468 ** Routines used to compute the sum, average, and total.
1469 **
1470 ** The SUM() function follows the (broken) SQL standard which means
1471 ** that it returns NULL if it sums over no inputs.  TOTAL returns
1472 ** 0.0 in that case.  In addition, TOTAL always returns a float where
1473 ** SUM might return an integer if it never encounters a floating point
1474 ** value.  TOTAL never fails, but SUM might through an exception if
1475 ** it overflows an integer.
1476 */
1477 static void sumStep(sqlite3_context *context, int argc, sqlite3_value **argv){
1478   SumCtx *p;
1479   int type;
1480   assert( argc==1 );
1481   UNUSED_PARAMETER(argc);
1482   p = sqlite3_aggregate_context(context, sizeof(*p));
1483   type = sqlite3_value_numeric_type(argv[0]);
1484   if( p && type!=SQLITE_NULL ){
1485     p->cnt++;
1486     if( type==SQLITE_INTEGER ){
1487       i64 v = sqlite3_value_int64(argv[0]);
1488       p->rSum += v;
1489       if( (p->approx|p->overflow)==0 && sqlite3AddInt64(&p->iSum, v) ){
1490         p->overflow = 1;
1491       }
1492     }else{
1493       p->rSum += sqlite3_value_double(argv[0]);
1494       p->approx = 1;
1495     }
1496   }
1497 }
1498 static void sumFinalize(sqlite3_context *context){
1499   SumCtx *p;
1500   p = sqlite3_aggregate_context(context, 0);
1501   if( p && p->cnt>0 ){
1502     if( p->overflow ){
1503       sqlite3_result_error(context,"integer overflow",-1);
1504     }else if( p->approx ){
1505       sqlite3_result_double(context, p->rSum);
1506     }else{
1507       sqlite3_result_int64(context, p->iSum);
1508     }
1509   }
1510 }
1511 static void avgFinalize(sqlite3_context *context){
1512   SumCtx *p;
1513   p = sqlite3_aggregate_context(context, 0);
1514   if( p && p->cnt>0 ){
1515     sqlite3_result_double(context, p->rSum/(double)p->cnt);
1516   }
1517 }
1518 static void totalFinalize(sqlite3_context *context){
1519   SumCtx *p;
1520   p = sqlite3_aggregate_context(context, 0);
1521   /* (double)0 In case of SQLITE_OMIT_FLOATING_POINT... */
1522   sqlite3_result_double(context, p ? p->rSum : (double)0);
1523 }
1524 
1525 /*
1526 ** The following structure keeps track of state information for the
1527 ** count() aggregate function.
1528 */
1529 typedef struct CountCtx CountCtx;
1530 struct CountCtx {
1531   i64 n;
1532 };
1533 
1534 /*
1535 ** Routines to implement the count() aggregate function.
1536 */
1537 static void countStep(sqlite3_context *context, int argc, sqlite3_value **argv){
1538   CountCtx *p;
1539   p = sqlite3_aggregate_context(context, sizeof(*p));
1540   if( (argc==0 || SQLITE_NULL!=sqlite3_value_type(argv[0])) && p ){
1541     p->n++;
1542   }
1543 
1544 #ifndef SQLITE_OMIT_DEPRECATED
1545   /* The sqlite3_aggregate_count() function is deprecated.  But just to make
1546   ** sure it still operates correctly, verify that its count agrees with our
1547   ** internal count when using count(*) and when the total count can be
1548   ** expressed as a 32-bit integer. */
1549   assert( argc==1 || p==0 || p->n>0x7fffffff
1550           || p->n==sqlite3_aggregate_count(context) );
1551 #endif
1552 }
1553 static void countFinalize(sqlite3_context *context){
1554   CountCtx *p;
1555   p = sqlite3_aggregate_context(context, 0);
1556   sqlite3_result_int64(context, p ? p->n : 0);
1557 }
1558 
1559 /*
1560 ** Routines to implement min() and max() aggregate functions.
1561 */
1562 static void minmaxStep(
1563   sqlite3_context *context,
1564   int NotUsed,
1565   sqlite3_value **argv
1566 ){
1567   Mem *pArg  = (Mem *)argv[0];
1568   Mem *pBest;
1569   UNUSED_PARAMETER(NotUsed);
1570 
1571   pBest = (Mem *)sqlite3_aggregate_context(context, sizeof(*pBest));
1572   if( !pBest ) return;
1573 
1574   if( sqlite3_value_type(argv[0])==SQLITE_NULL ){
1575     if( pBest->flags ) sqlite3SkipAccumulatorLoad(context);
1576   }else if( pBest->flags ){
1577     int max;
1578     int cmp;
1579     CollSeq *pColl = sqlite3GetFuncCollSeq(context);
1580     /* This step function is used for both the min() and max() aggregates,
1581     ** the only difference between the two being that the sense of the
1582     ** comparison is inverted. For the max() aggregate, the
1583     ** sqlite3_user_data() function returns (void *)-1. For min() it
1584     ** returns (void *)db, where db is the sqlite3* database pointer.
1585     ** Therefore the next statement sets variable 'max' to 1 for the max()
1586     ** aggregate, or 0 for min().
1587     */
1588     max = sqlite3_user_data(context)!=0;
1589     cmp = sqlite3MemCompare(pBest, pArg, pColl);
1590     if( (max && cmp<0) || (!max && cmp>0) ){
1591       sqlite3VdbeMemCopy(pBest, pArg);
1592     }else{
1593       sqlite3SkipAccumulatorLoad(context);
1594     }
1595   }else{
1596     pBest->db = sqlite3_context_db_handle(context);
1597     sqlite3VdbeMemCopy(pBest, pArg);
1598   }
1599 }
1600 static void minMaxFinalize(sqlite3_context *context){
1601   sqlite3_value *pRes;
1602   pRes = (sqlite3_value *)sqlite3_aggregate_context(context, 0);
1603   if( pRes ){
1604     if( pRes->flags ){
1605       sqlite3_result_value(context, pRes);
1606     }
1607     sqlite3VdbeMemRelease(pRes);
1608   }
1609 }
1610 
1611 /*
1612 ** group_concat(EXPR, ?SEPARATOR?)
1613 */
1614 static void groupConcatStep(
1615   sqlite3_context *context,
1616   int argc,
1617   sqlite3_value **argv
1618 ){
1619   const char *zVal;
1620   StrAccum *pAccum;
1621   const char *zSep;
1622   int nVal, nSep;
1623   assert( argc==1 || argc==2 );
1624   if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
1625   pAccum = (StrAccum*)sqlite3_aggregate_context(context, sizeof(*pAccum));
1626 
1627   if( pAccum ){
1628     sqlite3 *db = sqlite3_context_db_handle(context);
1629     int firstTerm = pAccum->mxAlloc==0;
1630     pAccum->mxAlloc = db->aLimit[SQLITE_LIMIT_LENGTH];
1631     if( !firstTerm ){
1632       if( argc==2 ){
1633         zSep = (char*)sqlite3_value_text(argv[1]);
1634         nSep = sqlite3_value_bytes(argv[1]);
1635       }else{
1636         zSep = ",";
1637         nSep = 1;
1638       }
1639       if( zSep ) sqlite3StrAccumAppend(pAccum, zSep, nSep);
1640     }
1641     zVal = (char*)sqlite3_value_text(argv[0]);
1642     nVal = sqlite3_value_bytes(argv[0]);
1643     if( zVal ) sqlite3StrAccumAppend(pAccum, zVal, nVal);
1644   }
1645 }
1646 static void groupConcatFinalize(sqlite3_context *context){
1647   StrAccum *pAccum;
1648   pAccum = sqlite3_aggregate_context(context, 0);
1649   if( pAccum ){
1650     if( pAccum->accError==STRACCUM_TOOBIG ){
1651       sqlite3_result_error_toobig(context);
1652     }else if( pAccum->accError==STRACCUM_NOMEM ){
1653       sqlite3_result_error_nomem(context);
1654     }else{
1655       sqlite3_result_text(context, sqlite3StrAccumFinish(pAccum), -1,
1656                           sqlite3_free);
1657     }
1658   }
1659 }
1660 
1661 /*
1662 ** This routine does per-connection function registration.  Most
1663 ** of the built-in functions above are part of the global function set.
1664 ** This routine only deals with those that are not global.
1665 */
1666 void sqlite3RegisterPerConnectionBuiltinFunctions(sqlite3 *db){
1667   int rc = sqlite3_overload_function(db, "MATCH", 2);
1668   assert( rc==SQLITE_NOMEM || rc==SQLITE_OK );
1669   if( rc==SQLITE_NOMEM ){
1670     sqlite3OomFault(db);
1671   }
1672 }
1673 
1674 /*
1675 ** Set the LIKEOPT flag on the 2-argument function with the given name.
1676 */
1677 static void setLikeOptFlag(sqlite3 *db, const char *zName, u8 flagVal){
1678   FuncDef *pDef;
1679   pDef = sqlite3FindFunction(db, zName, 2, SQLITE_UTF8, 0);
1680   if( ALWAYS(pDef) ){
1681     pDef->funcFlags |= flagVal;
1682   }
1683 }
1684 
1685 /*
1686 ** Register the built-in LIKE and GLOB functions.  The caseSensitive
1687 ** parameter determines whether or not the LIKE operator is case
1688 ** sensitive.  GLOB is always case sensitive.
1689 */
1690 void sqlite3RegisterLikeFunctions(sqlite3 *db, int caseSensitive){
1691   struct compareInfo *pInfo;
1692   if( caseSensitive ){
1693     pInfo = (struct compareInfo*)&likeInfoAlt;
1694   }else{
1695     pInfo = (struct compareInfo*)&likeInfoNorm;
1696   }
1697   sqlite3CreateFunc(db, "like", 2, SQLITE_UTF8, pInfo, likeFunc, 0, 0, 0);
1698   sqlite3CreateFunc(db, "like", 3, SQLITE_UTF8, pInfo, likeFunc, 0, 0, 0);
1699   sqlite3CreateFunc(db, "glob", 2, SQLITE_UTF8,
1700       (struct compareInfo*)&globInfo, likeFunc, 0, 0, 0);
1701   setLikeOptFlag(db, "glob", SQLITE_FUNC_LIKE | SQLITE_FUNC_CASE);
1702   setLikeOptFlag(db, "like",
1703       caseSensitive ? (SQLITE_FUNC_LIKE | SQLITE_FUNC_CASE) : SQLITE_FUNC_LIKE);
1704 }
1705 
1706 /*
1707 ** pExpr points to an expression which implements a function.  If
1708 ** it is appropriate to apply the LIKE optimization to that function
1709 ** then set aWc[0] through aWc[2] to the wildcard characters and the
1710 ** escape character and then return TRUE.  If the function is not a
1711 ** LIKE-style function then return FALSE.
1712 **
1713 ** The expression "a LIKE b ESCAPE c" is only considered a valid LIKE
1714 ** operator if c is a string literal that is exactly one byte in length.
1715 ** That one byte is stored in aWc[3].  aWc[3] is set to zero if there is
1716 ** no ESCAPE clause.
1717 **
1718 ** *pIsNocase is set to true if uppercase and lowercase are equivalent for
1719 ** the function (default for LIKE).  If the function makes the distinction
1720 ** between uppercase and lowercase (as does GLOB) then *pIsNocase is set to
1721 ** false.
1722 */
1723 int sqlite3IsLikeFunction(sqlite3 *db, Expr *pExpr, int *pIsNocase, char *aWc){
1724   FuncDef *pDef;
1725   int nExpr;
1726   if( pExpr->op!=TK_FUNCTION || !pExpr->x.pList ){
1727     return 0;
1728   }
1729   assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
1730   nExpr = pExpr->x.pList->nExpr;
1731   pDef = sqlite3FindFunction(db, pExpr->u.zToken, nExpr, SQLITE_UTF8, 0);
1732   if( NEVER(pDef==0) || (pDef->funcFlags & SQLITE_FUNC_LIKE)==0 ){
1733     return 0;
1734   }
1735   if( nExpr<3 ){
1736     aWc[3] = 0;
1737   }else{
1738     Expr *pEscape = pExpr->x.pList->a[2].pExpr;
1739     char *zEscape;
1740     if( pEscape->op!=TK_STRING ) return 0;
1741     zEscape = pEscape->u.zToken;
1742     if( zEscape[0]==0 || zEscape[1]!=0 ) return 0;
1743     aWc[3] = zEscape[0];
1744   }
1745 
1746   /* The memcpy() statement assumes that the wildcard characters are
1747   ** the first three statements in the compareInfo structure.  The
1748   ** asserts() that follow verify that assumption
1749   */
1750   memcpy(aWc, pDef->pUserData, 3);
1751   assert( (char*)&likeInfoAlt == (char*)&likeInfoAlt.matchAll );
1752   assert( &((char*)&likeInfoAlt)[1] == (char*)&likeInfoAlt.matchOne );
1753   assert( &((char*)&likeInfoAlt)[2] == (char*)&likeInfoAlt.matchSet );
1754   *pIsNocase = (pDef->funcFlags & SQLITE_FUNC_CASE)==0;
1755   return 1;
1756 }
1757 
1758 /*
1759 ** All of the FuncDef structures in the aBuiltinFunc[] array above
1760 ** to the global function hash table.  This occurs at start-time (as
1761 ** a consequence of calling sqlite3_initialize()).
1762 **
1763 ** After this routine runs
1764 */
1765 void sqlite3RegisterBuiltinFunctions(void){
1766   /*
1767   ** The following array holds FuncDef structures for all of the functions
1768   ** defined in this file.
1769   **
1770   ** The array cannot be constant since changes are made to the
1771   ** FuncDef.pHash elements at start-time.  The elements of this array
1772   ** are read-only after initialization is complete.
1773   **
1774   ** For peak efficiency, put the most frequently used function last.
1775   */
1776   static FuncDef aBuiltinFunc[] = {
1777 #ifdef SQLITE_SOUNDEX
1778     FUNCTION(soundex,            1, 0, 0, soundexFunc      ),
1779 #endif
1780 #ifndef SQLITE_OMIT_LOAD_EXTENSION
1781     VFUNCTION(load_extension,    1, 0, 0, loadExt          ),
1782     VFUNCTION(load_extension,    2, 0, 0, loadExt          ),
1783 #endif
1784 #if SQLITE_USER_AUTHENTICATION
1785     FUNCTION(sqlite_crypt,       2, 0, 0, sqlite3CryptFunc ),
1786 #endif
1787 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
1788     DFUNCTION(sqlite_compileoption_used,1, 0, 0, compileoptionusedFunc  ),
1789     DFUNCTION(sqlite_compileoption_get, 1, 0, 0, compileoptiongetFunc  ),
1790 #endif /* SQLITE_OMIT_COMPILEOPTION_DIAGS */
1791     FUNCTION2(unlikely,          1, 0, 0, noopFunc,  SQLITE_FUNC_UNLIKELY),
1792     FUNCTION2(likelihood,        2, 0, 0, noopFunc,  SQLITE_FUNC_UNLIKELY),
1793     FUNCTION2(likely,            1, 0, 0, noopFunc,  SQLITE_FUNC_UNLIKELY),
1794 #ifdef SQLITE_DEBUG
1795     FUNCTION2(affinity,          1, 0, 0, noopFunc,  SQLITE_FUNC_AFFINITY),
1796 #endif
1797     FUNCTION(ltrim,              1, 1, 0, trimFunc         ),
1798     FUNCTION(ltrim,              2, 1, 0, trimFunc         ),
1799     FUNCTION(rtrim,              1, 2, 0, trimFunc         ),
1800     FUNCTION(rtrim,              2, 2, 0, trimFunc         ),
1801     FUNCTION(trim,               1, 3, 0, trimFunc         ),
1802     FUNCTION(trim,               2, 3, 0, trimFunc         ),
1803     FUNCTION(min,               -1, 0, 1, minmaxFunc       ),
1804     FUNCTION(min,                0, 0, 1, 0                ),
1805     AGGREGATE2(min,              1, 0, 1, minmaxStep,      minMaxFinalize,
1806                                           SQLITE_FUNC_MINMAX ),
1807     FUNCTION(max,               -1, 1, 1, minmaxFunc       ),
1808     FUNCTION(max,                0, 1, 1, 0                ),
1809     AGGREGATE2(max,              1, 1, 1, minmaxStep,      minMaxFinalize,
1810                                           SQLITE_FUNC_MINMAX ),
1811     FUNCTION2(typeof,            1, 0, 0, typeofFunc,  SQLITE_FUNC_TYPEOF),
1812     FUNCTION2(length,            1, 0, 0, lengthFunc,  SQLITE_FUNC_LENGTH),
1813     FUNCTION(instr,              2, 0, 0, instrFunc        ),
1814     FUNCTION(printf,            -1, 0, 0, printfFunc       ),
1815     FUNCTION(unicode,            1, 0, 0, unicodeFunc      ),
1816     FUNCTION(char,              -1, 0, 0, charFunc         ),
1817     FUNCTION(abs,                1, 0, 0, absFunc          ),
1818 #ifndef SQLITE_OMIT_FLOATING_POINT
1819     FUNCTION(round,              1, 0, 0, roundFunc        ),
1820     FUNCTION(round,              2, 0, 0, roundFunc        ),
1821 #endif
1822     FUNCTION(upper,              1, 0, 0, upperFunc        ),
1823     FUNCTION(lower,              1, 0, 0, lowerFunc        ),
1824     FUNCTION(hex,                1, 0, 0, hexFunc          ),
1825     FUNCTION2(ifnull,            2, 0, 0, noopFunc,  SQLITE_FUNC_COALESCE),
1826     VFUNCTION(random,            0, 0, 0, randomFunc       ),
1827     VFUNCTION(randomblob,        1, 0, 0, randomBlob       ),
1828     FUNCTION(nullif,             2, 0, 1, nullifFunc       ),
1829     DFUNCTION(sqlite_version,    0, 0, 0, versionFunc      ),
1830     DFUNCTION(sqlite_source_id,  0, 0, 0, sourceidFunc     ),
1831     FUNCTION(sqlite_log,         2, 0, 0, errlogFunc       ),
1832     FUNCTION(quote,              1, 0, 0, quoteFunc        ),
1833     VFUNCTION(last_insert_rowid, 0, 0, 0, last_insert_rowid),
1834     VFUNCTION(changes,           0, 0, 0, changes          ),
1835     VFUNCTION(total_changes,     0, 0, 0, total_changes    ),
1836     FUNCTION(replace,            3, 0, 0, replaceFunc      ),
1837     FUNCTION(zeroblob,           1, 0, 0, zeroblobFunc     ),
1838     FUNCTION(substr,             2, 0, 0, substrFunc       ),
1839     FUNCTION(substr,             3, 0, 0, substrFunc       ),
1840     AGGREGATE(sum,               1, 0, 0, sumStep,         sumFinalize    ),
1841     AGGREGATE(total,             1, 0, 0, sumStep,         totalFinalize    ),
1842     AGGREGATE(avg,               1, 0, 0, sumStep,         avgFinalize    ),
1843     AGGREGATE2(count,            0, 0, 0, countStep,       countFinalize,
1844                SQLITE_FUNC_COUNT  ),
1845     AGGREGATE(count,             1, 0, 0, countStep,       countFinalize  ),
1846     AGGREGATE(group_concat,      1, 0, 0, groupConcatStep, groupConcatFinalize),
1847     AGGREGATE(group_concat,      2, 0, 0, groupConcatStep, groupConcatFinalize),
1848 
1849     LIKEFUNC(glob, 2, &globInfo, SQLITE_FUNC_LIKE|SQLITE_FUNC_CASE),
1850 #ifdef SQLITE_CASE_SENSITIVE_LIKE
1851     LIKEFUNC(like, 2, &likeInfoAlt, SQLITE_FUNC_LIKE|SQLITE_FUNC_CASE),
1852     LIKEFUNC(like, 3, &likeInfoAlt, SQLITE_FUNC_LIKE|SQLITE_FUNC_CASE),
1853 #else
1854     LIKEFUNC(like, 2, &likeInfoNorm, SQLITE_FUNC_LIKE),
1855     LIKEFUNC(like, 3, &likeInfoNorm, SQLITE_FUNC_LIKE),
1856 #endif
1857 #ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION
1858     FUNCTION(unknown,           -1, 0, 0, unknownFunc      ),
1859 #endif
1860     FUNCTION(coalesce,           1, 0, 0, 0                ),
1861     FUNCTION(coalesce,           0, 0, 0, 0                ),
1862     FUNCTION2(coalesce,         -1, 0, 0, noopFunc,  SQLITE_FUNC_COALESCE),
1863   };
1864 #ifndef SQLITE_OMIT_ALTERTABLE
1865   sqlite3AlterFunctions();
1866 #endif
1867 #if defined(SQLITE_ENABLE_STAT3) || defined(SQLITE_ENABLE_STAT4)
1868   sqlite3AnalyzeFunctions();
1869 #endif
1870   sqlite3RegisterDateTimeFunctions();
1871   sqlite3InsertBuiltinFuncs(aBuiltinFunc, ArraySize(aBuiltinFunc));
1872 
1873 #if 0  /* Enable to print out how the built-in functions are hashed */
1874   {
1875     int i;
1876     FuncDef *p;
1877     for(i=0; i<SQLITE_FUNC_HASH_SZ; i++){
1878       printf("FUNC-HASH %02d:", i);
1879       for(p=sqlite3BuiltinFunctions.a[i]; p; p=p->u.pHash){
1880         int n = sqlite3Strlen30(p->zName);
1881         int h = p->zName[0] + n;
1882         printf(" %s(%d)", p->zName, h);
1883       }
1884       printf("\n");
1885     }
1886   }
1887 #endif
1888 }
1889