xref: /sqlite-3.40.0/src/vdbeapi.c (revision 4c8404e5)
1 /*
2 ** 2004 May 26
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 **
13 ** This file contains code use to implement APIs that are part of the
14 ** VDBE.
15 */
16 #include "sqliteInt.h"
17 #include "vdbeInt.h"
18 
19 #ifndef SQLITE_OMIT_DEPRECATED
20 /*
21 ** Return TRUE (non-zero) of the statement supplied as an argument needs
22 ** to be recompiled.  A statement needs to be recompiled whenever the
23 ** execution environment changes in a way that would alter the program
24 ** that sqlite3_prepare() generates.  For example, if new functions or
25 ** collating sequences are registered or if an authorizer function is
26 ** added or changed.
27 */
28 int sqlite3_expired(sqlite3_stmt *pStmt){
29   Vdbe *p = (Vdbe*)pStmt;
30   return p==0 || p->expired;
31 }
32 #endif
33 
34 /*
35 ** Check on a Vdbe to make sure it has not been finalized.  Log
36 ** an error and return true if it has been finalized (or is otherwise
37 ** invalid).  Return false if it is ok.
38 */
39 static int vdbeSafety(Vdbe *p){
40   if( p->db==0 ){
41     sqlite3_log(SQLITE_MISUSE, "API called with finalized prepared statement");
42     return 1;
43   }else{
44     return 0;
45   }
46 }
47 static int vdbeSafetyNotNull(Vdbe *p){
48   if( p==0 ){
49     sqlite3_log(SQLITE_MISUSE, "API called with NULL prepared statement");
50     return 1;
51   }else{
52     return vdbeSafety(p);
53   }
54 }
55 
56 #ifndef SQLITE_OMIT_TRACE
57 /*
58 ** Invoke the profile callback.  This routine is only called if we already
59 ** know that the profile callback is defined and needs to be invoked.
60 */
61 static SQLITE_NOINLINE void invokeProfileCallback(sqlite3 *db, Vdbe *p){
62   sqlite3_int64 iNow;
63   sqlite3_int64 iElapse;
64   assert( p->startTime>0 );
65   assert( (db->mTrace & (SQLITE_TRACE_PROFILE|SQLITE_TRACE_XPROFILE))!=0 );
66   assert( db->init.busy==0 );
67   assert( p->zSql!=0 );
68   sqlite3OsCurrentTimeInt64(db->pVfs, &iNow);
69   iElapse = (iNow - p->startTime)*1000000;
70 #ifndef SQLITE_OMIT_DEPRECATED
71   if( db->xProfile ){
72     db->xProfile(db->pProfileArg, p->zSql, iElapse);
73   }
74 #endif
75   if( db->mTrace & SQLITE_TRACE_PROFILE ){
76     db->trace.xV2(SQLITE_TRACE_PROFILE, db->pTraceArg, p, (void*)&iElapse);
77   }
78   p->startTime = 0;
79 }
80 /*
81 ** The checkProfileCallback(DB,P) macro checks to see if a profile callback
82 ** is needed, and it invokes the callback if it is needed.
83 */
84 # define checkProfileCallback(DB,P) \
85    if( ((P)->startTime)>0 ){ invokeProfileCallback(DB,P); }
86 #else
87 # define checkProfileCallback(DB,P)  /*no-op*/
88 #endif
89 
90 /*
91 ** The following routine destroys a virtual machine that is created by
92 ** the sqlite3_compile() routine. The integer returned is an SQLITE_
93 ** success/failure code that describes the result of executing the virtual
94 ** machine.
95 **
96 ** This routine sets the error code and string returned by
97 ** sqlite3_errcode(), sqlite3_errmsg() and sqlite3_errmsg16().
98 */
99 int sqlite3_finalize(sqlite3_stmt *pStmt){
100   int rc;
101   if( pStmt==0 ){
102     /* IMPLEMENTATION-OF: R-57228-12904 Invoking sqlite3_finalize() on a NULL
103     ** pointer is a harmless no-op. */
104     rc = SQLITE_OK;
105   }else{
106     Vdbe *v = (Vdbe*)pStmt;
107     sqlite3 *db = v->db;
108     if( vdbeSafety(v) ) return SQLITE_MISUSE_BKPT;
109     sqlite3_mutex_enter(db->mutex);
110     checkProfileCallback(db, v);
111     assert( v->eVdbeState>=VDBE_READY_STATE );
112     rc = sqlite3VdbeReset(v);
113     sqlite3VdbeDelete(v);
114     rc = sqlite3ApiExit(db, rc);
115     sqlite3LeaveMutexAndCloseZombie(db);
116   }
117   return rc;
118 }
119 
120 /*
121 ** Terminate the current execution of an SQL statement and reset it
122 ** back to its starting state so that it can be reused. A success code from
123 ** the prior execution is returned.
124 **
125 ** This routine sets the error code and string returned by
126 ** sqlite3_errcode(), sqlite3_errmsg() and sqlite3_errmsg16().
127 */
128 int sqlite3_reset(sqlite3_stmt *pStmt){
129   int rc;
130   if( pStmt==0 ){
131     rc = SQLITE_OK;
132   }else{
133     Vdbe *v = (Vdbe*)pStmt;
134     sqlite3 *db = v->db;
135     sqlite3_mutex_enter(db->mutex);
136     checkProfileCallback(db, v);
137     rc = sqlite3VdbeReset(v);
138     sqlite3VdbeRewind(v);
139     assert( (rc & (db->errMask))==rc );
140     rc = sqlite3ApiExit(db, rc);
141     sqlite3_mutex_leave(db->mutex);
142   }
143   return rc;
144 }
145 
146 /*
147 ** Set all the parameters in the compiled SQL statement to NULL.
148 */
149 int sqlite3_clear_bindings(sqlite3_stmt *pStmt){
150   int i;
151   int rc = SQLITE_OK;
152   Vdbe *p = (Vdbe*)pStmt;
153 #if SQLITE_THREADSAFE
154   sqlite3_mutex *mutex = ((Vdbe*)pStmt)->db->mutex;
155 #endif
156   sqlite3_mutex_enter(mutex);
157   for(i=0; i<p->nVar; i++){
158     sqlite3VdbeMemRelease(&p->aVar[i]);
159     p->aVar[i].flags = MEM_Null;
160   }
161   assert( (p->prepFlags & SQLITE_PREPARE_SAVESQL)!=0 || p->expmask==0 );
162   if( p->expmask ){
163     p->expired = 1;
164   }
165   sqlite3_mutex_leave(mutex);
166   return rc;
167 }
168 
169 
170 /**************************** sqlite3_value_  *******************************
171 ** The following routines extract information from a Mem or sqlite3_value
172 ** structure.
173 */
174 const void *sqlite3_value_blob(sqlite3_value *pVal){
175   Mem *p = (Mem*)pVal;
176   if( p->flags & (MEM_Blob|MEM_Str) ){
177     if( ExpandBlob(p)!=SQLITE_OK ){
178       assert( p->flags==MEM_Null && p->z==0 );
179       return 0;
180     }
181     p->flags |= MEM_Blob;
182     return p->n ? p->z : 0;
183   }else{
184     return sqlite3_value_text(pVal);
185   }
186 }
187 int sqlite3_value_bytes(sqlite3_value *pVal){
188   return sqlite3ValueBytes(pVal, SQLITE_UTF8);
189 }
190 int sqlite3_value_bytes16(sqlite3_value *pVal){
191   return sqlite3ValueBytes(pVal, SQLITE_UTF16NATIVE);
192 }
193 double sqlite3_value_double(sqlite3_value *pVal){
194   return sqlite3VdbeRealValue((Mem*)pVal);
195 }
196 int sqlite3_value_int(sqlite3_value *pVal){
197   return (int)sqlite3VdbeIntValue((Mem*)pVal);
198 }
199 sqlite_int64 sqlite3_value_int64(sqlite3_value *pVal){
200   return sqlite3VdbeIntValue((Mem*)pVal);
201 }
202 unsigned int sqlite3_value_subtype(sqlite3_value *pVal){
203   Mem *pMem = (Mem*)pVal;
204   return ((pMem->flags & MEM_Subtype) ? pMem->eSubtype : 0);
205 }
206 void *sqlite3_value_pointer(sqlite3_value *pVal, const char *zPType){
207   Mem *p = (Mem*)pVal;
208   if( (p->flags&(MEM_TypeMask|MEM_Term|MEM_Subtype)) ==
209                  (MEM_Null|MEM_Term|MEM_Subtype)
210    && zPType!=0
211    && p->eSubtype=='p'
212    && strcmp(p->u.zPType, zPType)==0
213   ){
214     return (void*)p->z;
215   }else{
216     return 0;
217   }
218 }
219 const unsigned char *sqlite3_value_text(sqlite3_value *pVal){
220   return (const unsigned char *)sqlite3ValueText(pVal, SQLITE_UTF8);
221 }
222 #ifndef SQLITE_OMIT_UTF16
223 const void *sqlite3_value_text16(sqlite3_value* pVal){
224   return sqlite3ValueText(pVal, SQLITE_UTF16NATIVE);
225 }
226 const void *sqlite3_value_text16be(sqlite3_value *pVal){
227   return sqlite3ValueText(pVal, SQLITE_UTF16BE);
228 }
229 const void *sqlite3_value_text16le(sqlite3_value *pVal){
230   return sqlite3ValueText(pVal, SQLITE_UTF16LE);
231 }
232 #endif /* SQLITE_OMIT_UTF16 */
233 /* EVIDENCE-OF: R-12793-43283 Every value in SQLite has one of five
234 ** fundamental datatypes: 64-bit signed integer 64-bit IEEE floating
235 ** point number string BLOB NULL
236 */
237 int sqlite3_value_type(sqlite3_value* pVal){
238   static const u8 aType[] = {
239      SQLITE_BLOB,     /* 0x00 (not possible) */
240      SQLITE_NULL,     /* 0x01 NULL */
241      SQLITE_TEXT,     /* 0x02 TEXT */
242      SQLITE_NULL,     /* 0x03 (not possible) */
243      SQLITE_INTEGER,  /* 0x04 INTEGER */
244      SQLITE_NULL,     /* 0x05 (not possible) */
245      SQLITE_INTEGER,  /* 0x06 INTEGER + TEXT */
246      SQLITE_NULL,     /* 0x07 (not possible) */
247      SQLITE_FLOAT,    /* 0x08 FLOAT */
248      SQLITE_NULL,     /* 0x09 (not possible) */
249      SQLITE_FLOAT,    /* 0x0a FLOAT + TEXT */
250      SQLITE_NULL,     /* 0x0b (not possible) */
251      SQLITE_INTEGER,  /* 0x0c (not possible) */
252      SQLITE_NULL,     /* 0x0d (not possible) */
253      SQLITE_INTEGER,  /* 0x0e (not possible) */
254      SQLITE_NULL,     /* 0x0f (not possible) */
255      SQLITE_BLOB,     /* 0x10 BLOB */
256      SQLITE_NULL,     /* 0x11 (not possible) */
257      SQLITE_TEXT,     /* 0x12 (not possible) */
258      SQLITE_NULL,     /* 0x13 (not possible) */
259      SQLITE_INTEGER,  /* 0x14 INTEGER + BLOB */
260      SQLITE_NULL,     /* 0x15 (not possible) */
261      SQLITE_INTEGER,  /* 0x16 (not possible) */
262      SQLITE_NULL,     /* 0x17 (not possible) */
263      SQLITE_FLOAT,    /* 0x18 FLOAT + BLOB */
264      SQLITE_NULL,     /* 0x19 (not possible) */
265      SQLITE_FLOAT,    /* 0x1a (not possible) */
266      SQLITE_NULL,     /* 0x1b (not possible) */
267      SQLITE_INTEGER,  /* 0x1c (not possible) */
268      SQLITE_NULL,     /* 0x1d (not possible) */
269      SQLITE_INTEGER,  /* 0x1e (not possible) */
270      SQLITE_NULL,     /* 0x1f (not possible) */
271      SQLITE_FLOAT,    /* 0x20 INTREAL */
272      SQLITE_NULL,     /* 0x21 (not possible) */
273      SQLITE_TEXT,     /* 0x22 INTREAL + TEXT */
274      SQLITE_NULL,     /* 0x23 (not possible) */
275      SQLITE_FLOAT,    /* 0x24 (not possible) */
276      SQLITE_NULL,     /* 0x25 (not possible) */
277      SQLITE_FLOAT,    /* 0x26 (not possible) */
278      SQLITE_NULL,     /* 0x27 (not possible) */
279      SQLITE_FLOAT,    /* 0x28 (not possible) */
280      SQLITE_NULL,     /* 0x29 (not possible) */
281      SQLITE_FLOAT,    /* 0x2a (not possible) */
282      SQLITE_NULL,     /* 0x2b (not possible) */
283      SQLITE_FLOAT,    /* 0x2c (not possible) */
284      SQLITE_NULL,     /* 0x2d (not possible) */
285      SQLITE_FLOAT,    /* 0x2e (not possible) */
286      SQLITE_NULL,     /* 0x2f (not possible) */
287      SQLITE_BLOB,     /* 0x30 (not possible) */
288      SQLITE_NULL,     /* 0x31 (not possible) */
289      SQLITE_TEXT,     /* 0x32 (not possible) */
290      SQLITE_NULL,     /* 0x33 (not possible) */
291      SQLITE_FLOAT,    /* 0x34 (not possible) */
292      SQLITE_NULL,     /* 0x35 (not possible) */
293      SQLITE_FLOAT,    /* 0x36 (not possible) */
294      SQLITE_NULL,     /* 0x37 (not possible) */
295      SQLITE_FLOAT,    /* 0x38 (not possible) */
296      SQLITE_NULL,     /* 0x39 (not possible) */
297      SQLITE_FLOAT,    /* 0x3a (not possible) */
298      SQLITE_NULL,     /* 0x3b (not possible) */
299      SQLITE_FLOAT,    /* 0x3c (not possible) */
300      SQLITE_NULL,     /* 0x3d (not possible) */
301      SQLITE_FLOAT,    /* 0x3e (not possible) */
302      SQLITE_NULL,     /* 0x3f (not possible) */
303   };
304 #ifdef SQLITE_DEBUG
305   {
306     int eType = SQLITE_BLOB;
307     if( pVal->flags & MEM_Null ){
308       eType = SQLITE_NULL;
309     }else if( pVal->flags & (MEM_Real|MEM_IntReal) ){
310       eType = SQLITE_FLOAT;
311     }else if( pVal->flags & MEM_Int ){
312       eType = SQLITE_INTEGER;
313     }else if( pVal->flags & MEM_Str ){
314       eType = SQLITE_TEXT;
315     }
316     assert( eType == aType[pVal->flags&MEM_AffMask] );
317   }
318 #endif
319   return aType[pVal->flags&MEM_AffMask];
320 }
321 
322 /* Return true if a parameter to xUpdate represents an unchanged column */
323 int sqlite3_value_nochange(sqlite3_value *pVal){
324   return (pVal->flags&(MEM_Null|MEM_Zero))==(MEM_Null|MEM_Zero);
325 }
326 
327 /* Return true if a parameter value originated from an sqlite3_bind() */
328 int sqlite3_value_frombind(sqlite3_value *pVal){
329   return (pVal->flags&MEM_FromBind)!=0;
330 }
331 
332 /* Make a copy of an sqlite3_value object
333 */
334 sqlite3_value *sqlite3_value_dup(const sqlite3_value *pOrig){
335   sqlite3_value *pNew;
336   if( pOrig==0 ) return 0;
337   pNew = sqlite3_malloc( sizeof(*pNew) );
338   if( pNew==0 ) return 0;
339   memset(pNew, 0, sizeof(*pNew));
340   memcpy(pNew, pOrig, MEMCELLSIZE);
341   pNew->flags &= ~MEM_Dyn;
342   pNew->db = 0;
343   if( pNew->flags&(MEM_Str|MEM_Blob) ){
344     pNew->flags &= ~(MEM_Static|MEM_Dyn);
345     pNew->flags |= MEM_Ephem;
346     if( sqlite3VdbeMemMakeWriteable(pNew)!=SQLITE_OK ){
347       sqlite3ValueFree(pNew);
348       pNew = 0;
349     }
350   }else if( pNew->flags & MEM_Null ){
351     /* Do not duplicate pointer values */
352     pNew->flags &= ~(MEM_Term|MEM_Subtype);
353   }
354   return pNew;
355 }
356 
357 /* Destroy an sqlite3_value object previously obtained from
358 ** sqlite3_value_dup().
359 */
360 void sqlite3_value_free(sqlite3_value *pOld){
361   sqlite3ValueFree(pOld);
362 }
363 
364 
365 /**************************** sqlite3_result_  *******************************
366 ** The following routines are used by user-defined functions to specify
367 ** the function result.
368 **
369 ** The setStrOrError() function calls sqlite3VdbeMemSetStr() to store the
370 ** result as a string or blob.  Appropriate errors are set if the string/blob
371 ** is too big or if an OOM occurs.
372 **
373 ** The invokeValueDestructor(P,X) routine invokes destructor function X()
374 ** on value P is not going to be used and need to be destroyed.
375 */
376 static void setResultStrOrError(
377   sqlite3_context *pCtx,  /* Function context */
378   const char *z,          /* String pointer */
379   int n,                  /* Bytes in string, or negative */
380   u8 enc,                 /* Encoding of z.  0 for BLOBs */
381   void (*xDel)(void*)     /* Destructor function */
382 ){
383   Mem *pOut = pCtx->pOut;
384   int rc = sqlite3VdbeMemSetStr(pOut, z, n, enc, xDel);
385   if( rc ){
386     if( rc==SQLITE_TOOBIG ){
387       sqlite3_result_error_toobig(pCtx);
388     }else{
389       /* The only errors possible from sqlite3VdbeMemSetStr are
390       ** SQLITE_TOOBIG and SQLITE_NOMEM */
391       assert( rc==SQLITE_NOMEM );
392       sqlite3_result_error_nomem(pCtx);
393     }
394     return;
395   }
396   sqlite3VdbeChangeEncoding(pOut, pCtx->enc);
397   if( sqlite3VdbeMemTooBig(pOut) ){
398     sqlite3_result_error_toobig(pCtx);
399   }
400 }
401 static int invokeValueDestructor(
402   const void *p,             /* Value to destroy */
403   void (*xDel)(void*),       /* The destructor */
404   sqlite3_context *pCtx      /* Set a SQLITE_TOOBIG error if no NULL */
405 ){
406   assert( xDel!=SQLITE_DYNAMIC );
407   if( xDel==0 ){
408     /* noop */
409   }else if( xDel==SQLITE_TRANSIENT ){
410     /* noop */
411   }else{
412     xDel((void*)p);
413   }
414   sqlite3_result_error_toobig(pCtx);
415   return SQLITE_TOOBIG;
416 }
417 void sqlite3_result_blob(
418   sqlite3_context *pCtx,
419   const void *z,
420   int n,
421   void (*xDel)(void *)
422 ){
423   assert( n>=0 );
424   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
425   setResultStrOrError(pCtx, z, n, 0, xDel);
426 }
427 void sqlite3_result_blob64(
428   sqlite3_context *pCtx,
429   const void *z,
430   sqlite3_uint64 n,
431   void (*xDel)(void *)
432 ){
433   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
434   assert( xDel!=SQLITE_DYNAMIC );
435   if( n>0x7fffffff ){
436     (void)invokeValueDestructor(z, xDel, pCtx);
437   }else{
438     setResultStrOrError(pCtx, z, (int)n, 0, xDel);
439   }
440 }
441 void sqlite3_result_double(sqlite3_context *pCtx, double rVal){
442   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
443   sqlite3VdbeMemSetDouble(pCtx->pOut, rVal);
444 }
445 void sqlite3_result_error(sqlite3_context *pCtx, const char *z, int n){
446   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
447   pCtx->isError = SQLITE_ERROR;
448   sqlite3VdbeMemSetStr(pCtx->pOut, z, n, SQLITE_UTF8, SQLITE_TRANSIENT);
449 }
450 #ifndef SQLITE_OMIT_UTF16
451 void sqlite3_result_error16(sqlite3_context *pCtx, const void *z, int n){
452   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
453   pCtx->isError = SQLITE_ERROR;
454   sqlite3VdbeMemSetStr(pCtx->pOut, z, n, SQLITE_UTF16NATIVE, SQLITE_TRANSIENT);
455 }
456 #endif
457 void sqlite3_result_int(sqlite3_context *pCtx, int iVal){
458   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
459   sqlite3VdbeMemSetInt64(pCtx->pOut, (i64)iVal);
460 }
461 void sqlite3_result_int64(sqlite3_context *pCtx, i64 iVal){
462   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
463   sqlite3VdbeMemSetInt64(pCtx->pOut, iVal);
464 }
465 void sqlite3_result_null(sqlite3_context *pCtx){
466   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
467   sqlite3VdbeMemSetNull(pCtx->pOut);
468 }
469 void sqlite3_result_pointer(
470   sqlite3_context *pCtx,
471   void *pPtr,
472   const char *zPType,
473   void (*xDestructor)(void*)
474 ){
475   Mem *pOut = pCtx->pOut;
476   assert( sqlite3_mutex_held(pOut->db->mutex) );
477   sqlite3VdbeMemRelease(pOut);
478   pOut->flags = MEM_Null;
479   sqlite3VdbeMemSetPointer(pOut, pPtr, zPType, xDestructor);
480 }
481 void sqlite3_result_subtype(sqlite3_context *pCtx, unsigned int eSubtype){
482   Mem *pOut = pCtx->pOut;
483   assert( sqlite3_mutex_held(pOut->db->mutex) );
484   pOut->eSubtype = eSubtype & 0xff;
485   pOut->flags |= MEM_Subtype;
486 }
487 void sqlite3_result_text(
488   sqlite3_context *pCtx,
489   const char *z,
490   int n,
491   void (*xDel)(void *)
492 ){
493   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
494   setResultStrOrError(pCtx, z, n, SQLITE_UTF8, xDel);
495 }
496 void sqlite3_result_text64(
497   sqlite3_context *pCtx,
498   const char *z,
499   sqlite3_uint64 n,
500   void (*xDel)(void *),
501   unsigned char enc
502 ){
503   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
504   assert( xDel!=SQLITE_DYNAMIC );
505   if( enc==SQLITE_UTF16 ) enc = SQLITE_UTF16NATIVE;
506   if( n>0x7fffffff ){
507     (void)invokeValueDestructor(z, xDel, pCtx);
508   }else{
509     setResultStrOrError(pCtx, z, (int)n, enc, xDel);
510   }
511 }
512 #ifndef SQLITE_OMIT_UTF16
513 void sqlite3_result_text16(
514   sqlite3_context *pCtx,
515   const void *z,
516   int n,
517   void (*xDel)(void *)
518 ){
519   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
520   setResultStrOrError(pCtx, z, n, SQLITE_UTF16NATIVE, xDel);
521 }
522 void sqlite3_result_text16be(
523   sqlite3_context *pCtx,
524   const void *z,
525   int n,
526   void (*xDel)(void *)
527 ){
528   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
529   setResultStrOrError(pCtx, z, n, SQLITE_UTF16BE, xDel);
530 }
531 void sqlite3_result_text16le(
532   sqlite3_context *pCtx,
533   const void *z,
534   int n,
535   void (*xDel)(void *)
536 ){
537   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
538   setResultStrOrError(pCtx, z, n, SQLITE_UTF16LE, xDel);
539 }
540 #endif /* SQLITE_OMIT_UTF16 */
541 void sqlite3_result_value(sqlite3_context *pCtx, sqlite3_value *pValue){
542   Mem *pOut = pCtx->pOut;
543   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
544   sqlite3VdbeMemCopy(pOut, pValue);
545   sqlite3VdbeChangeEncoding(pOut, pCtx->enc);
546   if( sqlite3VdbeMemTooBig(pOut) ){
547     sqlite3_result_error_toobig(pCtx);
548   }
549 }
550 void sqlite3_result_zeroblob(sqlite3_context *pCtx, int n){
551   sqlite3_result_zeroblob64(pCtx, n>0 ? n : 0);
552 }
553 int sqlite3_result_zeroblob64(sqlite3_context *pCtx, u64 n){
554   Mem *pOut = pCtx->pOut;
555   assert( sqlite3_mutex_held(pOut->db->mutex) );
556   if( n>(u64)pOut->db->aLimit[SQLITE_LIMIT_LENGTH] ){
557     sqlite3_result_error_toobig(pCtx);
558     return SQLITE_TOOBIG;
559   }
560 #ifndef SQLITE_OMIT_INCRBLOB
561   sqlite3VdbeMemSetZeroBlob(pCtx->pOut, (int)n);
562   return SQLITE_OK;
563 #else
564   return sqlite3VdbeMemSetZeroBlob(pCtx->pOut, (int)n);
565 #endif
566 }
567 void sqlite3_result_error_code(sqlite3_context *pCtx, int errCode){
568   pCtx->isError = errCode ? errCode : -1;
569 #ifdef SQLITE_DEBUG
570   if( pCtx->pVdbe ) pCtx->pVdbe->rcApp = errCode;
571 #endif
572   if( pCtx->pOut->flags & MEM_Null ){
573     setResultStrOrError(pCtx, sqlite3ErrStr(errCode), -1, SQLITE_UTF8,
574                         SQLITE_STATIC);
575   }
576 }
577 
578 /* Force an SQLITE_TOOBIG error. */
579 void sqlite3_result_error_toobig(sqlite3_context *pCtx){
580   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
581   pCtx->isError = SQLITE_TOOBIG;
582   sqlite3VdbeMemSetStr(pCtx->pOut, "string or blob too big", -1,
583                        SQLITE_UTF8, SQLITE_STATIC);
584 }
585 
586 /* An SQLITE_NOMEM error. */
587 void sqlite3_result_error_nomem(sqlite3_context *pCtx){
588   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
589   sqlite3VdbeMemSetNull(pCtx->pOut);
590   pCtx->isError = SQLITE_NOMEM_BKPT;
591   sqlite3OomFault(pCtx->pOut->db);
592 }
593 
594 #ifndef SQLITE_UNTESTABLE
595 /* Force the INT64 value currently stored as the result to be
596 ** a MEM_IntReal value.  See the SQLITE_TESTCTRL_RESULT_INTREAL
597 ** test-control.
598 */
599 void sqlite3ResultIntReal(sqlite3_context *pCtx){
600   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
601   if( pCtx->pOut->flags & MEM_Int ){
602     pCtx->pOut->flags &= ~MEM_Int;
603     pCtx->pOut->flags |= MEM_IntReal;
604   }
605 }
606 #endif
607 
608 
609 /*
610 ** This function is called after a transaction has been committed. It
611 ** invokes callbacks registered with sqlite3_wal_hook() as required.
612 */
613 static int doWalCallbacks(sqlite3 *db){
614   int rc = SQLITE_OK;
615 #ifndef SQLITE_OMIT_WAL
616   int i;
617   for(i=0; i<db->nDb; i++){
618     Btree *pBt = db->aDb[i].pBt;
619     if( pBt ){
620       int nEntry;
621       sqlite3BtreeEnter(pBt);
622       nEntry = sqlite3PagerWalCallback(sqlite3BtreePager(pBt));
623       sqlite3BtreeLeave(pBt);
624       if( nEntry>0 && db->xWalCallback && rc==SQLITE_OK ){
625         rc = db->xWalCallback(db->pWalArg, db, db->aDb[i].zDbSName, nEntry);
626       }
627     }
628   }
629 #endif
630   return rc;
631 }
632 
633 
634 /*
635 ** Execute the statement pStmt, either until a row of data is ready, the
636 ** statement is completely executed or an error occurs.
637 **
638 ** This routine implements the bulk of the logic behind the sqlite_step()
639 ** API.  The only thing omitted is the automatic recompile if a
640 ** schema change has occurred.  That detail is handled by the
641 ** outer sqlite3_step() wrapper procedure.
642 */
643 static int sqlite3Step(Vdbe *p){
644   sqlite3 *db;
645   int rc;
646 
647   assert(p);
648   db = p->db;
649   if( p->eVdbeState!=VDBE_RUN_STATE ){
650     restart_step:
651     if( p->eVdbeState==VDBE_READY_STATE ){
652       if( p->expired ){
653         p->rc = SQLITE_SCHEMA;
654         rc = SQLITE_ERROR;
655         if( (p->prepFlags & SQLITE_PREPARE_SAVESQL)!=0 ){
656           /* If this statement was prepared using saved SQL and an
657           ** error has occurred, then return the error code in p->rc to the
658           ** caller. Set the error code in the database handle to the same
659           ** value.
660           */
661           rc = sqlite3VdbeTransferError(p);
662         }
663         goto end_of_step;
664       }
665 
666       /* If there are no other statements currently running, then
667       ** reset the interrupt flag.  This prevents a call to sqlite3_interrupt
668       ** from interrupting a statement that has not yet started.
669       */
670       if( db->nVdbeActive==0 ){
671         AtomicStore(&db->u1.isInterrupted, 0);
672       }
673 
674       assert( db->nVdbeWrite>0 || db->autoCommit==0
675           || (db->nDeferredCons==0 && db->nDeferredImmCons==0)
676       );
677 
678 #ifndef SQLITE_OMIT_TRACE
679       if( (db->mTrace & (SQLITE_TRACE_PROFILE|SQLITE_TRACE_XPROFILE))!=0
680           && !db->init.busy && p->zSql ){
681         sqlite3OsCurrentTimeInt64(db->pVfs, &p->startTime);
682       }else{
683         assert( p->startTime==0 );
684       }
685 #endif
686 
687       db->nVdbeActive++;
688       if( p->readOnly==0 ) db->nVdbeWrite++;
689       if( p->bIsReader ) db->nVdbeRead++;
690       p->pc = 0;
691       p->eVdbeState = VDBE_RUN_STATE;
692     }else
693 
694     if( ALWAYS(p->eVdbeState==VDBE_HALT_STATE) ){
695       /* We used to require that sqlite3_reset() be called before retrying
696       ** sqlite3_step() after any error or after SQLITE_DONE.  But beginning
697       ** with version 3.7.0, we changed this so that sqlite3_reset() would
698       ** be called automatically instead of throwing the SQLITE_MISUSE error.
699       ** This "automatic-reset" change is not technically an incompatibility,
700       ** since any application that receives an SQLITE_MISUSE is broken by
701       ** definition.
702       **
703       ** Nevertheless, some published applications that were originally written
704       ** for version 3.6.23 or earlier do in fact depend on SQLITE_MISUSE
705       ** returns, and those were broken by the automatic-reset change.  As a
706       ** a work-around, the SQLITE_OMIT_AUTORESET compile-time restores the
707       ** legacy behavior of returning SQLITE_MISUSE for cases where the
708       ** previous sqlite3_step() returned something other than a SQLITE_LOCKED
709       ** or SQLITE_BUSY error.
710       */
711 #ifdef SQLITE_OMIT_AUTORESET
712       if( (rc = p->rc&0xff)==SQLITE_BUSY || rc==SQLITE_LOCKED ){
713         sqlite3_reset((sqlite3_stmt*)p);
714       }else{
715         return SQLITE_MISUSE_BKPT;
716       }
717 #else
718       sqlite3_reset((sqlite3_stmt*)p);
719 #endif
720       assert( p->eVdbeState==VDBE_READY_STATE );
721       goto restart_step;
722     }
723   }
724 
725 #ifdef SQLITE_DEBUG
726   p->rcApp = SQLITE_OK;
727 #endif
728 #ifndef SQLITE_OMIT_EXPLAIN
729   if( p->explain ){
730     rc = sqlite3VdbeList(p);
731   }else
732 #endif /* SQLITE_OMIT_EXPLAIN */
733   {
734     db->nVdbeExec++;
735     rc = sqlite3VdbeExec(p);
736     db->nVdbeExec--;
737   }
738 
739   if( rc==SQLITE_ROW ){
740     assert( p->rc==SQLITE_OK );
741     assert( db->mallocFailed==0 );
742     db->errCode = SQLITE_ROW;
743     return SQLITE_ROW;
744   }else{
745 #ifndef SQLITE_OMIT_TRACE
746     /* If the statement completed successfully, invoke the profile callback */
747     checkProfileCallback(db, p);
748 #endif
749 
750     if( rc==SQLITE_DONE && db->autoCommit ){
751       assert( p->rc==SQLITE_OK );
752       p->rc = doWalCallbacks(db);
753       if( p->rc!=SQLITE_OK ){
754         rc = SQLITE_ERROR;
755       }
756     }else if( rc!=SQLITE_DONE && (p->prepFlags & SQLITE_PREPARE_SAVESQL)!=0 ){
757       /* If this statement was prepared using saved SQL and an
758       ** error has occurred, then return the error code in p->rc to the
759       ** caller. Set the error code in the database handle to the same value.
760       */
761       rc = sqlite3VdbeTransferError(p);
762     }
763   }
764 
765   db->errCode = rc;
766   if( SQLITE_NOMEM==sqlite3ApiExit(p->db, p->rc) ){
767     p->rc = SQLITE_NOMEM_BKPT;
768     if( (p->prepFlags & SQLITE_PREPARE_SAVESQL)!=0 ) rc = p->rc;
769   }
770 end_of_step:
771   /* There are only a limited number of result codes allowed from the
772   ** statements prepared using the legacy sqlite3_prepare() interface */
773   assert( (p->prepFlags & SQLITE_PREPARE_SAVESQL)!=0
774        || rc==SQLITE_ROW  || rc==SQLITE_DONE   || rc==SQLITE_ERROR
775        || (rc&0xff)==SQLITE_BUSY || rc==SQLITE_MISUSE
776   );
777   return (rc&db->errMask);
778 }
779 
780 /*
781 ** This is the top-level implementation of sqlite3_step().  Call
782 ** sqlite3Step() to do most of the work.  If a schema error occurs,
783 ** call sqlite3Reprepare() and try again.
784 */
785 int sqlite3_step(sqlite3_stmt *pStmt){
786   int rc = SQLITE_OK;      /* Result from sqlite3Step() */
787   Vdbe *v = (Vdbe*)pStmt;  /* the prepared statement */
788   int cnt = 0;             /* Counter to prevent infinite loop of reprepares */
789   sqlite3 *db;             /* The database connection */
790 
791   if( vdbeSafetyNotNull(v) ){
792     return SQLITE_MISUSE_BKPT;
793   }
794   db = v->db;
795   sqlite3_mutex_enter(db->mutex);
796   while( (rc = sqlite3Step(v))==SQLITE_SCHEMA
797          && cnt++ < SQLITE_MAX_SCHEMA_RETRY ){
798     int savedPc = v->pc;
799     rc = sqlite3Reprepare(v);
800     if( rc!=SQLITE_OK ){
801       /* This case occurs after failing to recompile an sql statement.
802       ** The error message from the SQL compiler has already been loaded
803       ** into the database handle. This block copies the error message
804       ** from the database handle into the statement and sets the statement
805       ** program counter to 0 to ensure that when the statement is
806       ** finalized or reset the parser error message is available via
807       ** sqlite3_errmsg() and sqlite3_errcode().
808       */
809       const char *zErr = (const char *)sqlite3_value_text(db->pErr);
810       sqlite3DbFree(db, v->zErrMsg);
811       if( !db->mallocFailed ){
812         v->zErrMsg = sqlite3DbStrDup(db, zErr);
813         v->rc = rc = sqlite3ApiExit(db, rc);
814       } else {
815         v->zErrMsg = 0;
816         v->rc = rc = SQLITE_NOMEM_BKPT;
817       }
818       break;
819     }
820     sqlite3_reset(pStmt);
821     if( savedPc>=0 ){
822       /* Setting minWriteFileFormat to 254 is a signal to the OP_Init and
823       ** OP_Trace opcodes to *not* perform SQLITE_TRACE_STMT because it has
824       ** already been done once on a prior invocation that failed due to
825       ** SQLITE_SCHEMA.   tag-20220401a  */
826       v->minWriteFileFormat = 254;
827     }
828     assert( v->expired==0 );
829   }
830   sqlite3_mutex_leave(db->mutex);
831   return rc;
832 }
833 
834 
835 /*
836 ** Extract the user data from a sqlite3_context structure and return a
837 ** pointer to it.
838 */
839 void *sqlite3_user_data(sqlite3_context *p){
840   assert( p && p->pFunc );
841   return p->pFunc->pUserData;
842 }
843 
844 /*
845 ** Extract the user data from a sqlite3_context structure and return a
846 ** pointer to it.
847 **
848 ** IMPLEMENTATION-OF: R-46798-50301 The sqlite3_context_db_handle() interface
849 ** returns a copy of the pointer to the database connection (the 1st
850 ** parameter) of the sqlite3_create_function() and
851 ** sqlite3_create_function16() routines that originally registered the
852 ** application defined function.
853 */
854 sqlite3 *sqlite3_context_db_handle(sqlite3_context *p){
855   assert( p && p->pOut );
856   return p->pOut->db;
857 }
858 
859 /*
860 ** If this routine is invoked from within an xColumn method of a virtual
861 ** table, then it returns true if and only if the the call is during an
862 ** UPDATE operation and the value of the column will not be modified
863 ** by the UPDATE.
864 **
865 ** If this routine is called from any context other than within the
866 ** xColumn method of a virtual table, then the return value is meaningless
867 ** and arbitrary.
868 **
869 ** Virtual table implements might use this routine to optimize their
870 ** performance by substituting a NULL result, or some other light-weight
871 ** value, as a signal to the xUpdate routine that the column is unchanged.
872 */
873 int sqlite3_vtab_nochange(sqlite3_context *p){
874   assert( p );
875   return sqlite3_value_nochange(p->pOut);
876 }
877 
878 /*
879 ** Implementation of sqlite3_vtab_in_first() (if bNext==0) and
880 ** sqlite3_vtab_in_next() (if bNext!=0).
881 */
882 static int valueFromValueList(
883   sqlite3_value *pVal,        /* Pointer to the ValueList object */
884   sqlite3_value **ppOut,      /* Store the next value from the list here */
885   int bNext                   /* 1 for _next(). 0 for _first() */
886 ){
887   int rc;
888   ValueList *pRhs;
889 
890   *ppOut = 0;
891   if( pVal==0 ) return SQLITE_MISUSE;
892   pRhs = (ValueList*)sqlite3_value_pointer(pVal, "ValueList");
893   if( pRhs==0 ) return SQLITE_MISUSE;
894   if( bNext ){
895     rc = sqlite3BtreeNext(pRhs->pCsr, 0);
896   }else{
897     int dummy = 0;
898     rc = sqlite3BtreeFirst(pRhs->pCsr, &dummy);
899     assert( rc==SQLITE_OK || sqlite3BtreeEof(pRhs->pCsr) );
900     if( sqlite3BtreeEof(pRhs->pCsr) ) rc = SQLITE_DONE;
901   }
902   if( rc==SQLITE_OK ){
903     u32 sz;       /* Size of current row in bytes */
904     Mem sMem;     /* Raw content of current row */
905     memset(&sMem, 0, sizeof(sMem));
906     sz = sqlite3BtreePayloadSize(pRhs->pCsr);
907     rc = sqlite3VdbeMemFromBtreeZeroOffset(pRhs->pCsr,(int)sz,&sMem);
908     if( rc==SQLITE_OK ){
909       u8 *zBuf = (u8*)sMem.z;
910       u32 iSerial;
911       sqlite3_value *pOut = pRhs->pOut;
912       int iOff = 1 + getVarint32(&zBuf[1], iSerial);
913       sqlite3VdbeSerialGet(&zBuf[iOff], iSerial, pOut);
914       pOut->enc = ENC(pOut->db);
915       if( (pOut->flags & MEM_Ephem)!=0 && sqlite3VdbeMemMakeWriteable(pOut) ){
916         rc = SQLITE_NOMEM;
917       }else{
918         *ppOut = pOut;
919       }
920     }
921     sqlite3VdbeMemRelease(&sMem);
922   }
923   return rc;
924 }
925 
926 /*
927 ** Set the iterator value pVal to point to the first value in the set.
928 ** Set (*ppOut) to point to this value before returning.
929 */
930 int sqlite3_vtab_in_first(sqlite3_value *pVal, sqlite3_value **ppOut){
931   return valueFromValueList(pVal, ppOut, 0);
932 }
933 
934 /*
935 ** Set the iterator value pVal to point to the next value in the set.
936 ** Set (*ppOut) to point to this value before returning.
937 */
938 int sqlite3_vtab_in_next(sqlite3_value *pVal, sqlite3_value **ppOut){
939   return valueFromValueList(pVal, ppOut, 1);
940 }
941 
942 /*
943 ** Return the current time for a statement.  If the current time
944 ** is requested more than once within the same run of a single prepared
945 ** statement, the exact same time is returned for each invocation regardless
946 ** of the amount of time that elapses between invocations.  In other words,
947 ** the time returned is always the time of the first call.
948 */
949 sqlite3_int64 sqlite3StmtCurrentTime(sqlite3_context *p){
950   int rc;
951 #ifndef SQLITE_ENABLE_STAT4
952   sqlite3_int64 *piTime = &p->pVdbe->iCurrentTime;
953   assert( p->pVdbe!=0 );
954 #else
955   sqlite3_int64 iTime = 0;
956   sqlite3_int64 *piTime = p->pVdbe!=0 ? &p->pVdbe->iCurrentTime : &iTime;
957 #endif
958   if( *piTime==0 ){
959     rc = sqlite3OsCurrentTimeInt64(p->pOut->db->pVfs, piTime);
960     if( rc ) *piTime = 0;
961   }
962   return *piTime;
963 }
964 
965 /*
966 ** Create a new aggregate context for p and return a pointer to
967 ** its pMem->z element.
968 */
969 static SQLITE_NOINLINE void *createAggContext(sqlite3_context *p, int nByte){
970   Mem *pMem = p->pMem;
971   assert( (pMem->flags & MEM_Agg)==0 );
972   if( nByte<=0 ){
973     sqlite3VdbeMemSetNull(pMem);
974     pMem->z = 0;
975   }else{
976     sqlite3VdbeMemClearAndResize(pMem, nByte);
977     pMem->flags = MEM_Agg;
978     pMem->u.pDef = p->pFunc;
979     if( pMem->z ){
980       memset(pMem->z, 0, nByte);
981     }
982   }
983   return (void*)pMem->z;
984 }
985 
986 /*
987 ** Allocate or return the aggregate context for a user function.  A new
988 ** context is allocated on the first call.  Subsequent calls return the
989 ** same context that was returned on prior calls.
990 */
991 void *sqlite3_aggregate_context(sqlite3_context *p, int nByte){
992   assert( p && p->pFunc && p->pFunc->xFinalize );
993   assert( sqlite3_mutex_held(p->pOut->db->mutex) );
994   testcase( nByte<0 );
995   if( (p->pMem->flags & MEM_Agg)==0 ){
996     return createAggContext(p, nByte);
997   }else{
998     return (void*)p->pMem->z;
999   }
1000 }
1001 
1002 /*
1003 ** Return the auxiliary data pointer, if any, for the iArg'th argument to
1004 ** the user-function defined by pCtx.
1005 **
1006 ** The left-most argument is 0.
1007 **
1008 ** Undocumented behavior:  If iArg is negative then access a cache of
1009 ** auxiliary data pointers that is available to all functions within a
1010 ** single prepared statement.  The iArg values must match.
1011 */
1012 void *sqlite3_get_auxdata(sqlite3_context *pCtx, int iArg){
1013   AuxData *pAuxData;
1014 
1015   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
1016 #if SQLITE_ENABLE_STAT4
1017   if( pCtx->pVdbe==0 ) return 0;
1018 #else
1019   assert( pCtx->pVdbe!=0 );
1020 #endif
1021   for(pAuxData=pCtx->pVdbe->pAuxData; pAuxData; pAuxData=pAuxData->pNextAux){
1022     if(  pAuxData->iAuxArg==iArg && (pAuxData->iAuxOp==pCtx->iOp || iArg<0) ){
1023       return pAuxData->pAux;
1024     }
1025   }
1026   return 0;
1027 }
1028 
1029 /*
1030 ** Set the auxiliary data pointer and delete function, for the iArg'th
1031 ** argument to the user-function defined by pCtx. Any previous value is
1032 ** deleted by calling the delete function specified when it was set.
1033 **
1034 ** The left-most argument is 0.
1035 **
1036 ** Undocumented behavior:  If iArg is negative then make the data available
1037 ** to all functions within the current prepared statement using iArg as an
1038 ** access code.
1039 */
1040 void sqlite3_set_auxdata(
1041   sqlite3_context *pCtx,
1042   int iArg,
1043   void *pAux,
1044   void (*xDelete)(void*)
1045 ){
1046   AuxData *pAuxData;
1047   Vdbe *pVdbe = pCtx->pVdbe;
1048 
1049   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
1050 #ifdef SQLITE_ENABLE_STAT4
1051   if( pVdbe==0 ) goto failed;
1052 #else
1053   assert( pVdbe!=0 );
1054 #endif
1055 
1056   for(pAuxData=pVdbe->pAuxData; pAuxData; pAuxData=pAuxData->pNextAux){
1057     if( pAuxData->iAuxArg==iArg && (pAuxData->iAuxOp==pCtx->iOp || iArg<0) ){
1058       break;
1059     }
1060   }
1061   if( pAuxData==0 ){
1062     pAuxData = sqlite3DbMallocZero(pVdbe->db, sizeof(AuxData));
1063     if( !pAuxData ) goto failed;
1064     pAuxData->iAuxOp = pCtx->iOp;
1065     pAuxData->iAuxArg = iArg;
1066     pAuxData->pNextAux = pVdbe->pAuxData;
1067     pVdbe->pAuxData = pAuxData;
1068     if( pCtx->isError==0 ) pCtx->isError = -1;
1069   }else if( pAuxData->xDeleteAux ){
1070     pAuxData->xDeleteAux(pAuxData->pAux);
1071   }
1072 
1073   pAuxData->pAux = pAux;
1074   pAuxData->xDeleteAux = xDelete;
1075   return;
1076 
1077 failed:
1078   if( xDelete ){
1079     xDelete(pAux);
1080   }
1081 }
1082 
1083 #ifndef SQLITE_OMIT_DEPRECATED
1084 /*
1085 ** Return the number of times the Step function of an aggregate has been
1086 ** called.
1087 **
1088 ** This function is deprecated.  Do not use it for new code.  It is
1089 ** provide only to avoid breaking legacy code.  New aggregate function
1090 ** implementations should keep their own counts within their aggregate
1091 ** context.
1092 */
1093 int sqlite3_aggregate_count(sqlite3_context *p){
1094   assert( p && p->pMem && p->pFunc && p->pFunc->xFinalize );
1095   return p->pMem->n;
1096 }
1097 #endif
1098 
1099 /*
1100 ** Return the number of columns in the result set for the statement pStmt.
1101 */
1102 int sqlite3_column_count(sqlite3_stmt *pStmt){
1103   Vdbe *pVm = (Vdbe *)pStmt;
1104   return pVm ? pVm->nResColumn : 0;
1105 }
1106 
1107 /*
1108 ** Return the number of values available from the current row of the
1109 ** currently executing statement pStmt.
1110 */
1111 int sqlite3_data_count(sqlite3_stmt *pStmt){
1112   Vdbe *pVm = (Vdbe *)pStmt;
1113   if( pVm==0 || pVm->pResultSet==0 ) return 0;
1114   return pVm->nResColumn;
1115 }
1116 
1117 /*
1118 ** Return a pointer to static memory containing an SQL NULL value.
1119 */
1120 static const Mem *columnNullValue(void){
1121   /* Even though the Mem structure contains an element
1122   ** of type i64, on certain architectures (x86) with certain compiler
1123   ** switches (-Os), gcc may align this Mem object on a 4-byte boundary
1124   ** instead of an 8-byte one. This all works fine, except that when
1125   ** running with SQLITE_DEBUG defined the SQLite code sometimes assert()s
1126   ** that a Mem structure is located on an 8-byte boundary. To prevent
1127   ** these assert()s from failing, when building with SQLITE_DEBUG defined
1128   ** using gcc, we force nullMem to be 8-byte aligned using the magical
1129   ** __attribute__((aligned(8))) macro.  */
1130   static const Mem nullMem
1131 #if defined(SQLITE_DEBUG) && defined(__GNUC__)
1132     __attribute__((aligned(8)))
1133 #endif
1134     = {
1135         /* .u          = */ {0},
1136         /* .z          = */ (char*)0,
1137         /* .n          = */ (int)0,
1138         /* .flags      = */ (u16)MEM_Null,
1139         /* .enc        = */ (u8)0,
1140         /* .eSubtype   = */ (u8)0,
1141         /* .db         = */ (sqlite3*)0,
1142         /* .szMalloc   = */ (int)0,
1143         /* .uTemp      = */ (u32)0,
1144         /* .zMalloc    = */ (char*)0,
1145         /* .xDel       = */ (void(*)(void*))0,
1146 #ifdef SQLITE_DEBUG
1147         /* .pScopyFrom = */ (Mem*)0,
1148         /* .mScopyFlags= */ 0,
1149 #endif
1150       };
1151   return &nullMem;
1152 }
1153 
1154 /*
1155 ** Check to see if column iCol of the given statement is valid.  If
1156 ** it is, return a pointer to the Mem for the value of that column.
1157 ** If iCol is not valid, return a pointer to a Mem which has a value
1158 ** of NULL.
1159 */
1160 static Mem *columnMem(sqlite3_stmt *pStmt, int i){
1161   Vdbe *pVm;
1162   Mem *pOut;
1163 
1164   pVm = (Vdbe *)pStmt;
1165   if( pVm==0 ) return (Mem*)columnNullValue();
1166   assert( pVm->db );
1167   sqlite3_mutex_enter(pVm->db->mutex);
1168   if( pVm->pResultSet!=0 && i<pVm->nResColumn && i>=0 ){
1169     pOut = &pVm->pResultSet[i];
1170   }else{
1171     sqlite3Error(pVm->db, SQLITE_RANGE);
1172     pOut = (Mem*)columnNullValue();
1173   }
1174   return pOut;
1175 }
1176 
1177 /*
1178 ** This function is called after invoking an sqlite3_value_XXX function on a
1179 ** column value (i.e. a value returned by evaluating an SQL expression in the
1180 ** select list of a SELECT statement) that may cause a malloc() failure. If
1181 ** malloc() has failed, the threads mallocFailed flag is cleared and the result
1182 ** code of statement pStmt set to SQLITE_NOMEM.
1183 **
1184 ** Specifically, this is called from within:
1185 **
1186 **     sqlite3_column_int()
1187 **     sqlite3_column_int64()
1188 **     sqlite3_column_text()
1189 **     sqlite3_column_text16()
1190 **     sqlite3_column_real()
1191 **     sqlite3_column_bytes()
1192 **     sqlite3_column_bytes16()
1193 **     sqiite3_column_blob()
1194 */
1195 static void columnMallocFailure(sqlite3_stmt *pStmt)
1196 {
1197   /* If malloc() failed during an encoding conversion within an
1198   ** sqlite3_column_XXX API, then set the return code of the statement to
1199   ** SQLITE_NOMEM. The next call to _step() (if any) will return SQLITE_ERROR
1200   ** and _finalize() will return NOMEM.
1201   */
1202   Vdbe *p = (Vdbe *)pStmt;
1203   if( p ){
1204     assert( p->db!=0 );
1205     assert( sqlite3_mutex_held(p->db->mutex) );
1206     p->rc = sqlite3ApiExit(p->db, p->rc);
1207     sqlite3_mutex_leave(p->db->mutex);
1208   }
1209 }
1210 
1211 /**************************** sqlite3_column_  *******************************
1212 ** The following routines are used to access elements of the current row
1213 ** in the result set.
1214 */
1215 const void *sqlite3_column_blob(sqlite3_stmt *pStmt, int i){
1216   const void *val;
1217   val = sqlite3_value_blob( columnMem(pStmt,i) );
1218   /* Even though there is no encoding conversion, value_blob() might
1219   ** need to call malloc() to expand the result of a zeroblob()
1220   ** expression.
1221   */
1222   columnMallocFailure(pStmt);
1223   return val;
1224 }
1225 int sqlite3_column_bytes(sqlite3_stmt *pStmt, int i){
1226   int val = sqlite3_value_bytes( columnMem(pStmt,i) );
1227   columnMallocFailure(pStmt);
1228   return val;
1229 }
1230 int sqlite3_column_bytes16(sqlite3_stmt *pStmt, int i){
1231   int val = sqlite3_value_bytes16( columnMem(pStmt,i) );
1232   columnMallocFailure(pStmt);
1233   return val;
1234 }
1235 double sqlite3_column_double(sqlite3_stmt *pStmt, int i){
1236   double val = sqlite3_value_double( columnMem(pStmt,i) );
1237   columnMallocFailure(pStmt);
1238   return val;
1239 }
1240 int sqlite3_column_int(sqlite3_stmt *pStmt, int i){
1241   int val = sqlite3_value_int( columnMem(pStmt,i) );
1242   columnMallocFailure(pStmt);
1243   return val;
1244 }
1245 sqlite_int64 sqlite3_column_int64(sqlite3_stmt *pStmt, int i){
1246   sqlite_int64 val = sqlite3_value_int64( columnMem(pStmt,i) );
1247   columnMallocFailure(pStmt);
1248   return val;
1249 }
1250 const unsigned char *sqlite3_column_text(sqlite3_stmt *pStmt, int i){
1251   const unsigned char *val = sqlite3_value_text( columnMem(pStmt,i) );
1252   columnMallocFailure(pStmt);
1253   return val;
1254 }
1255 sqlite3_value *sqlite3_column_value(sqlite3_stmt *pStmt, int i){
1256   Mem *pOut = columnMem(pStmt, i);
1257   if( pOut->flags&MEM_Static ){
1258     pOut->flags &= ~MEM_Static;
1259     pOut->flags |= MEM_Ephem;
1260   }
1261   columnMallocFailure(pStmt);
1262   return (sqlite3_value *)pOut;
1263 }
1264 #ifndef SQLITE_OMIT_UTF16
1265 const void *sqlite3_column_text16(sqlite3_stmt *pStmt, int i){
1266   const void *val = sqlite3_value_text16( columnMem(pStmt,i) );
1267   columnMallocFailure(pStmt);
1268   return val;
1269 }
1270 #endif /* SQLITE_OMIT_UTF16 */
1271 int sqlite3_column_type(sqlite3_stmt *pStmt, int i){
1272   int iType = sqlite3_value_type( columnMem(pStmt,i) );
1273   columnMallocFailure(pStmt);
1274   return iType;
1275 }
1276 
1277 /*
1278 ** Convert the N-th element of pStmt->pColName[] into a string using
1279 ** xFunc() then return that string.  If N is out of range, return 0.
1280 **
1281 ** There are up to 5 names for each column.  useType determines which
1282 ** name is returned.  Here are the names:
1283 **
1284 **    0      The column name as it should be displayed for output
1285 **    1      The datatype name for the column
1286 **    2      The name of the database that the column derives from
1287 **    3      The name of the table that the column derives from
1288 **    4      The name of the table column that the result column derives from
1289 **
1290 ** If the result is not a simple column reference (if it is an expression
1291 ** or a constant) then useTypes 2, 3, and 4 return NULL.
1292 */
1293 static const void *columnName(
1294   sqlite3_stmt *pStmt,     /* The statement */
1295   int N,                   /* Which column to get the name for */
1296   int useUtf16,            /* True to return the name as UTF16 */
1297   int useType              /* What type of name */
1298 ){
1299   const void *ret;
1300   Vdbe *p;
1301   int n;
1302   sqlite3 *db;
1303 #ifdef SQLITE_ENABLE_API_ARMOR
1304   if( pStmt==0 ){
1305     (void)SQLITE_MISUSE_BKPT;
1306     return 0;
1307   }
1308 #endif
1309   ret = 0;
1310   p = (Vdbe *)pStmt;
1311   db = p->db;
1312   assert( db!=0 );
1313   n = sqlite3_column_count(pStmt);
1314   if( N<n && N>=0 ){
1315     N += useType*n;
1316     sqlite3_mutex_enter(db->mutex);
1317     assert( db->mallocFailed==0 );
1318 #ifndef SQLITE_OMIT_UTF16
1319     if( useUtf16 ){
1320       ret = sqlite3_value_text16((sqlite3_value*)&p->aColName[N]);
1321     }else
1322 #endif
1323     {
1324       ret = sqlite3_value_text((sqlite3_value*)&p->aColName[N]);
1325     }
1326     /* A malloc may have failed inside of the _text() call. If this
1327     ** is the case, clear the mallocFailed flag and return NULL.
1328     */
1329     if( db->mallocFailed ){
1330       sqlite3OomClear(db);
1331       ret = 0;
1332     }
1333     sqlite3_mutex_leave(db->mutex);
1334   }
1335   return ret;
1336 }
1337 
1338 /*
1339 ** Return the name of the Nth column of the result set returned by SQL
1340 ** statement pStmt.
1341 */
1342 const char *sqlite3_column_name(sqlite3_stmt *pStmt, int N){
1343   return columnName(pStmt, N, 0, COLNAME_NAME);
1344 }
1345 #ifndef SQLITE_OMIT_UTF16
1346 const void *sqlite3_column_name16(sqlite3_stmt *pStmt, int N){
1347   return columnName(pStmt, N, 1, COLNAME_NAME);
1348 }
1349 #endif
1350 
1351 /*
1352 ** Constraint:  If you have ENABLE_COLUMN_METADATA then you must
1353 ** not define OMIT_DECLTYPE.
1354 */
1355 #if defined(SQLITE_OMIT_DECLTYPE) && defined(SQLITE_ENABLE_COLUMN_METADATA)
1356 # error "Must not define both SQLITE_OMIT_DECLTYPE \
1357          and SQLITE_ENABLE_COLUMN_METADATA"
1358 #endif
1359 
1360 #ifndef SQLITE_OMIT_DECLTYPE
1361 /*
1362 ** Return the column declaration type (if applicable) of the 'i'th column
1363 ** of the result set of SQL statement pStmt.
1364 */
1365 const char *sqlite3_column_decltype(sqlite3_stmt *pStmt, int N){
1366   return columnName(pStmt, N, 0, COLNAME_DECLTYPE);
1367 }
1368 #ifndef SQLITE_OMIT_UTF16
1369 const void *sqlite3_column_decltype16(sqlite3_stmt *pStmt, int N){
1370   return columnName(pStmt, N, 1, COLNAME_DECLTYPE);
1371 }
1372 #endif /* SQLITE_OMIT_UTF16 */
1373 #endif /* SQLITE_OMIT_DECLTYPE */
1374 
1375 #ifdef SQLITE_ENABLE_COLUMN_METADATA
1376 /*
1377 ** Return the name of the database from which a result column derives.
1378 ** NULL is returned if the result column is an expression or constant or
1379 ** anything else which is not an unambiguous reference to a database column.
1380 */
1381 const char *sqlite3_column_database_name(sqlite3_stmt *pStmt, int N){
1382   return columnName(pStmt, N, 0, COLNAME_DATABASE);
1383 }
1384 #ifndef SQLITE_OMIT_UTF16
1385 const void *sqlite3_column_database_name16(sqlite3_stmt *pStmt, int N){
1386   return columnName(pStmt, N, 1, COLNAME_DATABASE);
1387 }
1388 #endif /* SQLITE_OMIT_UTF16 */
1389 
1390 /*
1391 ** Return the name of the table from which a result column derives.
1392 ** NULL is returned if the result column is an expression or constant or
1393 ** anything else which is not an unambiguous reference to a database column.
1394 */
1395 const char *sqlite3_column_table_name(sqlite3_stmt *pStmt, int N){
1396   return columnName(pStmt, N, 0, COLNAME_TABLE);
1397 }
1398 #ifndef SQLITE_OMIT_UTF16
1399 const void *sqlite3_column_table_name16(sqlite3_stmt *pStmt, int N){
1400   return columnName(pStmt, N, 1, COLNAME_TABLE);
1401 }
1402 #endif /* SQLITE_OMIT_UTF16 */
1403 
1404 /*
1405 ** Return the name of the table column from which a result column derives.
1406 ** NULL is returned if the result column is an expression or constant or
1407 ** anything else which is not an unambiguous reference to a database column.
1408 */
1409 const char *sqlite3_column_origin_name(sqlite3_stmt *pStmt, int N){
1410   return columnName(pStmt, N, 0, COLNAME_COLUMN);
1411 }
1412 #ifndef SQLITE_OMIT_UTF16
1413 const void *sqlite3_column_origin_name16(sqlite3_stmt *pStmt, int N){
1414   return columnName(pStmt, N, 1, COLNAME_COLUMN);
1415 }
1416 #endif /* SQLITE_OMIT_UTF16 */
1417 #endif /* SQLITE_ENABLE_COLUMN_METADATA */
1418 
1419 
1420 /******************************* sqlite3_bind_  ***************************
1421 **
1422 ** Routines used to attach values to wildcards in a compiled SQL statement.
1423 */
1424 /*
1425 ** Unbind the value bound to variable i in virtual machine p. This is the
1426 ** the same as binding a NULL value to the column. If the "i" parameter is
1427 ** out of range, then SQLITE_RANGE is returned. Othewise SQLITE_OK.
1428 **
1429 ** A successful evaluation of this routine acquires the mutex on p.
1430 ** the mutex is released if any kind of error occurs.
1431 **
1432 ** The error code stored in database p->db is overwritten with the return
1433 ** value in any case.
1434 */
1435 static int vdbeUnbind(Vdbe *p, unsigned int i){
1436   Mem *pVar;
1437   if( vdbeSafetyNotNull(p) ){
1438     return SQLITE_MISUSE_BKPT;
1439   }
1440   sqlite3_mutex_enter(p->db->mutex);
1441   if( p->eVdbeState!=VDBE_READY_STATE ){
1442     sqlite3Error(p->db, SQLITE_MISUSE);
1443     sqlite3_mutex_leave(p->db->mutex);
1444     sqlite3_log(SQLITE_MISUSE,
1445         "bind on a busy prepared statement: [%s]", p->zSql);
1446     return SQLITE_MISUSE_BKPT;
1447   }
1448   if( i>=(unsigned int)p->nVar ){
1449     sqlite3Error(p->db, SQLITE_RANGE);
1450     sqlite3_mutex_leave(p->db->mutex);
1451     return SQLITE_RANGE;
1452   }
1453   pVar = &p->aVar[i];
1454   sqlite3VdbeMemRelease(pVar);
1455   pVar->flags = MEM_Null;
1456   p->db->errCode = SQLITE_OK;
1457 
1458   /* If the bit corresponding to this variable in Vdbe.expmask is set, then
1459   ** binding a new value to this variable invalidates the current query plan.
1460   **
1461   ** IMPLEMENTATION-OF: R-57496-20354 If the specific value bound to a host
1462   ** parameter in the WHERE clause might influence the choice of query plan
1463   ** for a statement, then the statement will be automatically recompiled,
1464   ** as if there had been a schema change, on the first sqlite3_step() call
1465   ** following any change to the bindings of that parameter.
1466   */
1467   assert( (p->prepFlags & SQLITE_PREPARE_SAVESQL)!=0 || p->expmask==0 );
1468   if( p->expmask!=0 && (p->expmask & (i>=31 ? 0x80000000 : (u32)1<<i))!=0 ){
1469     p->expired = 1;
1470   }
1471   return SQLITE_OK;
1472 }
1473 
1474 /*
1475 ** Bind a text or BLOB value.
1476 */
1477 static int bindText(
1478   sqlite3_stmt *pStmt,   /* The statement to bind against */
1479   int i,                 /* Index of the parameter to bind */
1480   const void *zData,     /* Pointer to the data to be bound */
1481   i64 nData,             /* Number of bytes of data to be bound */
1482   void (*xDel)(void*),   /* Destructor for the data */
1483   u8 encoding            /* Encoding for the data */
1484 ){
1485   Vdbe *p = (Vdbe *)pStmt;
1486   Mem *pVar;
1487   int rc;
1488 
1489   rc = vdbeUnbind(p, (u32)(i-1));
1490   if( rc==SQLITE_OK ){
1491     if( zData!=0 ){
1492       pVar = &p->aVar[i-1];
1493       rc = sqlite3VdbeMemSetStr(pVar, zData, nData, encoding, xDel);
1494       if( rc==SQLITE_OK && encoding!=0 ){
1495         rc = sqlite3VdbeChangeEncoding(pVar, ENC(p->db));
1496       }
1497       if( rc ){
1498         sqlite3Error(p->db, rc);
1499         rc = sqlite3ApiExit(p->db, rc);
1500       }
1501     }
1502     sqlite3_mutex_leave(p->db->mutex);
1503   }else if( xDel!=SQLITE_STATIC && xDel!=SQLITE_TRANSIENT ){
1504     xDel((void*)zData);
1505   }
1506   return rc;
1507 }
1508 
1509 
1510 /*
1511 ** Bind a blob value to an SQL statement variable.
1512 */
1513 int sqlite3_bind_blob(
1514   sqlite3_stmt *pStmt,
1515   int i,
1516   const void *zData,
1517   int nData,
1518   void (*xDel)(void*)
1519 ){
1520 #ifdef SQLITE_ENABLE_API_ARMOR
1521   if( nData<0 ) return SQLITE_MISUSE_BKPT;
1522 #endif
1523   return bindText(pStmt, i, zData, nData, xDel, 0);
1524 }
1525 int sqlite3_bind_blob64(
1526   sqlite3_stmt *pStmt,
1527   int i,
1528   const void *zData,
1529   sqlite3_uint64 nData,
1530   void (*xDel)(void*)
1531 ){
1532   assert( xDel!=SQLITE_DYNAMIC );
1533   return bindText(pStmt, i, zData, nData, xDel, 0);
1534 }
1535 int sqlite3_bind_double(sqlite3_stmt *pStmt, int i, double rValue){
1536   int rc;
1537   Vdbe *p = (Vdbe *)pStmt;
1538   rc = vdbeUnbind(p, (u32)(i-1));
1539   if( rc==SQLITE_OK ){
1540     sqlite3VdbeMemSetDouble(&p->aVar[i-1], rValue);
1541     sqlite3_mutex_leave(p->db->mutex);
1542   }
1543   return rc;
1544 }
1545 int sqlite3_bind_int(sqlite3_stmt *p, int i, int iValue){
1546   return sqlite3_bind_int64(p, i, (i64)iValue);
1547 }
1548 int sqlite3_bind_int64(sqlite3_stmt *pStmt, int i, sqlite_int64 iValue){
1549   int rc;
1550   Vdbe *p = (Vdbe *)pStmt;
1551   rc = vdbeUnbind(p, (u32)(i-1));
1552   if( rc==SQLITE_OK ){
1553     sqlite3VdbeMemSetInt64(&p->aVar[i-1], iValue);
1554     sqlite3_mutex_leave(p->db->mutex);
1555   }
1556   return rc;
1557 }
1558 int sqlite3_bind_null(sqlite3_stmt *pStmt, int i){
1559   int rc;
1560   Vdbe *p = (Vdbe*)pStmt;
1561   rc = vdbeUnbind(p, (u32)(i-1));
1562   if( rc==SQLITE_OK ){
1563     sqlite3_mutex_leave(p->db->mutex);
1564   }
1565   return rc;
1566 }
1567 int sqlite3_bind_pointer(
1568   sqlite3_stmt *pStmt,
1569   int i,
1570   void *pPtr,
1571   const char *zPTtype,
1572   void (*xDestructor)(void*)
1573 ){
1574   int rc;
1575   Vdbe *p = (Vdbe*)pStmt;
1576   rc = vdbeUnbind(p, (u32)(i-1));
1577   if( rc==SQLITE_OK ){
1578     sqlite3VdbeMemSetPointer(&p->aVar[i-1], pPtr, zPTtype, xDestructor);
1579     sqlite3_mutex_leave(p->db->mutex);
1580   }else if( xDestructor ){
1581     xDestructor(pPtr);
1582   }
1583   return rc;
1584 }
1585 int sqlite3_bind_text(
1586   sqlite3_stmt *pStmt,
1587   int i,
1588   const char *zData,
1589   int nData,
1590   void (*xDel)(void*)
1591 ){
1592   return bindText(pStmt, i, zData, nData, xDel, SQLITE_UTF8);
1593 }
1594 int sqlite3_bind_text64(
1595   sqlite3_stmt *pStmt,
1596   int i,
1597   const char *zData,
1598   sqlite3_uint64 nData,
1599   void (*xDel)(void*),
1600   unsigned char enc
1601 ){
1602   assert( xDel!=SQLITE_DYNAMIC );
1603   if( enc==SQLITE_UTF16 ) enc = SQLITE_UTF16NATIVE;
1604   return bindText(pStmt, i, zData, nData, xDel, enc);
1605 }
1606 #ifndef SQLITE_OMIT_UTF16
1607 int sqlite3_bind_text16(
1608   sqlite3_stmt *pStmt,
1609   int i,
1610   const void *zData,
1611   int nData,
1612   void (*xDel)(void*)
1613 ){
1614   return bindText(pStmt, i, zData, nData, xDel, SQLITE_UTF16NATIVE);
1615 }
1616 #endif /* SQLITE_OMIT_UTF16 */
1617 int sqlite3_bind_value(sqlite3_stmt *pStmt, int i, const sqlite3_value *pValue){
1618   int rc;
1619   switch( sqlite3_value_type((sqlite3_value*)pValue) ){
1620     case SQLITE_INTEGER: {
1621       rc = sqlite3_bind_int64(pStmt, i, pValue->u.i);
1622       break;
1623     }
1624     case SQLITE_FLOAT: {
1625       assert( pValue->flags & (MEM_Real|MEM_IntReal) );
1626       rc = sqlite3_bind_double(pStmt, i,
1627           (pValue->flags & MEM_Real) ? pValue->u.r : (double)pValue->u.i
1628       );
1629       break;
1630     }
1631     case SQLITE_BLOB: {
1632       if( pValue->flags & MEM_Zero ){
1633         rc = sqlite3_bind_zeroblob(pStmt, i, pValue->u.nZero);
1634       }else{
1635         rc = sqlite3_bind_blob(pStmt, i, pValue->z, pValue->n,SQLITE_TRANSIENT);
1636       }
1637       break;
1638     }
1639     case SQLITE_TEXT: {
1640       rc = bindText(pStmt,i,  pValue->z, pValue->n, SQLITE_TRANSIENT,
1641                               pValue->enc);
1642       break;
1643     }
1644     default: {
1645       rc = sqlite3_bind_null(pStmt, i);
1646       break;
1647     }
1648   }
1649   return rc;
1650 }
1651 int sqlite3_bind_zeroblob(sqlite3_stmt *pStmt, int i, int n){
1652   int rc;
1653   Vdbe *p = (Vdbe *)pStmt;
1654   rc = vdbeUnbind(p, (u32)(i-1));
1655   if( rc==SQLITE_OK ){
1656 #ifndef SQLITE_OMIT_INCRBLOB
1657     sqlite3VdbeMemSetZeroBlob(&p->aVar[i-1], n);
1658 #else
1659     rc = sqlite3VdbeMemSetZeroBlob(&p->aVar[i-1], n);
1660 #endif
1661     sqlite3_mutex_leave(p->db->mutex);
1662   }
1663   return rc;
1664 }
1665 int sqlite3_bind_zeroblob64(sqlite3_stmt *pStmt, int i, sqlite3_uint64 n){
1666   int rc;
1667   Vdbe *p = (Vdbe *)pStmt;
1668   sqlite3_mutex_enter(p->db->mutex);
1669   if( n>(u64)p->db->aLimit[SQLITE_LIMIT_LENGTH] ){
1670     rc = SQLITE_TOOBIG;
1671   }else{
1672     assert( (n & 0x7FFFFFFF)==n );
1673     rc = sqlite3_bind_zeroblob(pStmt, i, n);
1674   }
1675   rc = sqlite3ApiExit(p->db, rc);
1676   sqlite3_mutex_leave(p->db->mutex);
1677   return rc;
1678 }
1679 
1680 /*
1681 ** Return the number of wildcards that can be potentially bound to.
1682 ** This routine is added to support DBD::SQLite.
1683 */
1684 int sqlite3_bind_parameter_count(sqlite3_stmt *pStmt){
1685   Vdbe *p = (Vdbe*)pStmt;
1686   return p ? p->nVar : 0;
1687 }
1688 
1689 /*
1690 ** Return the name of a wildcard parameter.  Return NULL if the index
1691 ** is out of range or if the wildcard is unnamed.
1692 **
1693 ** The result is always UTF-8.
1694 */
1695 const char *sqlite3_bind_parameter_name(sqlite3_stmt *pStmt, int i){
1696   Vdbe *p = (Vdbe*)pStmt;
1697   if( p==0 ) return 0;
1698   return sqlite3VListNumToName(p->pVList, i);
1699 }
1700 
1701 /*
1702 ** Given a wildcard parameter name, return the index of the variable
1703 ** with that name.  If there is no variable with the given name,
1704 ** return 0.
1705 */
1706 int sqlite3VdbeParameterIndex(Vdbe *p, const char *zName, int nName){
1707   if( p==0 || zName==0 ) return 0;
1708   return sqlite3VListNameToNum(p->pVList, zName, nName);
1709 }
1710 int sqlite3_bind_parameter_index(sqlite3_stmt *pStmt, const char *zName){
1711   return sqlite3VdbeParameterIndex((Vdbe*)pStmt, zName, sqlite3Strlen30(zName));
1712 }
1713 
1714 /*
1715 ** Transfer all bindings from the first statement over to the second.
1716 */
1717 int sqlite3TransferBindings(sqlite3_stmt *pFromStmt, sqlite3_stmt *pToStmt){
1718   Vdbe *pFrom = (Vdbe*)pFromStmt;
1719   Vdbe *pTo = (Vdbe*)pToStmt;
1720   int i;
1721   assert( pTo->db==pFrom->db );
1722   assert( pTo->nVar==pFrom->nVar );
1723   sqlite3_mutex_enter(pTo->db->mutex);
1724   for(i=0; i<pFrom->nVar; i++){
1725     sqlite3VdbeMemMove(&pTo->aVar[i], &pFrom->aVar[i]);
1726   }
1727   sqlite3_mutex_leave(pTo->db->mutex);
1728   return SQLITE_OK;
1729 }
1730 
1731 #ifndef SQLITE_OMIT_DEPRECATED
1732 /*
1733 ** Deprecated external interface.  Internal/core SQLite code
1734 ** should call sqlite3TransferBindings.
1735 **
1736 ** It is misuse to call this routine with statements from different
1737 ** database connections.  But as this is a deprecated interface, we
1738 ** will not bother to check for that condition.
1739 **
1740 ** If the two statements contain a different number of bindings, then
1741 ** an SQLITE_ERROR is returned.  Nothing else can go wrong, so otherwise
1742 ** SQLITE_OK is returned.
1743 */
1744 int sqlite3_transfer_bindings(sqlite3_stmt *pFromStmt, sqlite3_stmt *pToStmt){
1745   Vdbe *pFrom = (Vdbe*)pFromStmt;
1746   Vdbe *pTo = (Vdbe*)pToStmt;
1747   if( pFrom->nVar!=pTo->nVar ){
1748     return SQLITE_ERROR;
1749   }
1750   assert( (pTo->prepFlags & SQLITE_PREPARE_SAVESQL)!=0 || pTo->expmask==0 );
1751   if( pTo->expmask ){
1752     pTo->expired = 1;
1753   }
1754   assert( (pFrom->prepFlags & SQLITE_PREPARE_SAVESQL)!=0 || pFrom->expmask==0 );
1755   if( pFrom->expmask ){
1756     pFrom->expired = 1;
1757   }
1758   return sqlite3TransferBindings(pFromStmt, pToStmt);
1759 }
1760 #endif
1761 
1762 /*
1763 ** Return the sqlite3* database handle to which the prepared statement given
1764 ** in the argument belongs.  This is the same database handle that was
1765 ** the first argument to the sqlite3_prepare() that was used to create
1766 ** the statement in the first place.
1767 */
1768 sqlite3 *sqlite3_db_handle(sqlite3_stmt *pStmt){
1769   return pStmt ? ((Vdbe*)pStmt)->db : 0;
1770 }
1771 
1772 /*
1773 ** Return true if the prepared statement is guaranteed to not modify the
1774 ** database.
1775 */
1776 int sqlite3_stmt_readonly(sqlite3_stmt *pStmt){
1777   return pStmt ? ((Vdbe*)pStmt)->readOnly : 1;
1778 }
1779 
1780 /*
1781 ** Return 1 if the statement is an EXPLAIN and return 2 if the
1782 ** statement is an EXPLAIN QUERY PLAN
1783 */
1784 int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt){
1785   return pStmt ? ((Vdbe*)pStmt)->explain : 0;
1786 }
1787 
1788 /*
1789 ** Return true if the prepared statement is in need of being reset.
1790 */
1791 int sqlite3_stmt_busy(sqlite3_stmt *pStmt){
1792   Vdbe *v = (Vdbe*)pStmt;
1793   return v!=0 && v->eVdbeState==VDBE_RUN_STATE;
1794 }
1795 
1796 /*
1797 ** Return a pointer to the next prepared statement after pStmt associated
1798 ** with database connection pDb.  If pStmt is NULL, return the first
1799 ** prepared statement for the database connection.  Return NULL if there
1800 ** are no more.
1801 */
1802 sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt){
1803   sqlite3_stmt *pNext;
1804 #ifdef SQLITE_ENABLE_API_ARMOR
1805   if( !sqlite3SafetyCheckOk(pDb) ){
1806     (void)SQLITE_MISUSE_BKPT;
1807     return 0;
1808   }
1809 #endif
1810   sqlite3_mutex_enter(pDb->mutex);
1811   if( pStmt==0 ){
1812     pNext = (sqlite3_stmt*)pDb->pVdbe;
1813   }else{
1814     pNext = (sqlite3_stmt*)((Vdbe*)pStmt)->pVNext;
1815   }
1816   sqlite3_mutex_leave(pDb->mutex);
1817   return pNext;
1818 }
1819 
1820 /*
1821 ** Return the value of a status counter for a prepared statement
1822 */
1823 int sqlite3_stmt_status(sqlite3_stmt *pStmt, int op, int resetFlag){
1824   Vdbe *pVdbe = (Vdbe*)pStmt;
1825   u32 v;
1826 #ifdef SQLITE_ENABLE_API_ARMOR
1827   if( !pStmt
1828    || (op!=SQLITE_STMTSTATUS_MEMUSED && (op<0||op>=ArraySize(pVdbe->aCounter)))
1829   ){
1830     (void)SQLITE_MISUSE_BKPT;
1831     return 0;
1832   }
1833 #endif
1834   if( op==SQLITE_STMTSTATUS_MEMUSED ){
1835     sqlite3 *db = pVdbe->db;
1836     sqlite3_mutex_enter(db->mutex);
1837     v = 0;
1838     db->pnBytesFreed = (int*)&v;
1839     assert( db->lookaside.pEnd==db->lookaside.pTrueEnd );
1840     db->lookaside.pEnd = db->lookaside.pStart;
1841     sqlite3VdbeDelete(pVdbe);
1842     db->pnBytesFreed = 0;
1843     db->lookaside.pEnd = db->lookaside.pTrueEnd;
1844     sqlite3_mutex_leave(db->mutex);
1845   }else{
1846     v = pVdbe->aCounter[op];
1847     if( resetFlag ) pVdbe->aCounter[op] = 0;
1848   }
1849   return (int)v;
1850 }
1851 
1852 /*
1853 ** Return the SQL associated with a prepared statement
1854 */
1855 const char *sqlite3_sql(sqlite3_stmt *pStmt){
1856   Vdbe *p = (Vdbe *)pStmt;
1857   return p ? p->zSql : 0;
1858 }
1859 
1860 /*
1861 ** Return the SQL associated with a prepared statement with
1862 ** bound parameters expanded.  Space to hold the returned string is
1863 ** obtained from sqlite3_malloc().  The caller is responsible for
1864 ** freeing the returned string by passing it to sqlite3_free().
1865 **
1866 ** The SQLITE_TRACE_SIZE_LIMIT puts an upper bound on the size of
1867 ** expanded bound parameters.
1868 */
1869 char *sqlite3_expanded_sql(sqlite3_stmt *pStmt){
1870 #ifdef SQLITE_OMIT_TRACE
1871   return 0;
1872 #else
1873   char *z = 0;
1874   const char *zSql = sqlite3_sql(pStmt);
1875   if( zSql ){
1876     Vdbe *p = (Vdbe *)pStmt;
1877     sqlite3_mutex_enter(p->db->mutex);
1878     z = sqlite3VdbeExpandSql(p, zSql);
1879     sqlite3_mutex_leave(p->db->mutex);
1880   }
1881   return z;
1882 #endif
1883 }
1884 
1885 #ifdef SQLITE_ENABLE_NORMALIZE
1886 /*
1887 ** Return the normalized SQL associated with a prepared statement.
1888 */
1889 const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt){
1890   Vdbe *p = (Vdbe *)pStmt;
1891   if( p==0 ) return 0;
1892   if( p->zNormSql==0 && ALWAYS(p->zSql!=0) ){
1893     sqlite3_mutex_enter(p->db->mutex);
1894     p->zNormSql = sqlite3Normalize(p, p->zSql);
1895     sqlite3_mutex_leave(p->db->mutex);
1896   }
1897   return p->zNormSql;
1898 }
1899 #endif /* SQLITE_ENABLE_NORMALIZE */
1900 
1901 #ifdef SQLITE_ENABLE_PREUPDATE_HOOK
1902 /*
1903 ** Allocate and populate an UnpackedRecord structure based on the serialized
1904 ** record in nKey/pKey. Return a pointer to the new UnpackedRecord structure
1905 ** if successful, or a NULL pointer if an OOM error is encountered.
1906 */
1907 static UnpackedRecord *vdbeUnpackRecord(
1908   KeyInfo *pKeyInfo,
1909   int nKey,
1910   const void *pKey
1911 ){
1912   UnpackedRecord *pRet;           /* Return value */
1913 
1914   pRet = sqlite3VdbeAllocUnpackedRecord(pKeyInfo);
1915   if( pRet ){
1916     memset(pRet->aMem, 0, sizeof(Mem)*(pKeyInfo->nKeyField+1));
1917     sqlite3VdbeRecordUnpack(pKeyInfo, nKey, pKey, pRet);
1918   }
1919   return pRet;
1920 }
1921 
1922 /*
1923 ** This function is called from within a pre-update callback to retrieve
1924 ** a field of the row currently being updated or deleted.
1925 */
1926 int sqlite3_preupdate_old(sqlite3 *db, int iIdx, sqlite3_value **ppValue){
1927   PreUpdate *p = db->pPreUpdate;
1928   Mem *pMem;
1929   int rc = SQLITE_OK;
1930 
1931   /* Test that this call is being made from within an SQLITE_DELETE or
1932   ** SQLITE_UPDATE pre-update callback, and that iIdx is within range. */
1933   if( !p || p->op==SQLITE_INSERT ){
1934     rc = SQLITE_MISUSE_BKPT;
1935     goto preupdate_old_out;
1936   }
1937   if( p->pPk ){
1938     iIdx = sqlite3TableColumnToIndex(p->pPk, iIdx);
1939   }
1940   if( iIdx>=p->pCsr->nField || iIdx<0 ){
1941     rc = SQLITE_RANGE;
1942     goto preupdate_old_out;
1943   }
1944 
1945   /* If the old.* record has not yet been loaded into memory, do so now. */
1946   if( p->pUnpacked==0 ){
1947     u32 nRec;
1948     u8 *aRec;
1949 
1950     assert( p->pCsr->eCurType==CURTYPE_BTREE );
1951     nRec = sqlite3BtreePayloadSize(p->pCsr->uc.pCursor);
1952     aRec = sqlite3DbMallocRaw(db, nRec);
1953     if( !aRec ) goto preupdate_old_out;
1954     rc = sqlite3BtreePayload(p->pCsr->uc.pCursor, 0, nRec, aRec);
1955     if( rc==SQLITE_OK ){
1956       p->pUnpacked = vdbeUnpackRecord(&p->keyinfo, nRec, aRec);
1957       if( !p->pUnpacked ) rc = SQLITE_NOMEM;
1958     }
1959     if( rc!=SQLITE_OK ){
1960       sqlite3DbFree(db, aRec);
1961       goto preupdate_old_out;
1962     }
1963     p->aRecord = aRec;
1964   }
1965 
1966   pMem = *ppValue = &p->pUnpacked->aMem[iIdx];
1967   if( iIdx==p->pTab->iPKey ){
1968     sqlite3VdbeMemSetInt64(pMem, p->iKey1);
1969   }else if( iIdx>=p->pUnpacked->nField ){
1970     *ppValue = (sqlite3_value *)columnNullValue();
1971   }else if( p->pTab->aCol[iIdx].affinity==SQLITE_AFF_REAL ){
1972     if( pMem->flags & (MEM_Int|MEM_IntReal) ){
1973       testcase( pMem->flags & MEM_Int );
1974       testcase( pMem->flags & MEM_IntReal );
1975       sqlite3VdbeMemRealify(pMem);
1976     }
1977   }
1978 
1979  preupdate_old_out:
1980   sqlite3Error(db, rc);
1981   return sqlite3ApiExit(db, rc);
1982 }
1983 #endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
1984 
1985 #ifdef SQLITE_ENABLE_PREUPDATE_HOOK
1986 /*
1987 ** This function is called from within a pre-update callback to retrieve
1988 ** the number of columns in the row being updated, deleted or inserted.
1989 */
1990 int sqlite3_preupdate_count(sqlite3 *db){
1991   PreUpdate *p = db->pPreUpdate;
1992   return (p ? p->keyinfo.nKeyField : 0);
1993 }
1994 #endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
1995 
1996 #ifdef SQLITE_ENABLE_PREUPDATE_HOOK
1997 /*
1998 ** This function is designed to be called from within a pre-update callback
1999 ** only. It returns zero if the change that caused the callback was made
2000 ** immediately by a user SQL statement. Or, if the change was made by a
2001 ** trigger program, it returns the number of trigger programs currently
2002 ** on the stack (1 for a top-level trigger, 2 for a trigger fired by a
2003 ** top-level trigger etc.).
2004 **
2005 ** For the purposes of the previous paragraph, a foreign key CASCADE, SET NULL
2006 ** or SET DEFAULT action is considered a trigger.
2007 */
2008 int sqlite3_preupdate_depth(sqlite3 *db){
2009   PreUpdate *p = db->pPreUpdate;
2010   return (p ? p->v->nFrame : 0);
2011 }
2012 #endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
2013 
2014 #ifdef SQLITE_ENABLE_PREUPDATE_HOOK
2015 /*
2016 ** This function is designed to be called from within a pre-update callback
2017 ** only.
2018 */
2019 int sqlite3_preupdate_blobwrite(sqlite3 *db){
2020   PreUpdate *p = db->pPreUpdate;
2021   return (p ? p->iBlobWrite : -1);
2022 }
2023 #endif
2024 
2025 #ifdef SQLITE_ENABLE_PREUPDATE_HOOK
2026 /*
2027 ** This function is called from within a pre-update callback to retrieve
2028 ** a field of the row currently being updated or inserted.
2029 */
2030 int sqlite3_preupdate_new(sqlite3 *db, int iIdx, sqlite3_value **ppValue){
2031   PreUpdate *p = db->pPreUpdate;
2032   int rc = SQLITE_OK;
2033   Mem *pMem;
2034 
2035   if( !p || p->op==SQLITE_DELETE ){
2036     rc = SQLITE_MISUSE_BKPT;
2037     goto preupdate_new_out;
2038   }
2039   if( p->pPk && p->op!=SQLITE_UPDATE ){
2040     iIdx = sqlite3TableColumnToIndex(p->pPk, iIdx);
2041   }
2042   if( iIdx>=p->pCsr->nField || iIdx<0 ){
2043     rc = SQLITE_RANGE;
2044     goto preupdate_new_out;
2045   }
2046 
2047   if( p->op==SQLITE_INSERT ){
2048     /* For an INSERT, memory cell p->iNewReg contains the serialized record
2049     ** that is being inserted. Deserialize it. */
2050     UnpackedRecord *pUnpack = p->pNewUnpacked;
2051     if( !pUnpack ){
2052       Mem *pData = &p->v->aMem[p->iNewReg];
2053       rc = ExpandBlob(pData);
2054       if( rc!=SQLITE_OK ) goto preupdate_new_out;
2055       pUnpack = vdbeUnpackRecord(&p->keyinfo, pData->n, pData->z);
2056       if( !pUnpack ){
2057         rc = SQLITE_NOMEM;
2058         goto preupdate_new_out;
2059       }
2060       p->pNewUnpacked = pUnpack;
2061     }
2062     pMem = &pUnpack->aMem[iIdx];
2063     if( iIdx==p->pTab->iPKey ){
2064       sqlite3VdbeMemSetInt64(pMem, p->iKey2);
2065     }else if( iIdx>=pUnpack->nField ){
2066       pMem = (sqlite3_value *)columnNullValue();
2067     }
2068   }else{
2069     /* For an UPDATE, memory cell (p->iNewReg+1+iIdx) contains the required
2070     ** value. Make a copy of the cell contents and return a pointer to it.
2071     ** It is not safe to return a pointer to the memory cell itself as the
2072     ** caller may modify the value text encoding.
2073     */
2074     assert( p->op==SQLITE_UPDATE );
2075     if( !p->aNew ){
2076       p->aNew = (Mem *)sqlite3DbMallocZero(db, sizeof(Mem) * p->pCsr->nField);
2077       if( !p->aNew ){
2078         rc = SQLITE_NOMEM;
2079         goto preupdate_new_out;
2080       }
2081     }
2082     assert( iIdx>=0 && iIdx<p->pCsr->nField );
2083     pMem = &p->aNew[iIdx];
2084     if( pMem->flags==0 ){
2085       if( iIdx==p->pTab->iPKey ){
2086         sqlite3VdbeMemSetInt64(pMem, p->iKey2);
2087       }else{
2088         rc = sqlite3VdbeMemCopy(pMem, &p->v->aMem[p->iNewReg+1+iIdx]);
2089         if( rc!=SQLITE_OK ) goto preupdate_new_out;
2090       }
2091     }
2092   }
2093   *ppValue = pMem;
2094 
2095  preupdate_new_out:
2096   sqlite3Error(db, rc);
2097   return sqlite3ApiExit(db, rc);
2098 }
2099 #endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
2100 
2101 #ifdef SQLITE_ENABLE_STMT_SCANSTATUS
2102 /*
2103 ** Return status data for a single loop within query pStmt.
2104 */
2105 int sqlite3_stmt_scanstatus(
2106   sqlite3_stmt *pStmt,            /* Prepared statement being queried */
2107   int idx,                        /* Index of loop to report on */
2108   int iScanStatusOp,              /* Which metric to return */
2109   void *pOut                      /* OUT: Write the answer here */
2110 ){
2111   Vdbe *p = (Vdbe*)pStmt;
2112   ScanStatus *pScan;
2113   if( idx<0 || idx>=p->nScan ) return 1;
2114   pScan = &p->aScan[idx];
2115   switch( iScanStatusOp ){
2116     case SQLITE_SCANSTAT_NLOOP: {
2117       *(sqlite3_int64*)pOut = p->anExec[pScan->addrLoop];
2118       break;
2119     }
2120     case SQLITE_SCANSTAT_NVISIT: {
2121       *(sqlite3_int64*)pOut = p->anExec[pScan->addrVisit];
2122       break;
2123     }
2124     case SQLITE_SCANSTAT_EST: {
2125       double r = 1.0;
2126       LogEst x = pScan->nEst;
2127       while( x<100 ){
2128         x += 10;
2129         r *= 0.5;
2130       }
2131       *(double*)pOut = r*sqlite3LogEstToInt(x);
2132       break;
2133     }
2134     case SQLITE_SCANSTAT_NAME: {
2135       *(const char**)pOut = pScan->zName;
2136       break;
2137     }
2138     case SQLITE_SCANSTAT_EXPLAIN: {
2139       if( pScan->addrExplain ){
2140         *(const char**)pOut = p->aOp[ pScan->addrExplain ].p4.z;
2141       }else{
2142         *(const char**)pOut = 0;
2143       }
2144       break;
2145     }
2146     case SQLITE_SCANSTAT_SELECTID: {
2147       if( pScan->addrExplain ){
2148         *(int*)pOut = p->aOp[ pScan->addrExplain ].p1;
2149       }else{
2150         *(int*)pOut = -1;
2151       }
2152       break;
2153     }
2154     default: {
2155       return 1;
2156     }
2157   }
2158   return 0;
2159 }
2160 
2161 /*
2162 ** Zero all counters associated with the sqlite3_stmt_scanstatus() data.
2163 */
2164 void sqlite3_stmt_scanstatus_reset(sqlite3_stmt *pStmt){
2165   Vdbe *p = (Vdbe*)pStmt;
2166   memset(p->anExec, 0, p->nOp * sizeof(i64));
2167 }
2168 #endif /* SQLITE_ENABLE_STMT_SCANSTATUS */
2169