xref: /sqlite-3.40.0/src/vdbeapi.c (revision fb8e71c5)
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     rc = sqlite3VdbeFinalize(v);
112     rc = sqlite3ApiExit(db, rc);
113     sqlite3LeaveMutexAndCloseZombie(db);
114   }
115   return rc;
116 }
117 
118 /*
119 ** Terminate the current execution of an SQL statement and reset it
120 ** back to its starting state so that it can be reused. A success code from
121 ** the prior execution is returned.
122 **
123 ** This routine sets the error code and string returned by
124 ** sqlite3_errcode(), sqlite3_errmsg() and sqlite3_errmsg16().
125 */
126 int sqlite3_reset(sqlite3_stmt *pStmt){
127   int rc;
128   if( pStmt==0 ){
129     rc = SQLITE_OK;
130   }else{
131     Vdbe *v = (Vdbe*)pStmt;
132     sqlite3 *db = v->db;
133     sqlite3_mutex_enter(db->mutex);
134     checkProfileCallback(db, v);
135     rc = sqlite3VdbeReset(v);
136     sqlite3VdbeRewind(v);
137     assert( (rc & (db->errMask))==rc );
138     rc = sqlite3ApiExit(db, rc);
139     sqlite3_mutex_leave(db->mutex);
140   }
141   return rc;
142 }
143 
144 /*
145 ** Set all the parameters in the compiled SQL statement to NULL.
146 */
147 int sqlite3_clear_bindings(sqlite3_stmt *pStmt){
148   int i;
149   int rc = SQLITE_OK;
150   Vdbe *p = (Vdbe*)pStmt;
151 #if SQLITE_THREADSAFE
152   sqlite3_mutex *mutex = ((Vdbe*)pStmt)->db->mutex;
153 #endif
154   sqlite3_mutex_enter(mutex);
155   for(i=0; i<p->nVar; i++){
156     sqlite3VdbeMemRelease(&p->aVar[i]);
157     p->aVar[i].flags = MEM_Null;
158   }
159   assert( (p->prepFlags & SQLITE_PREPARE_SAVESQL)!=0 || p->expmask==0 );
160   if( p->expmask ){
161     p->expired = 1;
162   }
163   sqlite3_mutex_leave(mutex);
164   return rc;
165 }
166 
167 
168 /**************************** sqlite3_value_  *******************************
169 ** The following routines extract information from a Mem or sqlite3_value
170 ** structure.
171 */
172 const void *sqlite3_value_blob(sqlite3_value *pVal){
173   Mem *p = (Mem*)pVal;
174   if( p->flags & (MEM_Blob|MEM_Str) ){
175     if( ExpandBlob(p)!=SQLITE_OK ){
176       assert( p->flags==MEM_Null && p->z==0 );
177       return 0;
178     }
179     p->flags |= MEM_Blob;
180     return p->n ? p->z : 0;
181   }else{
182     return sqlite3_value_text(pVal);
183   }
184 }
185 int sqlite3_value_bytes(sqlite3_value *pVal){
186   return sqlite3ValueBytes(pVal, SQLITE_UTF8);
187 }
188 int sqlite3_value_bytes16(sqlite3_value *pVal){
189   return sqlite3ValueBytes(pVal, SQLITE_UTF16NATIVE);
190 }
191 double sqlite3_value_double(sqlite3_value *pVal){
192   return sqlite3VdbeRealValue((Mem*)pVal);
193 }
194 int sqlite3_value_int(sqlite3_value *pVal){
195   return (int)sqlite3VdbeIntValue((Mem*)pVal);
196 }
197 sqlite_int64 sqlite3_value_int64(sqlite3_value *pVal){
198   return sqlite3VdbeIntValue((Mem*)pVal);
199 }
200 unsigned int sqlite3_value_subtype(sqlite3_value *pVal){
201   Mem *pMem = (Mem*)pVal;
202   return ((pMem->flags & MEM_Subtype) ? pMem->eSubtype : 0);
203 }
204 void *sqlite3_value_pointer(sqlite3_value *pVal, const char *zPType){
205   Mem *p = (Mem*)pVal;
206   if( (p->flags&(MEM_TypeMask|MEM_Term|MEM_Subtype)) ==
207                  (MEM_Null|MEM_Term|MEM_Subtype)
208    && zPType!=0
209    && p->eSubtype=='p'
210    && strcmp(p->u.zPType, zPType)==0
211   ){
212     return (void*)p->z;
213   }else{
214     return 0;
215   }
216 }
217 const unsigned char *sqlite3_value_text(sqlite3_value *pVal){
218   return (const unsigned char *)sqlite3ValueText(pVal, SQLITE_UTF8);
219 }
220 #ifndef SQLITE_OMIT_UTF16
221 const void *sqlite3_value_text16(sqlite3_value* pVal){
222   return sqlite3ValueText(pVal, SQLITE_UTF16NATIVE);
223 }
224 const void *sqlite3_value_text16be(sqlite3_value *pVal){
225   return sqlite3ValueText(pVal, SQLITE_UTF16BE);
226 }
227 const void *sqlite3_value_text16le(sqlite3_value *pVal){
228   return sqlite3ValueText(pVal, SQLITE_UTF16LE);
229 }
230 #endif /* SQLITE_OMIT_UTF16 */
231 /* EVIDENCE-OF: R-12793-43283 Every value in SQLite has one of five
232 ** fundamental datatypes: 64-bit signed integer 64-bit IEEE floating
233 ** point number string BLOB NULL
234 */
235 int sqlite3_value_type(sqlite3_value* pVal){
236   static const u8 aType[] = {
237      SQLITE_BLOB,     /* 0x00 (not possible) */
238      SQLITE_NULL,     /* 0x01 NULL */
239      SQLITE_TEXT,     /* 0x02 TEXT */
240      SQLITE_NULL,     /* 0x03 (not possible) */
241      SQLITE_INTEGER,  /* 0x04 INTEGER */
242      SQLITE_NULL,     /* 0x05 (not possible) */
243      SQLITE_INTEGER,  /* 0x06 INTEGER + TEXT */
244      SQLITE_NULL,     /* 0x07 (not possible) */
245      SQLITE_FLOAT,    /* 0x08 FLOAT */
246      SQLITE_NULL,     /* 0x09 (not possible) */
247      SQLITE_FLOAT,    /* 0x0a FLOAT + TEXT */
248      SQLITE_NULL,     /* 0x0b (not possible) */
249      SQLITE_INTEGER,  /* 0x0c (not possible) */
250      SQLITE_NULL,     /* 0x0d (not possible) */
251      SQLITE_INTEGER,  /* 0x0e (not possible) */
252      SQLITE_NULL,     /* 0x0f (not possible) */
253      SQLITE_BLOB,     /* 0x10 BLOB */
254      SQLITE_NULL,     /* 0x11 (not possible) */
255      SQLITE_TEXT,     /* 0x12 (not possible) */
256      SQLITE_NULL,     /* 0x13 (not possible) */
257      SQLITE_INTEGER,  /* 0x14 INTEGER + BLOB */
258      SQLITE_NULL,     /* 0x15 (not possible) */
259      SQLITE_INTEGER,  /* 0x16 (not possible) */
260      SQLITE_NULL,     /* 0x17 (not possible) */
261      SQLITE_FLOAT,    /* 0x18 FLOAT + BLOB */
262      SQLITE_NULL,     /* 0x19 (not possible) */
263      SQLITE_FLOAT,    /* 0x1a (not possible) */
264      SQLITE_NULL,     /* 0x1b (not possible) */
265      SQLITE_INTEGER,  /* 0x1c (not possible) */
266      SQLITE_NULL,     /* 0x1d (not possible) */
267      SQLITE_INTEGER,  /* 0x1e (not possible) */
268      SQLITE_NULL,     /* 0x1f (not possible) */
269      SQLITE_FLOAT,    /* 0x20 INTREAL */
270      SQLITE_NULL,     /* 0x21 (not possible) */
271      SQLITE_TEXT,     /* 0x22 INTREAL + TEXT */
272      SQLITE_NULL,     /* 0x23 (not possible) */
273      SQLITE_FLOAT,    /* 0x24 (not possible) */
274      SQLITE_NULL,     /* 0x25 (not possible) */
275      SQLITE_FLOAT,    /* 0x26 (not possible) */
276      SQLITE_NULL,     /* 0x27 (not possible) */
277      SQLITE_FLOAT,    /* 0x28 (not possible) */
278      SQLITE_NULL,     /* 0x29 (not possible) */
279      SQLITE_FLOAT,    /* 0x2a (not possible) */
280      SQLITE_NULL,     /* 0x2b (not possible) */
281      SQLITE_FLOAT,    /* 0x2c (not possible) */
282      SQLITE_NULL,     /* 0x2d (not possible) */
283      SQLITE_FLOAT,    /* 0x2e (not possible) */
284      SQLITE_NULL,     /* 0x2f (not possible) */
285      SQLITE_BLOB,     /* 0x30 (not possible) */
286      SQLITE_NULL,     /* 0x31 (not possible) */
287      SQLITE_TEXT,     /* 0x32 (not possible) */
288      SQLITE_NULL,     /* 0x33 (not possible) */
289      SQLITE_FLOAT,    /* 0x34 (not possible) */
290      SQLITE_NULL,     /* 0x35 (not possible) */
291      SQLITE_FLOAT,    /* 0x36 (not possible) */
292      SQLITE_NULL,     /* 0x37 (not possible) */
293      SQLITE_FLOAT,    /* 0x38 (not possible) */
294      SQLITE_NULL,     /* 0x39 (not possible) */
295      SQLITE_FLOAT,    /* 0x3a (not possible) */
296      SQLITE_NULL,     /* 0x3b (not possible) */
297      SQLITE_FLOAT,    /* 0x3c (not possible) */
298      SQLITE_NULL,     /* 0x3d (not possible) */
299      SQLITE_FLOAT,    /* 0x3e (not possible) */
300      SQLITE_NULL,     /* 0x3f (not possible) */
301   };
302 #ifdef SQLITE_DEBUG
303   {
304     int eType = SQLITE_BLOB;
305     if( pVal->flags & MEM_Null ){
306       eType = SQLITE_NULL;
307     }else if( pVal->flags & (MEM_Real|MEM_IntReal) ){
308       eType = SQLITE_FLOAT;
309     }else if( pVal->flags & MEM_Int ){
310       eType = SQLITE_INTEGER;
311     }else if( pVal->flags & MEM_Str ){
312       eType = SQLITE_TEXT;
313     }
314     assert( eType == aType[pVal->flags&MEM_AffMask] );
315   }
316 #endif
317   return aType[pVal->flags&MEM_AffMask];
318 }
319 
320 /* Return true if a parameter to xUpdate represents an unchanged column */
321 int sqlite3_value_nochange(sqlite3_value *pVal){
322   return (pVal->flags&(MEM_Null|MEM_Zero))==(MEM_Null|MEM_Zero);
323 }
324 
325 /* Return true if a parameter value originated from an sqlite3_bind() */
326 int sqlite3_value_frombind(sqlite3_value *pVal){
327   return (pVal->flags&MEM_FromBind)!=0;
328 }
329 
330 /* Make a copy of an sqlite3_value object
331 */
332 sqlite3_value *sqlite3_value_dup(const sqlite3_value *pOrig){
333   sqlite3_value *pNew;
334   if( pOrig==0 ) return 0;
335   pNew = sqlite3_malloc( sizeof(*pNew) );
336   if( pNew==0 ) return 0;
337   memset(pNew, 0, sizeof(*pNew));
338   memcpy(pNew, pOrig, MEMCELLSIZE);
339   pNew->flags &= ~MEM_Dyn;
340   pNew->db = 0;
341   if( pNew->flags&(MEM_Str|MEM_Blob) ){
342     pNew->flags &= ~(MEM_Static|MEM_Dyn);
343     pNew->flags |= MEM_Ephem;
344     if( sqlite3VdbeMemMakeWriteable(pNew)!=SQLITE_OK ){
345       sqlite3ValueFree(pNew);
346       pNew = 0;
347     }
348   }
349   return pNew;
350 }
351 
352 /* Destroy an sqlite3_value object previously obtained from
353 ** sqlite3_value_dup().
354 */
355 void sqlite3_value_free(sqlite3_value *pOld){
356   sqlite3ValueFree(pOld);
357 }
358 
359 
360 /**************************** sqlite3_result_  *******************************
361 ** The following routines are used by user-defined functions to specify
362 ** the function result.
363 **
364 ** The setStrOrError() function calls sqlite3VdbeMemSetStr() to store the
365 ** result as a string or blob.  Appropriate errors are set if the string/blob
366 ** is too big or if an OOM occurs.
367 **
368 ** The invokeValueDestructor(P,X) routine invokes destructor function X()
369 ** on value P is not going to be used and need to be destroyed.
370 */
371 static void setResultStrOrError(
372   sqlite3_context *pCtx,  /* Function context */
373   const char *z,          /* String pointer */
374   int n,                  /* Bytes in string, or negative */
375   u8 enc,                 /* Encoding of z.  0 for BLOBs */
376   void (*xDel)(void*)     /* Destructor function */
377 ){
378   int rc = sqlite3VdbeMemSetStr(pCtx->pOut, z, n, enc, xDel);
379   if( rc ){
380     if( rc==SQLITE_TOOBIG ){
381       sqlite3_result_error_toobig(pCtx);
382     }else{
383       /* The only errors possible from sqlite3VdbeMemSetStr are
384       ** SQLITE_TOOBIG and SQLITE_NOMEM */
385       assert( rc==SQLITE_NOMEM );
386       sqlite3_result_error_nomem(pCtx);
387     }
388   }
389 }
390 static int invokeValueDestructor(
391   const void *p,             /* Value to destroy */
392   void (*xDel)(void*),       /* The destructor */
393   sqlite3_context *pCtx      /* Set a SQLITE_TOOBIG error if no NULL */
394 ){
395   assert( xDel!=SQLITE_DYNAMIC );
396   if( xDel==0 ){
397     /* noop */
398   }else if( xDel==SQLITE_TRANSIENT ){
399     /* noop */
400   }else{
401     xDel((void*)p);
402   }
403   sqlite3_result_error_toobig(pCtx);
404   return SQLITE_TOOBIG;
405 }
406 void sqlite3_result_blob(
407   sqlite3_context *pCtx,
408   const void *z,
409   int n,
410   void (*xDel)(void *)
411 ){
412   assert( n>=0 );
413   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
414   setResultStrOrError(pCtx, z, n, 0, xDel);
415 }
416 void sqlite3_result_blob64(
417   sqlite3_context *pCtx,
418   const void *z,
419   sqlite3_uint64 n,
420   void (*xDel)(void *)
421 ){
422   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
423   assert( xDel!=SQLITE_DYNAMIC );
424   if( n>0x7fffffff ){
425     (void)invokeValueDestructor(z, xDel, pCtx);
426   }else{
427     setResultStrOrError(pCtx, z, (int)n, 0, xDel);
428   }
429 }
430 void sqlite3_result_double(sqlite3_context *pCtx, double rVal){
431   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
432   sqlite3VdbeMemSetDouble(pCtx->pOut, rVal);
433 }
434 void sqlite3_result_error(sqlite3_context *pCtx, const char *z, int n){
435   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
436   pCtx->isError = SQLITE_ERROR;
437   sqlite3VdbeMemSetStr(pCtx->pOut, z, n, SQLITE_UTF8, SQLITE_TRANSIENT);
438 }
439 #ifndef SQLITE_OMIT_UTF16
440 void sqlite3_result_error16(sqlite3_context *pCtx, const void *z, int n){
441   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
442   pCtx->isError = SQLITE_ERROR;
443   sqlite3VdbeMemSetStr(pCtx->pOut, z, n, SQLITE_UTF16NATIVE, SQLITE_TRANSIENT);
444 }
445 #endif
446 void sqlite3_result_int(sqlite3_context *pCtx, int iVal){
447   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
448   sqlite3VdbeMemSetInt64(pCtx->pOut, (i64)iVal);
449 }
450 void sqlite3_result_int64(sqlite3_context *pCtx, i64 iVal){
451   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
452   sqlite3VdbeMemSetInt64(pCtx->pOut, iVal);
453 }
454 void sqlite3_result_null(sqlite3_context *pCtx){
455   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
456   sqlite3VdbeMemSetNull(pCtx->pOut);
457 }
458 void sqlite3_result_pointer(
459   sqlite3_context *pCtx,
460   void *pPtr,
461   const char *zPType,
462   void (*xDestructor)(void*)
463 ){
464   Mem *pOut = pCtx->pOut;
465   assert( sqlite3_mutex_held(pOut->db->mutex) );
466   sqlite3VdbeMemRelease(pOut);
467   pOut->flags = MEM_Null;
468   sqlite3VdbeMemSetPointer(pOut, pPtr, zPType, xDestructor);
469 }
470 void sqlite3_result_subtype(sqlite3_context *pCtx, unsigned int eSubtype){
471   Mem *pOut = pCtx->pOut;
472   assert( sqlite3_mutex_held(pOut->db->mutex) );
473   pOut->eSubtype = eSubtype & 0xff;
474   pOut->flags |= MEM_Subtype;
475 }
476 void sqlite3_result_text(
477   sqlite3_context *pCtx,
478   const char *z,
479   int n,
480   void (*xDel)(void *)
481 ){
482   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
483   setResultStrOrError(pCtx, z, n, SQLITE_UTF8, xDel);
484 }
485 void sqlite3_result_text64(
486   sqlite3_context *pCtx,
487   const char *z,
488   sqlite3_uint64 n,
489   void (*xDel)(void *),
490   unsigned char enc
491 ){
492   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
493   assert( xDel!=SQLITE_DYNAMIC );
494   if( enc==SQLITE_UTF16 ) enc = SQLITE_UTF16NATIVE;
495   if( n>0x7fffffff ){
496     (void)invokeValueDestructor(z, xDel, pCtx);
497   }else{
498     setResultStrOrError(pCtx, z, (int)n, enc, xDel);
499   }
500 }
501 #ifndef SQLITE_OMIT_UTF16
502 void sqlite3_result_text16(
503   sqlite3_context *pCtx,
504   const void *z,
505   int n,
506   void (*xDel)(void *)
507 ){
508   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
509   setResultStrOrError(pCtx, z, n, SQLITE_UTF16NATIVE, xDel);
510 }
511 void sqlite3_result_text16be(
512   sqlite3_context *pCtx,
513   const void *z,
514   int n,
515   void (*xDel)(void *)
516 ){
517   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
518   setResultStrOrError(pCtx, z, n, SQLITE_UTF16BE, xDel);
519 }
520 void sqlite3_result_text16le(
521   sqlite3_context *pCtx,
522   const void *z,
523   int n,
524   void (*xDel)(void *)
525 ){
526   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
527   setResultStrOrError(pCtx, z, n, SQLITE_UTF16LE, xDel);
528 }
529 #endif /* SQLITE_OMIT_UTF16 */
530 void sqlite3_result_value(sqlite3_context *pCtx, sqlite3_value *pValue){
531   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
532   sqlite3VdbeMemCopy(pCtx->pOut, pValue);
533 }
534 void sqlite3_result_zeroblob(sqlite3_context *pCtx, int n){
535   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
536   sqlite3VdbeMemSetZeroBlob(pCtx->pOut, n);
537 }
538 int sqlite3_result_zeroblob64(sqlite3_context *pCtx, u64 n){
539   Mem *pOut = pCtx->pOut;
540   assert( sqlite3_mutex_held(pOut->db->mutex) );
541   if( n>(u64)pOut->db->aLimit[SQLITE_LIMIT_LENGTH] ){
542     return SQLITE_TOOBIG;
543   }
544   sqlite3VdbeMemSetZeroBlob(pCtx->pOut, (int)n);
545   return SQLITE_OK;
546 }
547 void sqlite3_result_error_code(sqlite3_context *pCtx, int errCode){
548   pCtx->isError = errCode ? errCode : -1;
549 #ifdef SQLITE_DEBUG
550   if( pCtx->pVdbe ) pCtx->pVdbe->rcApp = errCode;
551 #endif
552   if( pCtx->pOut->flags & MEM_Null ){
553     sqlite3VdbeMemSetStr(pCtx->pOut, sqlite3ErrStr(errCode), -1,
554                          SQLITE_UTF8, SQLITE_STATIC);
555   }
556 }
557 
558 /* Force an SQLITE_TOOBIG error. */
559 void sqlite3_result_error_toobig(sqlite3_context *pCtx){
560   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
561   pCtx->isError = SQLITE_TOOBIG;
562   sqlite3VdbeMemSetStr(pCtx->pOut, "string or blob too big", -1,
563                        SQLITE_UTF8, SQLITE_STATIC);
564 }
565 
566 /* An SQLITE_NOMEM error. */
567 void sqlite3_result_error_nomem(sqlite3_context *pCtx){
568   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
569   sqlite3VdbeMemSetNull(pCtx->pOut);
570   pCtx->isError = SQLITE_NOMEM_BKPT;
571   sqlite3OomFault(pCtx->pOut->db);
572 }
573 
574 #ifndef SQLITE_UNTESTABLE
575 /* Force the INT64 value currently stored as the result to be
576 ** a MEM_IntReal value.  See the SQLITE_TESTCTRL_RESULT_INTREAL
577 ** test-control.
578 */
579 void sqlite3ResultIntReal(sqlite3_context *pCtx){
580   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
581   if( pCtx->pOut->flags & MEM_Int ){
582     pCtx->pOut->flags &= ~MEM_Int;
583     pCtx->pOut->flags |= MEM_IntReal;
584   }
585 }
586 #endif
587 
588 
589 /*
590 ** This function is called after a transaction has been committed. It
591 ** invokes callbacks registered with sqlite3_wal_hook() as required.
592 */
593 static int doWalCallbacks(sqlite3 *db){
594   int rc = SQLITE_OK;
595 #ifndef SQLITE_OMIT_WAL
596   int i;
597   for(i=0; i<db->nDb; i++){
598     Btree *pBt = db->aDb[i].pBt;
599     if( pBt ){
600       int nEntry;
601       sqlite3BtreeEnter(pBt);
602       nEntry = sqlite3PagerWalCallback(sqlite3BtreePager(pBt));
603       sqlite3BtreeLeave(pBt);
604       if( nEntry>0 && db->xWalCallback && rc==SQLITE_OK ){
605         rc = db->xWalCallback(db->pWalArg, db, db->aDb[i].zDbSName, nEntry);
606       }
607     }
608   }
609 #endif
610   return rc;
611 }
612 
613 
614 /*
615 ** Execute the statement pStmt, either until a row of data is ready, the
616 ** statement is completely executed or an error occurs.
617 **
618 ** This routine implements the bulk of the logic behind the sqlite_step()
619 ** API.  The only thing omitted is the automatic recompile if a
620 ** schema change has occurred.  That detail is handled by the
621 ** outer sqlite3_step() wrapper procedure.
622 */
623 static int sqlite3Step(Vdbe *p){
624   sqlite3 *db;
625   int rc;
626 
627   assert(p);
628   if( p->iVdbeMagic!=VDBE_MAGIC_RUN ){
629     /* We used to require that sqlite3_reset() be called before retrying
630     ** sqlite3_step() after any error or after SQLITE_DONE.  But beginning
631     ** with version 3.7.0, we changed this so that sqlite3_reset() would
632     ** be called automatically instead of throwing the SQLITE_MISUSE error.
633     ** This "automatic-reset" change is not technically an incompatibility,
634     ** since any application that receives an SQLITE_MISUSE is broken by
635     ** definition.
636     **
637     ** Nevertheless, some published applications that were originally written
638     ** for version 3.6.23 or earlier do in fact depend on SQLITE_MISUSE
639     ** returns, and those were broken by the automatic-reset change.  As a
640     ** a work-around, the SQLITE_OMIT_AUTORESET compile-time restores the
641     ** legacy behavior of returning SQLITE_MISUSE for cases where the
642     ** previous sqlite3_step() returned something other than a SQLITE_LOCKED
643     ** or SQLITE_BUSY error.
644     */
645 #ifdef SQLITE_OMIT_AUTORESET
646     if( (rc = p->rc&0xff)==SQLITE_BUSY || rc==SQLITE_LOCKED ){
647       sqlite3_reset((sqlite3_stmt*)p);
648     }else{
649       return SQLITE_MISUSE_BKPT;
650     }
651 #else
652     sqlite3_reset((sqlite3_stmt*)p);
653 #endif
654   }
655 
656   /* Check that malloc() has not failed. If it has, return early. */
657   db = p->db;
658   if( db->mallocFailed ){
659     p->rc = SQLITE_NOMEM;
660     return SQLITE_NOMEM_BKPT;
661   }
662 
663   if( p->pc<0 && p->expired ){
664     p->rc = SQLITE_SCHEMA;
665     rc = SQLITE_ERROR;
666     if( (p->prepFlags & SQLITE_PREPARE_SAVESQL)!=0 ){
667       /* If this statement was prepared using saved SQL and an
668       ** error has occurred, then return the error code in p->rc to the
669       ** caller. Set the error code in the database handle to the same value.
670       */
671       rc = sqlite3VdbeTransferError(p);
672     }
673     goto end_of_step;
674   }
675   if( p->pc<0 ){
676     /* If there are no other statements currently running, then
677     ** reset the interrupt flag.  This prevents a call to sqlite3_interrupt
678     ** from interrupting a statement that has not yet started.
679     */
680     if( db->nVdbeActive==0 ){
681       AtomicStore(&db->u1.isInterrupted, 0);
682     }
683 
684     assert( db->nVdbeWrite>0 || db->autoCommit==0
685         || (db->nDeferredCons==0 && db->nDeferredImmCons==0)
686     );
687 
688 #ifndef SQLITE_OMIT_TRACE
689     if( (db->mTrace & (SQLITE_TRACE_PROFILE|SQLITE_TRACE_XPROFILE))!=0
690         && !db->init.busy && p->zSql ){
691       sqlite3OsCurrentTimeInt64(db->pVfs, &p->startTime);
692     }else{
693       assert( p->startTime==0 );
694     }
695 #endif
696 
697     db->nVdbeActive++;
698     if( p->readOnly==0 ) db->nVdbeWrite++;
699     if( p->bIsReader ) db->nVdbeRead++;
700     p->pc = 0;
701   }
702 #ifdef SQLITE_DEBUG
703   p->rcApp = SQLITE_OK;
704 #endif
705 #ifndef SQLITE_OMIT_EXPLAIN
706   if( p->explain ){
707     rc = sqlite3VdbeList(p);
708   }else
709 #endif /* SQLITE_OMIT_EXPLAIN */
710   {
711     db->nVdbeExec++;
712     rc = sqlite3VdbeExec(p);
713     db->nVdbeExec--;
714   }
715 
716   if( rc!=SQLITE_ROW ){
717 #ifndef SQLITE_OMIT_TRACE
718     /* If the statement completed successfully, invoke the profile callback */
719     checkProfileCallback(db, p);
720 #endif
721 
722     if( rc==SQLITE_DONE && db->autoCommit ){
723       assert( p->rc==SQLITE_OK );
724       p->rc = doWalCallbacks(db);
725       if( p->rc!=SQLITE_OK ){
726         rc = SQLITE_ERROR;
727       }
728     }else if( rc!=SQLITE_DONE && (p->prepFlags & SQLITE_PREPARE_SAVESQL)!=0 ){
729       /* If this statement was prepared using saved SQL and an
730       ** error has occurred, then return the error code in p->rc to the
731       ** caller. Set the error code in the database handle to the same value.
732       */
733       rc = sqlite3VdbeTransferError(p);
734     }
735   }
736 
737   db->errCode = rc;
738   if( SQLITE_NOMEM==sqlite3ApiExit(p->db, p->rc) ){
739     p->rc = SQLITE_NOMEM_BKPT;
740     if( (p->prepFlags & SQLITE_PREPARE_SAVESQL)!=0 ) rc = p->rc;
741   }
742 end_of_step:
743   /* There are only a limited number of result codes allowed from the
744   ** statements prepared using the legacy sqlite3_prepare() interface */
745   assert( (p->prepFlags & SQLITE_PREPARE_SAVESQL)!=0
746        || rc==SQLITE_ROW  || rc==SQLITE_DONE   || rc==SQLITE_ERROR
747        || (rc&0xff)==SQLITE_BUSY || rc==SQLITE_MISUSE
748   );
749   return (rc&db->errMask);
750 }
751 
752 /*
753 ** This is the top-level implementation of sqlite3_step().  Call
754 ** sqlite3Step() to do most of the work.  If a schema error occurs,
755 ** call sqlite3Reprepare() and try again.
756 */
757 int sqlite3_step(sqlite3_stmt *pStmt){
758   int rc = SQLITE_OK;      /* Result from sqlite3Step() */
759   Vdbe *v = (Vdbe*)pStmt;  /* the prepared statement */
760   int cnt = 0;             /* Counter to prevent infinite loop of reprepares */
761   sqlite3 *db;             /* The database connection */
762 
763   if( vdbeSafetyNotNull(v) ){
764     return SQLITE_MISUSE_BKPT;
765   }
766   db = v->db;
767   sqlite3_mutex_enter(db->mutex);
768   v->doingRerun = 0;
769   while( (rc = sqlite3Step(v))==SQLITE_SCHEMA
770          && cnt++ < SQLITE_MAX_SCHEMA_RETRY ){
771     int savedPc = v->pc;
772     rc = sqlite3Reprepare(v);
773     if( rc!=SQLITE_OK ){
774       /* This case occurs after failing to recompile an sql statement.
775       ** The error message from the SQL compiler has already been loaded
776       ** into the database handle. This block copies the error message
777       ** from the database handle into the statement and sets the statement
778       ** program counter to 0 to ensure that when the statement is
779       ** finalized or reset the parser error message is available via
780       ** sqlite3_errmsg() and sqlite3_errcode().
781       */
782       const char *zErr = (const char *)sqlite3_value_text(db->pErr);
783       sqlite3DbFree(db, v->zErrMsg);
784       if( !db->mallocFailed ){
785         v->zErrMsg = sqlite3DbStrDup(db, zErr);
786         v->rc = rc = sqlite3ApiExit(db, rc);
787       } else {
788         v->zErrMsg = 0;
789         v->rc = rc = SQLITE_NOMEM_BKPT;
790       }
791       break;
792     }
793     sqlite3_reset(pStmt);
794     if( savedPc>=0 ) v->doingRerun = 1;
795     assert( v->expired==0 );
796   }
797   sqlite3_mutex_leave(db->mutex);
798   return rc;
799 }
800 
801 
802 /*
803 ** Extract the user data from a sqlite3_context structure and return a
804 ** pointer to it.
805 */
806 void *sqlite3_user_data(sqlite3_context *p){
807   assert( p && p->pFunc );
808   return p->pFunc->pUserData;
809 }
810 
811 /*
812 ** Extract the user data from a sqlite3_context structure and return a
813 ** pointer to it.
814 **
815 ** IMPLEMENTATION-OF: R-46798-50301 The sqlite3_context_db_handle() interface
816 ** returns a copy of the pointer to the database connection (the 1st
817 ** parameter) of the sqlite3_create_function() and
818 ** sqlite3_create_function16() routines that originally registered the
819 ** application defined function.
820 */
821 sqlite3 *sqlite3_context_db_handle(sqlite3_context *p){
822   assert( p && p->pOut );
823   return p->pOut->db;
824 }
825 
826 /*
827 ** If this routine is invoked from within an xColumn method of a virtual
828 ** table, then it returns true if and only if the the call is during an
829 ** UPDATE operation and the value of the column will not be modified
830 ** by the UPDATE.
831 **
832 ** If this routine is called from any context other than within the
833 ** xColumn method of a virtual table, then the return value is meaningless
834 ** and arbitrary.
835 **
836 ** Virtual table implements might use this routine to optimize their
837 ** performance by substituting a NULL result, or some other light-weight
838 ** value, as a signal to the xUpdate routine that the column is unchanged.
839 */
840 int sqlite3_vtab_nochange(sqlite3_context *p){
841   assert( p );
842   return sqlite3_value_nochange(p->pOut);
843 }
844 
845 /*
846 ** Return the current time for a statement.  If the current time
847 ** is requested more than once within the same run of a single prepared
848 ** statement, the exact same time is returned for each invocation regardless
849 ** of the amount of time that elapses between invocations.  In other words,
850 ** the time returned is always the time of the first call.
851 */
852 sqlite3_int64 sqlite3StmtCurrentTime(sqlite3_context *p){
853   int rc;
854 #ifndef SQLITE_ENABLE_STAT4
855   sqlite3_int64 *piTime = &p->pVdbe->iCurrentTime;
856   assert( p->pVdbe!=0 );
857 #else
858   sqlite3_int64 iTime = 0;
859   sqlite3_int64 *piTime = p->pVdbe!=0 ? &p->pVdbe->iCurrentTime : &iTime;
860 #endif
861   if( *piTime==0 ){
862     rc = sqlite3OsCurrentTimeInt64(p->pOut->db->pVfs, piTime);
863     if( rc ) *piTime = 0;
864   }
865   return *piTime;
866 }
867 
868 /*
869 ** Create a new aggregate context for p and return a pointer to
870 ** its pMem->z element.
871 */
872 static SQLITE_NOINLINE void *createAggContext(sqlite3_context *p, int nByte){
873   Mem *pMem = p->pMem;
874   assert( (pMem->flags & MEM_Agg)==0 );
875   if( nByte<=0 ){
876     sqlite3VdbeMemSetNull(pMem);
877     pMem->z = 0;
878   }else{
879     sqlite3VdbeMemClearAndResize(pMem, nByte);
880     pMem->flags = MEM_Agg;
881     pMem->u.pDef = p->pFunc;
882     if( pMem->z ){
883       memset(pMem->z, 0, nByte);
884     }
885   }
886   return (void*)pMem->z;
887 }
888 
889 /*
890 ** Allocate or return the aggregate context for a user function.  A new
891 ** context is allocated on the first call.  Subsequent calls return the
892 ** same context that was returned on prior calls.
893 */
894 void *sqlite3_aggregate_context(sqlite3_context *p, int nByte){
895   assert( p && p->pFunc && p->pFunc->xFinalize );
896   assert( sqlite3_mutex_held(p->pOut->db->mutex) );
897   testcase( nByte<0 );
898   if( (p->pMem->flags & MEM_Agg)==0 ){
899     return createAggContext(p, nByte);
900   }else{
901     return (void*)p->pMem->z;
902   }
903 }
904 
905 /*
906 ** Return the auxiliary data pointer, if any, for the iArg'th argument to
907 ** the user-function defined by pCtx.
908 **
909 ** The left-most argument is 0.
910 **
911 ** Undocumented behavior:  If iArg is negative then access a cache of
912 ** auxiliary data pointers that is available to all functions within a
913 ** single prepared statement.  The iArg values must match.
914 */
915 void *sqlite3_get_auxdata(sqlite3_context *pCtx, int iArg){
916   AuxData *pAuxData;
917 
918   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
919 #if SQLITE_ENABLE_STAT4
920   if( pCtx->pVdbe==0 ) return 0;
921 #else
922   assert( pCtx->pVdbe!=0 );
923 #endif
924   for(pAuxData=pCtx->pVdbe->pAuxData; pAuxData; pAuxData=pAuxData->pNextAux){
925     if(  pAuxData->iAuxArg==iArg && (pAuxData->iAuxOp==pCtx->iOp || iArg<0) ){
926       return pAuxData->pAux;
927     }
928   }
929   return 0;
930 }
931 
932 /*
933 ** Set the auxiliary data pointer and delete function, for the iArg'th
934 ** argument to the user-function defined by pCtx. Any previous value is
935 ** deleted by calling the delete function specified when it was set.
936 **
937 ** The left-most argument is 0.
938 **
939 ** Undocumented behavior:  If iArg is negative then make the data available
940 ** to all functions within the current prepared statement using iArg as an
941 ** access code.
942 */
943 void sqlite3_set_auxdata(
944   sqlite3_context *pCtx,
945   int iArg,
946   void *pAux,
947   void (*xDelete)(void*)
948 ){
949   AuxData *pAuxData;
950   Vdbe *pVdbe = pCtx->pVdbe;
951 
952   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
953 #ifdef SQLITE_ENABLE_STAT4
954   if( pVdbe==0 ) goto failed;
955 #else
956   assert( pVdbe!=0 );
957 #endif
958 
959   for(pAuxData=pVdbe->pAuxData; pAuxData; pAuxData=pAuxData->pNextAux){
960     if( pAuxData->iAuxArg==iArg && (pAuxData->iAuxOp==pCtx->iOp || iArg<0) ){
961       break;
962     }
963   }
964   if( pAuxData==0 ){
965     pAuxData = sqlite3DbMallocZero(pVdbe->db, sizeof(AuxData));
966     if( !pAuxData ) goto failed;
967     pAuxData->iAuxOp = pCtx->iOp;
968     pAuxData->iAuxArg = iArg;
969     pAuxData->pNextAux = pVdbe->pAuxData;
970     pVdbe->pAuxData = pAuxData;
971     if( pCtx->isError==0 ) pCtx->isError = -1;
972   }else if( pAuxData->xDeleteAux ){
973     pAuxData->xDeleteAux(pAuxData->pAux);
974   }
975 
976   pAuxData->pAux = pAux;
977   pAuxData->xDeleteAux = xDelete;
978   return;
979 
980 failed:
981   if( xDelete ){
982     xDelete(pAux);
983   }
984 }
985 
986 #ifndef SQLITE_OMIT_DEPRECATED
987 /*
988 ** Return the number of times the Step function of an aggregate has been
989 ** called.
990 **
991 ** This function is deprecated.  Do not use it for new code.  It is
992 ** provide only to avoid breaking legacy code.  New aggregate function
993 ** implementations should keep their own counts within their aggregate
994 ** context.
995 */
996 int sqlite3_aggregate_count(sqlite3_context *p){
997   assert( p && p->pMem && p->pFunc && p->pFunc->xFinalize );
998   return p->pMem->n;
999 }
1000 #endif
1001 
1002 /*
1003 ** Return the number of columns in the result set for the statement pStmt.
1004 */
1005 int sqlite3_column_count(sqlite3_stmt *pStmt){
1006   Vdbe *pVm = (Vdbe *)pStmt;
1007   return pVm ? pVm->nResColumn : 0;
1008 }
1009 
1010 /*
1011 ** Return the number of values available from the current row of the
1012 ** currently executing statement pStmt.
1013 */
1014 int sqlite3_data_count(sqlite3_stmt *pStmt){
1015   Vdbe *pVm = (Vdbe *)pStmt;
1016   if( pVm==0 || pVm->pResultSet==0 ) return 0;
1017   return pVm->nResColumn;
1018 }
1019 
1020 /*
1021 ** Return a pointer to static memory containing an SQL NULL value.
1022 */
1023 static const Mem *columnNullValue(void){
1024   /* Even though the Mem structure contains an element
1025   ** of type i64, on certain architectures (x86) with certain compiler
1026   ** switches (-Os), gcc may align this Mem object on a 4-byte boundary
1027   ** instead of an 8-byte one. This all works fine, except that when
1028   ** running with SQLITE_DEBUG defined the SQLite code sometimes assert()s
1029   ** that a Mem structure is located on an 8-byte boundary. To prevent
1030   ** these assert()s from failing, when building with SQLITE_DEBUG defined
1031   ** using gcc, we force nullMem to be 8-byte aligned using the magical
1032   ** __attribute__((aligned(8))) macro.  */
1033   static const Mem nullMem
1034 #if defined(SQLITE_DEBUG) && defined(__GNUC__)
1035     __attribute__((aligned(8)))
1036 #endif
1037     = {
1038         /* .u          = */ {0},
1039         /* .flags      = */ (u16)MEM_Null,
1040         /* .enc        = */ (u8)0,
1041         /* .eSubtype   = */ (u8)0,
1042         /* .n          = */ (int)0,
1043         /* .z          = */ (char*)0,
1044         /* .zMalloc    = */ (char*)0,
1045         /* .szMalloc   = */ (int)0,
1046         /* .uTemp      = */ (u32)0,
1047         /* .db         = */ (sqlite3*)0,
1048         /* .xDel       = */ (void(*)(void*))0,
1049 #ifdef SQLITE_DEBUG
1050         /* .pScopyFrom = */ (Mem*)0,
1051         /* .mScopyFlags= */ 0,
1052 #endif
1053       };
1054   return &nullMem;
1055 }
1056 
1057 /*
1058 ** Check to see if column iCol of the given statement is valid.  If
1059 ** it is, return a pointer to the Mem for the value of that column.
1060 ** If iCol is not valid, return a pointer to a Mem which has a value
1061 ** of NULL.
1062 */
1063 static Mem *columnMem(sqlite3_stmt *pStmt, int i){
1064   Vdbe *pVm;
1065   Mem *pOut;
1066 
1067   pVm = (Vdbe *)pStmt;
1068   if( pVm==0 ) return (Mem*)columnNullValue();
1069   assert( pVm->db );
1070   sqlite3_mutex_enter(pVm->db->mutex);
1071   if( pVm->pResultSet!=0 && i<pVm->nResColumn && i>=0 ){
1072     pOut = &pVm->pResultSet[i];
1073   }else{
1074     sqlite3Error(pVm->db, SQLITE_RANGE);
1075     pOut = (Mem*)columnNullValue();
1076   }
1077   return pOut;
1078 }
1079 
1080 /*
1081 ** This function is called after invoking an sqlite3_value_XXX function on a
1082 ** column value (i.e. a value returned by evaluating an SQL expression in the
1083 ** select list of a SELECT statement) that may cause a malloc() failure. If
1084 ** malloc() has failed, the threads mallocFailed flag is cleared and the result
1085 ** code of statement pStmt set to SQLITE_NOMEM.
1086 **
1087 ** Specifically, this is called from within:
1088 **
1089 **     sqlite3_column_int()
1090 **     sqlite3_column_int64()
1091 **     sqlite3_column_text()
1092 **     sqlite3_column_text16()
1093 **     sqlite3_column_real()
1094 **     sqlite3_column_bytes()
1095 **     sqlite3_column_bytes16()
1096 **     sqiite3_column_blob()
1097 */
1098 static void columnMallocFailure(sqlite3_stmt *pStmt)
1099 {
1100   /* If malloc() failed during an encoding conversion within an
1101   ** sqlite3_column_XXX API, then set the return code of the statement to
1102   ** SQLITE_NOMEM. The next call to _step() (if any) will return SQLITE_ERROR
1103   ** and _finalize() will return NOMEM.
1104   */
1105   Vdbe *p = (Vdbe *)pStmt;
1106   if( p ){
1107     assert( p->db!=0 );
1108     assert( sqlite3_mutex_held(p->db->mutex) );
1109     p->rc = sqlite3ApiExit(p->db, p->rc);
1110     sqlite3_mutex_leave(p->db->mutex);
1111   }
1112 }
1113 
1114 /**************************** sqlite3_column_  *******************************
1115 ** The following routines are used to access elements of the current row
1116 ** in the result set.
1117 */
1118 const void *sqlite3_column_blob(sqlite3_stmt *pStmt, int i){
1119   const void *val;
1120   val = sqlite3_value_blob( columnMem(pStmt,i) );
1121   /* Even though there is no encoding conversion, value_blob() might
1122   ** need to call malloc() to expand the result of a zeroblob()
1123   ** expression.
1124   */
1125   columnMallocFailure(pStmt);
1126   return val;
1127 }
1128 int sqlite3_column_bytes(sqlite3_stmt *pStmt, int i){
1129   int val = sqlite3_value_bytes( columnMem(pStmt,i) );
1130   columnMallocFailure(pStmt);
1131   return val;
1132 }
1133 int sqlite3_column_bytes16(sqlite3_stmt *pStmt, int i){
1134   int val = sqlite3_value_bytes16( columnMem(pStmt,i) );
1135   columnMallocFailure(pStmt);
1136   return val;
1137 }
1138 double sqlite3_column_double(sqlite3_stmt *pStmt, int i){
1139   double val = sqlite3_value_double( columnMem(pStmt,i) );
1140   columnMallocFailure(pStmt);
1141   return val;
1142 }
1143 int sqlite3_column_int(sqlite3_stmt *pStmt, int i){
1144   int val = sqlite3_value_int( columnMem(pStmt,i) );
1145   columnMallocFailure(pStmt);
1146   return val;
1147 }
1148 sqlite_int64 sqlite3_column_int64(sqlite3_stmt *pStmt, int i){
1149   sqlite_int64 val = sqlite3_value_int64( columnMem(pStmt,i) );
1150   columnMallocFailure(pStmt);
1151   return val;
1152 }
1153 const unsigned char *sqlite3_column_text(sqlite3_stmt *pStmt, int i){
1154   const unsigned char *val = sqlite3_value_text( columnMem(pStmt,i) );
1155   columnMallocFailure(pStmt);
1156   return val;
1157 }
1158 sqlite3_value *sqlite3_column_value(sqlite3_stmt *pStmt, int i){
1159   Mem *pOut = columnMem(pStmt, i);
1160   if( pOut->flags&MEM_Static ){
1161     pOut->flags &= ~MEM_Static;
1162     pOut->flags |= MEM_Ephem;
1163   }
1164   columnMallocFailure(pStmt);
1165   return (sqlite3_value *)pOut;
1166 }
1167 #ifndef SQLITE_OMIT_UTF16
1168 const void *sqlite3_column_text16(sqlite3_stmt *pStmt, int i){
1169   const void *val = sqlite3_value_text16( columnMem(pStmt,i) );
1170   columnMallocFailure(pStmt);
1171   return val;
1172 }
1173 #endif /* SQLITE_OMIT_UTF16 */
1174 int sqlite3_column_type(sqlite3_stmt *pStmt, int i){
1175   int iType = sqlite3_value_type( columnMem(pStmt,i) );
1176   columnMallocFailure(pStmt);
1177   return iType;
1178 }
1179 
1180 /*
1181 ** Convert the N-th element of pStmt->pColName[] into a string using
1182 ** xFunc() then return that string.  If N is out of range, return 0.
1183 **
1184 ** There are up to 5 names for each column.  useType determines which
1185 ** name is returned.  Here are the names:
1186 **
1187 **    0      The column name as it should be displayed for output
1188 **    1      The datatype name for the column
1189 **    2      The name of the database that the column derives from
1190 **    3      The name of the table that the column derives from
1191 **    4      The name of the table column that the result column derives from
1192 **
1193 ** If the result is not a simple column reference (if it is an expression
1194 ** or a constant) then useTypes 2, 3, and 4 return NULL.
1195 */
1196 static const void *columnName(
1197   sqlite3_stmt *pStmt,     /* The statement */
1198   int N,                   /* Which column to get the name for */
1199   int useUtf16,            /* True to return the name as UTF16 */
1200   int useType              /* What type of name */
1201 ){
1202   const void *ret;
1203   Vdbe *p;
1204   int n;
1205   sqlite3 *db;
1206 #ifdef SQLITE_ENABLE_API_ARMOR
1207   if( pStmt==0 ){
1208     (void)SQLITE_MISUSE_BKPT;
1209     return 0;
1210   }
1211 #endif
1212   ret = 0;
1213   p = (Vdbe *)pStmt;
1214   db = p->db;
1215   assert( db!=0 );
1216   n = sqlite3_column_count(pStmt);
1217   if( N<n && N>=0 ){
1218     N += useType*n;
1219     sqlite3_mutex_enter(db->mutex);
1220     assert( db->mallocFailed==0 );
1221 #ifndef SQLITE_OMIT_UTF16
1222     if( useUtf16 ){
1223       ret = sqlite3_value_text16((sqlite3_value*)&p->aColName[N]);
1224     }else
1225 #endif
1226     {
1227       ret = sqlite3_value_text((sqlite3_value*)&p->aColName[N]);
1228     }
1229     /* A malloc may have failed inside of the _text() call. If this
1230     ** is the case, clear the mallocFailed flag and return NULL.
1231     */
1232     if( db->mallocFailed ){
1233       sqlite3OomClear(db);
1234       ret = 0;
1235     }
1236     sqlite3_mutex_leave(db->mutex);
1237   }
1238   return ret;
1239 }
1240 
1241 /*
1242 ** Return the name of the Nth column of the result set returned by SQL
1243 ** statement pStmt.
1244 */
1245 const char *sqlite3_column_name(sqlite3_stmt *pStmt, int N){
1246   return columnName(pStmt, N, 0, COLNAME_NAME);
1247 }
1248 #ifndef SQLITE_OMIT_UTF16
1249 const void *sqlite3_column_name16(sqlite3_stmt *pStmt, int N){
1250   return columnName(pStmt, N, 1, COLNAME_NAME);
1251 }
1252 #endif
1253 
1254 /*
1255 ** Constraint:  If you have ENABLE_COLUMN_METADATA then you must
1256 ** not define OMIT_DECLTYPE.
1257 */
1258 #if defined(SQLITE_OMIT_DECLTYPE) && defined(SQLITE_ENABLE_COLUMN_METADATA)
1259 # error "Must not define both SQLITE_OMIT_DECLTYPE \
1260          and SQLITE_ENABLE_COLUMN_METADATA"
1261 #endif
1262 
1263 #ifndef SQLITE_OMIT_DECLTYPE
1264 /*
1265 ** Return the column declaration type (if applicable) of the 'i'th column
1266 ** of the result set of SQL statement pStmt.
1267 */
1268 const char *sqlite3_column_decltype(sqlite3_stmt *pStmt, int N){
1269   return columnName(pStmt, N, 0, COLNAME_DECLTYPE);
1270 }
1271 #ifndef SQLITE_OMIT_UTF16
1272 const void *sqlite3_column_decltype16(sqlite3_stmt *pStmt, int N){
1273   return columnName(pStmt, N, 1, COLNAME_DECLTYPE);
1274 }
1275 #endif /* SQLITE_OMIT_UTF16 */
1276 #endif /* SQLITE_OMIT_DECLTYPE */
1277 
1278 #ifdef SQLITE_ENABLE_COLUMN_METADATA
1279 /*
1280 ** Return the name of the database from which a result column derives.
1281 ** NULL is returned if the result column is an expression or constant or
1282 ** anything else which is not an unambiguous reference to a database column.
1283 */
1284 const char *sqlite3_column_database_name(sqlite3_stmt *pStmt, int N){
1285   return columnName(pStmt, N, 0, COLNAME_DATABASE);
1286 }
1287 #ifndef SQLITE_OMIT_UTF16
1288 const void *sqlite3_column_database_name16(sqlite3_stmt *pStmt, int N){
1289   return columnName(pStmt, N, 1, COLNAME_DATABASE);
1290 }
1291 #endif /* SQLITE_OMIT_UTF16 */
1292 
1293 /*
1294 ** Return the name of the table from which a result column derives.
1295 ** NULL is returned if the result column is an expression or constant or
1296 ** anything else which is not an unambiguous reference to a database column.
1297 */
1298 const char *sqlite3_column_table_name(sqlite3_stmt *pStmt, int N){
1299   return columnName(pStmt, N, 0, COLNAME_TABLE);
1300 }
1301 #ifndef SQLITE_OMIT_UTF16
1302 const void *sqlite3_column_table_name16(sqlite3_stmt *pStmt, int N){
1303   return columnName(pStmt, N, 1, COLNAME_TABLE);
1304 }
1305 #endif /* SQLITE_OMIT_UTF16 */
1306 
1307 /*
1308 ** Return the name of the table column from which a result column derives.
1309 ** NULL is returned if the result column is an expression or constant or
1310 ** anything else which is not an unambiguous reference to a database column.
1311 */
1312 const char *sqlite3_column_origin_name(sqlite3_stmt *pStmt, int N){
1313   return columnName(pStmt, N, 0, COLNAME_COLUMN);
1314 }
1315 #ifndef SQLITE_OMIT_UTF16
1316 const void *sqlite3_column_origin_name16(sqlite3_stmt *pStmt, int N){
1317   return columnName(pStmt, N, 1, COLNAME_COLUMN);
1318 }
1319 #endif /* SQLITE_OMIT_UTF16 */
1320 #endif /* SQLITE_ENABLE_COLUMN_METADATA */
1321 
1322 
1323 /******************************* sqlite3_bind_  ***************************
1324 **
1325 ** Routines used to attach values to wildcards in a compiled SQL statement.
1326 */
1327 /*
1328 ** Unbind the value bound to variable i in virtual machine p. This is the
1329 ** the same as binding a NULL value to the column. If the "i" parameter is
1330 ** out of range, then SQLITE_RANGE is returned. Othewise SQLITE_OK.
1331 **
1332 ** A successful evaluation of this routine acquires the mutex on p.
1333 ** the mutex is released if any kind of error occurs.
1334 **
1335 ** The error code stored in database p->db is overwritten with the return
1336 ** value in any case.
1337 */
1338 static int vdbeUnbind(Vdbe *p, int i){
1339   Mem *pVar;
1340   if( vdbeSafetyNotNull(p) ){
1341     return SQLITE_MISUSE_BKPT;
1342   }
1343   sqlite3_mutex_enter(p->db->mutex);
1344   if( p->iVdbeMagic!=VDBE_MAGIC_RUN || p->pc>=0 ){
1345     sqlite3Error(p->db, SQLITE_MISUSE);
1346     sqlite3_mutex_leave(p->db->mutex);
1347     sqlite3_log(SQLITE_MISUSE,
1348         "bind on a busy prepared statement: [%s]", p->zSql);
1349     return SQLITE_MISUSE_BKPT;
1350   }
1351   if( i<1 || i>p->nVar ){
1352     sqlite3Error(p->db, SQLITE_RANGE);
1353     sqlite3_mutex_leave(p->db->mutex);
1354     return SQLITE_RANGE;
1355   }
1356   i--;
1357   pVar = &p->aVar[i];
1358   sqlite3VdbeMemRelease(pVar);
1359   pVar->flags = MEM_Null;
1360   p->db->errCode = SQLITE_OK;
1361 
1362   /* If the bit corresponding to this variable in Vdbe.expmask is set, then
1363   ** binding a new value to this variable invalidates the current query plan.
1364   **
1365   ** IMPLEMENTATION-OF: R-57496-20354 If the specific value bound to a host
1366   ** parameter in the WHERE clause might influence the choice of query plan
1367   ** for a statement, then the statement will be automatically recompiled,
1368   ** as if there had been a schema change, on the first sqlite3_step() call
1369   ** following any change to the bindings of that parameter.
1370   */
1371   assert( (p->prepFlags & SQLITE_PREPARE_SAVESQL)!=0 || p->expmask==0 );
1372   if( p->expmask!=0 && (p->expmask & (i>=31 ? 0x80000000 : (u32)1<<i))!=0 ){
1373     p->expired = 1;
1374   }
1375   return SQLITE_OK;
1376 }
1377 
1378 /*
1379 ** Bind a text or BLOB value.
1380 */
1381 static int bindText(
1382   sqlite3_stmt *pStmt,   /* The statement to bind against */
1383   int i,                 /* Index of the parameter to bind */
1384   const void *zData,     /* Pointer to the data to be bound */
1385   i64 nData,             /* Number of bytes of data to be bound */
1386   void (*xDel)(void*),   /* Destructor for the data */
1387   u8 encoding            /* Encoding for the data */
1388 ){
1389   Vdbe *p = (Vdbe *)pStmt;
1390   Mem *pVar;
1391   int rc;
1392 
1393   rc = vdbeUnbind(p, i);
1394   if( rc==SQLITE_OK ){
1395     if( zData!=0 ){
1396       pVar = &p->aVar[i-1];
1397       rc = sqlite3VdbeMemSetStr(pVar, zData, nData, encoding, xDel);
1398       if( rc==SQLITE_OK && encoding!=0 ){
1399         rc = sqlite3VdbeChangeEncoding(pVar, ENC(p->db));
1400       }
1401       if( rc ){
1402         sqlite3Error(p->db, rc);
1403         rc = sqlite3ApiExit(p->db, rc);
1404       }
1405     }
1406     sqlite3_mutex_leave(p->db->mutex);
1407   }else if( xDel!=SQLITE_STATIC && xDel!=SQLITE_TRANSIENT ){
1408     xDel((void*)zData);
1409   }
1410   return rc;
1411 }
1412 
1413 
1414 /*
1415 ** Bind a blob value to an SQL statement variable.
1416 */
1417 int sqlite3_bind_blob(
1418   sqlite3_stmt *pStmt,
1419   int i,
1420   const void *zData,
1421   int nData,
1422   void (*xDel)(void*)
1423 ){
1424 #ifdef SQLITE_ENABLE_API_ARMOR
1425   if( nData<0 ) return SQLITE_MISUSE_BKPT;
1426 #endif
1427   return bindText(pStmt, i, zData, nData, xDel, 0);
1428 }
1429 int sqlite3_bind_blob64(
1430   sqlite3_stmt *pStmt,
1431   int i,
1432   const void *zData,
1433   sqlite3_uint64 nData,
1434   void (*xDel)(void*)
1435 ){
1436   assert( xDel!=SQLITE_DYNAMIC );
1437   return bindText(pStmt, i, zData, nData, xDel, 0);
1438 }
1439 int sqlite3_bind_double(sqlite3_stmt *pStmt, int i, double rValue){
1440   int rc;
1441   Vdbe *p = (Vdbe *)pStmt;
1442   rc = vdbeUnbind(p, i);
1443   if( rc==SQLITE_OK ){
1444     sqlite3VdbeMemSetDouble(&p->aVar[i-1], rValue);
1445     sqlite3_mutex_leave(p->db->mutex);
1446   }
1447   return rc;
1448 }
1449 int sqlite3_bind_int(sqlite3_stmt *p, int i, int iValue){
1450   return sqlite3_bind_int64(p, i, (i64)iValue);
1451 }
1452 int sqlite3_bind_int64(sqlite3_stmt *pStmt, int i, sqlite_int64 iValue){
1453   int rc;
1454   Vdbe *p = (Vdbe *)pStmt;
1455   rc = vdbeUnbind(p, i);
1456   if( rc==SQLITE_OK ){
1457     sqlite3VdbeMemSetInt64(&p->aVar[i-1], iValue);
1458     sqlite3_mutex_leave(p->db->mutex);
1459   }
1460   return rc;
1461 }
1462 int sqlite3_bind_null(sqlite3_stmt *pStmt, int i){
1463   int rc;
1464   Vdbe *p = (Vdbe*)pStmt;
1465   rc = vdbeUnbind(p, i);
1466   if( rc==SQLITE_OK ){
1467     sqlite3_mutex_leave(p->db->mutex);
1468   }
1469   return rc;
1470 }
1471 int sqlite3_bind_pointer(
1472   sqlite3_stmt *pStmt,
1473   int i,
1474   void *pPtr,
1475   const char *zPTtype,
1476   void (*xDestructor)(void*)
1477 ){
1478   int rc;
1479   Vdbe *p = (Vdbe*)pStmt;
1480   rc = vdbeUnbind(p, i);
1481   if( rc==SQLITE_OK ){
1482     sqlite3VdbeMemSetPointer(&p->aVar[i-1], pPtr, zPTtype, xDestructor);
1483     sqlite3_mutex_leave(p->db->mutex);
1484   }else if( xDestructor ){
1485     xDestructor(pPtr);
1486   }
1487   return rc;
1488 }
1489 int sqlite3_bind_text(
1490   sqlite3_stmt *pStmt,
1491   int i,
1492   const char *zData,
1493   int nData,
1494   void (*xDel)(void*)
1495 ){
1496   return bindText(pStmt, i, zData, nData, xDel, SQLITE_UTF8);
1497 }
1498 int sqlite3_bind_text64(
1499   sqlite3_stmt *pStmt,
1500   int i,
1501   const char *zData,
1502   sqlite3_uint64 nData,
1503   void (*xDel)(void*),
1504   unsigned char enc
1505 ){
1506   assert( xDel!=SQLITE_DYNAMIC );
1507   if( enc==SQLITE_UTF16 ) enc = SQLITE_UTF16NATIVE;
1508   return bindText(pStmt, i, zData, nData, xDel, enc);
1509 }
1510 #ifndef SQLITE_OMIT_UTF16
1511 int sqlite3_bind_text16(
1512   sqlite3_stmt *pStmt,
1513   int i,
1514   const void *zData,
1515   int nData,
1516   void (*xDel)(void*)
1517 ){
1518   return bindText(pStmt, i, zData, nData, xDel, SQLITE_UTF16NATIVE);
1519 }
1520 #endif /* SQLITE_OMIT_UTF16 */
1521 int sqlite3_bind_value(sqlite3_stmt *pStmt, int i, const sqlite3_value *pValue){
1522   int rc;
1523   switch( sqlite3_value_type((sqlite3_value*)pValue) ){
1524     case SQLITE_INTEGER: {
1525       rc = sqlite3_bind_int64(pStmt, i, pValue->u.i);
1526       break;
1527     }
1528     case SQLITE_FLOAT: {
1529       rc = sqlite3_bind_double(pStmt, i, pValue->u.r);
1530       break;
1531     }
1532     case SQLITE_BLOB: {
1533       if( pValue->flags & MEM_Zero ){
1534         rc = sqlite3_bind_zeroblob(pStmt, i, pValue->u.nZero);
1535       }else{
1536         rc = sqlite3_bind_blob(pStmt, i, pValue->z, pValue->n,SQLITE_TRANSIENT);
1537       }
1538       break;
1539     }
1540     case SQLITE_TEXT: {
1541       rc = bindText(pStmt,i,  pValue->z, pValue->n, SQLITE_TRANSIENT,
1542                               pValue->enc);
1543       break;
1544     }
1545     default: {
1546       rc = sqlite3_bind_null(pStmt, i);
1547       break;
1548     }
1549   }
1550   return rc;
1551 }
1552 int sqlite3_bind_zeroblob(sqlite3_stmt *pStmt, int i, int n){
1553   int rc;
1554   Vdbe *p = (Vdbe *)pStmt;
1555   rc = vdbeUnbind(p, i);
1556   if( rc==SQLITE_OK ){
1557     sqlite3VdbeMemSetZeroBlob(&p->aVar[i-1], n);
1558     sqlite3_mutex_leave(p->db->mutex);
1559   }
1560   return rc;
1561 }
1562 int sqlite3_bind_zeroblob64(sqlite3_stmt *pStmt, int i, sqlite3_uint64 n){
1563   int rc;
1564   Vdbe *p = (Vdbe *)pStmt;
1565   sqlite3_mutex_enter(p->db->mutex);
1566   if( n>(u64)p->db->aLimit[SQLITE_LIMIT_LENGTH] ){
1567     rc = SQLITE_TOOBIG;
1568   }else{
1569     assert( (n & 0x7FFFFFFF)==n );
1570     rc = sqlite3_bind_zeroblob(pStmt, i, n);
1571   }
1572   rc = sqlite3ApiExit(p->db, rc);
1573   sqlite3_mutex_leave(p->db->mutex);
1574   return rc;
1575 }
1576 
1577 /*
1578 ** Return the number of wildcards that can be potentially bound to.
1579 ** This routine is added to support DBD::SQLite.
1580 */
1581 int sqlite3_bind_parameter_count(sqlite3_stmt *pStmt){
1582   Vdbe *p = (Vdbe*)pStmt;
1583   return p ? p->nVar : 0;
1584 }
1585 
1586 /*
1587 ** Return the name of a wildcard parameter.  Return NULL if the index
1588 ** is out of range or if the wildcard is unnamed.
1589 **
1590 ** The result is always UTF-8.
1591 */
1592 const char *sqlite3_bind_parameter_name(sqlite3_stmt *pStmt, int i){
1593   Vdbe *p = (Vdbe*)pStmt;
1594   if( p==0 ) return 0;
1595   return sqlite3VListNumToName(p->pVList, i);
1596 }
1597 
1598 /*
1599 ** Given a wildcard parameter name, return the index of the variable
1600 ** with that name.  If there is no variable with the given name,
1601 ** return 0.
1602 */
1603 int sqlite3VdbeParameterIndex(Vdbe *p, const char *zName, int nName){
1604   if( p==0 || zName==0 ) return 0;
1605   return sqlite3VListNameToNum(p->pVList, zName, nName);
1606 }
1607 int sqlite3_bind_parameter_index(sqlite3_stmt *pStmt, const char *zName){
1608   return sqlite3VdbeParameterIndex((Vdbe*)pStmt, zName, sqlite3Strlen30(zName));
1609 }
1610 
1611 /*
1612 ** Transfer all bindings from the first statement over to the second.
1613 */
1614 int sqlite3TransferBindings(sqlite3_stmt *pFromStmt, sqlite3_stmt *pToStmt){
1615   Vdbe *pFrom = (Vdbe*)pFromStmt;
1616   Vdbe *pTo = (Vdbe*)pToStmt;
1617   int i;
1618   assert( pTo->db==pFrom->db );
1619   assert( pTo->nVar==pFrom->nVar );
1620   sqlite3_mutex_enter(pTo->db->mutex);
1621   for(i=0; i<pFrom->nVar; i++){
1622     sqlite3VdbeMemMove(&pTo->aVar[i], &pFrom->aVar[i]);
1623   }
1624   sqlite3_mutex_leave(pTo->db->mutex);
1625   return SQLITE_OK;
1626 }
1627 
1628 #ifndef SQLITE_OMIT_DEPRECATED
1629 /*
1630 ** Deprecated external interface.  Internal/core SQLite code
1631 ** should call sqlite3TransferBindings.
1632 **
1633 ** It is misuse to call this routine with statements from different
1634 ** database connections.  But as this is a deprecated interface, we
1635 ** will not bother to check for that condition.
1636 **
1637 ** If the two statements contain a different number of bindings, then
1638 ** an SQLITE_ERROR is returned.  Nothing else can go wrong, so otherwise
1639 ** SQLITE_OK is returned.
1640 */
1641 int sqlite3_transfer_bindings(sqlite3_stmt *pFromStmt, sqlite3_stmt *pToStmt){
1642   Vdbe *pFrom = (Vdbe*)pFromStmt;
1643   Vdbe *pTo = (Vdbe*)pToStmt;
1644   if( pFrom->nVar!=pTo->nVar ){
1645     return SQLITE_ERROR;
1646   }
1647   assert( (pTo->prepFlags & SQLITE_PREPARE_SAVESQL)!=0 || pTo->expmask==0 );
1648   if( pTo->expmask ){
1649     pTo->expired = 1;
1650   }
1651   assert( (pFrom->prepFlags & SQLITE_PREPARE_SAVESQL)!=0 || pFrom->expmask==0 );
1652   if( pFrom->expmask ){
1653     pFrom->expired = 1;
1654   }
1655   return sqlite3TransferBindings(pFromStmt, pToStmt);
1656 }
1657 #endif
1658 
1659 /*
1660 ** Return the sqlite3* database handle to which the prepared statement given
1661 ** in the argument belongs.  This is the same database handle that was
1662 ** the first argument to the sqlite3_prepare() that was used to create
1663 ** the statement in the first place.
1664 */
1665 sqlite3 *sqlite3_db_handle(sqlite3_stmt *pStmt){
1666   return pStmt ? ((Vdbe*)pStmt)->db : 0;
1667 }
1668 
1669 /*
1670 ** Return true if the prepared statement is guaranteed to not modify the
1671 ** database.
1672 */
1673 int sqlite3_stmt_readonly(sqlite3_stmt *pStmt){
1674   return pStmt ? ((Vdbe*)pStmt)->readOnly : 1;
1675 }
1676 
1677 /*
1678 ** Return 1 if the statement is an EXPLAIN and return 2 if the
1679 ** statement is an EXPLAIN QUERY PLAN
1680 */
1681 int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt){
1682   return pStmt ? ((Vdbe*)pStmt)->explain : 0;
1683 }
1684 
1685 /*
1686 ** Return true if the prepared statement is in need of being reset.
1687 */
1688 int sqlite3_stmt_busy(sqlite3_stmt *pStmt){
1689   Vdbe *v = (Vdbe*)pStmt;
1690   return v!=0 && v->iVdbeMagic==VDBE_MAGIC_RUN && v->pc>=0;
1691 }
1692 
1693 /*
1694 ** Return a pointer to the next prepared statement after pStmt associated
1695 ** with database connection pDb.  If pStmt is NULL, return the first
1696 ** prepared statement for the database connection.  Return NULL if there
1697 ** are no more.
1698 */
1699 sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt){
1700   sqlite3_stmt *pNext;
1701 #ifdef SQLITE_ENABLE_API_ARMOR
1702   if( !sqlite3SafetyCheckOk(pDb) ){
1703     (void)SQLITE_MISUSE_BKPT;
1704     return 0;
1705   }
1706 #endif
1707   sqlite3_mutex_enter(pDb->mutex);
1708   if( pStmt==0 ){
1709     pNext = (sqlite3_stmt*)pDb->pVdbe;
1710   }else{
1711     pNext = (sqlite3_stmt*)((Vdbe*)pStmt)->pNext;
1712   }
1713   sqlite3_mutex_leave(pDb->mutex);
1714   return pNext;
1715 }
1716 
1717 /*
1718 ** Return the value of a status counter for a prepared statement
1719 */
1720 int sqlite3_stmt_status(sqlite3_stmt *pStmt, int op, int resetFlag){
1721   Vdbe *pVdbe = (Vdbe*)pStmt;
1722   u32 v;
1723 #ifdef SQLITE_ENABLE_API_ARMOR
1724   if( !pStmt
1725    || (op!=SQLITE_STMTSTATUS_MEMUSED && (op<0||op>=ArraySize(pVdbe->aCounter)))
1726   ){
1727     (void)SQLITE_MISUSE_BKPT;
1728     return 0;
1729   }
1730 #endif
1731   if( op==SQLITE_STMTSTATUS_MEMUSED ){
1732     sqlite3 *db = pVdbe->db;
1733     sqlite3_mutex_enter(db->mutex);
1734     v = 0;
1735     db->pnBytesFreed = (int*)&v;
1736     sqlite3VdbeClearObject(db, pVdbe);
1737     sqlite3DbFree(db, pVdbe);
1738     db->pnBytesFreed = 0;
1739     sqlite3_mutex_leave(db->mutex);
1740   }else{
1741     v = pVdbe->aCounter[op];
1742     if( resetFlag ) pVdbe->aCounter[op] = 0;
1743   }
1744   return (int)v;
1745 }
1746 
1747 /*
1748 ** Return the SQL associated with a prepared statement
1749 */
1750 const char *sqlite3_sql(sqlite3_stmt *pStmt){
1751   Vdbe *p = (Vdbe *)pStmt;
1752   return p ? p->zSql : 0;
1753 }
1754 
1755 /*
1756 ** Return the SQL associated with a prepared statement with
1757 ** bound parameters expanded.  Space to hold the returned string is
1758 ** obtained from sqlite3_malloc().  The caller is responsible for
1759 ** freeing the returned string by passing it to sqlite3_free().
1760 **
1761 ** The SQLITE_TRACE_SIZE_LIMIT puts an upper bound on the size of
1762 ** expanded bound parameters.
1763 */
1764 char *sqlite3_expanded_sql(sqlite3_stmt *pStmt){
1765 #ifdef SQLITE_OMIT_TRACE
1766   return 0;
1767 #else
1768   char *z = 0;
1769   const char *zSql = sqlite3_sql(pStmt);
1770   if( zSql ){
1771     Vdbe *p = (Vdbe *)pStmt;
1772     sqlite3_mutex_enter(p->db->mutex);
1773     z = sqlite3VdbeExpandSql(p, zSql);
1774     sqlite3_mutex_leave(p->db->mutex);
1775   }
1776   return z;
1777 #endif
1778 }
1779 
1780 #ifdef SQLITE_ENABLE_NORMALIZE
1781 /*
1782 ** Return the normalized SQL associated with a prepared statement.
1783 */
1784 const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt){
1785   Vdbe *p = (Vdbe *)pStmt;
1786   if( p==0 ) return 0;
1787   if( p->zNormSql==0 && ALWAYS(p->zSql!=0) ){
1788     sqlite3_mutex_enter(p->db->mutex);
1789     p->zNormSql = sqlite3Normalize(p, p->zSql);
1790     sqlite3_mutex_leave(p->db->mutex);
1791   }
1792   return p->zNormSql;
1793 }
1794 #endif /* SQLITE_ENABLE_NORMALIZE */
1795 
1796 #ifdef SQLITE_ENABLE_PREUPDATE_HOOK
1797 /*
1798 ** Allocate and populate an UnpackedRecord structure based on the serialized
1799 ** record in nKey/pKey. Return a pointer to the new UnpackedRecord structure
1800 ** if successful, or a NULL pointer if an OOM error is encountered.
1801 */
1802 static UnpackedRecord *vdbeUnpackRecord(
1803   KeyInfo *pKeyInfo,
1804   int nKey,
1805   const void *pKey
1806 ){
1807   UnpackedRecord *pRet;           /* Return value */
1808 
1809   pRet = sqlite3VdbeAllocUnpackedRecord(pKeyInfo);
1810   if( pRet ){
1811     memset(pRet->aMem, 0, sizeof(Mem)*(pKeyInfo->nKeyField+1));
1812     sqlite3VdbeRecordUnpack(pKeyInfo, nKey, pKey, pRet);
1813   }
1814   return pRet;
1815 }
1816 
1817 /*
1818 ** This function is called from within a pre-update callback to retrieve
1819 ** a field of the row currently being updated or deleted.
1820 */
1821 int sqlite3_preupdate_old(sqlite3 *db, int iIdx, sqlite3_value **ppValue){
1822   PreUpdate *p = db->pPreUpdate;
1823   Mem *pMem;
1824   int rc = SQLITE_OK;
1825 
1826   /* Test that this call is being made from within an SQLITE_DELETE or
1827   ** SQLITE_UPDATE pre-update callback, and that iIdx is within range. */
1828   if( !p || p->op==SQLITE_INSERT ){
1829     rc = SQLITE_MISUSE_BKPT;
1830     goto preupdate_old_out;
1831   }
1832   if( p->pPk ){
1833     iIdx = sqlite3TableColumnToIndex(p->pPk, iIdx);
1834   }
1835   if( iIdx>=p->pCsr->nField || iIdx<0 ){
1836     rc = SQLITE_RANGE;
1837     goto preupdate_old_out;
1838   }
1839 
1840   /* If the old.* record has not yet been loaded into memory, do so now. */
1841   if( p->pUnpacked==0 ){
1842     u32 nRec;
1843     u8 *aRec;
1844 
1845     nRec = sqlite3BtreePayloadSize(p->pCsr->uc.pCursor);
1846     aRec = sqlite3DbMallocRaw(db, nRec);
1847     if( !aRec ) goto preupdate_old_out;
1848     rc = sqlite3BtreePayload(p->pCsr->uc.pCursor, 0, nRec, aRec);
1849     if( rc==SQLITE_OK ){
1850       p->pUnpacked = vdbeUnpackRecord(&p->keyinfo, nRec, aRec);
1851       if( !p->pUnpacked ) rc = SQLITE_NOMEM;
1852     }
1853     if( rc!=SQLITE_OK ){
1854       sqlite3DbFree(db, aRec);
1855       goto preupdate_old_out;
1856     }
1857     p->aRecord = aRec;
1858   }
1859 
1860   pMem = *ppValue = &p->pUnpacked->aMem[iIdx];
1861   if( iIdx==p->pTab->iPKey ){
1862     sqlite3VdbeMemSetInt64(pMem, p->iKey1);
1863   }else if( iIdx>=p->pUnpacked->nField ){
1864     *ppValue = (sqlite3_value *)columnNullValue();
1865   }else if( p->pTab->aCol[iIdx].affinity==SQLITE_AFF_REAL ){
1866     if( pMem->flags & (MEM_Int|MEM_IntReal) ){
1867       testcase( pMem->flags & MEM_Int );
1868       testcase( pMem->flags & MEM_IntReal );
1869       sqlite3VdbeMemRealify(pMem);
1870     }
1871   }
1872 
1873  preupdate_old_out:
1874   sqlite3Error(db, rc);
1875   return sqlite3ApiExit(db, rc);
1876 }
1877 #endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
1878 
1879 #ifdef SQLITE_ENABLE_PREUPDATE_HOOK
1880 /*
1881 ** This function is called from within a pre-update callback to retrieve
1882 ** the number of columns in the row being updated, deleted or inserted.
1883 */
1884 int sqlite3_preupdate_count(sqlite3 *db){
1885   PreUpdate *p = db->pPreUpdate;
1886   return (p ? p->keyinfo.nKeyField : 0);
1887 }
1888 #endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
1889 
1890 #ifdef SQLITE_ENABLE_PREUPDATE_HOOK
1891 /*
1892 ** This function is designed to be called from within a pre-update callback
1893 ** only. It returns zero if the change that caused the callback was made
1894 ** immediately by a user SQL statement. Or, if the change was made by a
1895 ** trigger program, it returns the number of trigger programs currently
1896 ** on the stack (1 for a top-level trigger, 2 for a trigger fired by a
1897 ** top-level trigger etc.).
1898 **
1899 ** For the purposes of the previous paragraph, a foreign key CASCADE, SET NULL
1900 ** or SET DEFAULT action is considered a trigger.
1901 */
1902 int sqlite3_preupdate_depth(sqlite3 *db){
1903   PreUpdate *p = db->pPreUpdate;
1904   return (p ? p->v->nFrame : 0);
1905 }
1906 #endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
1907 
1908 #ifdef SQLITE_ENABLE_PREUPDATE_HOOK
1909 /*
1910 ** This function is designed to be called from within a pre-update callback
1911 ** only.
1912 */
1913 int sqlite3_preupdate_blobwrite(sqlite3 *db){
1914   PreUpdate *p = db->pPreUpdate;
1915   return (p ? p->iBlobWrite : -1);
1916 }
1917 #endif
1918 
1919 #ifdef SQLITE_ENABLE_PREUPDATE_HOOK
1920 /*
1921 ** This function is called from within a pre-update callback to retrieve
1922 ** a field of the row currently being updated or inserted.
1923 */
1924 int sqlite3_preupdate_new(sqlite3 *db, int iIdx, sqlite3_value **ppValue){
1925   PreUpdate *p = db->pPreUpdate;
1926   int rc = SQLITE_OK;
1927   Mem *pMem;
1928 
1929   if( !p || p->op==SQLITE_DELETE ){
1930     rc = SQLITE_MISUSE_BKPT;
1931     goto preupdate_new_out;
1932   }
1933   if( p->pPk && p->op!=SQLITE_UPDATE ){
1934     iIdx = sqlite3TableColumnToIndex(p->pPk, iIdx);
1935   }
1936   if( iIdx>=p->pCsr->nField || iIdx<0 ){
1937     rc = SQLITE_RANGE;
1938     goto preupdate_new_out;
1939   }
1940 
1941   if( p->op==SQLITE_INSERT ){
1942     /* For an INSERT, memory cell p->iNewReg contains the serialized record
1943     ** that is being inserted. Deserialize it. */
1944     UnpackedRecord *pUnpack = p->pNewUnpacked;
1945     if( !pUnpack ){
1946       Mem *pData = &p->v->aMem[p->iNewReg];
1947       rc = ExpandBlob(pData);
1948       if( rc!=SQLITE_OK ) goto preupdate_new_out;
1949       pUnpack = vdbeUnpackRecord(&p->keyinfo, pData->n, pData->z);
1950       if( !pUnpack ){
1951         rc = SQLITE_NOMEM;
1952         goto preupdate_new_out;
1953       }
1954       p->pNewUnpacked = pUnpack;
1955     }
1956     pMem = &pUnpack->aMem[iIdx];
1957     if( iIdx==p->pTab->iPKey ){
1958       sqlite3VdbeMemSetInt64(pMem, p->iKey2);
1959     }else if( iIdx>=pUnpack->nField ){
1960       pMem = (sqlite3_value *)columnNullValue();
1961     }
1962   }else{
1963     /* For an UPDATE, memory cell (p->iNewReg+1+iIdx) contains the required
1964     ** value. Make a copy of the cell contents and return a pointer to it.
1965     ** It is not safe to return a pointer to the memory cell itself as the
1966     ** caller may modify the value text encoding.
1967     */
1968     assert( p->op==SQLITE_UPDATE );
1969     if( !p->aNew ){
1970       p->aNew = (Mem *)sqlite3DbMallocZero(db, sizeof(Mem) * p->pCsr->nField);
1971       if( !p->aNew ){
1972         rc = SQLITE_NOMEM;
1973         goto preupdate_new_out;
1974       }
1975     }
1976     assert( iIdx>=0 && iIdx<p->pCsr->nField );
1977     pMem = &p->aNew[iIdx];
1978     if( pMem->flags==0 ){
1979       if( iIdx==p->pTab->iPKey ){
1980         sqlite3VdbeMemSetInt64(pMem, p->iKey2);
1981       }else{
1982         rc = sqlite3VdbeMemCopy(pMem, &p->v->aMem[p->iNewReg+1+iIdx]);
1983         if( rc!=SQLITE_OK ) goto preupdate_new_out;
1984       }
1985     }
1986   }
1987   *ppValue = pMem;
1988 
1989  preupdate_new_out:
1990   sqlite3Error(db, rc);
1991   return sqlite3ApiExit(db, rc);
1992 }
1993 #endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
1994 
1995 #ifdef SQLITE_ENABLE_STMT_SCANSTATUS
1996 /*
1997 ** Return status data for a single loop within query pStmt.
1998 */
1999 int sqlite3_stmt_scanstatus(
2000   sqlite3_stmt *pStmt,            /* Prepared statement being queried */
2001   int idx,                        /* Index of loop to report on */
2002   int iScanStatusOp,              /* Which metric to return */
2003   void *pOut                      /* OUT: Write the answer here */
2004 ){
2005   Vdbe *p = (Vdbe*)pStmt;
2006   ScanStatus *pScan;
2007   if( idx<0 || idx>=p->nScan ) return 1;
2008   pScan = &p->aScan[idx];
2009   switch( iScanStatusOp ){
2010     case SQLITE_SCANSTAT_NLOOP: {
2011       *(sqlite3_int64*)pOut = p->anExec[pScan->addrLoop];
2012       break;
2013     }
2014     case SQLITE_SCANSTAT_NVISIT: {
2015       *(sqlite3_int64*)pOut = p->anExec[pScan->addrVisit];
2016       break;
2017     }
2018     case SQLITE_SCANSTAT_EST: {
2019       double r = 1.0;
2020       LogEst x = pScan->nEst;
2021       while( x<100 ){
2022         x += 10;
2023         r *= 0.5;
2024       }
2025       *(double*)pOut = r*sqlite3LogEstToInt(x);
2026       break;
2027     }
2028     case SQLITE_SCANSTAT_NAME: {
2029       *(const char**)pOut = pScan->zName;
2030       break;
2031     }
2032     case SQLITE_SCANSTAT_EXPLAIN: {
2033       if( pScan->addrExplain ){
2034         *(const char**)pOut = p->aOp[ pScan->addrExplain ].p4.z;
2035       }else{
2036         *(const char**)pOut = 0;
2037       }
2038       break;
2039     }
2040     case SQLITE_SCANSTAT_SELECTID: {
2041       if( pScan->addrExplain ){
2042         *(int*)pOut = p->aOp[ pScan->addrExplain ].p1;
2043       }else{
2044         *(int*)pOut = -1;
2045       }
2046       break;
2047     }
2048     default: {
2049       return 1;
2050     }
2051   }
2052   return 0;
2053 }
2054 
2055 /*
2056 ** Zero all counters associated with the sqlite3_stmt_scanstatus() data.
2057 */
2058 void sqlite3_stmt_scanstatus_reset(sqlite3_stmt *pStmt){
2059   Vdbe *p = (Vdbe*)pStmt;
2060   memset(p->anExec, 0, p->nOp * sizeof(i64));
2061 }
2062 #endif /* SQLITE_ENABLE_STMT_SCANSTATUS */
2063