xref: /sqlite-3.40.0/src/vdbeapi.c (revision a24832b7)
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   }else if( pNew->flags & MEM_Null ){
349     /* Do not duplicate pointer values */
350     pNew->flags &= ~(MEM_Term|MEM_Subtype);
351   }
352   return pNew;
353 }
354 
355 /* Destroy an sqlite3_value object previously obtained from
356 ** sqlite3_value_dup().
357 */
358 void sqlite3_value_free(sqlite3_value *pOld){
359   sqlite3ValueFree(pOld);
360 }
361 
362 
363 /**************************** sqlite3_result_  *******************************
364 ** The following routines are used by user-defined functions to specify
365 ** the function result.
366 **
367 ** The setStrOrError() function calls sqlite3VdbeMemSetStr() to store the
368 ** result as a string or blob.  Appropriate errors are set if the string/blob
369 ** is too big or if an OOM occurs.
370 **
371 ** The invokeValueDestructor(P,X) routine invokes destructor function X()
372 ** on value P is not going to be used and need to be destroyed.
373 */
374 static void setResultStrOrError(
375   sqlite3_context *pCtx,  /* Function context */
376   const char *z,          /* String pointer */
377   int n,                  /* Bytes in string, or negative */
378   u8 enc,                 /* Encoding of z.  0 for BLOBs */
379   void (*xDel)(void*)     /* Destructor function */
380 ){
381   Mem *pOut = pCtx->pOut;
382   int rc = sqlite3VdbeMemSetStr(pOut, z, n, enc, xDel);
383   if( rc ){
384     if( rc==SQLITE_TOOBIG ){
385       sqlite3_result_error_toobig(pCtx);
386     }else{
387       /* The only errors possible from sqlite3VdbeMemSetStr are
388       ** SQLITE_TOOBIG and SQLITE_NOMEM */
389       assert( rc==SQLITE_NOMEM );
390       sqlite3_result_error_nomem(pCtx);
391     }
392     return;
393   }
394   sqlite3VdbeChangeEncoding(pOut, pCtx->enc);
395   if( sqlite3VdbeMemTooBig(pOut) ){
396     sqlite3_result_error_toobig(pCtx);
397   }
398 }
399 static int invokeValueDestructor(
400   const void *p,             /* Value to destroy */
401   void (*xDel)(void*),       /* The destructor */
402   sqlite3_context *pCtx      /* Set a SQLITE_TOOBIG error if no NULL */
403 ){
404   assert( xDel!=SQLITE_DYNAMIC );
405   if( xDel==0 ){
406     /* noop */
407   }else if( xDel==SQLITE_TRANSIENT ){
408     /* noop */
409   }else{
410     xDel((void*)p);
411   }
412   sqlite3_result_error_toobig(pCtx);
413   return SQLITE_TOOBIG;
414 }
415 void sqlite3_result_blob(
416   sqlite3_context *pCtx,
417   const void *z,
418   int n,
419   void (*xDel)(void *)
420 ){
421   assert( n>=0 );
422   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
423   setResultStrOrError(pCtx, z, n, 0, xDel);
424 }
425 void sqlite3_result_blob64(
426   sqlite3_context *pCtx,
427   const void *z,
428   sqlite3_uint64 n,
429   void (*xDel)(void *)
430 ){
431   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
432   assert( xDel!=SQLITE_DYNAMIC );
433   if( n>0x7fffffff ){
434     (void)invokeValueDestructor(z, xDel, pCtx);
435   }else{
436     setResultStrOrError(pCtx, z, (int)n, 0, xDel);
437   }
438 }
439 void sqlite3_result_double(sqlite3_context *pCtx, double rVal){
440   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
441   sqlite3VdbeMemSetDouble(pCtx->pOut, rVal);
442 }
443 void sqlite3_result_error(sqlite3_context *pCtx, const char *z, int n){
444   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
445   pCtx->isError = SQLITE_ERROR;
446   sqlite3VdbeMemSetStr(pCtx->pOut, z, n, SQLITE_UTF8, SQLITE_TRANSIENT);
447 }
448 #ifndef SQLITE_OMIT_UTF16
449 void sqlite3_result_error16(sqlite3_context *pCtx, const void *z, int n){
450   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
451   pCtx->isError = SQLITE_ERROR;
452   sqlite3VdbeMemSetStr(pCtx->pOut, z, n, SQLITE_UTF16NATIVE, SQLITE_TRANSIENT);
453 }
454 #endif
455 void sqlite3_result_int(sqlite3_context *pCtx, int iVal){
456   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
457   sqlite3VdbeMemSetInt64(pCtx->pOut, (i64)iVal);
458 }
459 void sqlite3_result_int64(sqlite3_context *pCtx, i64 iVal){
460   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
461   sqlite3VdbeMemSetInt64(pCtx->pOut, iVal);
462 }
463 void sqlite3_result_null(sqlite3_context *pCtx){
464   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
465   sqlite3VdbeMemSetNull(pCtx->pOut);
466 }
467 void sqlite3_result_pointer(
468   sqlite3_context *pCtx,
469   void *pPtr,
470   const char *zPType,
471   void (*xDestructor)(void*)
472 ){
473   Mem *pOut = pCtx->pOut;
474   assert( sqlite3_mutex_held(pOut->db->mutex) );
475   sqlite3VdbeMemRelease(pOut);
476   pOut->flags = MEM_Null;
477   sqlite3VdbeMemSetPointer(pOut, pPtr, zPType, xDestructor);
478 }
479 void sqlite3_result_subtype(sqlite3_context *pCtx, unsigned int eSubtype){
480   Mem *pOut = pCtx->pOut;
481   assert( sqlite3_mutex_held(pOut->db->mutex) );
482   pOut->eSubtype = eSubtype & 0xff;
483   pOut->flags |= MEM_Subtype;
484 }
485 void sqlite3_result_text(
486   sqlite3_context *pCtx,
487   const char *z,
488   int n,
489   void (*xDel)(void *)
490 ){
491   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
492   setResultStrOrError(pCtx, z, n, SQLITE_UTF8, xDel);
493 }
494 void sqlite3_result_text64(
495   sqlite3_context *pCtx,
496   const char *z,
497   sqlite3_uint64 n,
498   void (*xDel)(void *),
499   unsigned char enc
500 ){
501   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
502   assert( xDel!=SQLITE_DYNAMIC );
503   if( enc==SQLITE_UTF16 ) enc = SQLITE_UTF16NATIVE;
504   if( n>0x7fffffff ){
505     (void)invokeValueDestructor(z, xDel, pCtx);
506   }else{
507     setResultStrOrError(pCtx, z, (int)n, enc, xDel);
508   }
509 }
510 #ifndef SQLITE_OMIT_UTF16
511 void sqlite3_result_text16(
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_UTF16NATIVE, xDel);
519 }
520 void sqlite3_result_text16be(
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_UTF16BE, xDel);
528 }
529 void sqlite3_result_text16le(
530   sqlite3_context *pCtx,
531   const void *z,
532   int n,
533   void (*xDel)(void *)
534 ){
535   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
536   setResultStrOrError(pCtx, z, n, SQLITE_UTF16LE, xDel);
537 }
538 #endif /* SQLITE_OMIT_UTF16 */
539 void sqlite3_result_value(sqlite3_context *pCtx, sqlite3_value *pValue){
540   Mem *pOut = pCtx->pOut;
541   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
542   sqlite3VdbeMemCopy(pOut, pValue);
543   sqlite3VdbeChangeEncoding(pOut, pCtx->enc);
544   if( sqlite3VdbeMemTooBig(pOut) ){
545     sqlite3_result_error_toobig(pCtx);
546   }
547 }
548 void sqlite3_result_zeroblob(sqlite3_context *pCtx, int n){
549   sqlite3_result_zeroblob64(pCtx, n>0 ? n : 0);
550 }
551 int sqlite3_result_zeroblob64(sqlite3_context *pCtx, u64 n){
552   Mem *pOut = pCtx->pOut;
553   assert( sqlite3_mutex_held(pOut->db->mutex) );
554   if( n>(u64)pOut->db->aLimit[SQLITE_LIMIT_LENGTH] ){
555     sqlite3_result_error_toobig(pCtx);
556     return SQLITE_TOOBIG;
557   }
558 #ifndef SQLITE_OMIT_INCRBLOB
559   sqlite3VdbeMemSetZeroBlob(pCtx->pOut, (int)n);
560   return SQLITE_OK;
561 #else
562   return sqlite3VdbeMemSetZeroBlob(pCtx->pOut, (int)n);
563 #endif
564 }
565 void sqlite3_result_error_code(sqlite3_context *pCtx, int errCode){
566   pCtx->isError = errCode ? errCode : -1;
567 #ifdef SQLITE_DEBUG
568   if( pCtx->pVdbe ) pCtx->pVdbe->rcApp = errCode;
569 #endif
570   if( pCtx->pOut->flags & MEM_Null ){
571     setResultStrOrError(pCtx, sqlite3ErrStr(errCode), -1, SQLITE_UTF8,
572                         SQLITE_STATIC);
573   }
574 }
575 
576 /* Force an SQLITE_TOOBIG error. */
577 void sqlite3_result_error_toobig(sqlite3_context *pCtx){
578   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
579   pCtx->isError = SQLITE_TOOBIG;
580   sqlite3VdbeMemSetStr(pCtx->pOut, "string or blob too big", -1,
581                        SQLITE_UTF8, SQLITE_STATIC);
582 }
583 
584 /* An SQLITE_NOMEM error. */
585 void sqlite3_result_error_nomem(sqlite3_context *pCtx){
586   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
587   sqlite3VdbeMemSetNull(pCtx->pOut);
588   pCtx->isError = SQLITE_NOMEM_BKPT;
589   sqlite3OomFault(pCtx->pOut->db);
590 }
591 
592 #ifndef SQLITE_UNTESTABLE
593 /* Force the INT64 value currently stored as the result to be
594 ** a MEM_IntReal value.  See the SQLITE_TESTCTRL_RESULT_INTREAL
595 ** test-control.
596 */
597 void sqlite3ResultIntReal(sqlite3_context *pCtx){
598   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
599   if( pCtx->pOut->flags & MEM_Int ){
600     pCtx->pOut->flags &= ~MEM_Int;
601     pCtx->pOut->flags |= MEM_IntReal;
602   }
603 }
604 #endif
605 
606 
607 /*
608 ** This function is called after a transaction has been committed. It
609 ** invokes callbacks registered with sqlite3_wal_hook() as required.
610 */
611 static int doWalCallbacks(sqlite3 *db){
612   int rc = SQLITE_OK;
613 #ifndef SQLITE_OMIT_WAL
614   int i;
615   for(i=0; i<db->nDb; i++){
616     Btree *pBt = db->aDb[i].pBt;
617     if( pBt ){
618       int nEntry;
619       sqlite3BtreeEnter(pBt);
620       nEntry = sqlite3PagerWalCallback(sqlite3BtreePager(pBt));
621       sqlite3BtreeLeave(pBt);
622       if( nEntry>0 && db->xWalCallback && rc==SQLITE_OK ){
623         rc = db->xWalCallback(db->pWalArg, db, db->aDb[i].zDbSName, nEntry);
624       }
625     }
626   }
627 #endif
628   return rc;
629 }
630 
631 
632 /*
633 ** Execute the statement pStmt, either until a row of data is ready, the
634 ** statement is completely executed or an error occurs.
635 **
636 ** This routine implements the bulk of the logic behind the sqlite_step()
637 ** API.  The only thing omitted is the automatic recompile if a
638 ** schema change has occurred.  That detail is handled by the
639 ** outer sqlite3_step() wrapper procedure.
640 */
641 static int sqlite3Step(Vdbe *p){
642   sqlite3 *db;
643   int rc;
644 
645   /* Check that malloc() has not failed. If it has, return early. */
646   db = p->db;
647   if( db->mallocFailed ){
648     p->rc = SQLITE_NOMEM;
649     return SQLITE_NOMEM_BKPT;
650   }
651 
652   assert(p);
653   if( p->eVdbeState!=VDBE_RUN_STATE ){
654     restart_step:
655     if( p->eVdbeState==VDBE_READY_STATE ){
656       if( p->expired ){
657         p->rc = SQLITE_SCHEMA;
658         rc = SQLITE_ERROR;
659         if( (p->prepFlags & SQLITE_PREPARE_SAVESQL)!=0 ){
660           /* If this statement was prepared using saved SQL and an
661           ** error has occurred, then return the error code in p->rc to the
662           ** caller. Set the error code in the database handle to the same
663           ** value.
664           */
665           rc = sqlite3VdbeTransferError(p);
666         }
667         goto end_of_step;
668       }
669 
670       /* If there are no other statements currently running, then
671       ** reset the interrupt flag.  This prevents a call to sqlite3_interrupt
672       ** from interrupting a statement that has not yet started.
673       */
674       if( db->nVdbeActive==0 ){
675         AtomicStore(&db->u1.isInterrupted, 0);
676       }
677 
678       assert( db->nVdbeWrite>0 || db->autoCommit==0
679           || (db->nDeferredCons==0 && db->nDeferredImmCons==0)
680       );
681 
682 #ifndef SQLITE_OMIT_TRACE
683       if( (db->mTrace & (SQLITE_TRACE_PROFILE|SQLITE_TRACE_XPROFILE))!=0
684           && !db->init.busy && p->zSql ){
685         sqlite3OsCurrentTimeInt64(db->pVfs, &p->startTime);
686       }else{
687         assert( p->startTime==0 );
688       }
689 #endif
690 
691       db->nVdbeActive++;
692       if( p->readOnly==0 ) db->nVdbeWrite++;
693       if( p->bIsReader ) db->nVdbeRead++;
694       p->pc = 0;
695       p->eVdbeState = VDBE_RUN_STATE;
696     }else
697 
698     if( ALWAYS(p->eVdbeState==VDBE_HALT_STATE) ){
699       /* We used to require that sqlite3_reset() be called before retrying
700       ** sqlite3_step() after any error or after SQLITE_DONE.  But beginning
701       ** with version 3.7.0, we changed this so that sqlite3_reset() would
702       ** be called automatically instead of throwing the SQLITE_MISUSE error.
703       ** This "automatic-reset" change is not technically an incompatibility,
704       ** since any application that receives an SQLITE_MISUSE is broken by
705       ** definition.
706       **
707       ** Nevertheless, some published applications that were originally written
708       ** for version 3.6.23 or earlier do in fact depend on SQLITE_MISUSE
709       ** returns, and those were broken by the automatic-reset change.  As a
710       ** a work-around, the SQLITE_OMIT_AUTORESET compile-time restores the
711       ** legacy behavior of returning SQLITE_MISUSE for cases where the
712       ** previous sqlite3_step() returned something other than a SQLITE_LOCKED
713       ** or SQLITE_BUSY error.
714       */
715 #ifdef SQLITE_OMIT_AUTORESET
716       if( (rc = p->rc&0xff)==SQLITE_BUSY || rc==SQLITE_LOCKED ){
717         sqlite3_reset((sqlite3_stmt*)p);
718       }else{
719         return SQLITE_MISUSE_BKPT;
720       }
721 #else
722       sqlite3_reset((sqlite3_stmt*)p);
723 #endif
724       assert( p->eVdbeState==VDBE_READY_STATE );
725       goto restart_step;
726     }
727   }
728 
729 #ifdef SQLITE_DEBUG
730   p->rcApp = SQLITE_OK;
731 #endif
732 #ifndef SQLITE_OMIT_EXPLAIN
733   if( p->explain ){
734     rc = sqlite3VdbeList(p);
735   }else
736 #endif /* SQLITE_OMIT_EXPLAIN */
737   {
738     db->nVdbeExec++;
739     rc = sqlite3VdbeExec(p);
740     db->nVdbeExec--;
741   }
742 
743   if( rc==SQLITE_ROW ){
744     assert( p->rc==SQLITE_OK );
745     assert( db->mallocFailed==0 );
746     db->errCode = SQLITE_ROW;
747     return SQLITE_ROW;
748   }else{
749 #ifndef SQLITE_OMIT_TRACE
750     /* If the statement completed successfully, invoke the profile callback */
751     checkProfileCallback(db, p);
752 #endif
753 
754     if( rc==SQLITE_DONE && db->autoCommit ){
755       assert( p->rc==SQLITE_OK );
756       p->rc = doWalCallbacks(db);
757       if( p->rc!=SQLITE_OK ){
758         rc = SQLITE_ERROR;
759       }
760     }else if( rc!=SQLITE_DONE && (p->prepFlags & SQLITE_PREPARE_SAVESQL)!=0 ){
761       /* If this statement was prepared using saved SQL and an
762       ** error has occurred, then return the error code in p->rc to the
763       ** caller. Set the error code in the database handle to the same value.
764       */
765       rc = sqlite3VdbeTransferError(p);
766     }
767   }
768 
769   db->errCode = rc;
770   if( SQLITE_NOMEM==sqlite3ApiExit(p->db, p->rc) ){
771     p->rc = SQLITE_NOMEM_BKPT;
772     if( (p->prepFlags & SQLITE_PREPARE_SAVESQL)!=0 ) rc = p->rc;
773   }
774 end_of_step:
775   /* There are only a limited number of result codes allowed from the
776   ** statements prepared using the legacy sqlite3_prepare() interface */
777   assert( (p->prepFlags & SQLITE_PREPARE_SAVESQL)!=0
778        || rc==SQLITE_ROW  || rc==SQLITE_DONE   || rc==SQLITE_ERROR
779        || (rc&0xff)==SQLITE_BUSY || rc==SQLITE_MISUSE
780   );
781   return (rc&db->errMask);
782 }
783 
784 /*
785 ** This is the top-level implementation of sqlite3_step().  Call
786 ** sqlite3Step() to do most of the work.  If a schema error occurs,
787 ** call sqlite3Reprepare() and try again.
788 */
789 int sqlite3_step(sqlite3_stmt *pStmt){
790   int rc = SQLITE_OK;      /* Result from sqlite3Step() */
791   Vdbe *v = (Vdbe*)pStmt;  /* the prepared statement */
792   int cnt = 0;             /* Counter to prevent infinite loop of reprepares */
793   sqlite3 *db;             /* The database connection */
794 
795   if( vdbeSafetyNotNull(v) ){
796     return SQLITE_MISUSE_BKPT;
797   }
798   db = v->db;
799   sqlite3_mutex_enter(db->mutex);
800   while( (rc = sqlite3Step(v))==SQLITE_SCHEMA
801          && cnt++ < SQLITE_MAX_SCHEMA_RETRY ){
802     int savedPc = v->pc;
803     rc = sqlite3Reprepare(v);
804     if( rc!=SQLITE_OK ){
805       /* This case occurs after failing to recompile an sql statement.
806       ** The error message from the SQL compiler has already been loaded
807       ** into the database handle. This block copies the error message
808       ** from the database handle into the statement and sets the statement
809       ** program counter to 0 to ensure that when the statement is
810       ** finalized or reset the parser error message is available via
811       ** sqlite3_errmsg() and sqlite3_errcode().
812       */
813       const char *zErr = (const char *)sqlite3_value_text(db->pErr);
814       sqlite3DbFree(db, v->zErrMsg);
815       if( !db->mallocFailed ){
816         v->zErrMsg = sqlite3DbStrDup(db, zErr);
817         v->rc = rc = sqlite3ApiExit(db, rc);
818       } else {
819         v->zErrMsg = 0;
820         v->rc = rc = SQLITE_NOMEM_BKPT;
821       }
822       break;
823     }
824     sqlite3_reset(pStmt);
825     if( savedPc>=0 ){
826       /* Setting minWriteFileFormat to 254 is a signal to the OP_Init and
827       ** OP_Trace opcodes to *not* perform SQLITE_TRACE_STMT because one
828       ** should output has already occurred due to SQLITE_SCHEMA.
829       ** tag-20220401a */
830       v->minWriteFileFormat = 254;
831     }
832     assert( v->expired==0 );
833   }
834   sqlite3_mutex_leave(db->mutex);
835   return rc;
836 }
837 
838 
839 /*
840 ** Extract the user data from a sqlite3_context structure and return a
841 ** pointer to it.
842 */
843 void *sqlite3_user_data(sqlite3_context *p){
844   assert( p && p->pFunc );
845   return p->pFunc->pUserData;
846 }
847 
848 /*
849 ** Extract the user data from a sqlite3_context structure and return a
850 ** pointer to it.
851 **
852 ** IMPLEMENTATION-OF: R-46798-50301 The sqlite3_context_db_handle() interface
853 ** returns a copy of the pointer to the database connection (the 1st
854 ** parameter) of the sqlite3_create_function() and
855 ** sqlite3_create_function16() routines that originally registered the
856 ** application defined function.
857 */
858 sqlite3 *sqlite3_context_db_handle(sqlite3_context *p){
859   assert( p && p->pOut );
860   return p->pOut->db;
861 }
862 
863 /*
864 ** If this routine is invoked from within an xColumn method of a virtual
865 ** table, then it returns true if and only if the the call is during an
866 ** UPDATE operation and the value of the column will not be modified
867 ** by the UPDATE.
868 **
869 ** If this routine is called from any context other than within the
870 ** xColumn method of a virtual table, then the return value is meaningless
871 ** and arbitrary.
872 **
873 ** Virtual table implements might use this routine to optimize their
874 ** performance by substituting a NULL result, or some other light-weight
875 ** value, as a signal to the xUpdate routine that the column is unchanged.
876 */
877 int sqlite3_vtab_nochange(sqlite3_context *p){
878   assert( p );
879   return sqlite3_value_nochange(p->pOut);
880 }
881 
882 /*
883 ** Implementation of sqlite3_vtab_in_first() (if bNext==0) and
884 ** sqlite3_vtab_in_next() (if bNext!=0).
885 */
886 static int valueFromValueList(
887   sqlite3_value *pVal,        /* Pointer to the ValueList object */
888   sqlite3_value **ppOut,      /* Store the next value from the list here */
889   int bNext                   /* 1 for _next(). 0 for _first() */
890 ){
891   int rc;
892   ValueList *pRhs;
893 
894   *ppOut = 0;
895   if( pVal==0 ) return SQLITE_MISUSE;
896   pRhs = (ValueList*)sqlite3_value_pointer(pVal, "ValueList");
897   if( pRhs==0 ) return SQLITE_MISUSE;
898   if( bNext ){
899     rc = sqlite3BtreeNext(pRhs->pCsr, 0);
900   }else{
901     int dummy = 0;
902     rc = sqlite3BtreeFirst(pRhs->pCsr, &dummy);
903     assert( rc==SQLITE_OK || sqlite3BtreeEof(pRhs->pCsr) );
904     if( sqlite3BtreeEof(pRhs->pCsr) ) rc = SQLITE_DONE;
905   }
906   if( rc==SQLITE_OK ){
907     u32 sz;       /* Size of current row in bytes */
908     Mem sMem;     /* Raw content of current row */
909     memset(&sMem, 0, sizeof(sMem));
910     sz = sqlite3BtreePayloadSize(pRhs->pCsr);
911     rc = sqlite3VdbeMemFromBtreeZeroOffset(pRhs->pCsr,(int)sz,&sMem);
912     if( rc==SQLITE_OK ){
913       u8 *zBuf = (u8*)sMem.z;
914       u32 iSerial;
915       sqlite3_value *pOut = pRhs->pOut;
916       int iOff = 1 + getVarint32(&zBuf[1], iSerial);
917       sqlite3VdbeSerialGet(&zBuf[iOff], iSerial, pOut);
918       pOut->enc = ENC(pOut->db);
919       if( (pOut->flags & MEM_Ephem)!=0 && sqlite3VdbeMemMakeWriteable(pOut) ){
920         rc = SQLITE_NOMEM;
921       }else{
922         *ppOut = pOut;
923       }
924     }
925     sqlite3VdbeMemRelease(&sMem);
926   }
927   return rc;
928 }
929 
930 /*
931 ** Set the iterator value pVal to point to the first value in the set.
932 ** Set (*ppOut) to point to this value before returning.
933 */
934 int sqlite3_vtab_in_first(sqlite3_value *pVal, sqlite3_value **ppOut){
935   return valueFromValueList(pVal, ppOut, 0);
936 }
937 
938 /*
939 ** Set the iterator value pVal to point to the next value in the set.
940 ** Set (*ppOut) to point to this value before returning.
941 */
942 int sqlite3_vtab_in_next(sqlite3_value *pVal, sqlite3_value **ppOut){
943   return valueFromValueList(pVal, ppOut, 1);
944 }
945 
946 /*
947 ** Return the current time for a statement.  If the current time
948 ** is requested more than once within the same run of a single prepared
949 ** statement, the exact same time is returned for each invocation regardless
950 ** of the amount of time that elapses between invocations.  In other words,
951 ** the time returned is always the time of the first call.
952 */
953 sqlite3_int64 sqlite3StmtCurrentTime(sqlite3_context *p){
954   int rc;
955 #ifndef SQLITE_ENABLE_STAT4
956   sqlite3_int64 *piTime = &p->pVdbe->iCurrentTime;
957   assert( p->pVdbe!=0 );
958 #else
959   sqlite3_int64 iTime = 0;
960   sqlite3_int64 *piTime = p->pVdbe!=0 ? &p->pVdbe->iCurrentTime : &iTime;
961 #endif
962   if( *piTime==0 ){
963     rc = sqlite3OsCurrentTimeInt64(p->pOut->db->pVfs, piTime);
964     if( rc ) *piTime = 0;
965   }
966   return *piTime;
967 }
968 
969 /*
970 ** Create a new aggregate context for p and return a pointer to
971 ** its pMem->z element.
972 */
973 static SQLITE_NOINLINE void *createAggContext(sqlite3_context *p, int nByte){
974   Mem *pMem = p->pMem;
975   assert( (pMem->flags & MEM_Agg)==0 );
976   if( nByte<=0 ){
977     sqlite3VdbeMemSetNull(pMem);
978     pMem->z = 0;
979   }else{
980     sqlite3VdbeMemClearAndResize(pMem, nByte);
981     pMem->flags = MEM_Agg;
982     pMem->u.pDef = p->pFunc;
983     if( pMem->z ){
984       memset(pMem->z, 0, nByte);
985     }
986   }
987   return (void*)pMem->z;
988 }
989 
990 /*
991 ** Allocate or return the aggregate context for a user function.  A new
992 ** context is allocated on the first call.  Subsequent calls return the
993 ** same context that was returned on prior calls.
994 */
995 void *sqlite3_aggregate_context(sqlite3_context *p, int nByte){
996   assert( p && p->pFunc && p->pFunc->xFinalize );
997   assert( sqlite3_mutex_held(p->pOut->db->mutex) );
998   testcase( nByte<0 );
999   if( (p->pMem->flags & MEM_Agg)==0 ){
1000     return createAggContext(p, nByte);
1001   }else{
1002     return (void*)p->pMem->z;
1003   }
1004 }
1005 
1006 /*
1007 ** Return the auxiliary data pointer, if any, for the iArg'th argument to
1008 ** the user-function defined by pCtx.
1009 **
1010 ** The left-most argument is 0.
1011 **
1012 ** Undocumented behavior:  If iArg is negative then access a cache of
1013 ** auxiliary data pointers that is available to all functions within a
1014 ** single prepared statement.  The iArg values must match.
1015 */
1016 void *sqlite3_get_auxdata(sqlite3_context *pCtx, int iArg){
1017   AuxData *pAuxData;
1018 
1019   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
1020 #if SQLITE_ENABLE_STAT4
1021   if( pCtx->pVdbe==0 ) return 0;
1022 #else
1023   assert( pCtx->pVdbe!=0 );
1024 #endif
1025   for(pAuxData=pCtx->pVdbe->pAuxData; pAuxData; pAuxData=pAuxData->pNextAux){
1026     if(  pAuxData->iAuxArg==iArg && (pAuxData->iAuxOp==pCtx->iOp || iArg<0) ){
1027       return pAuxData->pAux;
1028     }
1029   }
1030   return 0;
1031 }
1032 
1033 /*
1034 ** Set the auxiliary data pointer and delete function, for the iArg'th
1035 ** argument to the user-function defined by pCtx. Any previous value is
1036 ** deleted by calling the delete function specified when it was set.
1037 **
1038 ** The left-most argument is 0.
1039 **
1040 ** Undocumented behavior:  If iArg is negative then make the data available
1041 ** to all functions within the current prepared statement using iArg as an
1042 ** access code.
1043 */
1044 void sqlite3_set_auxdata(
1045   sqlite3_context *pCtx,
1046   int iArg,
1047   void *pAux,
1048   void (*xDelete)(void*)
1049 ){
1050   AuxData *pAuxData;
1051   Vdbe *pVdbe = pCtx->pVdbe;
1052 
1053   assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
1054 #ifdef SQLITE_ENABLE_STAT4
1055   if( pVdbe==0 ) goto failed;
1056 #else
1057   assert( pVdbe!=0 );
1058 #endif
1059 
1060   for(pAuxData=pVdbe->pAuxData; pAuxData; pAuxData=pAuxData->pNextAux){
1061     if( pAuxData->iAuxArg==iArg && (pAuxData->iAuxOp==pCtx->iOp || iArg<0) ){
1062       break;
1063     }
1064   }
1065   if( pAuxData==0 ){
1066     pAuxData = sqlite3DbMallocZero(pVdbe->db, sizeof(AuxData));
1067     if( !pAuxData ) goto failed;
1068     pAuxData->iAuxOp = pCtx->iOp;
1069     pAuxData->iAuxArg = iArg;
1070     pAuxData->pNextAux = pVdbe->pAuxData;
1071     pVdbe->pAuxData = pAuxData;
1072     if( pCtx->isError==0 ) pCtx->isError = -1;
1073   }else if( pAuxData->xDeleteAux ){
1074     pAuxData->xDeleteAux(pAuxData->pAux);
1075   }
1076 
1077   pAuxData->pAux = pAux;
1078   pAuxData->xDeleteAux = xDelete;
1079   return;
1080 
1081 failed:
1082   if( xDelete ){
1083     xDelete(pAux);
1084   }
1085 }
1086 
1087 #ifndef SQLITE_OMIT_DEPRECATED
1088 /*
1089 ** Return the number of times the Step function of an aggregate has been
1090 ** called.
1091 **
1092 ** This function is deprecated.  Do not use it for new code.  It is
1093 ** provide only to avoid breaking legacy code.  New aggregate function
1094 ** implementations should keep their own counts within their aggregate
1095 ** context.
1096 */
1097 int sqlite3_aggregate_count(sqlite3_context *p){
1098   assert( p && p->pMem && p->pFunc && p->pFunc->xFinalize );
1099   return p->pMem->n;
1100 }
1101 #endif
1102 
1103 /*
1104 ** Return the number of columns in the result set for the statement pStmt.
1105 */
1106 int sqlite3_column_count(sqlite3_stmt *pStmt){
1107   Vdbe *pVm = (Vdbe *)pStmt;
1108   return pVm ? pVm->nResColumn : 0;
1109 }
1110 
1111 /*
1112 ** Return the number of values available from the current row of the
1113 ** currently executing statement pStmt.
1114 */
1115 int sqlite3_data_count(sqlite3_stmt *pStmt){
1116   Vdbe *pVm = (Vdbe *)pStmt;
1117   if( pVm==0 || pVm->pResultSet==0 ) return 0;
1118   return pVm->nResColumn;
1119 }
1120 
1121 /*
1122 ** Return a pointer to static memory containing an SQL NULL value.
1123 */
1124 static const Mem *columnNullValue(void){
1125   /* Even though the Mem structure contains an element
1126   ** of type i64, on certain architectures (x86) with certain compiler
1127   ** switches (-Os), gcc may align this Mem object on a 4-byte boundary
1128   ** instead of an 8-byte one. This all works fine, except that when
1129   ** running with SQLITE_DEBUG defined the SQLite code sometimes assert()s
1130   ** that a Mem structure is located on an 8-byte boundary. To prevent
1131   ** these assert()s from failing, when building with SQLITE_DEBUG defined
1132   ** using gcc, we force nullMem to be 8-byte aligned using the magical
1133   ** __attribute__((aligned(8))) macro.  */
1134   static const Mem nullMem
1135 #if defined(SQLITE_DEBUG) && defined(__GNUC__)
1136     __attribute__((aligned(8)))
1137 #endif
1138     = {
1139         /* .u          = */ {0},
1140         /* .z          = */ (char*)0,
1141         /* .n          = */ (int)0,
1142         /* .flags      = */ (u16)MEM_Null,
1143         /* .enc        = */ (u8)0,
1144         /* .eSubtype   = */ (u8)0,
1145         /* .db         = */ (sqlite3*)0,
1146         /* .szMalloc   = */ (int)0,
1147         /* .uTemp      = */ (u32)0,
1148         /* .zMalloc    = */ (char*)0,
1149         /* .xDel       = */ (void(*)(void*))0,
1150 #ifdef SQLITE_DEBUG
1151         /* .pScopyFrom = */ (Mem*)0,
1152         /* .mScopyFlags= */ 0,
1153 #endif
1154       };
1155   return &nullMem;
1156 }
1157 
1158 /*
1159 ** Check to see if column iCol of the given statement is valid.  If
1160 ** it is, return a pointer to the Mem for the value of that column.
1161 ** If iCol is not valid, return a pointer to a Mem which has a value
1162 ** of NULL.
1163 */
1164 static Mem *columnMem(sqlite3_stmt *pStmt, int i){
1165   Vdbe *pVm;
1166   Mem *pOut;
1167 
1168   pVm = (Vdbe *)pStmt;
1169   if( pVm==0 ) return (Mem*)columnNullValue();
1170   assert( pVm->db );
1171   sqlite3_mutex_enter(pVm->db->mutex);
1172   if( pVm->pResultSet!=0 && i<pVm->nResColumn && i>=0 ){
1173     pOut = &pVm->pResultSet[i];
1174   }else{
1175     sqlite3Error(pVm->db, SQLITE_RANGE);
1176     pOut = (Mem*)columnNullValue();
1177   }
1178   return pOut;
1179 }
1180 
1181 /*
1182 ** This function is called after invoking an sqlite3_value_XXX function on a
1183 ** column value (i.e. a value returned by evaluating an SQL expression in the
1184 ** select list of a SELECT statement) that may cause a malloc() failure. If
1185 ** malloc() has failed, the threads mallocFailed flag is cleared and the result
1186 ** code of statement pStmt set to SQLITE_NOMEM.
1187 **
1188 ** Specifically, this is called from within:
1189 **
1190 **     sqlite3_column_int()
1191 **     sqlite3_column_int64()
1192 **     sqlite3_column_text()
1193 **     sqlite3_column_text16()
1194 **     sqlite3_column_real()
1195 **     sqlite3_column_bytes()
1196 **     sqlite3_column_bytes16()
1197 **     sqiite3_column_blob()
1198 */
1199 static void columnMallocFailure(sqlite3_stmt *pStmt)
1200 {
1201   /* If malloc() failed during an encoding conversion within an
1202   ** sqlite3_column_XXX API, then set the return code of the statement to
1203   ** SQLITE_NOMEM. The next call to _step() (if any) will return SQLITE_ERROR
1204   ** and _finalize() will return NOMEM.
1205   */
1206   Vdbe *p = (Vdbe *)pStmt;
1207   if( p ){
1208     assert( p->db!=0 );
1209     assert( sqlite3_mutex_held(p->db->mutex) );
1210     p->rc = sqlite3ApiExit(p->db, p->rc);
1211     sqlite3_mutex_leave(p->db->mutex);
1212   }
1213 }
1214 
1215 /**************************** sqlite3_column_  *******************************
1216 ** The following routines are used to access elements of the current row
1217 ** in the result set.
1218 */
1219 const void *sqlite3_column_blob(sqlite3_stmt *pStmt, int i){
1220   const void *val;
1221   val = sqlite3_value_blob( columnMem(pStmt,i) );
1222   /* Even though there is no encoding conversion, value_blob() might
1223   ** need to call malloc() to expand the result of a zeroblob()
1224   ** expression.
1225   */
1226   columnMallocFailure(pStmt);
1227   return val;
1228 }
1229 int sqlite3_column_bytes(sqlite3_stmt *pStmt, int i){
1230   int val = sqlite3_value_bytes( columnMem(pStmt,i) );
1231   columnMallocFailure(pStmt);
1232   return val;
1233 }
1234 int sqlite3_column_bytes16(sqlite3_stmt *pStmt, int i){
1235   int val = sqlite3_value_bytes16( columnMem(pStmt,i) );
1236   columnMallocFailure(pStmt);
1237   return val;
1238 }
1239 double sqlite3_column_double(sqlite3_stmt *pStmt, int i){
1240   double val = sqlite3_value_double( columnMem(pStmt,i) );
1241   columnMallocFailure(pStmt);
1242   return val;
1243 }
1244 int sqlite3_column_int(sqlite3_stmt *pStmt, int i){
1245   int val = sqlite3_value_int( columnMem(pStmt,i) );
1246   columnMallocFailure(pStmt);
1247   return val;
1248 }
1249 sqlite_int64 sqlite3_column_int64(sqlite3_stmt *pStmt, int i){
1250   sqlite_int64 val = sqlite3_value_int64( columnMem(pStmt,i) );
1251   columnMallocFailure(pStmt);
1252   return val;
1253 }
1254 const unsigned char *sqlite3_column_text(sqlite3_stmt *pStmt, int i){
1255   const unsigned char *val = sqlite3_value_text( columnMem(pStmt,i) );
1256   columnMallocFailure(pStmt);
1257   return val;
1258 }
1259 sqlite3_value *sqlite3_column_value(sqlite3_stmt *pStmt, int i){
1260   Mem *pOut = columnMem(pStmt, i);
1261   if( pOut->flags&MEM_Static ){
1262     pOut->flags &= ~MEM_Static;
1263     pOut->flags |= MEM_Ephem;
1264   }
1265   columnMallocFailure(pStmt);
1266   return (sqlite3_value *)pOut;
1267 }
1268 #ifndef SQLITE_OMIT_UTF16
1269 const void *sqlite3_column_text16(sqlite3_stmt *pStmt, int i){
1270   const void *val = sqlite3_value_text16( columnMem(pStmt,i) );
1271   columnMallocFailure(pStmt);
1272   return val;
1273 }
1274 #endif /* SQLITE_OMIT_UTF16 */
1275 int sqlite3_column_type(sqlite3_stmt *pStmt, int i){
1276   int iType = sqlite3_value_type( columnMem(pStmt,i) );
1277   columnMallocFailure(pStmt);
1278   return iType;
1279 }
1280 
1281 /*
1282 ** Convert the N-th element of pStmt->pColName[] into a string using
1283 ** xFunc() then return that string.  If N is out of range, return 0.
1284 **
1285 ** There are up to 5 names for each column.  useType determines which
1286 ** name is returned.  Here are the names:
1287 **
1288 **    0      The column name as it should be displayed for output
1289 **    1      The datatype name for the column
1290 **    2      The name of the database that the column derives from
1291 **    3      The name of the table that the column derives from
1292 **    4      The name of the table column that the result column derives from
1293 **
1294 ** If the result is not a simple column reference (if it is an expression
1295 ** or a constant) then useTypes 2, 3, and 4 return NULL.
1296 */
1297 static const void *columnName(
1298   sqlite3_stmt *pStmt,     /* The statement */
1299   int N,                   /* Which column to get the name for */
1300   int useUtf16,            /* True to return the name as UTF16 */
1301   int useType              /* What type of name */
1302 ){
1303   const void *ret;
1304   Vdbe *p;
1305   int n;
1306   sqlite3 *db;
1307 #ifdef SQLITE_ENABLE_API_ARMOR
1308   if( pStmt==0 ){
1309     (void)SQLITE_MISUSE_BKPT;
1310     return 0;
1311   }
1312 #endif
1313   ret = 0;
1314   p = (Vdbe *)pStmt;
1315   db = p->db;
1316   assert( db!=0 );
1317   n = sqlite3_column_count(pStmt);
1318   if( N<n && N>=0 ){
1319     N += useType*n;
1320     sqlite3_mutex_enter(db->mutex);
1321     assert( db->mallocFailed==0 );
1322 #ifndef SQLITE_OMIT_UTF16
1323     if( useUtf16 ){
1324       ret = sqlite3_value_text16((sqlite3_value*)&p->aColName[N]);
1325     }else
1326 #endif
1327     {
1328       ret = sqlite3_value_text((sqlite3_value*)&p->aColName[N]);
1329     }
1330     /* A malloc may have failed inside of the _text() call. If this
1331     ** is the case, clear the mallocFailed flag and return NULL.
1332     */
1333     if( db->mallocFailed ){
1334       sqlite3OomClear(db);
1335       ret = 0;
1336     }
1337     sqlite3_mutex_leave(db->mutex);
1338   }
1339   return ret;
1340 }
1341 
1342 /*
1343 ** Return the name of the Nth column of the result set returned by SQL
1344 ** statement pStmt.
1345 */
1346 const char *sqlite3_column_name(sqlite3_stmt *pStmt, int N){
1347   return columnName(pStmt, N, 0, COLNAME_NAME);
1348 }
1349 #ifndef SQLITE_OMIT_UTF16
1350 const void *sqlite3_column_name16(sqlite3_stmt *pStmt, int N){
1351   return columnName(pStmt, N, 1, COLNAME_NAME);
1352 }
1353 #endif
1354 
1355 /*
1356 ** Constraint:  If you have ENABLE_COLUMN_METADATA then you must
1357 ** not define OMIT_DECLTYPE.
1358 */
1359 #if defined(SQLITE_OMIT_DECLTYPE) && defined(SQLITE_ENABLE_COLUMN_METADATA)
1360 # error "Must not define both SQLITE_OMIT_DECLTYPE \
1361          and SQLITE_ENABLE_COLUMN_METADATA"
1362 #endif
1363 
1364 #ifndef SQLITE_OMIT_DECLTYPE
1365 /*
1366 ** Return the column declaration type (if applicable) of the 'i'th column
1367 ** of the result set of SQL statement pStmt.
1368 */
1369 const char *sqlite3_column_decltype(sqlite3_stmt *pStmt, int N){
1370   return columnName(pStmt, N, 0, COLNAME_DECLTYPE);
1371 }
1372 #ifndef SQLITE_OMIT_UTF16
1373 const void *sqlite3_column_decltype16(sqlite3_stmt *pStmt, int N){
1374   return columnName(pStmt, N, 1, COLNAME_DECLTYPE);
1375 }
1376 #endif /* SQLITE_OMIT_UTF16 */
1377 #endif /* SQLITE_OMIT_DECLTYPE */
1378 
1379 #ifdef SQLITE_ENABLE_COLUMN_METADATA
1380 /*
1381 ** Return the name of the database from which a result column derives.
1382 ** NULL is returned if the result column is an expression or constant or
1383 ** anything else which is not an unambiguous reference to a database column.
1384 */
1385 const char *sqlite3_column_database_name(sqlite3_stmt *pStmt, int N){
1386   return columnName(pStmt, N, 0, COLNAME_DATABASE);
1387 }
1388 #ifndef SQLITE_OMIT_UTF16
1389 const void *sqlite3_column_database_name16(sqlite3_stmt *pStmt, int N){
1390   return columnName(pStmt, N, 1, COLNAME_DATABASE);
1391 }
1392 #endif /* SQLITE_OMIT_UTF16 */
1393 
1394 /*
1395 ** Return the name of the table from which a result column derives.
1396 ** NULL is returned if the result column is an expression or constant or
1397 ** anything else which is not an unambiguous reference to a database column.
1398 */
1399 const char *sqlite3_column_table_name(sqlite3_stmt *pStmt, int N){
1400   return columnName(pStmt, N, 0, COLNAME_TABLE);
1401 }
1402 #ifndef SQLITE_OMIT_UTF16
1403 const void *sqlite3_column_table_name16(sqlite3_stmt *pStmt, int N){
1404   return columnName(pStmt, N, 1, COLNAME_TABLE);
1405 }
1406 #endif /* SQLITE_OMIT_UTF16 */
1407 
1408 /*
1409 ** Return the name of the table column from which a result column derives.
1410 ** NULL is returned if the result column is an expression or constant or
1411 ** anything else which is not an unambiguous reference to a database column.
1412 */
1413 const char *sqlite3_column_origin_name(sqlite3_stmt *pStmt, int N){
1414   return columnName(pStmt, N, 0, COLNAME_COLUMN);
1415 }
1416 #ifndef SQLITE_OMIT_UTF16
1417 const void *sqlite3_column_origin_name16(sqlite3_stmt *pStmt, int N){
1418   return columnName(pStmt, N, 1, COLNAME_COLUMN);
1419 }
1420 #endif /* SQLITE_OMIT_UTF16 */
1421 #endif /* SQLITE_ENABLE_COLUMN_METADATA */
1422 
1423 
1424 /******************************* sqlite3_bind_  ***************************
1425 **
1426 ** Routines used to attach values to wildcards in a compiled SQL statement.
1427 */
1428 /*
1429 ** Unbind the value bound to variable i in virtual machine p. This is the
1430 ** the same as binding a NULL value to the column. If the "i" parameter is
1431 ** out of range, then SQLITE_RANGE is returned. Othewise SQLITE_OK.
1432 **
1433 ** A successful evaluation of this routine acquires the mutex on p.
1434 ** the mutex is released if any kind of error occurs.
1435 **
1436 ** The error code stored in database p->db is overwritten with the return
1437 ** value in any case.
1438 */
1439 static int vdbeUnbind(Vdbe *p, int i){
1440   Mem *pVar;
1441   if( vdbeSafetyNotNull(p) ){
1442     return SQLITE_MISUSE_BKPT;
1443   }
1444   sqlite3_mutex_enter(p->db->mutex);
1445   if( p->eVdbeState!=VDBE_READY_STATE ){
1446     sqlite3Error(p->db, SQLITE_MISUSE);
1447     sqlite3_mutex_leave(p->db->mutex);
1448     sqlite3_log(SQLITE_MISUSE,
1449         "bind on a busy prepared statement: [%s]", p->zSql);
1450     return SQLITE_MISUSE_BKPT;
1451   }
1452   if( i<1 || i>p->nVar ){
1453     sqlite3Error(p->db, SQLITE_RANGE);
1454     sqlite3_mutex_leave(p->db->mutex);
1455     return SQLITE_RANGE;
1456   }
1457   i--;
1458   pVar = &p->aVar[i];
1459   sqlite3VdbeMemRelease(pVar);
1460   pVar->flags = MEM_Null;
1461   p->db->errCode = SQLITE_OK;
1462 
1463   /* If the bit corresponding to this variable in Vdbe.expmask is set, then
1464   ** binding a new value to this variable invalidates the current query plan.
1465   **
1466   ** IMPLEMENTATION-OF: R-57496-20354 If the specific value bound to a host
1467   ** parameter in the WHERE clause might influence the choice of query plan
1468   ** for a statement, then the statement will be automatically recompiled,
1469   ** as if there had been a schema change, on the first sqlite3_step() call
1470   ** following any change to the bindings of that parameter.
1471   */
1472   assert( (p->prepFlags & SQLITE_PREPARE_SAVESQL)!=0 || p->expmask==0 );
1473   if( p->expmask!=0 && (p->expmask & (i>=31 ? 0x80000000 : (u32)1<<i))!=0 ){
1474     p->expired = 1;
1475   }
1476   return SQLITE_OK;
1477 }
1478 
1479 /*
1480 ** Bind a text or BLOB value.
1481 */
1482 static int bindText(
1483   sqlite3_stmt *pStmt,   /* The statement to bind against */
1484   int i,                 /* Index of the parameter to bind */
1485   const void *zData,     /* Pointer to the data to be bound */
1486   i64 nData,             /* Number of bytes of data to be bound */
1487   void (*xDel)(void*),   /* Destructor for the data */
1488   u8 encoding            /* Encoding for the data */
1489 ){
1490   Vdbe *p = (Vdbe *)pStmt;
1491   Mem *pVar;
1492   int rc;
1493 
1494   rc = vdbeUnbind(p, i);
1495   if( rc==SQLITE_OK ){
1496     if( zData!=0 ){
1497       pVar = &p->aVar[i-1];
1498       rc = sqlite3VdbeMemSetStr(pVar, zData, nData, encoding, xDel);
1499       if( rc==SQLITE_OK && encoding!=0 ){
1500         rc = sqlite3VdbeChangeEncoding(pVar, ENC(p->db));
1501       }
1502       if( rc ){
1503         sqlite3Error(p->db, rc);
1504         rc = sqlite3ApiExit(p->db, rc);
1505       }
1506     }
1507     sqlite3_mutex_leave(p->db->mutex);
1508   }else if( xDel!=SQLITE_STATIC && xDel!=SQLITE_TRANSIENT ){
1509     xDel((void*)zData);
1510   }
1511   return rc;
1512 }
1513 
1514 
1515 /*
1516 ** Bind a blob value to an SQL statement variable.
1517 */
1518 int sqlite3_bind_blob(
1519   sqlite3_stmt *pStmt,
1520   int i,
1521   const void *zData,
1522   int nData,
1523   void (*xDel)(void*)
1524 ){
1525 #ifdef SQLITE_ENABLE_API_ARMOR
1526   if( nData<0 ) return SQLITE_MISUSE_BKPT;
1527 #endif
1528   return bindText(pStmt, i, zData, nData, xDel, 0);
1529 }
1530 int sqlite3_bind_blob64(
1531   sqlite3_stmt *pStmt,
1532   int i,
1533   const void *zData,
1534   sqlite3_uint64 nData,
1535   void (*xDel)(void*)
1536 ){
1537   assert( xDel!=SQLITE_DYNAMIC );
1538   return bindText(pStmt, i, zData, nData, xDel, 0);
1539 }
1540 int sqlite3_bind_double(sqlite3_stmt *pStmt, int i, double rValue){
1541   int rc;
1542   Vdbe *p = (Vdbe *)pStmt;
1543   rc = vdbeUnbind(p, i);
1544   if( rc==SQLITE_OK ){
1545     sqlite3VdbeMemSetDouble(&p->aVar[i-1], rValue);
1546     sqlite3_mutex_leave(p->db->mutex);
1547   }
1548   return rc;
1549 }
1550 int sqlite3_bind_int(sqlite3_stmt *p, int i, int iValue){
1551   return sqlite3_bind_int64(p, i, (i64)iValue);
1552 }
1553 int sqlite3_bind_int64(sqlite3_stmt *pStmt, int i, sqlite_int64 iValue){
1554   int rc;
1555   Vdbe *p = (Vdbe *)pStmt;
1556   rc = vdbeUnbind(p, i);
1557   if( rc==SQLITE_OK ){
1558     sqlite3VdbeMemSetInt64(&p->aVar[i-1], iValue);
1559     sqlite3_mutex_leave(p->db->mutex);
1560   }
1561   return rc;
1562 }
1563 int sqlite3_bind_null(sqlite3_stmt *pStmt, int i){
1564   int rc;
1565   Vdbe *p = (Vdbe*)pStmt;
1566   rc = vdbeUnbind(p, i);
1567   if( rc==SQLITE_OK ){
1568     sqlite3_mutex_leave(p->db->mutex);
1569   }
1570   return rc;
1571 }
1572 int sqlite3_bind_pointer(
1573   sqlite3_stmt *pStmt,
1574   int i,
1575   void *pPtr,
1576   const char *zPTtype,
1577   void (*xDestructor)(void*)
1578 ){
1579   int rc;
1580   Vdbe *p = (Vdbe*)pStmt;
1581   rc = vdbeUnbind(p, i);
1582   if( rc==SQLITE_OK ){
1583     sqlite3VdbeMemSetPointer(&p->aVar[i-1], pPtr, zPTtype, xDestructor);
1584     sqlite3_mutex_leave(p->db->mutex);
1585   }else if( xDestructor ){
1586     xDestructor(pPtr);
1587   }
1588   return rc;
1589 }
1590 int sqlite3_bind_text(
1591   sqlite3_stmt *pStmt,
1592   int i,
1593   const char *zData,
1594   int nData,
1595   void (*xDel)(void*)
1596 ){
1597   return bindText(pStmt, i, zData, nData, xDel, SQLITE_UTF8);
1598 }
1599 int sqlite3_bind_text64(
1600   sqlite3_stmt *pStmt,
1601   int i,
1602   const char *zData,
1603   sqlite3_uint64 nData,
1604   void (*xDel)(void*),
1605   unsigned char enc
1606 ){
1607   assert( xDel!=SQLITE_DYNAMIC );
1608   if( enc==SQLITE_UTF16 ) enc = SQLITE_UTF16NATIVE;
1609   return bindText(pStmt, i, zData, nData, xDel, enc);
1610 }
1611 #ifndef SQLITE_OMIT_UTF16
1612 int sqlite3_bind_text16(
1613   sqlite3_stmt *pStmt,
1614   int i,
1615   const void *zData,
1616   int nData,
1617   void (*xDel)(void*)
1618 ){
1619   return bindText(pStmt, i, zData, nData, xDel, SQLITE_UTF16NATIVE);
1620 }
1621 #endif /* SQLITE_OMIT_UTF16 */
1622 int sqlite3_bind_value(sqlite3_stmt *pStmt, int i, const sqlite3_value *pValue){
1623   int rc;
1624   switch( sqlite3_value_type((sqlite3_value*)pValue) ){
1625     case SQLITE_INTEGER: {
1626       rc = sqlite3_bind_int64(pStmt, i, pValue->u.i);
1627       break;
1628     }
1629     case SQLITE_FLOAT: {
1630       assert( pValue->flags & (MEM_Real|MEM_IntReal) );
1631       rc = sqlite3_bind_double(pStmt, i,
1632           (pValue->flags & MEM_Real) ? pValue->u.r : (double)pValue->u.i
1633       );
1634       break;
1635     }
1636     case SQLITE_BLOB: {
1637       if( pValue->flags & MEM_Zero ){
1638         rc = sqlite3_bind_zeroblob(pStmt, i, pValue->u.nZero);
1639       }else{
1640         rc = sqlite3_bind_blob(pStmt, i, pValue->z, pValue->n,SQLITE_TRANSIENT);
1641       }
1642       break;
1643     }
1644     case SQLITE_TEXT: {
1645       rc = bindText(pStmt,i,  pValue->z, pValue->n, SQLITE_TRANSIENT,
1646                               pValue->enc);
1647       break;
1648     }
1649     default: {
1650       rc = sqlite3_bind_null(pStmt, i);
1651       break;
1652     }
1653   }
1654   return rc;
1655 }
1656 int sqlite3_bind_zeroblob(sqlite3_stmt *pStmt, int i, int n){
1657   int rc;
1658   Vdbe *p = (Vdbe *)pStmt;
1659   rc = vdbeUnbind(p, i);
1660   if( rc==SQLITE_OK ){
1661 #ifndef SQLITE_OMIT_INCRBLOB
1662     sqlite3VdbeMemSetZeroBlob(&p->aVar[i-1], n);
1663 #else
1664     rc = sqlite3VdbeMemSetZeroBlob(&p->aVar[i-1], n);
1665 #endif
1666     sqlite3_mutex_leave(p->db->mutex);
1667   }
1668   return rc;
1669 }
1670 int sqlite3_bind_zeroblob64(sqlite3_stmt *pStmt, int i, sqlite3_uint64 n){
1671   int rc;
1672   Vdbe *p = (Vdbe *)pStmt;
1673   sqlite3_mutex_enter(p->db->mutex);
1674   if( n>(u64)p->db->aLimit[SQLITE_LIMIT_LENGTH] ){
1675     rc = SQLITE_TOOBIG;
1676   }else{
1677     assert( (n & 0x7FFFFFFF)==n );
1678     rc = sqlite3_bind_zeroblob(pStmt, i, n);
1679   }
1680   rc = sqlite3ApiExit(p->db, rc);
1681   sqlite3_mutex_leave(p->db->mutex);
1682   return rc;
1683 }
1684 
1685 /*
1686 ** Return the number of wildcards that can be potentially bound to.
1687 ** This routine is added to support DBD::SQLite.
1688 */
1689 int sqlite3_bind_parameter_count(sqlite3_stmt *pStmt){
1690   Vdbe *p = (Vdbe*)pStmt;
1691   return p ? p->nVar : 0;
1692 }
1693 
1694 /*
1695 ** Return the name of a wildcard parameter.  Return NULL if the index
1696 ** is out of range or if the wildcard is unnamed.
1697 **
1698 ** The result is always UTF-8.
1699 */
1700 const char *sqlite3_bind_parameter_name(sqlite3_stmt *pStmt, int i){
1701   Vdbe *p = (Vdbe*)pStmt;
1702   if( p==0 ) return 0;
1703   return sqlite3VListNumToName(p->pVList, i);
1704 }
1705 
1706 /*
1707 ** Given a wildcard parameter name, return the index of the variable
1708 ** with that name.  If there is no variable with the given name,
1709 ** return 0.
1710 */
1711 int sqlite3VdbeParameterIndex(Vdbe *p, const char *zName, int nName){
1712   if( p==0 || zName==0 ) return 0;
1713   return sqlite3VListNameToNum(p->pVList, zName, nName);
1714 }
1715 int sqlite3_bind_parameter_index(sqlite3_stmt *pStmt, const char *zName){
1716   return sqlite3VdbeParameterIndex((Vdbe*)pStmt, zName, sqlite3Strlen30(zName));
1717 }
1718 
1719 /*
1720 ** Transfer all bindings from the first statement over to the second.
1721 */
1722 int sqlite3TransferBindings(sqlite3_stmt *pFromStmt, sqlite3_stmt *pToStmt){
1723   Vdbe *pFrom = (Vdbe*)pFromStmt;
1724   Vdbe *pTo = (Vdbe*)pToStmt;
1725   int i;
1726   assert( pTo->db==pFrom->db );
1727   assert( pTo->nVar==pFrom->nVar );
1728   sqlite3_mutex_enter(pTo->db->mutex);
1729   for(i=0; i<pFrom->nVar; i++){
1730     sqlite3VdbeMemMove(&pTo->aVar[i], &pFrom->aVar[i]);
1731   }
1732   sqlite3_mutex_leave(pTo->db->mutex);
1733   return SQLITE_OK;
1734 }
1735 
1736 #ifndef SQLITE_OMIT_DEPRECATED
1737 /*
1738 ** Deprecated external interface.  Internal/core SQLite code
1739 ** should call sqlite3TransferBindings.
1740 **
1741 ** It is misuse to call this routine with statements from different
1742 ** database connections.  But as this is a deprecated interface, we
1743 ** will not bother to check for that condition.
1744 **
1745 ** If the two statements contain a different number of bindings, then
1746 ** an SQLITE_ERROR is returned.  Nothing else can go wrong, so otherwise
1747 ** SQLITE_OK is returned.
1748 */
1749 int sqlite3_transfer_bindings(sqlite3_stmt *pFromStmt, sqlite3_stmt *pToStmt){
1750   Vdbe *pFrom = (Vdbe*)pFromStmt;
1751   Vdbe *pTo = (Vdbe*)pToStmt;
1752   if( pFrom->nVar!=pTo->nVar ){
1753     return SQLITE_ERROR;
1754   }
1755   assert( (pTo->prepFlags & SQLITE_PREPARE_SAVESQL)!=0 || pTo->expmask==0 );
1756   if( pTo->expmask ){
1757     pTo->expired = 1;
1758   }
1759   assert( (pFrom->prepFlags & SQLITE_PREPARE_SAVESQL)!=0 || pFrom->expmask==0 );
1760   if( pFrom->expmask ){
1761     pFrom->expired = 1;
1762   }
1763   return sqlite3TransferBindings(pFromStmt, pToStmt);
1764 }
1765 #endif
1766 
1767 /*
1768 ** Return the sqlite3* database handle to which the prepared statement given
1769 ** in the argument belongs.  This is the same database handle that was
1770 ** the first argument to the sqlite3_prepare() that was used to create
1771 ** the statement in the first place.
1772 */
1773 sqlite3 *sqlite3_db_handle(sqlite3_stmt *pStmt){
1774   return pStmt ? ((Vdbe*)pStmt)->db : 0;
1775 }
1776 
1777 /*
1778 ** Return true if the prepared statement is guaranteed to not modify the
1779 ** database.
1780 */
1781 int sqlite3_stmt_readonly(sqlite3_stmt *pStmt){
1782   return pStmt ? ((Vdbe*)pStmt)->readOnly : 1;
1783 }
1784 
1785 /*
1786 ** Return 1 if the statement is an EXPLAIN and return 2 if the
1787 ** statement is an EXPLAIN QUERY PLAN
1788 */
1789 int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt){
1790   return pStmt ? ((Vdbe*)pStmt)->explain : 0;
1791 }
1792 
1793 /*
1794 ** Return true if the prepared statement is in need of being reset.
1795 */
1796 int sqlite3_stmt_busy(sqlite3_stmt *pStmt){
1797   Vdbe *v = (Vdbe*)pStmt;
1798   return v!=0 && v->eVdbeState==VDBE_RUN_STATE;
1799 }
1800 
1801 /*
1802 ** Return a pointer to the next prepared statement after pStmt associated
1803 ** with database connection pDb.  If pStmt is NULL, return the first
1804 ** prepared statement for the database connection.  Return NULL if there
1805 ** are no more.
1806 */
1807 sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt){
1808   sqlite3_stmt *pNext;
1809 #ifdef SQLITE_ENABLE_API_ARMOR
1810   if( !sqlite3SafetyCheckOk(pDb) ){
1811     (void)SQLITE_MISUSE_BKPT;
1812     return 0;
1813   }
1814 #endif
1815   sqlite3_mutex_enter(pDb->mutex);
1816   if( pStmt==0 ){
1817     pNext = (sqlite3_stmt*)pDb->pVdbe;
1818   }else{
1819     pNext = (sqlite3_stmt*)((Vdbe*)pStmt)->pNext;
1820   }
1821   sqlite3_mutex_leave(pDb->mutex);
1822   return pNext;
1823 }
1824 
1825 /*
1826 ** Return the value of a status counter for a prepared statement
1827 */
1828 int sqlite3_stmt_status(sqlite3_stmt *pStmt, int op, int resetFlag){
1829   Vdbe *pVdbe = (Vdbe*)pStmt;
1830   u32 v;
1831 #ifdef SQLITE_ENABLE_API_ARMOR
1832   if( !pStmt
1833    || (op!=SQLITE_STMTSTATUS_MEMUSED && (op<0||op>=ArraySize(pVdbe->aCounter)))
1834   ){
1835     (void)SQLITE_MISUSE_BKPT;
1836     return 0;
1837   }
1838 #endif
1839   if( op==SQLITE_STMTSTATUS_MEMUSED ){
1840     sqlite3 *db = pVdbe->db;
1841     sqlite3_mutex_enter(db->mutex);
1842     v = 0;
1843     db->pnBytesFreed = (int*)&v;
1844     sqlite3VdbeClearObject(db, pVdbe);
1845     sqlite3DbFree(db, pVdbe);
1846     db->pnBytesFreed = 0;
1847     sqlite3_mutex_leave(db->mutex);
1848   }else{
1849     v = pVdbe->aCounter[op];
1850     if( resetFlag ) pVdbe->aCounter[op] = 0;
1851   }
1852   return (int)v;
1853 }
1854 
1855 /*
1856 ** Return the SQL associated with a prepared statement
1857 */
1858 const char *sqlite3_sql(sqlite3_stmt *pStmt){
1859   Vdbe *p = (Vdbe *)pStmt;
1860   return p ? p->zSql : 0;
1861 }
1862 
1863 /*
1864 ** Return the SQL associated with a prepared statement with
1865 ** bound parameters expanded.  Space to hold the returned string is
1866 ** obtained from sqlite3_malloc().  The caller is responsible for
1867 ** freeing the returned string by passing it to sqlite3_free().
1868 **
1869 ** The SQLITE_TRACE_SIZE_LIMIT puts an upper bound on the size of
1870 ** expanded bound parameters.
1871 */
1872 char *sqlite3_expanded_sql(sqlite3_stmt *pStmt){
1873 #ifdef SQLITE_OMIT_TRACE
1874   return 0;
1875 #else
1876   char *z = 0;
1877   const char *zSql = sqlite3_sql(pStmt);
1878   if( zSql ){
1879     Vdbe *p = (Vdbe *)pStmt;
1880     sqlite3_mutex_enter(p->db->mutex);
1881     z = sqlite3VdbeExpandSql(p, zSql);
1882     sqlite3_mutex_leave(p->db->mutex);
1883   }
1884   return z;
1885 #endif
1886 }
1887 
1888 #ifdef SQLITE_ENABLE_NORMALIZE
1889 /*
1890 ** Return the normalized SQL associated with a prepared statement.
1891 */
1892 const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt){
1893   Vdbe *p = (Vdbe *)pStmt;
1894   if( p==0 ) return 0;
1895   if( p->zNormSql==0 && ALWAYS(p->zSql!=0) ){
1896     sqlite3_mutex_enter(p->db->mutex);
1897     p->zNormSql = sqlite3Normalize(p, p->zSql);
1898     sqlite3_mutex_leave(p->db->mutex);
1899   }
1900   return p->zNormSql;
1901 }
1902 #endif /* SQLITE_ENABLE_NORMALIZE */
1903 
1904 #ifdef SQLITE_ENABLE_PREUPDATE_HOOK
1905 /*
1906 ** Allocate and populate an UnpackedRecord structure based on the serialized
1907 ** record in nKey/pKey. Return a pointer to the new UnpackedRecord structure
1908 ** if successful, or a NULL pointer if an OOM error is encountered.
1909 */
1910 static UnpackedRecord *vdbeUnpackRecord(
1911   KeyInfo *pKeyInfo,
1912   int nKey,
1913   const void *pKey
1914 ){
1915   UnpackedRecord *pRet;           /* Return value */
1916 
1917   pRet = sqlite3VdbeAllocUnpackedRecord(pKeyInfo);
1918   if( pRet ){
1919     memset(pRet->aMem, 0, sizeof(Mem)*(pKeyInfo->nKeyField+1));
1920     sqlite3VdbeRecordUnpack(pKeyInfo, nKey, pKey, pRet);
1921   }
1922   return pRet;
1923 }
1924 
1925 /*
1926 ** This function is called from within a pre-update callback to retrieve
1927 ** a field of the row currently being updated or deleted.
1928 */
1929 int sqlite3_preupdate_old(sqlite3 *db, int iIdx, sqlite3_value **ppValue){
1930   PreUpdate *p = db->pPreUpdate;
1931   Mem *pMem;
1932   int rc = SQLITE_OK;
1933 
1934   /* Test that this call is being made from within an SQLITE_DELETE or
1935   ** SQLITE_UPDATE pre-update callback, and that iIdx is within range. */
1936   if( !p || p->op==SQLITE_INSERT ){
1937     rc = SQLITE_MISUSE_BKPT;
1938     goto preupdate_old_out;
1939   }
1940   if( p->pPk ){
1941     iIdx = sqlite3TableColumnToIndex(p->pPk, iIdx);
1942   }
1943   if( iIdx>=p->pCsr->nField || iIdx<0 ){
1944     rc = SQLITE_RANGE;
1945     goto preupdate_old_out;
1946   }
1947 
1948   /* If the old.* record has not yet been loaded into memory, do so now. */
1949   if( p->pUnpacked==0 ){
1950     u32 nRec;
1951     u8 *aRec;
1952 
1953     assert( p->pCsr->eCurType==CURTYPE_BTREE );
1954     nRec = sqlite3BtreePayloadSize(p->pCsr->uc.pCursor);
1955     aRec = sqlite3DbMallocRaw(db, nRec);
1956     if( !aRec ) goto preupdate_old_out;
1957     rc = sqlite3BtreePayload(p->pCsr->uc.pCursor, 0, nRec, aRec);
1958     if( rc==SQLITE_OK ){
1959       p->pUnpacked = vdbeUnpackRecord(&p->keyinfo, nRec, aRec);
1960       if( !p->pUnpacked ) rc = SQLITE_NOMEM;
1961     }
1962     if( rc!=SQLITE_OK ){
1963       sqlite3DbFree(db, aRec);
1964       goto preupdate_old_out;
1965     }
1966     p->aRecord = aRec;
1967   }
1968 
1969   pMem = *ppValue = &p->pUnpacked->aMem[iIdx];
1970   if( iIdx==p->pTab->iPKey ){
1971     sqlite3VdbeMemSetInt64(pMem, p->iKey1);
1972   }else if( iIdx>=p->pUnpacked->nField ){
1973     *ppValue = (sqlite3_value *)columnNullValue();
1974   }else if( p->pTab->aCol[iIdx].affinity==SQLITE_AFF_REAL ){
1975     if( pMem->flags & (MEM_Int|MEM_IntReal) ){
1976       testcase( pMem->flags & MEM_Int );
1977       testcase( pMem->flags & MEM_IntReal );
1978       sqlite3VdbeMemRealify(pMem);
1979     }
1980   }
1981 
1982  preupdate_old_out:
1983   sqlite3Error(db, rc);
1984   return sqlite3ApiExit(db, rc);
1985 }
1986 #endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
1987 
1988 #ifdef SQLITE_ENABLE_PREUPDATE_HOOK
1989 /*
1990 ** This function is called from within a pre-update callback to retrieve
1991 ** the number of columns in the row being updated, deleted or inserted.
1992 */
1993 int sqlite3_preupdate_count(sqlite3 *db){
1994   PreUpdate *p = db->pPreUpdate;
1995   return (p ? p->keyinfo.nKeyField : 0);
1996 }
1997 #endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
1998 
1999 #ifdef SQLITE_ENABLE_PREUPDATE_HOOK
2000 /*
2001 ** This function is designed to be called from within a pre-update callback
2002 ** only. It returns zero if the change that caused the callback was made
2003 ** immediately by a user SQL statement. Or, if the change was made by a
2004 ** trigger program, it returns the number of trigger programs currently
2005 ** on the stack (1 for a top-level trigger, 2 for a trigger fired by a
2006 ** top-level trigger etc.).
2007 **
2008 ** For the purposes of the previous paragraph, a foreign key CASCADE, SET NULL
2009 ** or SET DEFAULT action is considered a trigger.
2010 */
2011 int sqlite3_preupdate_depth(sqlite3 *db){
2012   PreUpdate *p = db->pPreUpdate;
2013   return (p ? p->v->nFrame : 0);
2014 }
2015 #endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
2016 
2017 #ifdef SQLITE_ENABLE_PREUPDATE_HOOK
2018 /*
2019 ** This function is designed to be called from within a pre-update callback
2020 ** only.
2021 */
2022 int sqlite3_preupdate_blobwrite(sqlite3 *db){
2023   PreUpdate *p = db->pPreUpdate;
2024   return (p ? p->iBlobWrite : -1);
2025 }
2026 #endif
2027 
2028 #ifdef SQLITE_ENABLE_PREUPDATE_HOOK
2029 /*
2030 ** This function is called from within a pre-update callback to retrieve
2031 ** a field of the row currently being updated or inserted.
2032 */
2033 int sqlite3_preupdate_new(sqlite3 *db, int iIdx, sqlite3_value **ppValue){
2034   PreUpdate *p = db->pPreUpdate;
2035   int rc = SQLITE_OK;
2036   Mem *pMem;
2037 
2038   if( !p || p->op==SQLITE_DELETE ){
2039     rc = SQLITE_MISUSE_BKPT;
2040     goto preupdate_new_out;
2041   }
2042   if( p->pPk && p->op!=SQLITE_UPDATE ){
2043     iIdx = sqlite3TableColumnToIndex(p->pPk, iIdx);
2044   }
2045   if( iIdx>=p->pCsr->nField || iIdx<0 ){
2046     rc = SQLITE_RANGE;
2047     goto preupdate_new_out;
2048   }
2049 
2050   if( p->op==SQLITE_INSERT ){
2051     /* For an INSERT, memory cell p->iNewReg contains the serialized record
2052     ** that is being inserted. Deserialize it. */
2053     UnpackedRecord *pUnpack = p->pNewUnpacked;
2054     if( !pUnpack ){
2055       Mem *pData = &p->v->aMem[p->iNewReg];
2056       rc = ExpandBlob(pData);
2057       if( rc!=SQLITE_OK ) goto preupdate_new_out;
2058       pUnpack = vdbeUnpackRecord(&p->keyinfo, pData->n, pData->z);
2059       if( !pUnpack ){
2060         rc = SQLITE_NOMEM;
2061         goto preupdate_new_out;
2062       }
2063       p->pNewUnpacked = pUnpack;
2064     }
2065     pMem = &pUnpack->aMem[iIdx];
2066     if( iIdx==p->pTab->iPKey ){
2067       sqlite3VdbeMemSetInt64(pMem, p->iKey2);
2068     }else if( iIdx>=pUnpack->nField ){
2069       pMem = (sqlite3_value *)columnNullValue();
2070     }
2071   }else{
2072     /* For an UPDATE, memory cell (p->iNewReg+1+iIdx) contains the required
2073     ** value. Make a copy of the cell contents and return a pointer to it.
2074     ** It is not safe to return a pointer to the memory cell itself as the
2075     ** caller may modify the value text encoding.
2076     */
2077     assert( p->op==SQLITE_UPDATE );
2078     if( !p->aNew ){
2079       p->aNew = (Mem *)sqlite3DbMallocZero(db, sizeof(Mem) * p->pCsr->nField);
2080       if( !p->aNew ){
2081         rc = SQLITE_NOMEM;
2082         goto preupdate_new_out;
2083       }
2084     }
2085     assert( iIdx>=0 && iIdx<p->pCsr->nField );
2086     pMem = &p->aNew[iIdx];
2087     if( pMem->flags==0 ){
2088       if( iIdx==p->pTab->iPKey ){
2089         sqlite3VdbeMemSetInt64(pMem, p->iKey2);
2090       }else{
2091         rc = sqlite3VdbeMemCopy(pMem, &p->v->aMem[p->iNewReg+1+iIdx]);
2092         if( rc!=SQLITE_OK ) goto preupdate_new_out;
2093       }
2094     }
2095   }
2096   *ppValue = pMem;
2097 
2098  preupdate_new_out:
2099   sqlite3Error(db, rc);
2100   return sqlite3ApiExit(db, rc);
2101 }
2102 #endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
2103 
2104 #ifdef SQLITE_ENABLE_STMT_SCANSTATUS
2105 /*
2106 ** Return status data for a single loop within query pStmt.
2107 */
2108 int sqlite3_stmt_scanstatus(
2109   sqlite3_stmt *pStmt,            /* Prepared statement being queried */
2110   int idx,                        /* Index of loop to report on */
2111   int iScanStatusOp,              /* Which metric to return */
2112   void *pOut                      /* OUT: Write the answer here */
2113 ){
2114   Vdbe *p = (Vdbe*)pStmt;
2115   ScanStatus *pScan;
2116   if( idx<0 || idx>=p->nScan ) return 1;
2117   pScan = &p->aScan[idx];
2118   switch( iScanStatusOp ){
2119     case SQLITE_SCANSTAT_NLOOP: {
2120       *(sqlite3_int64*)pOut = p->anExec[pScan->addrLoop];
2121       break;
2122     }
2123     case SQLITE_SCANSTAT_NVISIT: {
2124       *(sqlite3_int64*)pOut = p->anExec[pScan->addrVisit];
2125       break;
2126     }
2127     case SQLITE_SCANSTAT_EST: {
2128       double r = 1.0;
2129       LogEst x = pScan->nEst;
2130       while( x<100 ){
2131         x += 10;
2132         r *= 0.5;
2133       }
2134       *(double*)pOut = r*sqlite3LogEstToInt(x);
2135       break;
2136     }
2137     case SQLITE_SCANSTAT_NAME: {
2138       *(const char**)pOut = pScan->zName;
2139       break;
2140     }
2141     case SQLITE_SCANSTAT_EXPLAIN: {
2142       if( pScan->addrExplain ){
2143         *(const char**)pOut = p->aOp[ pScan->addrExplain ].p4.z;
2144       }else{
2145         *(const char**)pOut = 0;
2146       }
2147       break;
2148     }
2149     case SQLITE_SCANSTAT_SELECTID: {
2150       if( pScan->addrExplain ){
2151         *(int*)pOut = p->aOp[ pScan->addrExplain ].p1;
2152       }else{
2153         *(int*)pOut = -1;
2154       }
2155       break;
2156     }
2157     default: {
2158       return 1;
2159     }
2160   }
2161   return 0;
2162 }
2163 
2164 /*
2165 ** Zero all counters associated with the sqlite3_stmt_scanstatus() data.
2166 */
2167 void sqlite3_stmt_scanstatus_reset(sqlite3_stmt *pStmt){
2168   Vdbe *p = (Vdbe*)pStmt;
2169   memset(p->anExec, 0, p->nOp * sizeof(i64));
2170 }
2171 #endif /* SQLITE_ENABLE_STMT_SCANSTATUS */
2172