1 /*
2 ** 2003 September 6
3 **
4 ** The author disclaims copyright to this source code. In place of
5 ** a legal notice, here is a blessing:
6 **
7 ** May you do good and not evil.
8 ** May you find forgiveness for yourself and forgive others.
9 ** May you share freely, never taking more than you give.
10 **
11 *************************************************************************
12 ** This file contains code used for creating, destroying, and populating
13 ** a VDBE (or an "sqlite3_stmt" as it is known to the outside world.)
14 */
15 #include "sqliteInt.h"
16 #include "vdbeInt.h"
17
18 /*
19 ** Create a new virtual database engine.
20 */
sqlite3VdbeCreate(Parse * pParse)21 Vdbe *sqlite3VdbeCreate(Parse *pParse){
22 sqlite3 *db = pParse->db;
23 Vdbe *p;
24 p = sqlite3DbMallocRawNN(db, sizeof(Vdbe) );
25 if( p==0 ) return 0;
26 memset(&p->aOp, 0, sizeof(Vdbe)-offsetof(Vdbe,aOp));
27 p->db = db;
28 if( db->pVdbe ){
29 db->pVdbe->pPrev = p;
30 }
31 p->pNext = db->pVdbe;
32 p->pPrev = 0;
33 db->pVdbe = p;
34 p->magic = VDBE_MAGIC_INIT;
35 p->pParse = pParse;
36 assert( pParse->aLabel==0 );
37 assert( pParse->nLabel==0 );
38 assert( pParse->nOpAlloc==0 );
39 assert( pParse->szOpAlloc==0 );
40 return p;
41 }
42
43 /*
44 ** Change the error string stored in Vdbe.zErrMsg
45 */
sqlite3VdbeError(Vdbe * p,const char * zFormat,...)46 void sqlite3VdbeError(Vdbe *p, const char *zFormat, ...){
47 va_list ap;
48 sqlite3DbFree(p->db, p->zErrMsg);
49 va_start(ap, zFormat);
50 p->zErrMsg = sqlite3VMPrintf(p->db, zFormat, ap);
51 va_end(ap);
52 }
53
54 /*
55 ** Remember the SQL string for a prepared statement.
56 */
sqlite3VdbeSetSql(Vdbe * p,const char * z,int n,u8 prepFlags)57 void sqlite3VdbeSetSql(Vdbe *p, const char *z, int n, u8 prepFlags){
58 if( p==0 ) return;
59 p->prepFlags = prepFlags;
60 if( (prepFlags & SQLITE_PREPARE_SAVESQL)==0 ){
61 p->expmask = 0;
62 }
63 assert( p->zSql==0 );
64 p->zSql = sqlite3DbStrNDup(p->db, z, n);
65 }
66
67 /*
68 ** Swap all content between two VDBE structures.
69 */
sqlite3VdbeSwap(Vdbe * pA,Vdbe * pB)70 void sqlite3VdbeSwap(Vdbe *pA, Vdbe *pB){
71 Vdbe tmp, *pTmp;
72 char *zTmp;
73 assert( pA->db==pB->db );
74 tmp = *pA;
75 *pA = *pB;
76 *pB = tmp;
77 pTmp = pA->pNext;
78 pA->pNext = pB->pNext;
79 pB->pNext = pTmp;
80 pTmp = pA->pPrev;
81 pA->pPrev = pB->pPrev;
82 pB->pPrev = pTmp;
83 zTmp = pA->zSql;
84 pA->zSql = pB->zSql;
85 pB->zSql = zTmp;
86 pB->expmask = pA->expmask;
87 pB->prepFlags = pA->prepFlags;
88 memcpy(pB->aCounter, pA->aCounter, sizeof(pB->aCounter));
89 pB->aCounter[SQLITE_STMTSTATUS_REPREPARE]++;
90 }
91
92 /*
93 ** Resize the Vdbe.aOp array so that it is at least nOp elements larger
94 ** than its current size. nOp is guaranteed to be less than or equal
95 ** to 1024/sizeof(Op).
96 **
97 ** If an out-of-memory error occurs while resizing the array, return
98 ** SQLITE_NOMEM. In this case Vdbe.aOp and Parse.nOpAlloc remain
99 ** unchanged (this is so that any opcodes already allocated can be
100 ** correctly deallocated along with the rest of the Vdbe).
101 */
growOpArray(Vdbe * v,int nOp)102 static int growOpArray(Vdbe *v, int nOp){
103 VdbeOp *pNew;
104 Parse *p = v->pParse;
105
106 /* The SQLITE_TEST_REALLOC_STRESS compile-time option is designed to force
107 ** more frequent reallocs and hence provide more opportunities for
108 ** simulated OOM faults. SQLITE_TEST_REALLOC_STRESS is generally used
109 ** during testing only. With SQLITE_TEST_REALLOC_STRESS grow the op array
110 ** by the minimum* amount required until the size reaches 512. Normal
111 ** operation (without SQLITE_TEST_REALLOC_STRESS) is to double the current
112 ** size of the op array or add 1KB of space, whichever is smaller. */
113 #ifdef SQLITE_TEST_REALLOC_STRESS
114 int nNew = (p->nOpAlloc>=512 ? p->nOpAlloc*2 : p->nOpAlloc+nOp);
115 #else
116 int nNew = (p->nOpAlloc ? p->nOpAlloc*2 : (int)(1024/sizeof(Op)));
117 UNUSED_PARAMETER(nOp);
118 #endif
119
120 /* Ensure that the size of a VDBE does not grow too large */
121 if( nNew > p->db->aLimit[SQLITE_LIMIT_VDBE_OP] ){
122 sqlite3OomFault(p->db);
123 return SQLITE_NOMEM;
124 }
125
126 assert( nOp<=(1024/sizeof(Op)) );
127 assert( nNew>=(p->nOpAlloc+nOp) );
128 pNew = sqlite3DbRealloc(p->db, v->aOp, nNew*sizeof(Op));
129 if( pNew ){
130 p->szOpAlloc = sqlite3DbMallocSize(p->db, pNew);
131 p->nOpAlloc = p->szOpAlloc/sizeof(Op);
132 v->aOp = pNew;
133 }
134 return (pNew ? SQLITE_OK : SQLITE_NOMEM_BKPT);
135 }
136
137 #ifdef SQLITE_DEBUG
138 /* This routine is just a convenient place to set a breakpoint that will
139 ** fire after each opcode is inserted and displayed using
140 ** "PRAGMA vdbe_addoptrace=on".
141 */
test_addop_breakpoint(void)142 static void test_addop_breakpoint(void){
143 static int n = 0;
144 n++;
145 }
146 #endif
147
148 /*
149 ** Add a new instruction to the list of instructions current in the
150 ** VDBE. Return the address of the new instruction.
151 **
152 ** Parameters:
153 **
154 ** p Pointer to the VDBE
155 **
156 ** op The opcode for this instruction
157 **
158 ** p1, p2, p3 Operands
159 **
160 ** Use the sqlite3VdbeResolveLabel() function to fix an address and
161 ** the sqlite3VdbeChangeP4() function to change the value of the P4
162 ** operand.
163 */
growOp3(Vdbe * p,int op,int p1,int p2,int p3)164 static SQLITE_NOINLINE int growOp3(Vdbe *p, int op, int p1, int p2, int p3){
165 assert( p->pParse->nOpAlloc<=p->nOp );
166 if( growOpArray(p, 1) ) return 1;
167 assert( p->pParse->nOpAlloc>p->nOp );
168 return sqlite3VdbeAddOp3(p, op, p1, p2, p3);
169 }
sqlite3VdbeAddOp3(Vdbe * p,int op,int p1,int p2,int p3)170 int sqlite3VdbeAddOp3(Vdbe *p, int op, int p1, int p2, int p3){
171 int i;
172 VdbeOp *pOp;
173
174 i = p->nOp;
175 assert( p->magic==VDBE_MAGIC_INIT );
176 assert( op>=0 && op<0xff );
177 if( p->pParse->nOpAlloc<=i ){
178 return growOp3(p, op, p1, p2, p3);
179 }
180 p->nOp++;
181 pOp = &p->aOp[i];
182 pOp->opcode = (u8)op;
183 pOp->p5 = 0;
184 pOp->p1 = p1;
185 pOp->p2 = p2;
186 pOp->p3 = p3;
187 pOp->p4.p = 0;
188 pOp->p4type = P4_NOTUSED;
189 #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
190 pOp->zComment = 0;
191 #endif
192 #ifdef SQLITE_DEBUG
193 if( p->db->flags & SQLITE_VdbeAddopTrace ){
194 int jj, kk;
195 Parse *pParse = p->pParse;
196 for(jj=kk=0; jj<pParse->nColCache; jj++){
197 struct yColCache *x = pParse->aColCache + jj;
198 printf(" r[%d]={%d:%d}", x->iReg, x->iTable, x->iColumn);
199 kk++;
200 }
201 if( kk ) printf("\n");
202 sqlite3VdbePrintOp(0, i, &p->aOp[i]);
203 test_addop_breakpoint();
204 }
205 #endif
206 #ifdef VDBE_PROFILE
207 pOp->cycles = 0;
208 pOp->cnt = 0;
209 #endif
210 #ifdef SQLITE_VDBE_COVERAGE
211 pOp->iSrcLine = 0;
212 #endif
213 return i;
214 }
sqlite3VdbeAddOp0(Vdbe * p,int op)215 int sqlite3VdbeAddOp0(Vdbe *p, int op){
216 return sqlite3VdbeAddOp3(p, op, 0, 0, 0);
217 }
sqlite3VdbeAddOp1(Vdbe * p,int op,int p1)218 int sqlite3VdbeAddOp1(Vdbe *p, int op, int p1){
219 return sqlite3VdbeAddOp3(p, op, p1, 0, 0);
220 }
sqlite3VdbeAddOp2(Vdbe * p,int op,int p1,int p2)221 int sqlite3VdbeAddOp2(Vdbe *p, int op, int p1, int p2){
222 return sqlite3VdbeAddOp3(p, op, p1, p2, 0);
223 }
224
225 /* Generate code for an unconditional jump to instruction iDest
226 */
sqlite3VdbeGoto(Vdbe * p,int iDest)227 int sqlite3VdbeGoto(Vdbe *p, int iDest){
228 return sqlite3VdbeAddOp3(p, OP_Goto, 0, iDest, 0);
229 }
230
231 /* Generate code to cause the string zStr to be loaded into
232 ** register iDest
233 */
sqlite3VdbeLoadString(Vdbe * p,int iDest,const char * zStr)234 int sqlite3VdbeLoadString(Vdbe *p, int iDest, const char *zStr){
235 return sqlite3VdbeAddOp4(p, OP_String8, 0, iDest, 0, zStr, 0);
236 }
237
238 /*
239 ** Generate code that initializes multiple registers to string or integer
240 ** constants. The registers begin with iDest and increase consecutively.
241 ** One register is initialized for each characgter in zTypes[]. For each
242 ** "s" character in zTypes[], the register is a string if the argument is
243 ** not NULL, or OP_Null if the value is a null pointer. For each "i" character
244 ** in zTypes[], the register is initialized to an integer.
245 **
246 ** If the input string does not end with "X" then an OP_ResultRow instruction
247 ** is generated for the values inserted.
248 */
sqlite3VdbeMultiLoad(Vdbe * p,int iDest,const char * zTypes,...)249 void sqlite3VdbeMultiLoad(Vdbe *p, int iDest, const char *zTypes, ...){
250 va_list ap;
251 int i;
252 char c;
253 va_start(ap, zTypes);
254 for(i=0; (c = zTypes[i])!=0; i++){
255 if( c=='s' ){
256 const char *z = va_arg(ap, const char*);
257 sqlite3VdbeAddOp4(p, z==0 ? OP_Null : OP_String8, 0, iDest+i, 0, z, 0);
258 }else if( c=='i' ){
259 sqlite3VdbeAddOp2(p, OP_Integer, va_arg(ap, int), iDest+i);
260 }else{
261 goto skip_op_resultrow;
262 }
263 }
264 sqlite3VdbeAddOp2(p, OP_ResultRow, iDest, i);
265 skip_op_resultrow:
266 va_end(ap);
267 }
268
269 /*
270 ** Add an opcode that includes the p4 value as a pointer.
271 */
sqlite3VdbeAddOp4(Vdbe * p,int op,int p1,int p2,int p3,const char * zP4,int p4type)272 int sqlite3VdbeAddOp4(
273 Vdbe *p, /* Add the opcode to this VM */
274 int op, /* The new opcode */
275 int p1, /* The P1 operand */
276 int p2, /* The P2 operand */
277 int p3, /* The P3 operand */
278 const char *zP4, /* The P4 operand */
279 int p4type /* P4 operand type */
280 ){
281 int addr = sqlite3VdbeAddOp3(p, op, p1, p2, p3);
282 sqlite3VdbeChangeP4(p, addr, zP4, p4type);
283 return addr;
284 }
285
286 /*
287 ** Add an opcode that includes the p4 value with a P4_INT64 or
288 ** P4_REAL type.
289 */
sqlite3VdbeAddOp4Dup8(Vdbe * p,int op,int p1,int p2,int p3,const u8 * zP4,int p4type)290 int sqlite3VdbeAddOp4Dup8(
291 Vdbe *p, /* Add the opcode to this VM */
292 int op, /* The new opcode */
293 int p1, /* The P1 operand */
294 int p2, /* The P2 operand */
295 int p3, /* The P3 operand */
296 const u8 *zP4, /* The P4 operand */
297 int p4type /* P4 operand type */
298 ){
299 char *p4copy = sqlite3DbMallocRawNN(sqlite3VdbeDb(p), 8);
300 if( p4copy ) memcpy(p4copy, zP4, 8);
301 return sqlite3VdbeAddOp4(p, op, p1, p2, p3, p4copy, p4type);
302 }
303
304 /*
305 ** Add an OP_ParseSchema opcode. This routine is broken out from
306 ** sqlite3VdbeAddOp4() since it needs to also needs to mark all btrees
307 ** as having been used.
308 **
309 ** The zWhere string must have been obtained from sqlite3_malloc().
310 ** This routine will take ownership of the allocated memory.
311 */
sqlite3VdbeAddParseSchemaOp(Vdbe * p,int iDb,char * zWhere)312 void sqlite3VdbeAddParseSchemaOp(Vdbe *p, int iDb, char *zWhere){
313 int j;
314 sqlite3VdbeAddOp4(p, OP_ParseSchema, iDb, 0, 0, zWhere, P4_DYNAMIC);
315 for(j=0; j<p->db->nDb; j++) sqlite3VdbeUsesBtree(p, j);
316 }
317
318 /*
319 ** Add an opcode that includes the p4 value as an integer.
320 */
sqlite3VdbeAddOp4Int(Vdbe * p,int op,int p1,int p2,int p3,int p4)321 int sqlite3VdbeAddOp4Int(
322 Vdbe *p, /* Add the opcode to this VM */
323 int op, /* The new opcode */
324 int p1, /* The P1 operand */
325 int p2, /* The P2 operand */
326 int p3, /* The P3 operand */
327 int p4 /* The P4 operand as an integer */
328 ){
329 int addr = sqlite3VdbeAddOp3(p, op, p1, p2, p3);
330 if( p->db->mallocFailed==0 ){
331 VdbeOp *pOp = &p->aOp[addr];
332 pOp->p4type = P4_INT32;
333 pOp->p4.i = p4;
334 }
335 return addr;
336 }
337
338 /* Insert the end of a co-routine
339 */
sqlite3VdbeEndCoroutine(Vdbe * v,int regYield)340 void sqlite3VdbeEndCoroutine(Vdbe *v, int regYield){
341 sqlite3VdbeAddOp1(v, OP_EndCoroutine, regYield);
342
343 /* Clear the temporary register cache, thereby ensuring that each
344 ** co-routine has its own independent set of registers, because co-routines
345 ** might expect their registers to be preserved across an OP_Yield, and
346 ** that could cause problems if two or more co-routines are using the same
347 ** temporary register.
348 */
349 v->pParse->nTempReg = 0;
350 v->pParse->nRangeReg = 0;
351 }
352
353 /*
354 ** Create a new symbolic label for an instruction that has yet to be
355 ** coded. The symbolic label is really just a negative number. The
356 ** label can be used as the P2 value of an operation. Later, when
357 ** the label is resolved to a specific address, the VDBE will scan
358 ** through its operation list and change all values of P2 which match
359 ** the label into the resolved address.
360 **
361 ** The VDBE knows that a P2 value is a label because labels are
362 ** always negative and P2 values are suppose to be non-negative.
363 ** Hence, a negative P2 value is a label that has yet to be resolved.
364 **
365 ** Zero is returned if a malloc() fails.
366 */
sqlite3VdbeMakeLabel(Vdbe * v)367 int sqlite3VdbeMakeLabel(Vdbe *v){
368 Parse *p = v->pParse;
369 int i = p->nLabel++;
370 assert( v->magic==VDBE_MAGIC_INIT );
371 if( (i & (i-1))==0 ){
372 p->aLabel = sqlite3DbReallocOrFree(p->db, p->aLabel,
373 (i*2+1)*sizeof(p->aLabel[0]));
374 }
375 if( p->aLabel ){
376 p->aLabel[i] = -1;
377 }
378 return ADDR(i);
379 }
380
381 /*
382 ** Resolve label "x" to be the address of the next instruction to
383 ** be inserted. The parameter "x" must have been obtained from
384 ** a prior call to sqlite3VdbeMakeLabel().
385 */
sqlite3VdbeResolveLabel(Vdbe * v,int x)386 void sqlite3VdbeResolveLabel(Vdbe *v, int x){
387 Parse *p = v->pParse;
388 int j = ADDR(x);
389 assert( v->magic==VDBE_MAGIC_INIT );
390 assert( j<p->nLabel );
391 assert( j>=0 );
392 if( p->aLabel ){
393 p->aLabel[j] = v->nOp;
394 }
395 }
396
397 /*
398 ** Mark the VDBE as one that can only be run one time.
399 */
sqlite3VdbeRunOnlyOnce(Vdbe * p)400 void sqlite3VdbeRunOnlyOnce(Vdbe *p){
401 p->runOnlyOnce = 1;
402 }
403
404 /*
405 ** Mark the VDBE as one that can only be run multiple times.
406 */
sqlite3VdbeReusable(Vdbe * p)407 void sqlite3VdbeReusable(Vdbe *p){
408 p->runOnlyOnce = 0;
409 }
410
411 #ifdef SQLITE_DEBUG /* sqlite3AssertMayAbort() logic */
412
413 /*
414 ** The following type and function are used to iterate through all opcodes
415 ** in a Vdbe main program and each of the sub-programs (triggers) it may
416 ** invoke directly or indirectly. It should be used as follows:
417 **
418 ** Op *pOp;
419 ** VdbeOpIter sIter;
420 **
421 ** memset(&sIter, 0, sizeof(sIter));
422 ** sIter.v = v; // v is of type Vdbe*
423 ** while( (pOp = opIterNext(&sIter)) ){
424 ** // Do something with pOp
425 ** }
426 ** sqlite3DbFree(v->db, sIter.apSub);
427 **
428 */
429 typedef struct VdbeOpIter VdbeOpIter;
430 struct VdbeOpIter {
431 Vdbe *v; /* Vdbe to iterate through the opcodes of */
432 SubProgram **apSub; /* Array of subprograms */
433 int nSub; /* Number of entries in apSub */
434 int iAddr; /* Address of next instruction to return */
435 int iSub; /* 0 = main program, 1 = first sub-program etc. */
436 };
opIterNext(VdbeOpIter * p)437 static Op *opIterNext(VdbeOpIter *p){
438 Vdbe *v = p->v;
439 Op *pRet = 0;
440 Op *aOp;
441 int nOp;
442
443 if( p->iSub<=p->nSub ){
444
445 if( p->iSub==0 ){
446 aOp = v->aOp;
447 nOp = v->nOp;
448 }else{
449 aOp = p->apSub[p->iSub-1]->aOp;
450 nOp = p->apSub[p->iSub-1]->nOp;
451 }
452 assert( p->iAddr<nOp );
453
454 pRet = &aOp[p->iAddr];
455 p->iAddr++;
456 if( p->iAddr==nOp ){
457 p->iSub++;
458 p->iAddr = 0;
459 }
460
461 if( pRet->p4type==P4_SUBPROGRAM ){
462 int nByte = (p->nSub+1)*sizeof(SubProgram*);
463 int j;
464 for(j=0; j<p->nSub; j++){
465 if( p->apSub[j]==pRet->p4.pProgram ) break;
466 }
467 if( j==p->nSub ){
468 p->apSub = sqlite3DbReallocOrFree(v->db, p->apSub, nByte);
469 if( !p->apSub ){
470 pRet = 0;
471 }else{
472 p->apSub[p->nSub++] = pRet->p4.pProgram;
473 }
474 }
475 }
476 }
477
478 return pRet;
479 }
480
481 /*
482 ** Check if the program stored in the VM associated with pParse may
483 ** throw an ABORT exception (causing the statement, but not entire transaction
484 ** to be rolled back). This condition is true if the main program or any
485 ** sub-programs contains any of the following:
486 **
487 ** * OP_Halt with P1=SQLITE_CONSTRAINT and P2=OE_Abort.
488 ** * OP_HaltIfNull with P1=SQLITE_CONSTRAINT and P2=OE_Abort.
489 ** * OP_Destroy
490 ** * OP_VUpdate
491 ** * OP_VRename
492 ** * OP_FkCounter with P2==0 (immediate foreign key constraint)
493 ** * OP_CreateTable and OP_InitCoroutine (for CREATE TABLE AS SELECT ...)
494 **
495 ** Then check that the value of Parse.mayAbort is true if an
496 ** ABORT may be thrown, or false otherwise. Return true if it does
497 ** match, or false otherwise. This function is intended to be used as
498 ** part of an assert statement in the compiler. Similar to:
499 **
500 ** assert( sqlite3VdbeAssertMayAbort(pParse->pVdbe, pParse->mayAbort) );
501 */
sqlite3VdbeAssertMayAbort(Vdbe * v,int mayAbort)502 int sqlite3VdbeAssertMayAbort(Vdbe *v, int mayAbort){
503 int hasAbort = 0;
504 int hasFkCounter = 0;
505 int hasCreateTable = 0;
506 int hasInitCoroutine = 0;
507 Op *pOp;
508 VdbeOpIter sIter;
509 memset(&sIter, 0, sizeof(sIter));
510 sIter.v = v;
511
512 while( (pOp = opIterNext(&sIter))!=0 ){
513 int opcode = pOp->opcode;
514 if( opcode==OP_Destroy || opcode==OP_VUpdate || opcode==OP_VRename
515 || ((opcode==OP_Halt || opcode==OP_HaltIfNull)
516 && ((pOp->p1&0xff)==SQLITE_CONSTRAINT && pOp->p2==OE_Abort))
517 ){
518 hasAbort = 1;
519 break;
520 }
521 if( opcode==OP_CreateTable ) hasCreateTable = 1;
522 if( opcode==OP_InitCoroutine ) hasInitCoroutine = 1;
523 #ifndef SQLITE_OMIT_FOREIGN_KEY
524 if( opcode==OP_FkCounter && pOp->p1==0 && pOp->p2==1 ){
525 hasFkCounter = 1;
526 }
527 #endif
528 }
529 sqlite3DbFree(v->db, sIter.apSub);
530
531 /* Return true if hasAbort==mayAbort. Or if a malloc failure occurred.
532 ** If malloc failed, then the while() loop above may not have iterated
533 ** through all opcodes and hasAbort may be set incorrectly. Return
534 ** true for this case to prevent the assert() in the callers frame
535 ** from failing. */
536 return ( v->db->mallocFailed || hasAbort==mayAbort || hasFkCounter
537 || (hasCreateTable && hasInitCoroutine) );
538 }
539 #endif /* SQLITE_DEBUG - the sqlite3AssertMayAbort() function */
540
541 /*
542 ** This routine is called after all opcodes have been inserted. It loops
543 ** through all the opcodes and fixes up some details.
544 **
545 ** (1) For each jump instruction with a negative P2 value (a label)
546 ** resolve the P2 value to an actual address.
547 **
548 ** (2) Compute the maximum number of arguments used by any SQL function
549 ** and store that value in *pMaxFuncArgs.
550 **
551 ** (3) Update the Vdbe.readOnly and Vdbe.bIsReader flags to accurately
552 ** indicate what the prepared statement actually does.
553 **
554 ** (4) Initialize the p4.xAdvance pointer on opcodes that use it.
555 **
556 ** (5) Reclaim the memory allocated for storing labels.
557 **
558 ** This routine will only function correctly if the mkopcodeh.tcl generator
559 ** script numbers the opcodes correctly. Changes to this routine must be
560 ** coordinated with changes to mkopcodeh.tcl.
561 */
resolveP2Values(Vdbe * p,int * pMaxFuncArgs)562 static void resolveP2Values(Vdbe *p, int *pMaxFuncArgs){
563 int nMaxArgs = *pMaxFuncArgs;
564 Op *pOp;
565 Parse *pParse = p->pParse;
566 int *aLabel = pParse->aLabel;
567 p->readOnly = 1;
568 p->bIsReader = 0;
569 pOp = &p->aOp[p->nOp-1];
570 while(1){
571
572 /* Only JUMP opcodes and the short list of special opcodes in the switch
573 ** below need to be considered. The mkopcodeh.tcl generator script groups
574 ** all these opcodes together near the front of the opcode list. Skip
575 ** any opcode that does not need processing by virtual of the fact that
576 ** it is larger than SQLITE_MX_JUMP_OPCODE, as a performance optimization.
577 */
578 if( pOp->opcode<=SQLITE_MX_JUMP_OPCODE ){
579 /* NOTE: Be sure to update mkopcodeh.tcl when adding or removing
580 ** cases from this switch! */
581 switch( pOp->opcode ){
582 case OP_Transaction: {
583 if( pOp->p2!=0 ) p->readOnly = 0;
584 /* fall thru */
585 }
586 case OP_AutoCommit:
587 case OP_Savepoint: {
588 p->bIsReader = 1;
589 break;
590 }
591 #ifndef SQLITE_OMIT_WAL
592 case OP_Checkpoint:
593 #endif
594 case OP_Vacuum:
595 case OP_JournalMode: {
596 p->readOnly = 0;
597 p->bIsReader = 1;
598 break;
599 }
600 #ifndef SQLITE_OMIT_VIRTUALTABLE
601 case OP_VUpdate: {
602 if( pOp->p2>nMaxArgs ) nMaxArgs = pOp->p2;
603 break;
604 }
605 case OP_VFilter: {
606 int n;
607 assert( (pOp - p->aOp) >= 3 );
608 assert( pOp[-1].opcode==OP_Integer );
609 n = pOp[-1].p1;
610 if( n>nMaxArgs ) nMaxArgs = n;
611 break;
612 }
613 #endif
614 case OP_Next:
615 case OP_NextIfOpen:
616 case OP_SorterNext: {
617 pOp->p4.xAdvance = sqlite3BtreeNext;
618 pOp->p4type = P4_ADVANCE;
619 break;
620 }
621 case OP_Prev:
622 case OP_PrevIfOpen: {
623 pOp->p4.xAdvance = sqlite3BtreePrevious;
624 pOp->p4type = P4_ADVANCE;
625 break;
626 }
627 }
628 if( (sqlite3OpcodeProperty[pOp->opcode] & OPFLG_JUMP)!=0 && pOp->p2<0 ){
629 assert( ADDR(pOp->p2)<pParse->nLabel );
630 pOp->p2 = aLabel[ADDR(pOp->p2)];
631 }
632 }
633 if( pOp==p->aOp ) break;
634 pOp--;
635 }
636 sqlite3DbFree(p->db, pParse->aLabel);
637 pParse->aLabel = 0;
638 pParse->nLabel = 0;
639 *pMaxFuncArgs = nMaxArgs;
640 assert( p->bIsReader!=0 || DbMaskAllZero(p->btreeMask) );
641 }
642
643 /*
644 ** Return the address of the next instruction to be inserted.
645 */
sqlite3VdbeCurrentAddr(Vdbe * p)646 int sqlite3VdbeCurrentAddr(Vdbe *p){
647 assert( p->magic==VDBE_MAGIC_INIT );
648 return p->nOp;
649 }
650
651 /*
652 ** Verify that at least N opcode slots are available in p without
653 ** having to malloc for more space (except when compiled using
654 ** SQLITE_TEST_REALLOC_STRESS). This interface is used during testing
655 ** to verify that certain calls to sqlite3VdbeAddOpList() can never
656 ** fail due to a OOM fault and hence that the return value from
657 ** sqlite3VdbeAddOpList() will always be non-NULL.
658 */
659 #if defined(SQLITE_DEBUG) && !defined(SQLITE_TEST_REALLOC_STRESS)
sqlite3VdbeVerifyNoMallocRequired(Vdbe * p,int N)660 void sqlite3VdbeVerifyNoMallocRequired(Vdbe *p, int N){
661 assert( p->nOp + N <= p->pParse->nOpAlloc );
662 }
663 #endif
664
665 /*
666 ** Verify that the VM passed as the only argument does not contain
667 ** an OP_ResultRow opcode. Fail an assert() if it does. This is used
668 ** by code in pragma.c to ensure that the implementation of certain
669 ** pragmas comports with the flags specified in the mkpragmatab.tcl
670 ** script.
671 */
672 #if defined(SQLITE_DEBUG) && !defined(SQLITE_TEST_REALLOC_STRESS)
sqlite3VdbeVerifyNoResultRow(Vdbe * p)673 void sqlite3VdbeVerifyNoResultRow(Vdbe *p){
674 int i;
675 for(i=0; i<p->nOp; i++){
676 assert( p->aOp[i].opcode!=OP_ResultRow );
677 }
678 }
679 #endif
680
681 /*
682 ** This function returns a pointer to the array of opcodes associated with
683 ** the Vdbe passed as the first argument. It is the callers responsibility
684 ** to arrange for the returned array to be eventually freed using the
685 ** vdbeFreeOpArray() function.
686 **
687 ** Before returning, *pnOp is set to the number of entries in the returned
688 ** array. Also, *pnMaxArg is set to the larger of its current value and
689 ** the number of entries in the Vdbe.apArg[] array required to execute the
690 ** returned program.
691 */
sqlite3VdbeTakeOpArray(Vdbe * p,int * pnOp,int * pnMaxArg)692 VdbeOp *sqlite3VdbeTakeOpArray(Vdbe *p, int *pnOp, int *pnMaxArg){
693 VdbeOp *aOp = p->aOp;
694 assert( aOp && !p->db->mallocFailed );
695
696 /* Check that sqlite3VdbeUsesBtree() was not called on this VM */
697 assert( DbMaskAllZero(p->btreeMask) );
698
699 resolveP2Values(p, pnMaxArg);
700 *pnOp = p->nOp;
701 p->aOp = 0;
702 return aOp;
703 }
704
705 /*
706 ** Add a whole list of operations to the operation stack. Return a
707 ** pointer to the first operation inserted.
708 **
709 ** Non-zero P2 arguments to jump instructions are automatically adjusted
710 ** so that the jump target is relative to the first operation inserted.
711 */
sqlite3VdbeAddOpList(Vdbe * p,int nOp,VdbeOpList const * aOp,int iLineno)712 VdbeOp *sqlite3VdbeAddOpList(
713 Vdbe *p, /* Add opcodes to the prepared statement */
714 int nOp, /* Number of opcodes to add */
715 VdbeOpList const *aOp, /* The opcodes to be added */
716 int iLineno /* Source-file line number of first opcode */
717 ){
718 int i;
719 VdbeOp *pOut, *pFirst;
720 assert( nOp>0 );
721 assert( p->magic==VDBE_MAGIC_INIT );
722 if( p->nOp + nOp > p->pParse->nOpAlloc && growOpArray(p, nOp) ){
723 return 0;
724 }
725 pFirst = pOut = &p->aOp[p->nOp];
726 for(i=0; i<nOp; i++, aOp++, pOut++){
727 pOut->opcode = aOp->opcode;
728 pOut->p1 = aOp->p1;
729 pOut->p2 = aOp->p2;
730 assert( aOp->p2>=0 );
731 if( (sqlite3OpcodeProperty[aOp->opcode] & OPFLG_JUMP)!=0 && aOp->p2>0 ){
732 pOut->p2 += p->nOp;
733 }
734 pOut->p3 = aOp->p3;
735 pOut->p4type = P4_NOTUSED;
736 pOut->p4.p = 0;
737 pOut->p5 = 0;
738 #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
739 pOut->zComment = 0;
740 #endif
741 #ifdef SQLITE_VDBE_COVERAGE
742 pOut->iSrcLine = iLineno+i;
743 #else
744 (void)iLineno;
745 #endif
746 #ifdef SQLITE_DEBUG
747 if( p->db->flags & SQLITE_VdbeAddopTrace ){
748 sqlite3VdbePrintOp(0, i+p->nOp, &p->aOp[i+p->nOp]);
749 }
750 #endif
751 }
752 p->nOp += nOp;
753 return pFirst;
754 }
755
756 #if defined(SQLITE_ENABLE_STMT_SCANSTATUS)
757 /*
758 ** Add an entry to the array of counters managed by sqlite3_stmt_scanstatus().
759 */
sqlite3VdbeScanStatus(Vdbe * p,int addrExplain,int addrLoop,int addrVisit,LogEst nEst,const char * zName)760 void sqlite3VdbeScanStatus(
761 Vdbe *p, /* VM to add scanstatus() to */
762 int addrExplain, /* Address of OP_Explain (or 0) */
763 int addrLoop, /* Address of loop counter */
764 int addrVisit, /* Address of rows visited counter */
765 LogEst nEst, /* Estimated number of output rows */
766 const char *zName /* Name of table or index being scanned */
767 ){
768 int nByte = (p->nScan+1) * sizeof(ScanStatus);
769 ScanStatus *aNew;
770 aNew = (ScanStatus*)sqlite3DbRealloc(p->db, p->aScan, nByte);
771 if( aNew ){
772 ScanStatus *pNew = &aNew[p->nScan++];
773 pNew->addrExplain = addrExplain;
774 pNew->addrLoop = addrLoop;
775 pNew->addrVisit = addrVisit;
776 pNew->nEst = nEst;
777 pNew->zName = sqlite3DbStrDup(p->db, zName);
778 p->aScan = aNew;
779 }
780 }
781 #endif
782
783
784 /*
785 ** Change the value of the opcode, or P1, P2, P3, or P5 operands
786 ** for a specific instruction.
787 */
sqlite3VdbeChangeOpcode(Vdbe * p,u32 addr,u8 iNewOpcode)788 void sqlite3VdbeChangeOpcode(Vdbe *p, u32 addr, u8 iNewOpcode){
789 sqlite3VdbeGetOp(p,addr)->opcode = iNewOpcode;
790 }
sqlite3VdbeChangeP1(Vdbe * p,u32 addr,int val)791 void sqlite3VdbeChangeP1(Vdbe *p, u32 addr, int val){
792 sqlite3VdbeGetOp(p,addr)->p1 = val;
793 }
sqlite3VdbeChangeP2(Vdbe * p,u32 addr,int val)794 void sqlite3VdbeChangeP2(Vdbe *p, u32 addr, int val){
795 sqlite3VdbeGetOp(p,addr)->p2 = val;
796 }
sqlite3VdbeChangeP3(Vdbe * p,u32 addr,int val)797 void sqlite3VdbeChangeP3(Vdbe *p, u32 addr, int val){
798 sqlite3VdbeGetOp(p,addr)->p3 = val;
799 }
sqlite3VdbeChangeP5(Vdbe * p,u16 p5)800 void sqlite3VdbeChangeP5(Vdbe *p, u16 p5){
801 assert( p->nOp>0 || p->db->mallocFailed );
802 if( p->nOp>0 ) p->aOp[p->nOp-1].p5 = p5;
803 }
804
805 /*
806 ** Change the P2 operand of instruction addr so that it points to
807 ** the address of the next instruction to be coded.
808 */
sqlite3VdbeJumpHere(Vdbe * p,int addr)809 void sqlite3VdbeJumpHere(Vdbe *p, int addr){
810 sqlite3VdbeChangeP2(p, addr, p->nOp);
811 }
812
813
814 /*
815 ** If the input FuncDef structure is ephemeral, then free it. If
816 ** the FuncDef is not ephermal, then do nothing.
817 */
freeEphemeralFunction(sqlite3 * db,FuncDef * pDef)818 static void freeEphemeralFunction(sqlite3 *db, FuncDef *pDef){
819 if( (pDef->funcFlags & SQLITE_FUNC_EPHEM)!=0 ){
820 sqlite3DbFreeNN(db, pDef);
821 }
822 }
823
824 static void vdbeFreeOpArray(sqlite3 *, Op *, int);
825
826 /*
827 ** Delete a P4 value if necessary.
828 */
freeP4Mem(sqlite3 * db,Mem * p)829 static SQLITE_NOINLINE void freeP4Mem(sqlite3 *db, Mem *p){
830 if( p->szMalloc ) sqlite3DbFree(db, p->zMalloc);
831 sqlite3DbFreeNN(db, p);
832 }
freeP4FuncCtx(sqlite3 * db,sqlite3_context * p)833 static SQLITE_NOINLINE void freeP4FuncCtx(sqlite3 *db, sqlite3_context *p){
834 freeEphemeralFunction(db, p->pFunc);
835 sqlite3DbFreeNN(db, p);
836 }
freeP4(sqlite3 * db,int p4type,void * p4)837 static void freeP4(sqlite3 *db, int p4type, void *p4){
838 assert( db );
839 switch( p4type ){
840 case P4_FUNCCTX: {
841 freeP4FuncCtx(db, (sqlite3_context*)p4);
842 break;
843 }
844 case P4_REAL:
845 case P4_INT64:
846 case P4_DYNAMIC:
847 case P4_INTARRAY: {
848 sqlite3DbFree(db, p4);
849 break;
850 }
851 case P4_KEYINFO: {
852 if( db->pnBytesFreed==0 ) sqlite3KeyInfoUnref((KeyInfo*)p4);
853 break;
854 }
855 #ifdef SQLITE_ENABLE_CURSOR_HINTS
856 case P4_EXPR: {
857 sqlite3ExprDelete(db, (Expr*)p4);
858 break;
859 }
860 #endif
861 case P4_FUNCDEF: {
862 freeEphemeralFunction(db, (FuncDef*)p4);
863 break;
864 }
865 case P4_MEM: {
866 if( db->pnBytesFreed==0 ){
867 sqlite3ValueFree((sqlite3_value*)p4);
868 }else{
869 freeP4Mem(db, (Mem*)p4);
870 }
871 break;
872 }
873 case P4_VTAB : {
874 if( db->pnBytesFreed==0 ) sqlite3VtabUnlock((VTable *)p4);
875 break;
876 }
877 }
878 }
879
880 /*
881 ** Free the space allocated for aOp and any p4 values allocated for the
882 ** opcodes contained within. If aOp is not NULL it is assumed to contain
883 ** nOp entries.
884 */
vdbeFreeOpArray(sqlite3 * db,Op * aOp,int nOp)885 static void vdbeFreeOpArray(sqlite3 *db, Op *aOp, int nOp){
886 if( aOp ){
887 Op *pOp;
888 for(pOp=&aOp[nOp-1]; pOp>=aOp; pOp--){
889 if( pOp->p4type <= P4_FREE_IF_LE ) freeP4(db, pOp->p4type, pOp->p4.p);
890 #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
891 sqlite3DbFree(db, pOp->zComment);
892 #endif
893 }
894 sqlite3DbFreeNN(db, aOp);
895 }
896 }
897
898 /*
899 ** Link the SubProgram object passed as the second argument into the linked
900 ** list at Vdbe.pSubProgram. This list is used to delete all sub-program
901 ** objects when the VM is no longer required.
902 */
sqlite3VdbeLinkSubProgram(Vdbe * pVdbe,SubProgram * p)903 void sqlite3VdbeLinkSubProgram(Vdbe *pVdbe, SubProgram *p){
904 p->pNext = pVdbe->pProgram;
905 pVdbe->pProgram = p;
906 }
907
908 /*
909 ** Change the opcode at addr into OP_Noop
910 */
sqlite3VdbeChangeToNoop(Vdbe * p,int addr)911 int sqlite3VdbeChangeToNoop(Vdbe *p, int addr){
912 VdbeOp *pOp;
913 if( p->db->mallocFailed ) return 0;
914 assert( addr>=0 && addr<p->nOp );
915 pOp = &p->aOp[addr];
916 freeP4(p->db, pOp->p4type, pOp->p4.p);
917 pOp->p4type = P4_NOTUSED;
918 pOp->p4.z = 0;
919 pOp->opcode = OP_Noop;
920 return 1;
921 }
922
923 /*
924 ** If the last opcode is "op" and it is not a jump destination,
925 ** then remove it. Return true if and only if an opcode was removed.
926 */
sqlite3VdbeDeletePriorOpcode(Vdbe * p,u8 op)927 int sqlite3VdbeDeletePriorOpcode(Vdbe *p, u8 op){
928 if( p->nOp>0 && p->aOp[p->nOp-1].opcode==op ){
929 return sqlite3VdbeChangeToNoop(p, p->nOp-1);
930 }else{
931 return 0;
932 }
933 }
934
935 /*
936 ** Change the value of the P4 operand for a specific instruction.
937 ** This routine is useful when a large program is loaded from a
938 ** static array using sqlite3VdbeAddOpList but we want to make a
939 ** few minor changes to the program.
940 **
941 ** If n>=0 then the P4 operand is dynamic, meaning that a copy of
942 ** the string is made into memory obtained from sqlite3_malloc().
943 ** A value of n==0 means copy bytes of zP4 up to and including the
944 ** first null byte. If n>0 then copy n+1 bytes of zP4.
945 **
946 ** Other values of n (P4_STATIC, P4_COLLSEQ etc.) indicate that zP4 points
947 ** to a string or structure that is guaranteed to exist for the lifetime of
948 ** the Vdbe. In these cases we can just copy the pointer.
949 **
950 ** If addr<0 then change P4 on the most recently inserted instruction.
951 */
vdbeChangeP4Full(Vdbe * p,Op * pOp,const char * zP4,int n)952 static void SQLITE_NOINLINE vdbeChangeP4Full(
953 Vdbe *p,
954 Op *pOp,
955 const char *zP4,
956 int n
957 ){
958 if( pOp->p4type ){
959 freeP4(p->db, pOp->p4type, pOp->p4.p);
960 pOp->p4type = 0;
961 pOp->p4.p = 0;
962 }
963 if( n<0 ){
964 sqlite3VdbeChangeP4(p, (int)(pOp - p->aOp), zP4, n);
965 }else{
966 if( n==0 ) n = sqlite3Strlen30(zP4);
967 pOp->p4.z = sqlite3DbStrNDup(p->db, zP4, n);
968 pOp->p4type = P4_DYNAMIC;
969 }
970 }
sqlite3VdbeChangeP4(Vdbe * p,int addr,const char * zP4,int n)971 void sqlite3VdbeChangeP4(Vdbe *p, int addr, const char *zP4, int n){
972 Op *pOp;
973 sqlite3 *db;
974 assert( p!=0 );
975 db = p->db;
976 assert( p->magic==VDBE_MAGIC_INIT );
977 assert( p->aOp!=0 || db->mallocFailed );
978 if( db->mallocFailed ){
979 if( n!=P4_VTAB ) freeP4(db, n, (void*)*(char**)&zP4);
980 return;
981 }
982 assert( p->nOp>0 );
983 assert( addr<p->nOp );
984 if( addr<0 ){
985 addr = p->nOp - 1;
986 }
987 pOp = &p->aOp[addr];
988 if( n>=0 || pOp->p4type ){
989 vdbeChangeP4Full(p, pOp, zP4, n);
990 return;
991 }
992 if( n==P4_INT32 ){
993 /* Note: this cast is safe, because the origin data point was an int
994 ** that was cast to a (const char *). */
995 pOp->p4.i = SQLITE_PTR_TO_INT(zP4);
996 pOp->p4type = P4_INT32;
997 }else if( zP4!=0 ){
998 assert( n<0 );
999 pOp->p4.p = (void*)zP4;
1000 pOp->p4type = (signed char)n;
1001 if( n==P4_VTAB ) sqlite3VtabLock((VTable*)zP4);
1002 }
1003 }
1004
1005 /*
1006 ** Change the P4 operand of the most recently coded instruction
1007 ** to the value defined by the arguments. This is a high-speed
1008 ** version of sqlite3VdbeChangeP4().
1009 **
1010 ** The P4 operand must not have been previously defined. And the new
1011 ** P4 must not be P4_INT32. Use sqlite3VdbeChangeP4() in either of
1012 ** those cases.
1013 */
sqlite3VdbeAppendP4(Vdbe * p,void * pP4,int n)1014 void sqlite3VdbeAppendP4(Vdbe *p, void *pP4, int n){
1015 VdbeOp *pOp;
1016 assert( n!=P4_INT32 && n!=P4_VTAB );
1017 assert( n<=0 );
1018 if( p->db->mallocFailed ){
1019 freeP4(p->db, n, pP4);
1020 }else{
1021 assert( pP4!=0 );
1022 assert( p->nOp>0 );
1023 pOp = &p->aOp[p->nOp-1];
1024 assert( pOp->p4type==P4_NOTUSED );
1025 pOp->p4type = n;
1026 pOp->p4.p = pP4;
1027 }
1028 }
1029
1030 /*
1031 ** Set the P4 on the most recently added opcode to the KeyInfo for the
1032 ** index given.
1033 */
sqlite3VdbeSetP4KeyInfo(Parse * pParse,Index * pIdx)1034 void sqlite3VdbeSetP4KeyInfo(Parse *pParse, Index *pIdx){
1035 Vdbe *v = pParse->pVdbe;
1036 KeyInfo *pKeyInfo;
1037 assert( v!=0 );
1038 assert( pIdx!=0 );
1039 pKeyInfo = sqlite3KeyInfoOfIndex(pParse, pIdx);
1040 if( pKeyInfo ) sqlite3VdbeAppendP4(v, pKeyInfo, P4_KEYINFO);
1041 }
1042
1043 #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
1044 /*
1045 ** Change the comment on the most recently coded instruction. Or
1046 ** insert a No-op and add the comment to that new instruction. This
1047 ** makes the code easier to read during debugging. None of this happens
1048 ** in a production build.
1049 */
vdbeVComment(Vdbe * p,const char * zFormat,va_list ap)1050 static void vdbeVComment(Vdbe *p, const char *zFormat, va_list ap){
1051 assert( p->nOp>0 || p->aOp==0 );
1052 assert( p->aOp==0 || p->aOp[p->nOp-1].zComment==0 || p->db->mallocFailed );
1053 if( p->nOp ){
1054 assert( p->aOp );
1055 sqlite3DbFree(p->db, p->aOp[p->nOp-1].zComment);
1056 p->aOp[p->nOp-1].zComment = sqlite3VMPrintf(p->db, zFormat, ap);
1057 }
1058 }
sqlite3VdbeComment(Vdbe * p,const char * zFormat,...)1059 void sqlite3VdbeComment(Vdbe *p, const char *zFormat, ...){
1060 va_list ap;
1061 if( p ){
1062 va_start(ap, zFormat);
1063 vdbeVComment(p, zFormat, ap);
1064 va_end(ap);
1065 }
1066 }
sqlite3VdbeNoopComment(Vdbe * p,const char * zFormat,...)1067 void sqlite3VdbeNoopComment(Vdbe *p, const char *zFormat, ...){
1068 va_list ap;
1069 if( p ){
1070 sqlite3VdbeAddOp0(p, OP_Noop);
1071 va_start(ap, zFormat);
1072 vdbeVComment(p, zFormat, ap);
1073 va_end(ap);
1074 }
1075 }
1076 #endif /* NDEBUG */
1077
1078 #ifdef SQLITE_VDBE_COVERAGE
1079 /*
1080 ** Set the value if the iSrcLine field for the previously coded instruction.
1081 */
sqlite3VdbeSetLineNumber(Vdbe * v,int iLine)1082 void sqlite3VdbeSetLineNumber(Vdbe *v, int iLine){
1083 sqlite3VdbeGetOp(v,-1)->iSrcLine = iLine;
1084 }
1085 #endif /* SQLITE_VDBE_COVERAGE */
1086
1087 /*
1088 ** Return the opcode for a given address. If the address is -1, then
1089 ** return the most recently inserted opcode.
1090 **
1091 ** If a memory allocation error has occurred prior to the calling of this
1092 ** routine, then a pointer to a dummy VdbeOp will be returned. That opcode
1093 ** is readable but not writable, though it is cast to a writable value.
1094 ** The return of a dummy opcode allows the call to continue functioning
1095 ** after an OOM fault without having to check to see if the return from
1096 ** this routine is a valid pointer. But because the dummy.opcode is 0,
1097 ** dummy will never be written to. This is verified by code inspection and
1098 ** by running with Valgrind.
1099 */
sqlite3VdbeGetOp(Vdbe * p,int addr)1100 VdbeOp *sqlite3VdbeGetOp(Vdbe *p, int addr){
1101 /* C89 specifies that the constant "dummy" will be initialized to all
1102 ** zeros, which is correct. MSVC generates a warning, nevertheless. */
1103 static VdbeOp dummy; /* Ignore the MSVC warning about no initializer */
1104 assert( p->magic==VDBE_MAGIC_INIT );
1105 if( addr<0 ){
1106 addr = p->nOp - 1;
1107 }
1108 assert( (addr>=0 && addr<p->nOp) || p->db->mallocFailed );
1109 if( p->db->mallocFailed ){
1110 return (VdbeOp*)&dummy;
1111 }else{
1112 return &p->aOp[addr];
1113 }
1114 }
1115
1116 #if defined(SQLITE_ENABLE_EXPLAIN_COMMENTS)
1117 /*
1118 ** Return an integer value for one of the parameters to the opcode pOp
1119 ** determined by character c.
1120 */
translateP(char c,const Op * pOp)1121 static int translateP(char c, const Op *pOp){
1122 if( c=='1' ) return pOp->p1;
1123 if( c=='2' ) return pOp->p2;
1124 if( c=='3' ) return pOp->p3;
1125 if( c=='4' ) return pOp->p4.i;
1126 return pOp->p5;
1127 }
1128
1129 /*
1130 ** Compute a string for the "comment" field of a VDBE opcode listing.
1131 **
1132 ** The Synopsis: field in comments in the vdbe.c source file gets converted
1133 ** to an extra string that is appended to the sqlite3OpcodeName(). In the
1134 ** absence of other comments, this synopsis becomes the comment on the opcode.
1135 ** Some translation occurs:
1136 **
1137 ** "PX" -> "r[X]"
1138 ** "PX@PY" -> "r[X..X+Y-1]" or "r[x]" if y is 0 or 1
1139 ** "PX@PY+1" -> "r[X..X+Y]" or "r[x]" if y is 0
1140 ** "PY..PY" -> "r[X..Y]" or "r[x]" if y<=x
1141 */
displayComment(const Op * pOp,const char * zP4,char * zTemp,int nTemp)1142 static int displayComment(
1143 const Op *pOp, /* The opcode to be commented */
1144 const char *zP4, /* Previously obtained value for P4 */
1145 char *zTemp, /* Write result here */
1146 int nTemp /* Space available in zTemp[] */
1147 ){
1148 const char *zOpName;
1149 const char *zSynopsis;
1150 int nOpName;
1151 int ii, jj;
1152 char zAlt[50];
1153 zOpName = sqlite3OpcodeName(pOp->opcode);
1154 nOpName = sqlite3Strlen30(zOpName);
1155 if( zOpName[nOpName+1] ){
1156 int seenCom = 0;
1157 char c;
1158 zSynopsis = zOpName += nOpName + 1;
1159 if( strncmp(zSynopsis,"IF ",3)==0 ){
1160 if( pOp->p5 & SQLITE_STOREP2 ){
1161 sqlite3_snprintf(sizeof(zAlt), zAlt, "r[P2] = (%s)", zSynopsis+3);
1162 }else{
1163 sqlite3_snprintf(sizeof(zAlt), zAlt, "if %s goto P2", zSynopsis+3);
1164 }
1165 zSynopsis = zAlt;
1166 }
1167 for(ii=jj=0; jj<nTemp-1 && (c = zSynopsis[ii])!=0; ii++){
1168 if( c=='P' ){
1169 c = zSynopsis[++ii];
1170 if( c=='4' ){
1171 sqlite3_snprintf(nTemp-jj, zTemp+jj, "%s", zP4);
1172 }else if( c=='X' ){
1173 sqlite3_snprintf(nTemp-jj, zTemp+jj, "%s", pOp->zComment);
1174 seenCom = 1;
1175 }else{
1176 int v1 = translateP(c, pOp);
1177 int v2;
1178 sqlite3_snprintf(nTemp-jj, zTemp+jj, "%d", v1);
1179 if( strncmp(zSynopsis+ii+1, "@P", 2)==0 ){
1180 ii += 3;
1181 jj += sqlite3Strlen30(zTemp+jj);
1182 v2 = translateP(zSynopsis[ii], pOp);
1183 if( strncmp(zSynopsis+ii+1,"+1",2)==0 ){
1184 ii += 2;
1185 v2++;
1186 }
1187 if( v2>1 ){
1188 sqlite3_snprintf(nTemp-jj, zTemp+jj, "..%d", v1+v2-1);
1189 }
1190 }else if( strncmp(zSynopsis+ii+1, "..P3", 4)==0 && pOp->p3==0 ){
1191 ii += 4;
1192 }
1193 }
1194 jj += sqlite3Strlen30(zTemp+jj);
1195 }else{
1196 zTemp[jj++] = c;
1197 }
1198 }
1199 if( !seenCom && jj<nTemp-5 && pOp->zComment ){
1200 sqlite3_snprintf(nTemp-jj, zTemp+jj, "; %s", pOp->zComment);
1201 jj += sqlite3Strlen30(zTemp+jj);
1202 }
1203 if( jj<nTemp ) zTemp[jj] = 0;
1204 }else if( pOp->zComment ){
1205 sqlite3_snprintf(nTemp, zTemp, "%s", pOp->zComment);
1206 jj = sqlite3Strlen30(zTemp);
1207 }else{
1208 zTemp[0] = 0;
1209 jj = 0;
1210 }
1211 return jj;
1212 }
1213 #endif /* SQLITE_DEBUG */
1214
1215 #if VDBE_DISPLAY_P4 && defined(SQLITE_ENABLE_CURSOR_HINTS)
1216 /*
1217 ** Translate the P4.pExpr value for an OP_CursorHint opcode into text
1218 ** that can be displayed in the P4 column of EXPLAIN output.
1219 */
displayP4Expr(StrAccum * p,Expr * pExpr)1220 static void displayP4Expr(StrAccum *p, Expr *pExpr){
1221 const char *zOp = 0;
1222 switch( pExpr->op ){
1223 case TK_STRING:
1224 sqlite3XPrintf(p, "%Q", pExpr->u.zToken);
1225 break;
1226 case TK_INTEGER:
1227 sqlite3XPrintf(p, "%d", pExpr->u.iValue);
1228 break;
1229 case TK_NULL:
1230 sqlite3XPrintf(p, "NULL");
1231 break;
1232 case TK_REGISTER: {
1233 sqlite3XPrintf(p, "r[%d]", pExpr->iTable);
1234 break;
1235 }
1236 case TK_COLUMN: {
1237 if( pExpr->iColumn<0 ){
1238 sqlite3XPrintf(p, "rowid");
1239 }else{
1240 sqlite3XPrintf(p, "c%d", (int)pExpr->iColumn);
1241 }
1242 break;
1243 }
1244 case TK_LT: zOp = "LT"; break;
1245 case TK_LE: zOp = "LE"; break;
1246 case TK_GT: zOp = "GT"; break;
1247 case TK_GE: zOp = "GE"; break;
1248 case TK_NE: zOp = "NE"; break;
1249 case TK_EQ: zOp = "EQ"; break;
1250 case TK_IS: zOp = "IS"; break;
1251 case TK_ISNOT: zOp = "ISNOT"; break;
1252 case TK_AND: zOp = "AND"; break;
1253 case TK_OR: zOp = "OR"; break;
1254 case TK_PLUS: zOp = "ADD"; break;
1255 case TK_STAR: zOp = "MUL"; break;
1256 case TK_MINUS: zOp = "SUB"; break;
1257 case TK_REM: zOp = "REM"; break;
1258 case TK_BITAND: zOp = "BITAND"; break;
1259 case TK_BITOR: zOp = "BITOR"; break;
1260 case TK_SLASH: zOp = "DIV"; break;
1261 case TK_LSHIFT: zOp = "LSHIFT"; break;
1262 case TK_RSHIFT: zOp = "RSHIFT"; break;
1263 case TK_CONCAT: zOp = "CONCAT"; break;
1264 case TK_UMINUS: zOp = "MINUS"; break;
1265 case TK_UPLUS: zOp = "PLUS"; break;
1266 case TK_BITNOT: zOp = "BITNOT"; break;
1267 case TK_NOT: zOp = "NOT"; break;
1268 case TK_ISNULL: zOp = "ISNULL"; break;
1269 case TK_NOTNULL: zOp = "NOTNULL"; break;
1270
1271 default:
1272 sqlite3XPrintf(p, "%s", "expr");
1273 break;
1274 }
1275
1276 if( zOp ){
1277 sqlite3XPrintf(p, "%s(", zOp);
1278 displayP4Expr(p, pExpr->pLeft);
1279 if( pExpr->pRight ){
1280 sqlite3StrAccumAppend(p, ",", 1);
1281 displayP4Expr(p, pExpr->pRight);
1282 }
1283 sqlite3StrAccumAppend(p, ")", 1);
1284 }
1285 }
1286 #endif /* VDBE_DISPLAY_P4 && defined(SQLITE_ENABLE_CURSOR_HINTS) */
1287
1288
1289 #if VDBE_DISPLAY_P4
1290 /*
1291 ** Compute a string that describes the P4 parameter for an opcode.
1292 ** Use zTemp for any required temporary buffer space.
1293 */
displayP4(Op * pOp,char * zTemp,int nTemp)1294 static char *displayP4(Op *pOp, char *zTemp, int nTemp){
1295 char *zP4 = zTemp;
1296 StrAccum x;
1297 assert( nTemp>=20 );
1298 sqlite3StrAccumInit(&x, 0, zTemp, nTemp, 0);
1299 switch( pOp->p4type ){
1300 case P4_KEYINFO: {
1301 int j;
1302 KeyInfo *pKeyInfo = pOp->p4.pKeyInfo;
1303 assert( pKeyInfo->aSortOrder!=0 );
1304 sqlite3XPrintf(&x, "k(%d", pKeyInfo->nField);
1305 for(j=0; j<pKeyInfo->nField; j++){
1306 CollSeq *pColl = pKeyInfo->aColl[j];
1307 const char *zColl = pColl ? pColl->zName : "";
1308 if( strcmp(zColl, "BINARY")==0 ) zColl = "B";
1309 sqlite3XPrintf(&x, ",%s%s", pKeyInfo->aSortOrder[j] ? "-" : "", zColl);
1310 }
1311 sqlite3StrAccumAppend(&x, ")", 1);
1312 break;
1313 }
1314 #ifdef SQLITE_ENABLE_CURSOR_HINTS
1315 case P4_EXPR: {
1316 displayP4Expr(&x, pOp->p4.pExpr);
1317 break;
1318 }
1319 #endif
1320 case P4_COLLSEQ: {
1321 CollSeq *pColl = pOp->p4.pColl;
1322 sqlite3XPrintf(&x, "(%.20s)", pColl->zName);
1323 break;
1324 }
1325 case P4_FUNCDEF: {
1326 FuncDef *pDef = pOp->p4.pFunc;
1327 sqlite3XPrintf(&x, "%s(%d)", pDef->zName, pDef->nArg);
1328 break;
1329 }
1330 #if defined(SQLITE_DEBUG) || defined(VDBE_PROFILE)
1331 case P4_FUNCCTX: {
1332 FuncDef *pDef = pOp->p4.pCtx->pFunc;
1333 sqlite3XPrintf(&x, "%s(%d)", pDef->zName, pDef->nArg);
1334 break;
1335 }
1336 #endif
1337 case P4_INT64: {
1338 sqlite3XPrintf(&x, "%lld", *pOp->p4.pI64);
1339 break;
1340 }
1341 case P4_INT32: {
1342 sqlite3XPrintf(&x, "%d", pOp->p4.i);
1343 break;
1344 }
1345 case P4_REAL: {
1346 sqlite3XPrintf(&x, "%.16g", *pOp->p4.pReal);
1347 break;
1348 }
1349 case P4_MEM: {
1350 Mem *pMem = pOp->p4.pMem;
1351 if( pMem->flags & MEM_Str ){
1352 zP4 = pMem->z;
1353 }else if( pMem->flags & MEM_Int ){
1354 sqlite3XPrintf(&x, "%lld", pMem->u.i);
1355 }else if( pMem->flags & MEM_Real ){
1356 sqlite3XPrintf(&x, "%.16g", pMem->u.r);
1357 }else if( pMem->flags & MEM_Null ){
1358 zP4 = "NULL";
1359 }else{
1360 assert( pMem->flags & MEM_Blob );
1361 zP4 = "(blob)";
1362 }
1363 break;
1364 }
1365 #ifndef SQLITE_OMIT_VIRTUALTABLE
1366 case P4_VTAB: {
1367 sqlite3_vtab *pVtab = pOp->p4.pVtab->pVtab;
1368 sqlite3XPrintf(&x, "vtab:%p", pVtab);
1369 break;
1370 }
1371 #endif
1372 case P4_INTARRAY: {
1373 int i;
1374 int *ai = pOp->p4.ai;
1375 int n = ai[0]; /* The first element of an INTARRAY is always the
1376 ** count of the number of elements to follow */
1377 for(i=1; i<n; i++){
1378 sqlite3XPrintf(&x, ",%d", ai[i]);
1379 }
1380 zTemp[0] = '[';
1381 sqlite3StrAccumAppend(&x, "]", 1);
1382 break;
1383 }
1384 case P4_SUBPROGRAM: {
1385 sqlite3XPrintf(&x, "program");
1386 break;
1387 }
1388 case P4_ADVANCE: {
1389 zTemp[0] = 0;
1390 break;
1391 }
1392 case P4_TABLE: {
1393 sqlite3XPrintf(&x, "%s", pOp->p4.pTab->zName);
1394 break;
1395 }
1396 default: {
1397 zP4 = pOp->p4.z;
1398 if( zP4==0 ){
1399 zP4 = zTemp;
1400 zTemp[0] = 0;
1401 }
1402 }
1403 }
1404 sqlite3StrAccumFinish(&x);
1405 assert( zP4!=0 );
1406 return zP4;
1407 }
1408 #endif /* VDBE_DISPLAY_P4 */
1409
1410 /*
1411 ** Declare to the Vdbe that the BTree object at db->aDb[i] is used.
1412 **
1413 ** The prepared statements need to know in advance the complete set of
1414 ** attached databases that will be use. A mask of these databases
1415 ** is maintained in p->btreeMask. The p->lockMask value is the subset of
1416 ** p->btreeMask of databases that will require a lock.
1417 */
sqlite3VdbeUsesBtree(Vdbe * p,int i)1418 void sqlite3VdbeUsesBtree(Vdbe *p, int i){
1419 assert( i>=0 && i<p->db->nDb && i<(int)sizeof(yDbMask)*8 );
1420 assert( i<(int)sizeof(p->btreeMask)*8 );
1421 DbMaskSet(p->btreeMask, i);
1422 if( i!=1 && sqlite3BtreeSharable(p->db->aDb[i].pBt) ){
1423 DbMaskSet(p->lockMask, i);
1424 }
1425 }
1426
1427 #if !defined(SQLITE_OMIT_SHARED_CACHE)
1428 /*
1429 ** If SQLite is compiled to support shared-cache mode and to be threadsafe,
1430 ** this routine obtains the mutex associated with each BtShared structure
1431 ** that may be accessed by the VM passed as an argument. In doing so it also
1432 ** sets the BtShared.db member of each of the BtShared structures, ensuring
1433 ** that the correct busy-handler callback is invoked if required.
1434 **
1435 ** If SQLite is not threadsafe but does support shared-cache mode, then
1436 ** sqlite3BtreeEnter() is invoked to set the BtShared.db variables
1437 ** of all of BtShared structures accessible via the database handle
1438 ** associated with the VM.
1439 **
1440 ** If SQLite is not threadsafe and does not support shared-cache mode, this
1441 ** function is a no-op.
1442 **
1443 ** The p->btreeMask field is a bitmask of all btrees that the prepared
1444 ** statement p will ever use. Let N be the number of bits in p->btreeMask
1445 ** corresponding to btrees that use shared cache. Then the runtime of
1446 ** this routine is N*N. But as N is rarely more than 1, this should not
1447 ** be a problem.
1448 */
sqlite3VdbeEnter(Vdbe * p)1449 void sqlite3VdbeEnter(Vdbe *p){
1450 int i;
1451 sqlite3 *db;
1452 Db *aDb;
1453 int nDb;
1454 if( DbMaskAllZero(p->lockMask) ) return; /* The common case */
1455 db = p->db;
1456 aDb = db->aDb;
1457 nDb = db->nDb;
1458 for(i=0; i<nDb; i++){
1459 if( i!=1 && DbMaskTest(p->lockMask,i) && ALWAYS(aDb[i].pBt!=0) ){
1460 sqlite3BtreeEnter(aDb[i].pBt);
1461 }
1462 }
1463 }
1464 #endif
1465
1466 #if !defined(SQLITE_OMIT_SHARED_CACHE) && SQLITE_THREADSAFE>0
1467 /*
1468 ** Unlock all of the btrees previously locked by a call to sqlite3VdbeEnter().
1469 */
vdbeLeave(Vdbe * p)1470 static SQLITE_NOINLINE void vdbeLeave(Vdbe *p){
1471 int i;
1472 sqlite3 *db;
1473 Db *aDb;
1474 int nDb;
1475 db = p->db;
1476 aDb = db->aDb;
1477 nDb = db->nDb;
1478 for(i=0; i<nDb; i++){
1479 if( i!=1 && DbMaskTest(p->lockMask,i) && ALWAYS(aDb[i].pBt!=0) ){
1480 sqlite3BtreeLeave(aDb[i].pBt);
1481 }
1482 }
1483 }
sqlite3VdbeLeave(Vdbe * p)1484 void sqlite3VdbeLeave(Vdbe *p){
1485 if( DbMaskAllZero(p->lockMask) ) return; /* The common case */
1486 vdbeLeave(p);
1487 }
1488 #endif
1489
1490 #if defined(VDBE_PROFILE) || defined(SQLITE_DEBUG)
1491 /*
1492 ** Print a single opcode. This routine is used for debugging only.
1493 */
sqlite3VdbePrintOp(FILE * pOut,int pc,Op * pOp)1494 void sqlite3VdbePrintOp(FILE *pOut, int pc, Op *pOp){
1495 char *zP4;
1496 char zPtr[50];
1497 char zCom[100];
1498 static const char *zFormat1 = "%4d %-13s %4d %4d %4d %-13s %.2X %s\n";
1499 if( pOut==0 ) pOut = stdout;
1500 zP4 = displayP4(pOp, zPtr, sizeof(zPtr));
1501 #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
1502 displayComment(pOp, zP4, zCom, sizeof(zCom));
1503 #else
1504 zCom[0] = 0;
1505 #endif
1506 /* NB: The sqlite3OpcodeName() function is implemented by code created
1507 ** by the mkopcodeh.awk and mkopcodec.awk scripts which extract the
1508 ** information from the vdbe.c source text */
1509 fprintf(pOut, zFormat1, pc,
1510 sqlite3OpcodeName(pOp->opcode), pOp->p1, pOp->p2, pOp->p3, zP4, pOp->p5,
1511 zCom
1512 );
1513 fflush(pOut);
1514 }
1515 #endif
1516
1517 /*
1518 ** Initialize an array of N Mem element.
1519 */
initMemArray(Mem * p,int N,sqlite3 * db,u16 flags)1520 static void initMemArray(Mem *p, int N, sqlite3 *db, u16 flags){
1521 while( (N--)>0 ){
1522 p->db = db;
1523 p->flags = flags;
1524 p->szMalloc = 0;
1525 #ifdef SQLITE_DEBUG
1526 p->pScopyFrom = 0;
1527 #endif
1528 p++;
1529 }
1530 }
1531
1532 /*
1533 ** Release an array of N Mem elements
1534 */
releaseMemArray(Mem * p,int N)1535 static void releaseMemArray(Mem *p, int N){
1536 if( p && N ){
1537 Mem *pEnd = &p[N];
1538 sqlite3 *db = p->db;
1539 if( db->pnBytesFreed ){
1540 do{
1541 if( p->szMalloc ) sqlite3DbFree(db, p->zMalloc);
1542 }while( (++p)<pEnd );
1543 return;
1544 }
1545 do{
1546 assert( (&p[1])==pEnd || p[0].db==p[1].db );
1547 assert( sqlite3VdbeCheckMemInvariants(p) );
1548
1549 /* This block is really an inlined version of sqlite3VdbeMemRelease()
1550 ** that takes advantage of the fact that the memory cell value is
1551 ** being set to NULL after releasing any dynamic resources.
1552 **
1553 ** The justification for duplicating code is that according to
1554 ** callgrind, this causes a certain test case to hit the CPU 4.7
1555 ** percent less (x86 linux, gcc version 4.1.2, -O6) than if
1556 ** sqlite3MemRelease() were called from here. With -O2, this jumps
1557 ** to 6.6 percent. The test case is inserting 1000 rows into a table
1558 ** with no indexes using a single prepared INSERT statement, bind()
1559 ** and reset(). Inserts are grouped into a transaction.
1560 */
1561 testcase( p->flags & MEM_Agg );
1562 testcase( p->flags & MEM_Dyn );
1563 testcase( p->flags & MEM_Frame );
1564 testcase( p->flags & MEM_RowSet );
1565 if( p->flags&(MEM_Agg|MEM_Dyn|MEM_Frame|MEM_RowSet) ){
1566 sqlite3VdbeMemRelease(p);
1567 }else if( p->szMalloc ){
1568 sqlite3DbFreeNN(db, p->zMalloc);
1569 p->szMalloc = 0;
1570 }
1571
1572 p->flags = MEM_Undefined;
1573 }while( (++p)<pEnd );
1574 }
1575 }
1576
1577 /*
1578 ** Delete a VdbeFrame object and its contents. VdbeFrame objects are
1579 ** allocated by the OP_Program opcode in sqlite3VdbeExec().
1580 */
sqlite3VdbeFrameDelete(VdbeFrame * p)1581 void sqlite3VdbeFrameDelete(VdbeFrame *p){
1582 int i;
1583 Mem *aMem = VdbeFrameMem(p);
1584 VdbeCursor **apCsr = (VdbeCursor **)&aMem[p->nChildMem];
1585 for(i=0; i<p->nChildCsr; i++){
1586 sqlite3VdbeFreeCursor(p->v, apCsr[i]);
1587 }
1588 releaseMemArray(aMem, p->nChildMem);
1589 sqlite3VdbeDeleteAuxData(p->v->db, &p->pAuxData, -1, 0);
1590 sqlite3DbFree(p->v->db, p);
1591 }
1592
1593 #ifndef SQLITE_OMIT_EXPLAIN
1594 /*
1595 ** Give a listing of the program in the virtual machine.
1596 **
1597 ** The interface is the same as sqlite3VdbeExec(). But instead of
1598 ** running the code, it invokes the callback once for each instruction.
1599 ** This feature is used to implement "EXPLAIN".
1600 **
1601 ** When p->explain==1, each instruction is listed. When
1602 ** p->explain==2, only OP_Explain instructions are listed and these
1603 ** are shown in a different format. p->explain==2 is used to implement
1604 ** EXPLAIN QUERY PLAN.
1605 **
1606 ** When p->explain==1, first the main program is listed, then each of
1607 ** the trigger subprograms are listed one by one.
1608 */
sqlite3VdbeList(Vdbe * p)1609 int sqlite3VdbeList(
1610 Vdbe *p /* The VDBE */
1611 ){
1612 int nRow; /* Stop when row count reaches this */
1613 int nSub = 0; /* Number of sub-vdbes seen so far */
1614 SubProgram **apSub = 0; /* Array of sub-vdbes */
1615 Mem *pSub = 0; /* Memory cell hold array of subprogs */
1616 sqlite3 *db = p->db; /* The database connection */
1617 int i; /* Loop counter */
1618 int rc = SQLITE_OK; /* Return code */
1619 Mem *pMem = &p->aMem[1]; /* First Mem of result set */
1620
1621 assert( p->explain );
1622 assert( p->magic==VDBE_MAGIC_RUN );
1623 assert( p->rc==SQLITE_OK || p->rc==SQLITE_BUSY || p->rc==SQLITE_NOMEM );
1624
1625 /* Even though this opcode does not use dynamic strings for
1626 ** the result, result columns may become dynamic if the user calls
1627 ** sqlite3_column_text16(), causing a translation to UTF-16 encoding.
1628 */
1629 releaseMemArray(pMem, 8);
1630 p->pResultSet = 0;
1631
1632 if( p->rc==SQLITE_NOMEM_BKPT ){
1633 /* This happens if a malloc() inside a call to sqlite3_column_text() or
1634 ** sqlite3_column_text16() failed. */
1635 sqlite3OomFault(db);
1636 return SQLITE_ERROR;
1637 }
1638
1639 /* When the number of output rows reaches nRow, that means the
1640 ** listing has finished and sqlite3_step() should return SQLITE_DONE.
1641 ** nRow is the sum of the number of rows in the main program, plus
1642 ** the sum of the number of rows in all trigger subprograms encountered
1643 ** so far. The nRow value will increase as new trigger subprograms are
1644 ** encountered, but p->pc will eventually catch up to nRow.
1645 */
1646 nRow = p->nOp;
1647 if( p->explain==1 ){
1648 /* The first 8 memory cells are used for the result set. So we will
1649 ** commandeer the 9th cell to use as storage for an array of pointers
1650 ** to trigger subprograms. The VDBE is guaranteed to have at least 9
1651 ** cells. */
1652 assert( p->nMem>9 );
1653 pSub = &p->aMem[9];
1654 if( pSub->flags&MEM_Blob ){
1655 /* On the first call to sqlite3_step(), pSub will hold a NULL. It is
1656 ** initialized to a BLOB by the P4_SUBPROGRAM processing logic below */
1657 nSub = pSub->n/sizeof(Vdbe*);
1658 apSub = (SubProgram **)pSub->z;
1659 }
1660 for(i=0; i<nSub; i++){
1661 nRow += apSub[i]->nOp;
1662 }
1663 }
1664
1665 do{
1666 i = p->pc++;
1667 }while( i<nRow && p->explain==2 && p->aOp[i].opcode!=OP_Explain );
1668 if( i>=nRow ){
1669 p->rc = SQLITE_OK;
1670 rc = SQLITE_DONE;
1671 }else if( db->u1.isInterrupted ){
1672 p->rc = SQLITE_INTERRUPT;
1673 rc = SQLITE_ERROR;
1674 sqlite3VdbeError(p, sqlite3ErrStr(p->rc));
1675 }else{
1676 char *zP4;
1677 Op *pOp;
1678 if( i<p->nOp ){
1679 /* The output line number is small enough that we are still in the
1680 ** main program. */
1681 pOp = &p->aOp[i];
1682 }else{
1683 /* We are currently listing subprograms. Figure out which one and
1684 ** pick up the appropriate opcode. */
1685 int j;
1686 i -= p->nOp;
1687 for(j=0; i>=apSub[j]->nOp; j++){
1688 i -= apSub[j]->nOp;
1689 }
1690 pOp = &apSub[j]->aOp[i];
1691 }
1692 if( p->explain==1 ){
1693 pMem->flags = MEM_Int;
1694 pMem->u.i = i; /* Program counter */
1695 pMem++;
1696
1697 pMem->flags = MEM_Static|MEM_Str|MEM_Term;
1698 pMem->z = (char*)sqlite3OpcodeName(pOp->opcode); /* Opcode */
1699 assert( pMem->z!=0 );
1700 pMem->n = sqlite3Strlen30(pMem->z);
1701 pMem->enc = SQLITE_UTF8;
1702 pMem++;
1703
1704 /* When an OP_Program opcode is encounter (the only opcode that has
1705 ** a P4_SUBPROGRAM argument), expand the size of the array of subprograms
1706 ** kept in p->aMem[9].z to hold the new program - assuming this subprogram
1707 ** has not already been seen.
1708 */
1709 if( pOp->p4type==P4_SUBPROGRAM ){
1710 int nByte = (nSub+1)*sizeof(SubProgram*);
1711 int j;
1712 for(j=0; j<nSub; j++){
1713 if( apSub[j]==pOp->p4.pProgram ) break;
1714 }
1715 if( j==nSub && SQLITE_OK==sqlite3VdbeMemGrow(pSub, nByte, nSub!=0) ){
1716 apSub = (SubProgram **)pSub->z;
1717 apSub[nSub++] = pOp->p4.pProgram;
1718 pSub->flags |= MEM_Blob;
1719 pSub->n = nSub*sizeof(SubProgram*);
1720 }
1721 }
1722 }
1723
1724 pMem->flags = MEM_Int;
1725 pMem->u.i = pOp->p1; /* P1 */
1726 pMem++;
1727
1728 pMem->flags = MEM_Int;
1729 pMem->u.i = pOp->p2; /* P2 */
1730 pMem++;
1731
1732 pMem->flags = MEM_Int;
1733 pMem->u.i = pOp->p3; /* P3 */
1734 pMem++;
1735
1736 if( sqlite3VdbeMemClearAndResize(pMem, 100) ){ /* P4 */
1737 assert( p->db->mallocFailed );
1738 return SQLITE_ERROR;
1739 }
1740 pMem->flags = MEM_Str|MEM_Term;
1741 zP4 = displayP4(pOp, pMem->z, pMem->szMalloc);
1742 if( zP4!=pMem->z ){
1743 pMem->n = 0;
1744 sqlite3VdbeMemSetStr(pMem, zP4, -1, SQLITE_UTF8, 0);
1745 }else{
1746 assert( pMem->z!=0 );
1747 pMem->n = sqlite3Strlen30(pMem->z);
1748 pMem->enc = SQLITE_UTF8;
1749 }
1750 pMem++;
1751
1752 if( p->explain==1 ){
1753 if( sqlite3VdbeMemClearAndResize(pMem, 4) ){
1754 assert( p->db->mallocFailed );
1755 return SQLITE_ERROR;
1756 }
1757 pMem->flags = MEM_Str|MEM_Term;
1758 pMem->n = 2;
1759 sqlite3_snprintf(3, pMem->z, "%.2x", pOp->p5); /* P5 */
1760 pMem->enc = SQLITE_UTF8;
1761 pMem++;
1762
1763 #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
1764 if( sqlite3VdbeMemClearAndResize(pMem, 500) ){
1765 assert( p->db->mallocFailed );
1766 return SQLITE_ERROR;
1767 }
1768 pMem->flags = MEM_Str|MEM_Term;
1769 pMem->n = displayComment(pOp, zP4, pMem->z, 500);
1770 pMem->enc = SQLITE_UTF8;
1771 #else
1772 pMem->flags = MEM_Null; /* Comment */
1773 #endif
1774 }
1775
1776 p->nResColumn = 8 - 4*(p->explain-1);
1777 p->pResultSet = &p->aMem[1];
1778 p->rc = SQLITE_OK;
1779 rc = SQLITE_ROW;
1780 }
1781 return rc;
1782 }
1783 #endif /* SQLITE_OMIT_EXPLAIN */
1784
1785 #ifdef SQLITE_DEBUG
1786 /*
1787 ** Print the SQL that was used to generate a VDBE program.
1788 */
sqlite3VdbePrintSql(Vdbe * p)1789 void sqlite3VdbePrintSql(Vdbe *p){
1790 const char *z = 0;
1791 if( p->zSql ){
1792 z = p->zSql;
1793 }else if( p->nOp>=1 ){
1794 const VdbeOp *pOp = &p->aOp[0];
1795 if( pOp->opcode==OP_Init && pOp->p4.z!=0 ){
1796 z = pOp->p4.z;
1797 while( sqlite3Isspace(*z) ) z++;
1798 }
1799 }
1800 if( z ) printf("SQL: [%s]\n", z);
1801 }
1802 #endif
1803
1804 #if !defined(SQLITE_OMIT_TRACE) && defined(SQLITE_ENABLE_IOTRACE)
1805 /*
1806 ** Print an IOTRACE message showing SQL content.
1807 */
sqlite3VdbeIOTraceSql(Vdbe * p)1808 void sqlite3VdbeIOTraceSql(Vdbe *p){
1809 int nOp = p->nOp;
1810 VdbeOp *pOp;
1811 if( sqlite3IoTrace==0 ) return;
1812 if( nOp<1 ) return;
1813 pOp = &p->aOp[0];
1814 if( pOp->opcode==OP_Init && pOp->p4.z!=0 ){
1815 int i, j;
1816 char z[1000];
1817 sqlite3_snprintf(sizeof(z), z, "%s", pOp->p4.z);
1818 for(i=0; sqlite3Isspace(z[i]); i++){}
1819 for(j=0; z[i]; i++){
1820 if( sqlite3Isspace(z[i]) ){
1821 if( z[i-1]!=' ' ){
1822 z[j++] = ' ';
1823 }
1824 }else{
1825 z[j++] = z[i];
1826 }
1827 }
1828 z[j] = 0;
1829 sqlite3IoTrace("SQL %s\n", z);
1830 }
1831 }
1832 #endif /* !SQLITE_OMIT_TRACE && SQLITE_ENABLE_IOTRACE */
1833
1834 /* An instance of this object describes bulk memory available for use
1835 ** by subcomponents of a prepared statement. Space is allocated out
1836 ** of a ReusableSpace object by the allocSpace() routine below.
1837 */
1838 struct ReusableSpace {
1839 u8 *pSpace; /* Available memory */
1840 int nFree; /* Bytes of available memory */
1841 int nNeeded; /* Total bytes that could not be allocated */
1842 };
1843
1844 /* Try to allocate nByte bytes of 8-byte aligned bulk memory for pBuf
1845 ** from the ReusableSpace object. Return a pointer to the allocated
1846 ** memory on success. If insufficient memory is available in the
1847 ** ReusableSpace object, increase the ReusableSpace.nNeeded
1848 ** value by the amount needed and return NULL.
1849 **
1850 ** If pBuf is not initially NULL, that means that the memory has already
1851 ** been allocated by a prior call to this routine, so just return a copy
1852 ** of pBuf and leave ReusableSpace unchanged.
1853 **
1854 ** This allocator is employed to repurpose unused slots at the end of the
1855 ** opcode array of prepared state for other memory needs of the prepared
1856 ** statement.
1857 */
allocSpace(struct ReusableSpace * p,void * pBuf,int nByte)1858 static void *allocSpace(
1859 struct ReusableSpace *p, /* Bulk memory available for allocation */
1860 void *pBuf, /* Pointer to a prior allocation */
1861 int nByte /* Bytes of memory needed */
1862 ){
1863 assert( EIGHT_BYTE_ALIGNMENT(p->pSpace) );
1864 if( pBuf==0 ){
1865 nByte = ROUND8(nByte);
1866 if( nByte <= p->nFree ){
1867 p->nFree -= nByte;
1868 pBuf = &p->pSpace[p->nFree];
1869 }else{
1870 p->nNeeded += nByte;
1871 }
1872 }
1873 assert( EIGHT_BYTE_ALIGNMENT(pBuf) );
1874 return pBuf;
1875 }
1876
1877 /*
1878 ** Rewind the VDBE back to the beginning in preparation for
1879 ** running it.
1880 */
sqlite3VdbeRewind(Vdbe * p)1881 void sqlite3VdbeRewind(Vdbe *p){
1882 #if defined(SQLITE_DEBUG) || defined(VDBE_PROFILE)
1883 int i;
1884 #endif
1885 assert( p!=0 );
1886 assert( p->magic==VDBE_MAGIC_INIT || p->magic==VDBE_MAGIC_RESET );
1887
1888 /* There should be at least one opcode.
1889 */
1890 assert( p->nOp>0 );
1891
1892 /* Set the magic to VDBE_MAGIC_RUN sooner rather than later. */
1893 p->magic = VDBE_MAGIC_RUN;
1894
1895 #ifdef SQLITE_DEBUG
1896 for(i=0; i<p->nMem; i++){
1897 assert( p->aMem[i].db==p->db );
1898 }
1899 #endif
1900 p->pc = -1;
1901 p->rc = SQLITE_OK;
1902 p->errorAction = OE_Abort;
1903 p->nChange = 0;
1904 p->cacheCtr = 1;
1905 p->minWriteFileFormat = 255;
1906 p->iStatement = 0;
1907 p->nFkConstraint = 0;
1908 #ifdef VDBE_PROFILE
1909 for(i=0; i<p->nOp; i++){
1910 p->aOp[i].cnt = 0;
1911 p->aOp[i].cycles = 0;
1912 }
1913 #endif
1914 }
1915
1916 /*
1917 ** Prepare a virtual machine for execution for the first time after
1918 ** creating the virtual machine. This involves things such
1919 ** as allocating registers and initializing the program counter.
1920 ** After the VDBE has be prepped, it can be executed by one or more
1921 ** calls to sqlite3VdbeExec().
1922 **
1923 ** This function may be called exactly once on each virtual machine.
1924 ** After this routine is called the VM has been "packaged" and is ready
1925 ** to run. After this routine is called, further calls to
1926 ** sqlite3VdbeAddOp() functions are prohibited. This routine disconnects
1927 ** the Vdbe from the Parse object that helped generate it so that the
1928 ** the Vdbe becomes an independent entity and the Parse object can be
1929 ** destroyed.
1930 **
1931 ** Use the sqlite3VdbeRewind() procedure to restore a virtual machine back
1932 ** to its initial state after it has been run.
1933 */
sqlite3VdbeMakeReady(Vdbe * p,Parse * pParse)1934 void sqlite3VdbeMakeReady(
1935 Vdbe *p, /* The VDBE */
1936 Parse *pParse /* Parsing context */
1937 ){
1938 sqlite3 *db; /* The database connection */
1939 int nVar; /* Number of parameters */
1940 int nMem; /* Number of VM memory registers */
1941 int nCursor; /* Number of cursors required */
1942 int nArg; /* Number of arguments in subprograms */
1943 int n; /* Loop counter */
1944 struct ReusableSpace x; /* Reusable bulk memory */
1945
1946 assert( p!=0 );
1947 assert( p->nOp>0 );
1948 assert( pParse!=0 );
1949 assert( p->magic==VDBE_MAGIC_INIT );
1950 assert( pParse==p->pParse );
1951 db = p->db;
1952 assert( db->mallocFailed==0 );
1953 nVar = pParse->nVar;
1954 nMem = pParse->nMem;
1955 nCursor = pParse->nTab;
1956 nArg = pParse->nMaxArg;
1957
1958 /* Each cursor uses a memory cell. The first cursor (cursor 0) can
1959 ** use aMem[0] which is not otherwise used by the VDBE program. Allocate
1960 ** space at the end of aMem[] for cursors 1 and greater.
1961 ** See also: allocateCursor().
1962 */
1963 nMem += nCursor;
1964 if( nCursor==0 && nMem>0 ) nMem++; /* Space for aMem[0] even if not used */
1965
1966 /* Figure out how much reusable memory is available at the end of the
1967 ** opcode array. This extra memory will be reallocated for other elements
1968 ** of the prepared statement.
1969 */
1970 n = ROUND8(sizeof(Op)*p->nOp); /* Bytes of opcode memory used */
1971 x.pSpace = &((u8*)p->aOp)[n]; /* Unused opcode memory */
1972 assert( EIGHT_BYTE_ALIGNMENT(x.pSpace) );
1973 x.nFree = ROUNDDOWN8(pParse->szOpAlloc - n); /* Bytes of unused memory */
1974 assert( x.nFree>=0 );
1975 assert( EIGHT_BYTE_ALIGNMENT(&x.pSpace[x.nFree]) );
1976
1977 resolveP2Values(p, &nArg);
1978 p->usesStmtJournal = (u8)(pParse->isMultiWrite && pParse->mayAbort);
1979 if( pParse->explain && nMem<10 ){
1980 nMem = 10;
1981 }
1982 p->expired = 0;
1983
1984 /* Memory for registers, parameters, cursor, etc, is allocated in one or two
1985 ** passes. On the first pass, we try to reuse unused memory at the
1986 ** end of the opcode array. If we are unable to satisfy all memory
1987 ** requirements by reusing the opcode array tail, then the second
1988 ** pass will fill in the remainder using a fresh memory allocation.
1989 **
1990 ** This two-pass approach that reuses as much memory as possible from
1991 ** the leftover memory at the end of the opcode array. This can significantly
1992 ** reduce the amount of memory held by a prepared statement.
1993 */
1994 do {
1995 x.nNeeded = 0;
1996 p->aMem = allocSpace(&x, p->aMem, nMem*sizeof(Mem));
1997 p->aVar = allocSpace(&x, p->aVar, nVar*sizeof(Mem));
1998 p->apArg = allocSpace(&x, p->apArg, nArg*sizeof(Mem*));
1999 p->apCsr = allocSpace(&x, p->apCsr, nCursor*sizeof(VdbeCursor*));
2000 #ifdef SQLITE_ENABLE_STMT_SCANSTATUS
2001 p->anExec = allocSpace(&x, p->anExec, p->nOp*sizeof(i64));
2002 #endif
2003 if( x.nNeeded==0 ) break;
2004 x.pSpace = p->pFree = sqlite3DbMallocRawNN(db, x.nNeeded);
2005 x.nFree = x.nNeeded;
2006 }while( !db->mallocFailed );
2007
2008 p->pVList = pParse->pVList;
2009 pParse->pVList = 0;
2010 p->explain = pParse->explain;
2011 if( db->mallocFailed ){
2012 p->nVar = 0;
2013 p->nCursor = 0;
2014 p->nMem = 0;
2015 }else{
2016 p->nCursor = nCursor;
2017 p->nVar = (ynVar)nVar;
2018 initMemArray(p->aVar, nVar, db, MEM_Null);
2019 p->nMem = nMem;
2020 initMemArray(p->aMem, nMem, db, MEM_Undefined);
2021 memset(p->apCsr, 0, nCursor*sizeof(VdbeCursor*));
2022 #ifdef SQLITE_ENABLE_STMT_SCANSTATUS
2023 memset(p->anExec, 0, p->nOp*sizeof(i64));
2024 #endif
2025 }
2026 sqlite3VdbeRewind(p);
2027 }
2028
2029 /*
2030 ** Close a VDBE cursor and release all the resources that cursor
2031 ** happens to hold.
2032 */
sqlite3VdbeFreeCursor(Vdbe * p,VdbeCursor * pCx)2033 void sqlite3VdbeFreeCursor(Vdbe *p, VdbeCursor *pCx){
2034 if( pCx==0 ){
2035 return;
2036 }
2037 assert( pCx->pBtx==0 || pCx->eCurType==CURTYPE_BTREE );
2038 switch( pCx->eCurType ){
2039 case CURTYPE_SORTER: {
2040 sqlite3VdbeSorterClose(p->db, pCx);
2041 break;
2042 }
2043 case CURTYPE_BTREE: {
2044 if( pCx->isEphemeral ){
2045 if( pCx->pBtx ) sqlite3BtreeClose(pCx->pBtx);
2046 /* The pCx->pCursor will be close automatically, if it exists, by
2047 ** the call above. */
2048 }else{
2049 assert( pCx->uc.pCursor!=0 );
2050 sqlite3BtreeCloseCursor(pCx->uc.pCursor);
2051 }
2052 break;
2053 }
2054 #ifndef SQLITE_OMIT_VIRTUALTABLE
2055 case CURTYPE_VTAB: {
2056 sqlite3_vtab_cursor *pVCur = pCx->uc.pVCur;
2057 const sqlite3_module *pModule = pVCur->pVtab->pModule;
2058 assert( pVCur->pVtab->nRef>0 );
2059 pVCur->pVtab->nRef--;
2060 pModule->xClose(pVCur);
2061 break;
2062 }
2063 #endif
2064 }
2065 }
2066
2067 /*
2068 ** Close all cursors in the current frame.
2069 */
closeCursorsInFrame(Vdbe * p)2070 static void closeCursorsInFrame(Vdbe *p){
2071 if( p->apCsr ){
2072 int i;
2073 for(i=0; i<p->nCursor; i++){
2074 VdbeCursor *pC = p->apCsr[i];
2075 if( pC ){
2076 sqlite3VdbeFreeCursor(p, pC);
2077 p->apCsr[i] = 0;
2078 }
2079 }
2080 }
2081 }
2082
2083 /*
2084 ** Copy the values stored in the VdbeFrame structure to its Vdbe. This
2085 ** is used, for example, when a trigger sub-program is halted to restore
2086 ** control to the main program.
2087 */
sqlite3VdbeFrameRestore(VdbeFrame * pFrame)2088 int sqlite3VdbeFrameRestore(VdbeFrame *pFrame){
2089 Vdbe *v = pFrame->v;
2090 closeCursorsInFrame(v);
2091 #ifdef SQLITE_ENABLE_STMT_SCANSTATUS
2092 v->anExec = pFrame->anExec;
2093 #endif
2094 v->aOp = pFrame->aOp;
2095 v->nOp = pFrame->nOp;
2096 v->aMem = pFrame->aMem;
2097 v->nMem = pFrame->nMem;
2098 v->apCsr = pFrame->apCsr;
2099 v->nCursor = pFrame->nCursor;
2100 v->db->lastRowid = pFrame->lastRowid;
2101 v->nChange = pFrame->nChange;
2102 v->db->nChange = pFrame->nDbChange;
2103 sqlite3VdbeDeleteAuxData(v->db, &v->pAuxData, -1, 0);
2104 v->pAuxData = pFrame->pAuxData;
2105 pFrame->pAuxData = 0;
2106 return pFrame->pc;
2107 }
2108
2109 /*
2110 ** Close all cursors.
2111 **
2112 ** Also release any dynamic memory held by the VM in the Vdbe.aMem memory
2113 ** cell array. This is necessary as the memory cell array may contain
2114 ** pointers to VdbeFrame objects, which may in turn contain pointers to
2115 ** open cursors.
2116 */
closeAllCursors(Vdbe * p)2117 static void closeAllCursors(Vdbe *p){
2118 if( p->pFrame ){
2119 VdbeFrame *pFrame;
2120 for(pFrame=p->pFrame; pFrame->pParent; pFrame=pFrame->pParent);
2121 sqlite3VdbeFrameRestore(pFrame);
2122 p->pFrame = 0;
2123 p->nFrame = 0;
2124 }
2125 assert( p->nFrame==0 );
2126 closeCursorsInFrame(p);
2127 if( p->aMem ){
2128 releaseMemArray(p->aMem, p->nMem);
2129 }
2130 while( p->pDelFrame ){
2131 VdbeFrame *pDel = p->pDelFrame;
2132 p->pDelFrame = pDel->pParent;
2133 sqlite3VdbeFrameDelete(pDel);
2134 }
2135
2136 /* Delete any auxdata allocations made by the VM */
2137 if( p->pAuxData ) sqlite3VdbeDeleteAuxData(p->db, &p->pAuxData, -1, 0);
2138 assert( p->pAuxData==0 );
2139 }
2140
2141 /*
2142 ** Clean up the VM after a single run.
2143 */
Cleanup(Vdbe * p)2144 static void Cleanup(Vdbe *p){
2145 sqlite3 *db = p->db;
2146
2147 #ifdef SQLITE_DEBUG
2148 /* Execute assert() statements to ensure that the Vdbe.apCsr[] and
2149 ** Vdbe.aMem[] arrays have already been cleaned up. */
2150 int i;
2151 if( p->apCsr ) for(i=0; i<p->nCursor; i++) assert( p->apCsr[i]==0 );
2152 if( p->aMem ){
2153 for(i=0; i<p->nMem; i++) assert( p->aMem[i].flags==MEM_Undefined );
2154 }
2155 #endif
2156
2157 sqlite3DbFree(db, p->zErrMsg);
2158 p->zErrMsg = 0;
2159 p->pResultSet = 0;
2160 }
2161
2162 /*
2163 ** Set the number of result columns that will be returned by this SQL
2164 ** statement. This is now set at compile time, rather than during
2165 ** execution of the vdbe program so that sqlite3_column_count() can
2166 ** be called on an SQL statement before sqlite3_step().
2167 */
sqlite3VdbeSetNumCols(Vdbe * p,int nResColumn)2168 void sqlite3VdbeSetNumCols(Vdbe *p, int nResColumn){
2169 int n;
2170 sqlite3 *db = p->db;
2171
2172 if( p->nResColumn ){
2173 releaseMemArray(p->aColName, p->nResColumn*COLNAME_N);
2174 sqlite3DbFree(db, p->aColName);
2175 }
2176 n = nResColumn*COLNAME_N;
2177 p->nResColumn = (u16)nResColumn;
2178 p->aColName = (Mem*)sqlite3DbMallocRawNN(db, sizeof(Mem)*n );
2179 if( p->aColName==0 ) return;
2180 initMemArray(p->aColName, n, db, MEM_Null);
2181 }
2182
2183 /*
2184 ** Set the name of the idx'th column to be returned by the SQL statement.
2185 ** zName must be a pointer to a nul terminated string.
2186 **
2187 ** This call must be made after a call to sqlite3VdbeSetNumCols().
2188 **
2189 ** The final parameter, xDel, must be one of SQLITE_DYNAMIC, SQLITE_STATIC
2190 ** or SQLITE_TRANSIENT. If it is SQLITE_DYNAMIC, then the buffer pointed
2191 ** to by zName will be freed by sqlite3DbFree() when the vdbe is destroyed.
2192 */
sqlite3VdbeSetColName(Vdbe * p,int idx,int var,const char * zName,void (* xDel)(void *))2193 int sqlite3VdbeSetColName(
2194 Vdbe *p, /* Vdbe being configured */
2195 int idx, /* Index of column zName applies to */
2196 int var, /* One of the COLNAME_* constants */
2197 const char *zName, /* Pointer to buffer containing name */
2198 void (*xDel)(void*) /* Memory management strategy for zName */
2199 ){
2200 int rc;
2201 Mem *pColName;
2202 assert( idx<p->nResColumn );
2203 assert( var<COLNAME_N );
2204 if( p->db->mallocFailed ){
2205 assert( !zName || xDel!=SQLITE_DYNAMIC );
2206 return SQLITE_NOMEM_BKPT;
2207 }
2208 assert( p->aColName!=0 );
2209 pColName = &(p->aColName[idx+var*p->nResColumn]);
2210 rc = sqlite3VdbeMemSetStr(pColName, zName, -1, SQLITE_UTF8, xDel);
2211 assert( rc!=0 || !zName || (pColName->flags&MEM_Term)!=0 );
2212 return rc;
2213 }
2214
2215 /*
2216 ** A read or write transaction may or may not be active on database handle
2217 ** db. If a transaction is active, commit it. If there is a
2218 ** write-transaction spanning more than one database file, this routine
2219 ** takes care of the master journal trickery.
2220 */
vdbeCommit(sqlite3 * db,Vdbe * p)2221 static int vdbeCommit(sqlite3 *db, Vdbe *p){
2222 int i;
2223 int nTrans = 0; /* Number of databases with an active write-transaction
2224 ** that are candidates for a two-phase commit using a
2225 ** master-journal */
2226 int rc = SQLITE_OK;
2227 int needXcommit = 0;
2228
2229 #ifdef SQLITE_OMIT_VIRTUALTABLE
2230 /* With this option, sqlite3VtabSync() is defined to be simply
2231 ** SQLITE_OK so p is not used.
2232 */
2233 UNUSED_PARAMETER(p);
2234 #endif
2235
2236 /* Before doing anything else, call the xSync() callback for any
2237 ** virtual module tables written in this transaction. This has to
2238 ** be done before determining whether a master journal file is
2239 ** required, as an xSync() callback may add an attached database
2240 ** to the transaction.
2241 */
2242 rc = sqlite3VtabSync(db, p);
2243
2244 /* This loop determines (a) if the commit hook should be invoked and
2245 ** (b) how many database files have open write transactions, not
2246 ** including the temp database. (b) is important because if more than
2247 ** one database file has an open write transaction, a master journal
2248 ** file is required for an atomic commit.
2249 */
2250 for(i=0; rc==SQLITE_OK && i<db->nDb; i++){
2251 Btree *pBt = db->aDb[i].pBt;
2252 if( sqlite3BtreeIsInTrans(pBt) ){
2253 /* Whether or not a database might need a master journal depends upon
2254 ** its journal mode (among other things). This matrix determines which
2255 ** journal modes use a master journal and which do not */
2256 static const u8 aMJNeeded[] = {
2257 /* DELETE */ 1,
2258 /* PERSIST */ 1,
2259 /* OFF */ 0,
2260 /* TRUNCATE */ 1,
2261 /* MEMORY */ 0,
2262 /* WAL */ 0
2263 };
2264 Pager *pPager; /* Pager associated with pBt */
2265 needXcommit = 1;
2266 sqlite3BtreeEnter(pBt);
2267 pPager = sqlite3BtreePager(pBt);
2268 if( db->aDb[i].safety_level!=PAGER_SYNCHRONOUS_OFF
2269 && aMJNeeded[sqlite3PagerGetJournalMode(pPager)]
2270 ){
2271 assert( i!=1 );
2272 nTrans++;
2273 }
2274 rc = sqlite3PagerExclusiveLock(pPager);
2275 sqlite3BtreeLeave(pBt);
2276 }
2277 }
2278 if( rc!=SQLITE_OK ){
2279 return rc;
2280 }
2281
2282 /* If there are any write-transactions at all, invoke the commit hook */
2283 if( needXcommit && db->xCommitCallback ){
2284 rc = db->xCommitCallback(db->pCommitArg);
2285 if( rc ){
2286 return SQLITE_CONSTRAINT_COMMITHOOK;
2287 }
2288 }
2289
2290 /* The simple case - no more than one database file (not counting the
2291 ** TEMP database) has a transaction active. There is no need for the
2292 ** master-journal.
2293 **
2294 ** If the return value of sqlite3BtreeGetFilename() is a zero length
2295 ** string, it means the main database is :memory: or a temp file. In
2296 ** that case we do not support atomic multi-file commits, so use the
2297 ** simple case then too.
2298 */
2299 if( 0==sqlite3Strlen30(sqlite3BtreeGetFilename(db->aDb[0].pBt))
2300 || nTrans<=1
2301 ){
2302 for(i=0; rc==SQLITE_OK && i<db->nDb; i++){
2303 Btree *pBt = db->aDb[i].pBt;
2304 if( pBt ){
2305 rc = sqlite3BtreeCommitPhaseOne(pBt, 0);
2306 }
2307 }
2308
2309 /* Do the commit only if all databases successfully complete phase 1.
2310 ** If one of the BtreeCommitPhaseOne() calls fails, this indicates an
2311 ** IO error while deleting or truncating a journal file. It is unlikely,
2312 ** but could happen. In this case abandon processing and return the error.
2313 */
2314 for(i=0; rc==SQLITE_OK && i<db->nDb; i++){
2315 Btree *pBt = db->aDb[i].pBt;
2316 if( pBt ){
2317 rc = sqlite3BtreeCommitPhaseTwo(pBt, 0);
2318 }
2319 }
2320 if( rc==SQLITE_OK ){
2321 sqlite3VtabCommit(db);
2322 }
2323 }
2324
2325 /* The complex case - There is a multi-file write-transaction active.
2326 ** This requires a master journal file to ensure the transaction is
2327 ** committed atomically.
2328 */
2329 #ifndef SQLITE_OMIT_DISKIO
2330 else{
2331 sqlite3_vfs *pVfs = db->pVfs;
2332 char *zMaster = 0; /* File-name for the master journal */
2333 char const *zMainFile = sqlite3BtreeGetFilename(db->aDb[0].pBt);
2334 sqlite3_file *pMaster = 0;
2335 i64 offset = 0;
2336 int res;
2337 int retryCount = 0;
2338 int nMainFile;
2339
2340 /* Select a master journal file name */
2341 nMainFile = sqlite3Strlen30(zMainFile);
2342 zMaster = sqlite3MPrintf(db, "%s-mjXXXXXX9XXz", zMainFile);
2343 if( zMaster==0 ) return SQLITE_NOMEM_BKPT;
2344 do {
2345 u32 iRandom;
2346 if( retryCount ){
2347 if( retryCount>100 ){
2348 sqlite3_log(SQLITE_FULL, "MJ delete: %s", zMaster);
2349 sqlite3OsDelete(pVfs, zMaster, 0);
2350 break;
2351 }else if( retryCount==1 ){
2352 sqlite3_log(SQLITE_FULL, "MJ collide: %s", zMaster);
2353 }
2354 }
2355 retryCount++;
2356 sqlite3_randomness(sizeof(iRandom), &iRandom);
2357 sqlite3_snprintf(13, &zMaster[nMainFile], "-mj%06X9%02X",
2358 (iRandom>>8)&0xffffff, iRandom&0xff);
2359 /* The antipenultimate character of the master journal name must
2360 ** be "9" to avoid name collisions when using 8+3 filenames. */
2361 assert( zMaster[sqlite3Strlen30(zMaster)-3]=='9' );
2362 sqlite3FileSuffix3(zMainFile, zMaster);
2363 rc = sqlite3OsAccess(pVfs, zMaster, SQLITE_ACCESS_EXISTS, &res);
2364 }while( rc==SQLITE_OK && res );
2365 if( rc==SQLITE_OK ){
2366 /* Open the master journal. */
2367 rc = sqlite3OsOpenMalloc(pVfs, zMaster, &pMaster,
2368 SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE|
2369 SQLITE_OPEN_EXCLUSIVE|SQLITE_OPEN_MASTER_JOURNAL, 0
2370 );
2371 }
2372 if( rc!=SQLITE_OK ){
2373 sqlite3DbFree(db, zMaster);
2374 return rc;
2375 }
2376
2377 /* Write the name of each database file in the transaction into the new
2378 ** master journal file. If an error occurs at this point close
2379 ** and delete the master journal file. All the individual journal files
2380 ** still have 'null' as the master journal pointer, so they will roll
2381 ** back independently if a failure occurs.
2382 */
2383 for(i=0; i<db->nDb; i++){
2384 Btree *pBt = db->aDb[i].pBt;
2385 if( sqlite3BtreeIsInTrans(pBt) ){
2386 char const *zFile = sqlite3BtreeGetJournalname(pBt);
2387 if( zFile==0 ){
2388 continue; /* Ignore TEMP and :memory: databases */
2389 }
2390 assert( zFile[0]!=0 );
2391 rc = sqlite3OsWrite(pMaster, zFile, sqlite3Strlen30(zFile)+1, offset);
2392 offset += sqlite3Strlen30(zFile)+1;
2393 if( rc!=SQLITE_OK ){
2394 sqlite3OsCloseFree(pMaster);
2395 sqlite3OsDelete(pVfs, zMaster, 0);
2396 sqlite3DbFree(db, zMaster);
2397 return rc;
2398 }
2399 }
2400 }
2401
2402 /* Sync the master journal file. If the IOCAP_SEQUENTIAL device
2403 ** flag is set this is not required.
2404 */
2405 if( 0==(sqlite3OsDeviceCharacteristics(pMaster)&SQLITE_IOCAP_SEQUENTIAL)
2406 && SQLITE_OK!=(rc = sqlite3OsSync(pMaster, SQLITE_SYNC_NORMAL))
2407 ){
2408 sqlite3OsCloseFree(pMaster);
2409 sqlite3OsDelete(pVfs, zMaster, 0);
2410 sqlite3DbFree(db, zMaster);
2411 return rc;
2412 }
2413
2414 /* Sync all the db files involved in the transaction. The same call
2415 ** sets the master journal pointer in each individual journal. If
2416 ** an error occurs here, do not delete the master journal file.
2417 **
2418 ** If the error occurs during the first call to
2419 ** sqlite3BtreeCommitPhaseOne(), then there is a chance that the
2420 ** master journal file will be orphaned. But we cannot delete it,
2421 ** in case the master journal file name was written into the journal
2422 ** file before the failure occurred.
2423 */
2424 for(i=0; rc==SQLITE_OK && i<db->nDb; i++){
2425 Btree *pBt = db->aDb[i].pBt;
2426 if( pBt ){
2427 rc = sqlite3BtreeCommitPhaseOne(pBt, zMaster);
2428 }
2429 }
2430 sqlite3OsCloseFree(pMaster);
2431 assert( rc!=SQLITE_BUSY );
2432 if( rc!=SQLITE_OK ){
2433 sqlite3DbFree(db, zMaster);
2434 return rc;
2435 }
2436
2437 /* Delete the master journal file. This commits the transaction. After
2438 ** doing this the directory is synced again before any individual
2439 ** transaction files are deleted.
2440 */
2441 rc = sqlite3OsDelete(pVfs, zMaster, 1);
2442 sqlite3DbFree(db, zMaster);
2443 zMaster = 0;
2444 if( rc ){
2445 return rc;
2446 }
2447
2448 /* All files and directories have already been synced, so the following
2449 ** calls to sqlite3BtreeCommitPhaseTwo() are only closing files and
2450 ** deleting or truncating journals. If something goes wrong while
2451 ** this is happening we don't really care. The integrity of the
2452 ** transaction is already guaranteed, but some stray 'cold' journals
2453 ** may be lying around. Returning an error code won't help matters.
2454 */
2455 disable_simulated_io_errors();
2456 sqlite3BeginBenignMalloc();
2457 for(i=0; i<db->nDb; i++){
2458 Btree *pBt = db->aDb[i].pBt;
2459 if( pBt ){
2460 sqlite3BtreeCommitPhaseTwo(pBt, 1);
2461 }
2462 }
2463 sqlite3EndBenignMalloc();
2464 enable_simulated_io_errors();
2465
2466 sqlite3VtabCommit(db);
2467 }
2468 #endif
2469
2470 return rc;
2471 }
2472
2473 /*
2474 ** This routine checks that the sqlite3.nVdbeActive count variable
2475 ** matches the number of vdbe's in the list sqlite3.pVdbe that are
2476 ** currently active. An assertion fails if the two counts do not match.
2477 ** This is an internal self-check only - it is not an essential processing
2478 ** step.
2479 **
2480 ** This is a no-op if NDEBUG is defined.
2481 */
2482 #ifndef NDEBUG
checkActiveVdbeCnt(sqlite3 * db)2483 static void checkActiveVdbeCnt(sqlite3 *db){
2484 Vdbe *p;
2485 int cnt = 0;
2486 int nWrite = 0;
2487 int nRead = 0;
2488 p = db->pVdbe;
2489 while( p ){
2490 if( sqlite3_stmt_busy((sqlite3_stmt*)p) ){
2491 cnt++;
2492 if( p->readOnly==0 ) nWrite++;
2493 if( p->bIsReader ) nRead++;
2494 }
2495 p = p->pNext;
2496 }
2497 assert( cnt==db->nVdbeActive );
2498 assert( nWrite==db->nVdbeWrite );
2499 assert( nRead==db->nVdbeRead );
2500 }
2501 #else
2502 #define checkActiveVdbeCnt(x)
2503 #endif
2504
2505 /*
2506 ** If the Vdbe passed as the first argument opened a statement-transaction,
2507 ** close it now. Argument eOp must be either SAVEPOINT_ROLLBACK or
2508 ** SAVEPOINT_RELEASE. If it is SAVEPOINT_ROLLBACK, then the statement
2509 ** transaction is rolled back. If eOp is SAVEPOINT_RELEASE, then the
2510 ** statement transaction is committed.
2511 **
2512 ** If an IO error occurs, an SQLITE_IOERR_XXX error code is returned.
2513 ** Otherwise SQLITE_OK.
2514 */
vdbeCloseStatement(Vdbe * p,int eOp)2515 static SQLITE_NOINLINE int vdbeCloseStatement(Vdbe *p, int eOp){
2516 sqlite3 *const db = p->db;
2517 int rc = SQLITE_OK;
2518 int i;
2519 const int iSavepoint = p->iStatement-1;
2520
2521 assert( eOp==SAVEPOINT_ROLLBACK || eOp==SAVEPOINT_RELEASE);
2522 assert( db->nStatement>0 );
2523 assert( p->iStatement==(db->nStatement+db->nSavepoint) );
2524
2525 for(i=0; i<db->nDb; i++){
2526 int rc2 = SQLITE_OK;
2527 Btree *pBt = db->aDb[i].pBt;
2528 if( pBt ){
2529 if( eOp==SAVEPOINT_ROLLBACK ){
2530 rc2 = sqlite3BtreeSavepoint(pBt, SAVEPOINT_ROLLBACK, iSavepoint);
2531 }
2532 if( rc2==SQLITE_OK ){
2533 rc2 = sqlite3BtreeSavepoint(pBt, SAVEPOINT_RELEASE, iSavepoint);
2534 }
2535 if( rc==SQLITE_OK ){
2536 rc = rc2;
2537 }
2538 }
2539 }
2540 db->nStatement--;
2541 p->iStatement = 0;
2542
2543 if( rc==SQLITE_OK ){
2544 if( eOp==SAVEPOINT_ROLLBACK ){
2545 rc = sqlite3VtabSavepoint(db, SAVEPOINT_ROLLBACK, iSavepoint);
2546 }
2547 if( rc==SQLITE_OK ){
2548 rc = sqlite3VtabSavepoint(db, SAVEPOINT_RELEASE, iSavepoint);
2549 }
2550 }
2551
2552 /* If the statement transaction is being rolled back, also restore the
2553 ** database handles deferred constraint counter to the value it had when
2554 ** the statement transaction was opened. */
2555 if( eOp==SAVEPOINT_ROLLBACK ){
2556 db->nDeferredCons = p->nStmtDefCons;
2557 db->nDeferredImmCons = p->nStmtDefImmCons;
2558 }
2559 return rc;
2560 }
sqlite3VdbeCloseStatement(Vdbe * p,int eOp)2561 int sqlite3VdbeCloseStatement(Vdbe *p, int eOp){
2562 if( p->db->nStatement && p->iStatement ){
2563 return vdbeCloseStatement(p, eOp);
2564 }
2565 return SQLITE_OK;
2566 }
2567
2568
2569 /*
2570 ** This function is called when a transaction opened by the database
2571 ** handle associated with the VM passed as an argument is about to be
2572 ** committed. If there are outstanding deferred foreign key constraint
2573 ** violations, return SQLITE_ERROR. Otherwise, SQLITE_OK.
2574 **
2575 ** If there are outstanding FK violations and this function returns
2576 ** SQLITE_ERROR, set the result of the VM to SQLITE_CONSTRAINT_FOREIGNKEY
2577 ** and write an error message to it. Then return SQLITE_ERROR.
2578 */
2579 #ifndef SQLITE_OMIT_FOREIGN_KEY
sqlite3VdbeCheckFk(Vdbe * p,int deferred)2580 int sqlite3VdbeCheckFk(Vdbe *p, int deferred){
2581 sqlite3 *db = p->db;
2582 if( (deferred && (db->nDeferredCons+db->nDeferredImmCons)>0)
2583 || (!deferred && p->nFkConstraint>0)
2584 ){
2585 p->rc = SQLITE_CONSTRAINT_FOREIGNKEY;
2586 p->errorAction = OE_Abort;
2587 sqlite3VdbeError(p, "FOREIGN KEY constraint failed");
2588 return SQLITE_ERROR;
2589 }
2590 return SQLITE_OK;
2591 }
2592 #endif
2593
2594 /*
2595 ** This routine is called the when a VDBE tries to halt. If the VDBE
2596 ** has made changes and is in autocommit mode, then commit those
2597 ** changes. If a rollback is needed, then do the rollback.
2598 **
2599 ** This routine is the only way to move the state of a VM from
2600 ** SQLITE_MAGIC_RUN to SQLITE_MAGIC_HALT. It is harmless to
2601 ** call this on a VM that is in the SQLITE_MAGIC_HALT state.
2602 **
2603 ** Return an error code. If the commit could not complete because of
2604 ** lock contention, return SQLITE_BUSY. If SQLITE_BUSY is returned, it
2605 ** means the close did not happen and needs to be repeated.
2606 */
sqlite3VdbeHalt(Vdbe * p)2607 int sqlite3VdbeHalt(Vdbe *p){
2608 int rc; /* Used to store transient return codes */
2609 sqlite3 *db = p->db;
2610
2611 /* This function contains the logic that determines if a statement or
2612 ** transaction will be committed or rolled back as a result of the
2613 ** execution of this virtual machine.
2614 **
2615 ** If any of the following errors occur:
2616 **
2617 ** SQLITE_NOMEM
2618 ** SQLITE_IOERR
2619 ** SQLITE_FULL
2620 ** SQLITE_INTERRUPT
2621 **
2622 ** Then the internal cache might have been left in an inconsistent
2623 ** state. We need to rollback the statement transaction, if there is
2624 ** one, or the complete transaction if there is no statement transaction.
2625 */
2626
2627 if( p->magic!=VDBE_MAGIC_RUN ){
2628 return SQLITE_OK;
2629 }
2630 if( db->mallocFailed ){
2631 p->rc = SQLITE_NOMEM_BKPT;
2632 }
2633 closeAllCursors(p);
2634 checkActiveVdbeCnt(db);
2635
2636 /* No commit or rollback needed if the program never started or if the
2637 ** SQL statement does not read or write a database file. */
2638 if( p->pc>=0 && p->bIsReader ){
2639 int mrc; /* Primary error code from p->rc */
2640 int eStatementOp = 0;
2641 int isSpecialError; /* Set to true if a 'special' error */
2642
2643 /* Lock all btrees used by the statement */
2644 sqlite3VdbeEnter(p);
2645
2646 /* Check for one of the special errors */
2647 mrc = p->rc & 0xff;
2648 isSpecialError = mrc==SQLITE_NOMEM || mrc==SQLITE_IOERR
2649 || mrc==SQLITE_INTERRUPT || mrc==SQLITE_FULL;
2650 if( isSpecialError ){
2651 /* If the query was read-only and the error code is SQLITE_INTERRUPT,
2652 ** no rollback is necessary. Otherwise, at least a savepoint
2653 ** transaction must be rolled back to restore the database to a
2654 ** consistent state.
2655 **
2656 ** Even if the statement is read-only, it is important to perform
2657 ** a statement or transaction rollback operation. If the error
2658 ** occurred while writing to the journal, sub-journal or database
2659 ** file as part of an effort to free up cache space (see function
2660 ** pagerStress() in pager.c), the rollback is required to restore
2661 ** the pager to a consistent state.
2662 */
2663 if( !p->readOnly || mrc!=SQLITE_INTERRUPT ){
2664 if( (mrc==SQLITE_NOMEM || mrc==SQLITE_FULL) && p->usesStmtJournal ){
2665 eStatementOp = SAVEPOINT_ROLLBACK;
2666 }else{
2667 /* We are forced to roll back the active transaction. Before doing
2668 ** so, abort any other statements this handle currently has active.
2669 */
2670 sqlite3RollbackAll(db, SQLITE_ABORT_ROLLBACK);
2671 sqlite3CloseSavepoints(db);
2672 db->autoCommit = 1;
2673 p->nChange = 0;
2674 }
2675 }
2676 }
2677
2678 /* Check for immediate foreign key violations. */
2679 if( p->rc==SQLITE_OK ){
2680 sqlite3VdbeCheckFk(p, 0);
2681 }
2682
2683 /* If the auto-commit flag is set and this is the only active writer
2684 ** VM, then we do either a commit or rollback of the current transaction.
2685 **
2686 ** Note: This block also runs if one of the special errors handled
2687 ** above has occurred.
2688 */
2689 if( !sqlite3VtabInSync(db)
2690 && db->autoCommit
2691 && db->nVdbeWrite==(p->readOnly==0)
2692 ){
2693 if( p->rc==SQLITE_OK || (p->errorAction==OE_Fail && !isSpecialError) ){
2694 rc = sqlite3VdbeCheckFk(p, 1);
2695 if( rc!=SQLITE_OK ){
2696 if( NEVER(p->readOnly) ){
2697 sqlite3VdbeLeave(p);
2698 return SQLITE_ERROR;
2699 }
2700 rc = SQLITE_CONSTRAINT_FOREIGNKEY;
2701 }else{
2702 /* The auto-commit flag is true, the vdbe program was successful
2703 ** or hit an 'OR FAIL' constraint and there are no deferred foreign
2704 ** key constraints to hold up the transaction. This means a commit
2705 ** is required. */
2706 rc = vdbeCommit(db, p);
2707 }
2708 if( rc==SQLITE_BUSY && p->readOnly ){
2709 sqlite3VdbeLeave(p);
2710 return SQLITE_BUSY;
2711 }else if( rc!=SQLITE_OK ){
2712 p->rc = rc;
2713 sqlite3RollbackAll(db, SQLITE_OK);
2714 p->nChange = 0;
2715 }else{
2716 db->nDeferredCons = 0;
2717 db->nDeferredImmCons = 0;
2718 db->flags &= ~SQLITE_DeferFKs;
2719 sqlite3CommitInternalChanges(db);
2720 }
2721 }else{
2722 sqlite3RollbackAll(db, SQLITE_OK);
2723 p->nChange = 0;
2724 }
2725 db->nStatement = 0;
2726 }else if( eStatementOp==0 ){
2727 if( p->rc==SQLITE_OK || p->errorAction==OE_Fail ){
2728 eStatementOp = SAVEPOINT_RELEASE;
2729 }else if( p->errorAction==OE_Abort ){
2730 eStatementOp = SAVEPOINT_ROLLBACK;
2731 }else{
2732 sqlite3RollbackAll(db, SQLITE_ABORT_ROLLBACK);
2733 sqlite3CloseSavepoints(db);
2734 db->autoCommit = 1;
2735 p->nChange = 0;
2736 }
2737 }
2738
2739 /* If eStatementOp is non-zero, then a statement transaction needs to
2740 ** be committed or rolled back. Call sqlite3VdbeCloseStatement() to
2741 ** do so. If this operation returns an error, and the current statement
2742 ** error code is SQLITE_OK or SQLITE_CONSTRAINT, then promote the
2743 ** current statement error code.
2744 */
2745 if( eStatementOp ){
2746 rc = sqlite3VdbeCloseStatement(p, eStatementOp);
2747 if( rc ){
2748 if( p->rc==SQLITE_OK || (p->rc&0xff)==SQLITE_CONSTRAINT ){
2749 p->rc = rc;
2750 sqlite3DbFree(db, p->zErrMsg);
2751 p->zErrMsg = 0;
2752 }
2753 sqlite3RollbackAll(db, SQLITE_ABORT_ROLLBACK);
2754 sqlite3CloseSavepoints(db);
2755 db->autoCommit = 1;
2756 p->nChange = 0;
2757 }
2758 }
2759
2760 /* If this was an INSERT, UPDATE or DELETE and no statement transaction
2761 ** has been rolled back, update the database connection change-counter.
2762 */
2763 if( p->changeCntOn ){
2764 if( eStatementOp!=SAVEPOINT_ROLLBACK ){
2765 sqlite3VdbeSetChanges(db, p->nChange);
2766 }else{
2767 sqlite3VdbeSetChanges(db, 0);
2768 }
2769 p->nChange = 0;
2770 }
2771
2772 /* Release the locks */
2773 sqlite3VdbeLeave(p);
2774 }
2775
2776 /* We have successfully halted and closed the VM. Record this fact. */
2777 if( p->pc>=0 ){
2778 db->nVdbeActive--;
2779 if( !p->readOnly ) db->nVdbeWrite--;
2780 if( p->bIsReader ) db->nVdbeRead--;
2781 assert( db->nVdbeActive>=db->nVdbeRead );
2782 assert( db->nVdbeRead>=db->nVdbeWrite );
2783 assert( db->nVdbeWrite>=0 );
2784 }
2785 p->magic = VDBE_MAGIC_HALT;
2786 checkActiveVdbeCnt(db);
2787 if( db->mallocFailed ){
2788 p->rc = SQLITE_NOMEM_BKPT;
2789 }
2790
2791 /* If the auto-commit flag is set to true, then any locks that were held
2792 ** by connection db have now been released. Call sqlite3ConnectionUnlocked()
2793 ** to invoke any required unlock-notify callbacks.
2794 */
2795 if( db->autoCommit ){
2796 sqlite3ConnectionUnlocked(db);
2797 }
2798
2799 assert( db->nVdbeActive>0 || db->autoCommit==0 || db->nStatement==0 );
2800 return (p->rc==SQLITE_BUSY ? SQLITE_BUSY : SQLITE_OK);
2801 }
2802
2803
2804 /*
2805 ** Each VDBE holds the result of the most recent sqlite3_step() call
2806 ** in p->rc. This routine sets that result back to SQLITE_OK.
2807 */
sqlite3VdbeResetStepResult(Vdbe * p)2808 void sqlite3VdbeResetStepResult(Vdbe *p){
2809 p->rc = SQLITE_OK;
2810 }
2811
2812 /*
2813 ** Copy the error code and error message belonging to the VDBE passed
2814 ** as the first argument to its database handle (so that they will be
2815 ** returned by calls to sqlite3_errcode() and sqlite3_errmsg()).
2816 **
2817 ** This function does not clear the VDBE error code or message, just
2818 ** copies them to the database handle.
2819 */
sqlite3VdbeTransferError(Vdbe * p)2820 int sqlite3VdbeTransferError(Vdbe *p){
2821 sqlite3 *db = p->db;
2822 int rc = p->rc;
2823 if( p->zErrMsg ){
2824 db->bBenignMalloc++;
2825 sqlite3BeginBenignMalloc();
2826 if( db->pErr==0 ) db->pErr = sqlite3ValueNew(db);
2827 sqlite3ValueSetStr(db->pErr, -1, p->zErrMsg, SQLITE_UTF8, SQLITE_TRANSIENT);
2828 sqlite3EndBenignMalloc();
2829 db->bBenignMalloc--;
2830 }else if( db->pErr ){
2831 sqlite3ValueSetNull(db->pErr);
2832 }
2833 db->errCode = rc;
2834 return rc;
2835 }
2836
2837 #ifdef SQLITE_ENABLE_SQLLOG
2838 /*
2839 ** If an SQLITE_CONFIG_SQLLOG hook is registered and the VM has been run,
2840 ** invoke it.
2841 */
vdbeInvokeSqllog(Vdbe * v)2842 static void vdbeInvokeSqllog(Vdbe *v){
2843 if( sqlite3GlobalConfig.xSqllog && v->rc==SQLITE_OK && v->zSql && v->pc>=0 ){
2844 char *zExpanded = sqlite3VdbeExpandSql(v, v->zSql);
2845 assert( v->db->init.busy==0 );
2846 if( zExpanded ){
2847 sqlite3GlobalConfig.xSqllog(
2848 sqlite3GlobalConfig.pSqllogArg, v->db, zExpanded, 1
2849 );
2850 sqlite3DbFree(v->db, zExpanded);
2851 }
2852 }
2853 }
2854 #else
2855 # define vdbeInvokeSqllog(x)
2856 #endif
2857
2858 /*
2859 ** Clean up a VDBE after execution but do not delete the VDBE just yet.
2860 ** Write any error messages into *pzErrMsg. Return the result code.
2861 **
2862 ** After this routine is run, the VDBE should be ready to be executed
2863 ** again.
2864 **
2865 ** To look at it another way, this routine resets the state of the
2866 ** virtual machine from VDBE_MAGIC_RUN or VDBE_MAGIC_HALT back to
2867 ** VDBE_MAGIC_INIT.
2868 */
sqlite3VdbeReset(Vdbe * p)2869 int sqlite3VdbeReset(Vdbe *p){
2870 sqlite3 *db;
2871 db = p->db;
2872
2873 /* If the VM did not run to completion or if it encountered an
2874 ** error, then it might not have been halted properly. So halt
2875 ** it now.
2876 */
2877 sqlite3VdbeHalt(p);
2878
2879 /* If the VDBE has be run even partially, then transfer the error code
2880 ** and error message from the VDBE into the main database structure. But
2881 ** if the VDBE has just been set to run but has not actually executed any
2882 ** instructions yet, leave the main database error information unchanged.
2883 */
2884 if( p->pc>=0 ){
2885 vdbeInvokeSqllog(p);
2886 sqlite3VdbeTransferError(p);
2887 sqlite3DbFree(db, p->zErrMsg);
2888 p->zErrMsg = 0;
2889 if( p->runOnlyOnce ) p->expired = 1;
2890 }else if( p->rc && p->expired ){
2891 /* The expired flag was set on the VDBE before the first call
2892 ** to sqlite3_step(). For consistency (since sqlite3_step() was
2893 ** called), set the database error in this case as well.
2894 */
2895 sqlite3ErrorWithMsg(db, p->rc, p->zErrMsg ? "%s" : 0, p->zErrMsg);
2896 sqlite3DbFree(db, p->zErrMsg);
2897 p->zErrMsg = 0;
2898 }
2899
2900 /* Reclaim all memory used by the VDBE
2901 */
2902 Cleanup(p);
2903
2904 /* Save profiling information from this VDBE run.
2905 */
2906 #ifdef VDBE_PROFILE
2907 {
2908 FILE *out = fopen("vdbe_profile.out", "a");
2909 if( out ){
2910 int i;
2911 fprintf(out, "---- ");
2912 for(i=0; i<p->nOp; i++){
2913 fprintf(out, "%02x", p->aOp[i].opcode);
2914 }
2915 fprintf(out, "\n");
2916 if( p->zSql ){
2917 char c, pc = 0;
2918 fprintf(out, "-- ");
2919 for(i=0; (c = p->zSql[i])!=0; i++){
2920 if( pc=='\n' ) fprintf(out, "-- ");
2921 putc(c, out);
2922 pc = c;
2923 }
2924 if( pc!='\n' ) fprintf(out, "\n");
2925 }
2926 for(i=0; i<p->nOp; i++){
2927 char zHdr[100];
2928 sqlite3_snprintf(sizeof(zHdr), zHdr, "%6u %12llu %8llu ",
2929 p->aOp[i].cnt,
2930 p->aOp[i].cycles,
2931 p->aOp[i].cnt>0 ? p->aOp[i].cycles/p->aOp[i].cnt : 0
2932 );
2933 fprintf(out, "%s", zHdr);
2934 sqlite3VdbePrintOp(out, i, &p->aOp[i]);
2935 }
2936 fclose(out);
2937 }
2938 }
2939 #endif
2940 p->magic = VDBE_MAGIC_RESET;
2941 return p->rc & db->errMask;
2942 }
2943
2944 /*
2945 ** Clean up and delete a VDBE after execution. Return an integer which is
2946 ** the result code. Write any error message text into *pzErrMsg.
2947 */
sqlite3VdbeFinalize(Vdbe * p)2948 int sqlite3VdbeFinalize(Vdbe *p){
2949 int rc = SQLITE_OK;
2950 if( p->magic==VDBE_MAGIC_RUN || p->magic==VDBE_MAGIC_HALT ){
2951 rc = sqlite3VdbeReset(p);
2952 assert( (rc & p->db->errMask)==rc );
2953 }
2954 sqlite3VdbeDelete(p);
2955 return rc;
2956 }
2957
2958 /*
2959 ** If parameter iOp is less than zero, then invoke the destructor for
2960 ** all auxiliary data pointers currently cached by the VM passed as
2961 ** the first argument.
2962 **
2963 ** Or, if iOp is greater than or equal to zero, then the destructor is
2964 ** only invoked for those auxiliary data pointers created by the user
2965 ** function invoked by the OP_Function opcode at instruction iOp of
2966 ** VM pVdbe, and only then if:
2967 **
2968 ** * the associated function parameter is the 32nd or later (counting
2969 ** from left to right), or
2970 **
2971 ** * the corresponding bit in argument mask is clear (where the first
2972 ** function parameter corresponds to bit 0 etc.).
2973 */
sqlite3VdbeDeleteAuxData(sqlite3 * db,AuxData ** pp,int iOp,int mask)2974 void sqlite3VdbeDeleteAuxData(sqlite3 *db, AuxData **pp, int iOp, int mask){
2975 while( *pp ){
2976 AuxData *pAux = *pp;
2977 if( (iOp<0)
2978 || (pAux->iAuxOp==iOp
2979 && pAux->iAuxArg>=0
2980 && (pAux->iAuxArg>31 || !(mask & MASKBIT32(pAux->iAuxArg))))
2981 ){
2982 testcase( pAux->iAuxArg==31 );
2983 if( pAux->xDeleteAux ){
2984 pAux->xDeleteAux(pAux->pAux);
2985 }
2986 *pp = pAux->pNextAux;
2987 sqlite3DbFree(db, pAux);
2988 }else{
2989 pp= &pAux->pNextAux;
2990 }
2991 }
2992 }
2993
2994 /*
2995 ** Free all memory associated with the Vdbe passed as the second argument,
2996 ** except for object itself, which is preserved.
2997 **
2998 ** The difference between this function and sqlite3VdbeDelete() is that
2999 ** VdbeDelete() also unlinks the Vdbe from the list of VMs associated with
3000 ** the database connection and frees the object itself.
3001 */
sqlite3VdbeClearObject(sqlite3 * db,Vdbe * p)3002 void sqlite3VdbeClearObject(sqlite3 *db, Vdbe *p){
3003 SubProgram *pSub, *pNext;
3004 assert( p->db==0 || p->db==db );
3005 releaseMemArray(p->aColName, p->nResColumn*COLNAME_N);
3006 for(pSub=p->pProgram; pSub; pSub=pNext){
3007 pNext = pSub->pNext;
3008 vdbeFreeOpArray(db, pSub->aOp, pSub->nOp);
3009 sqlite3DbFree(db, pSub);
3010 }
3011 if( p->magic!=VDBE_MAGIC_INIT ){
3012 releaseMemArray(p->aVar, p->nVar);
3013 sqlite3DbFree(db, p->pVList);
3014 sqlite3DbFree(db, p->pFree);
3015 }
3016 vdbeFreeOpArray(db, p->aOp, p->nOp);
3017 sqlite3DbFree(db, p->aColName);
3018 sqlite3DbFree(db, p->zSql);
3019 #ifdef SQLITE_ENABLE_STMT_SCANSTATUS
3020 {
3021 int i;
3022 for(i=0; i<p->nScan; i++){
3023 sqlite3DbFree(db, p->aScan[i].zName);
3024 }
3025 sqlite3DbFree(db, p->aScan);
3026 }
3027 #endif
3028 }
3029
3030 /*
3031 ** Delete an entire VDBE.
3032 */
sqlite3VdbeDelete(Vdbe * p)3033 void sqlite3VdbeDelete(Vdbe *p){
3034 sqlite3 *db;
3035
3036 if( NEVER(p==0) ) return;
3037 db = p->db;
3038 assert( sqlite3_mutex_held(db->mutex) );
3039 sqlite3VdbeClearObject(db, p);
3040 if( p->pPrev ){
3041 p->pPrev->pNext = p->pNext;
3042 }else{
3043 assert( db->pVdbe==p );
3044 db->pVdbe = p->pNext;
3045 }
3046 if( p->pNext ){
3047 p->pNext->pPrev = p->pPrev;
3048 }
3049 p->magic = VDBE_MAGIC_DEAD;
3050 p->db = 0;
3051 sqlite3DbFreeNN(db, p);
3052 }
3053
3054 /*
3055 ** The cursor "p" has a pending seek operation that has not yet been
3056 ** carried out. Seek the cursor now. If an error occurs, return
3057 ** the appropriate error code.
3058 */
handleDeferredMoveto(VdbeCursor * p)3059 static int SQLITE_NOINLINE handleDeferredMoveto(VdbeCursor *p){
3060 int res, rc;
3061 #ifdef SQLITE_TEST
3062 extern int sqlite3_search_count;
3063 #endif
3064 assert( p->deferredMoveto );
3065 assert( p->isTable );
3066 assert( p->eCurType==CURTYPE_BTREE );
3067 rc = sqlite3BtreeMovetoUnpacked(p->uc.pCursor, 0, p->movetoTarget, 0, &res);
3068 if( rc ) return rc;
3069 if( res!=0 ) return SQLITE_CORRUPT_BKPT;
3070 #ifdef SQLITE_TEST
3071 sqlite3_search_count++;
3072 #endif
3073 p->deferredMoveto = 0;
3074 p->cacheStatus = CACHE_STALE;
3075 return SQLITE_OK;
3076 }
3077
3078 /*
3079 ** Something has moved cursor "p" out of place. Maybe the row it was
3080 ** pointed to was deleted out from under it. Or maybe the btree was
3081 ** rebalanced. Whatever the cause, try to restore "p" to the place it
3082 ** is supposed to be pointing. If the row was deleted out from under the
3083 ** cursor, set the cursor to point to a NULL row.
3084 */
handleMovedCursor(VdbeCursor * p)3085 static int SQLITE_NOINLINE handleMovedCursor(VdbeCursor *p){
3086 int isDifferentRow, rc;
3087 assert( p->eCurType==CURTYPE_BTREE );
3088 assert( p->uc.pCursor!=0 );
3089 assert( sqlite3BtreeCursorHasMoved(p->uc.pCursor) );
3090 rc = sqlite3BtreeCursorRestore(p->uc.pCursor, &isDifferentRow);
3091 p->cacheStatus = CACHE_STALE;
3092 if( isDifferentRow ) p->nullRow = 1;
3093 return rc;
3094 }
3095
3096 /*
3097 ** Check to ensure that the cursor is valid. Restore the cursor
3098 ** if need be. Return any I/O error from the restore operation.
3099 */
sqlite3VdbeCursorRestore(VdbeCursor * p)3100 int sqlite3VdbeCursorRestore(VdbeCursor *p){
3101 assert( p->eCurType==CURTYPE_BTREE );
3102 if( sqlite3BtreeCursorHasMoved(p->uc.pCursor) ){
3103 return handleMovedCursor(p);
3104 }
3105 return SQLITE_OK;
3106 }
3107
3108 /*
3109 ** Make sure the cursor p is ready to read or write the row to which it
3110 ** was last positioned. Return an error code if an OOM fault or I/O error
3111 ** prevents us from positioning the cursor to its correct position.
3112 **
3113 ** If a MoveTo operation is pending on the given cursor, then do that
3114 ** MoveTo now. If no move is pending, check to see if the row has been
3115 ** deleted out from under the cursor and if it has, mark the row as
3116 ** a NULL row.
3117 **
3118 ** If the cursor is already pointing to the correct row and that row has
3119 ** not been deleted out from under the cursor, then this routine is a no-op.
3120 */
sqlite3VdbeCursorMoveto(VdbeCursor ** pp,int * piCol)3121 int sqlite3VdbeCursorMoveto(VdbeCursor **pp, int *piCol){
3122 VdbeCursor *p = *pp;
3123 if( p->eCurType==CURTYPE_BTREE ){
3124 if( p->deferredMoveto ){
3125 int iMap;
3126 if( p->aAltMap && (iMap = p->aAltMap[1+*piCol])>0 ){
3127 *pp = p->pAltCursor;
3128 *piCol = iMap - 1;
3129 return SQLITE_OK;
3130 }
3131 return handleDeferredMoveto(p);
3132 }
3133 if( sqlite3BtreeCursorHasMoved(p->uc.pCursor) ){
3134 return handleMovedCursor(p);
3135 }
3136 }
3137 return SQLITE_OK;
3138 }
3139
3140 /*
3141 ** The following functions:
3142 **
3143 ** sqlite3VdbeSerialType()
3144 ** sqlite3VdbeSerialTypeLen()
3145 ** sqlite3VdbeSerialLen()
3146 ** sqlite3VdbeSerialPut()
3147 ** sqlite3VdbeSerialGet()
3148 **
3149 ** encapsulate the code that serializes values for storage in SQLite
3150 ** data and index records. Each serialized value consists of a
3151 ** 'serial-type' and a blob of data. The serial type is an 8-byte unsigned
3152 ** integer, stored as a varint.
3153 **
3154 ** In an SQLite index record, the serial type is stored directly before
3155 ** the blob of data that it corresponds to. In a table record, all serial
3156 ** types are stored at the start of the record, and the blobs of data at
3157 ** the end. Hence these functions allow the caller to handle the
3158 ** serial-type and data blob separately.
3159 **
3160 ** The following table describes the various storage classes for data:
3161 **
3162 ** serial type bytes of data type
3163 ** -------------- --------------- ---------------
3164 ** 0 0 NULL
3165 ** 1 1 signed integer
3166 ** 2 2 signed integer
3167 ** 3 3 signed integer
3168 ** 4 4 signed integer
3169 ** 5 6 signed integer
3170 ** 6 8 signed integer
3171 ** 7 8 IEEE float
3172 ** 8 0 Integer constant 0
3173 ** 9 0 Integer constant 1
3174 ** 10,11 reserved for expansion
3175 ** N>=12 and even (N-12)/2 BLOB
3176 ** N>=13 and odd (N-13)/2 text
3177 **
3178 ** The 8 and 9 types were added in 3.3.0, file format 4. Prior versions
3179 ** of SQLite will not understand those serial types.
3180 */
3181
3182 /*
3183 ** Return the serial-type for the value stored in pMem.
3184 */
sqlite3VdbeSerialType(Mem * pMem,int file_format,u32 * pLen)3185 u32 sqlite3VdbeSerialType(Mem *pMem, int file_format, u32 *pLen){
3186 int flags = pMem->flags;
3187 u32 n;
3188
3189 assert( pLen!=0 );
3190 if( flags&MEM_Null ){
3191 *pLen = 0;
3192 return 0;
3193 }
3194 if( flags&MEM_Int ){
3195 /* Figure out whether to use 1, 2, 4, 6 or 8 bytes. */
3196 # define MAX_6BYTE ((((i64)0x00008000)<<32)-1)
3197 i64 i = pMem->u.i;
3198 u64 u;
3199 if( i<0 ){
3200 u = ~i;
3201 }else{
3202 u = i;
3203 }
3204 if( u<=127 ){
3205 if( (i&1)==i && file_format>=4 ){
3206 *pLen = 0;
3207 return 8+(u32)u;
3208 }else{
3209 *pLen = 1;
3210 return 1;
3211 }
3212 }
3213 if( u<=32767 ){ *pLen = 2; return 2; }
3214 if( u<=8388607 ){ *pLen = 3; return 3; }
3215 if( u<=2147483647 ){ *pLen = 4; return 4; }
3216 if( u<=MAX_6BYTE ){ *pLen = 6; return 5; }
3217 *pLen = 8;
3218 return 6;
3219 }
3220 if( flags&MEM_Real ){
3221 *pLen = 8;
3222 return 7;
3223 }
3224 assert( pMem->db->mallocFailed || flags&(MEM_Str|MEM_Blob) );
3225 assert( pMem->n>=0 );
3226 n = (u32)pMem->n;
3227 if( flags & MEM_Zero ){
3228 n += pMem->u.nZero;
3229 }
3230 *pLen = n;
3231 return ((n*2) + 12 + ((flags&MEM_Str)!=0));
3232 }
3233
3234 /*
3235 ** The sizes for serial types less than 128
3236 */
3237 static const u8 sqlite3SmallTypeSizes[] = {
3238 /* 0 1 2 3 4 5 6 7 8 9 */
3239 /* 0 */ 0, 1, 2, 3, 4, 6, 8, 8, 0, 0,
3240 /* 10 */ 0, 0, 0, 0, 1, 1, 2, 2, 3, 3,
3241 /* 20 */ 4, 4, 5, 5, 6, 6, 7, 7, 8, 8,
3242 /* 30 */ 9, 9, 10, 10, 11, 11, 12, 12, 13, 13,
3243 /* 40 */ 14, 14, 15, 15, 16, 16, 17, 17, 18, 18,
3244 /* 50 */ 19, 19, 20, 20, 21, 21, 22, 22, 23, 23,
3245 /* 60 */ 24, 24, 25, 25, 26, 26, 27, 27, 28, 28,
3246 /* 70 */ 29, 29, 30, 30, 31, 31, 32, 32, 33, 33,
3247 /* 80 */ 34, 34, 35, 35, 36, 36, 37, 37, 38, 38,
3248 /* 90 */ 39, 39, 40, 40, 41, 41, 42, 42, 43, 43,
3249 /* 100 */ 44, 44, 45, 45, 46, 46, 47, 47, 48, 48,
3250 /* 110 */ 49, 49, 50, 50, 51, 51, 52, 52, 53, 53,
3251 /* 120 */ 54, 54, 55, 55, 56, 56, 57, 57
3252 };
3253
3254 /*
3255 ** Return the length of the data corresponding to the supplied serial-type.
3256 */
sqlite3VdbeSerialTypeLen(u32 serial_type)3257 u32 sqlite3VdbeSerialTypeLen(u32 serial_type){
3258 if( serial_type>=128 ){
3259 return (serial_type-12)/2;
3260 }else{
3261 assert( serial_type<12
3262 || sqlite3SmallTypeSizes[serial_type]==(serial_type - 12)/2 );
3263 return sqlite3SmallTypeSizes[serial_type];
3264 }
3265 }
sqlite3VdbeOneByteSerialTypeLen(u8 serial_type)3266 u8 sqlite3VdbeOneByteSerialTypeLen(u8 serial_type){
3267 assert( serial_type<128 );
3268 return sqlite3SmallTypeSizes[serial_type];
3269 }
3270
3271 /*
3272 ** If we are on an architecture with mixed-endian floating
3273 ** points (ex: ARM7) then swap the lower 4 bytes with the
3274 ** upper 4 bytes. Return the result.
3275 **
3276 ** For most architectures, this is a no-op.
3277 **
3278 ** (later): It is reported to me that the mixed-endian problem
3279 ** on ARM7 is an issue with GCC, not with the ARM7 chip. It seems
3280 ** that early versions of GCC stored the two words of a 64-bit
3281 ** float in the wrong order. And that error has been propagated
3282 ** ever since. The blame is not necessarily with GCC, though.
3283 ** GCC might have just copying the problem from a prior compiler.
3284 ** I am also told that newer versions of GCC that follow a different
3285 ** ABI get the byte order right.
3286 **
3287 ** Developers using SQLite on an ARM7 should compile and run their
3288 ** application using -DSQLITE_DEBUG=1 at least once. With DEBUG
3289 ** enabled, some asserts below will ensure that the byte order of
3290 ** floating point values is correct.
3291 **
3292 ** (2007-08-30) Frank van Vugt has studied this problem closely
3293 ** and has send his findings to the SQLite developers. Frank
3294 ** writes that some Linux kernels offer floating point hardware
3295 ** emulation that uses only 32-bit mantissas instead of a full
3296 ** 48-bits as required by the IEEE standard. (This is the
3297 ** CONFIG_FPE_FASTFPE option.) On such systems, floating point
3298 ** byte swapping becomes very complicated. To avoid problems,
3299 ** the necessary byte swapping is carried out using a 64-bit integer
3300 ** rather than a 64-bit float. Frank assures us that the code here
3301 ** works for him. We, the developers, have no way to independently
3302 ** verify this, but Frank seems to know what he is talking about
3303 ** so we trust him.
3304 */
3305 #ifdef SQLITE_MIXED_ENDIAN_64BIT_FLOAT
floatSwap(u64 in)3306 static u64 floatSwap(u64 in){
3307 union {
3308 u64 r;
3309 u32 i[2];
3310 } u;
3311 u32 t;
3312
3313 u.r = in;
3314 t = u.i[0];
3315 u.i[0] = u.i[1];
3316 u.i[1] = t;
3317 return u.r;
3318 }
3319 # define swapMixedEndianFloat(X) X = floatSwap(X)
3320 #else
3321 # define swapMixedEndianFloat(X)
3322 #endif
3323
3324 /*
3325 ** Write the serialized data blob for the value stored in pMem into
3326 ** buf. It is assumed that the caller has allocated sufficient space.
3327 ** Return the number of bytes written.
3328 **
3329 ** nBuf is the amount of space left in buf[]. The caller is responsible
3330 ** for allocating enough space to buf[] to hold the entire field, exclusive
3331 ** of the pMem->u.nZero bytes for a MEM_Zero value.
3332 **
3333 ** Return the number of bytes actually written into buf[]. The number
3334 ** of bytes in the zero-filled tail is included in the return value only
3335 ** if those bytes were zeroed in buf[].
3336 */
sqlite3VdbeSerialPut(u8 * buf,Mem * pMem,u32 serial_type)3337 u32 sqlite3VdbeSerialPut(u8 *buf, Mem *pMem, u32 serial_type){
3338 u32 len;
3339
3340 /* Integer and Real */
3341 if( serial_type<=7 && serial_type>0 ){
3342 u64 v;
3343 u32 i;
3344 if( serial_type==7 ){
3345 assert( sizeof(v)==sizeof(pMem->u.r) );
3346 memcpy(&v, &pMem->u.r, sizeof(v));
3347 swapMixedEndianFloat(v);
3348 }else{
3349 v = pMem->u.i;
3350 }
3351 len = i = sqlite3SmallTypeSizes[serial_type];
3352 assert( i>0 );
3353 do{
3354 buf[--i] = (u8)(v&0xFF);
3355 v >>= 8;
3356 }while( i );
3357 return len;
3358 }
3359
3360 /* String or blob */
3361 if( serial_type>=12 ){
3362 assert( pMem->n + ((pMem->flags & MEM_Zero)?pMem->u.nZero:0)
3363 == (int)sqlite3VdbeSerialTypeLen(serial_type) );
3364 len = pMem->n;
3365 if( len>0 ) memcpy(buf, pMem->z, len);
3366 return len;
3367 }
3368
3369 /* NULL or constants 0 or 1 */
3370 return 0;
3371 }
3372
3373 /* Input "x" is a sequence of unsigned characters that represent a
3374 ** big-endian integer. Return the equivalent native integer
3375 */
3376 #define ONE_BYTE_INT(x) ((i8)(x)[0])
3377 #define TWO_BYTE_INT(x) (256*(i8)((x)[0])|(x)[1])
3378 #define THREE_BYTE_INT(x) (65536*(i8)((x)[0])|((x)[1]<<8)|(x)[2])
3379 #define FOUR_BYTE_UINT(x) (((u32)(x)[0]<<24)|((x)[1]<<16)|((x)[2]<<8)|(x)[3])
3380 #define FOUR_BYTE_INT(x) (16777216*(i8)((x)[0])|((x)[1]<<16)|((x)[2]<<8)|(x)[3])
3381
3382 /*
3383 ** Deserialize the data blob pointed to by buf as serial type serial_type
3384 ** and store the result in pMem. Return the number of bytes read.
3385 **
3386 ** This function is implemented as two separate routines for performance.
3387 ** The few cases that require local variables are broken out into a separate
3388 ** routine so that in most cases the overhead of moving the stack pointer
3389 ** is avoided.
3390 */
serialGet(const unsigned char * buf,u32 serial_type,Mem * pMem)3391 static u32 SQLITE_NOINLINE serialGet(
3392 const unsigned char *buf, /* Buffer to deserialize from */
3393 u32 serial_type, /* Serial type to deserialize */
3394 Mem *pMem /* Memory cell to write value into */
3395 ){
3396 u64 x = FOUR_BYTE_UINT(buf);
3397 u32 y = FOUR_BYTE_UINT(buf+4);
3398 x = (x<<32) + y;
3399 if( serial_type==6 ){
3400 /* EVIDENCE-OF: R-29851-52272 Value is a big-endian 64-bit
3401 ** twos-complement integer. */
3402 pMem->u.i = *(i64*)&x;
3403 pMem->flags = MEM_Int;
3404 testcase( pMem->u.i<0 );
3405 }else{
3406 /* EVIDENCE-OF: R-57343-49114 Value is a big-endian IEEE 754-2008 64-bit
3407 ** floating point number. */
3408 #if !defined(NDEBUG) && !defined(SQLITE_OMIT_FLOATING_POINT)
3409 /* Verify that integers and floating point values use the same
3410 ** byte order. Or, that if SQLITE_MIXED_ENDIAN_64BIT_FLOAT is
3411 ** defined that 64-bit floating point values really are mixed
3412 ** endian.
3413 */
3414 static const u64 t1 = ((u64)0x3ff00000)<<32;
3415 static const double r1 = 1.0;
3416 u64 t2 = t1;
3417 swapMixedEndianFloat(t2);
3418 assert( sizeof(r1)==sizeof(t2) && memcmp(&r1, &t2, sizeof(r1))==0 );
3419 #endif
3420 assert( sizeof(x)==8 && sizeof(pMem->u.r)==8 );
3421 swapMixedEndianFloat(x);
3422 memcpy(&pMem->u.r, &x, sizeof(x));
3423 pMem->flags = sqlite3IsNaN(pMem->u.r) ? MEM_Null : MEM_Real;
3424 }
3425 return 8;
3426 }
sqlite3VdbeSerialGet(const unsigned char * buf,u32 serial_type,Mem * pMem)3427 u32 sqlite3VdbeSerialGet(
3428 const unsigned char *buf, /* Buffer to deserialize from */
3429 u32 serial_type, /* Serial type to deserialize */
3430 Mem *pMem /* Memory cell to write value into */
3431 ){
3432 switch( serial_type ){
3433 case 10: /* Reserved for future use */
3434 case 11: /* Reserved for future use */
3435 case 0: { /* Null */
3436 /* EVIDENCE-OF: R-24078-09375 Value is a NULL. */
3437 pMem->flags = MEM_Null;
3438 break;
3439 }
3440 case 1: {
3441 /* EVIDENCE-OF: R-44885-25196 Value is an 8-bit twos-complement
3442 ** integer. */
3443 pMem->u.i = ONE_BYTE_INT(buf);
3444 pMem->flags = MEM_Int;
3445 testcase( pMem->u.i<0 );
3446 return 1;
3447 }
3448 case 2: { /* 2-byte signed integer */
3449 /* EVIDENCE-OF: R-49794-35026 Value is a big-endian 16-bit
3450 ** twos-complement integer. */
3451 pMem->u.i = TWO_BYTE_INT(buf);
3452 pMem->flags = MEM_Int;
3453 testcase( pMem->u.i<0 );
3454 return 2;
3455 }
3456 case 3: { /* 3-byte signed integer */
3457 /* EVIDENCE-OF: R-37839-54301 Value is a big-endian 24-bit
3458 ** twos-complement integer. */
3459 pMem->u.i = THREE_BYTE_INT(buf);
3460 pMem->flags = MEM_Int;
3461 testcase( pMem->u.i<0 );
3462 return 3;
3463 }
3464 case 4: { /* 4-byte signed integer */
3465 /* EVIDENCE-OF: R-01849-26079 Value is a big-endian 32-bit
3466 ** twos-complement integer. */
3467 pMem->u.i = FOUR_BYTE_INT(buf);
3468 #ifdef __HP_cc
3469 /* Work around a sign-extension bug in the HP compiler for HP/UX */
3470 if( buf[0]&0x80 ) pMem->u.i |= 0xffffffff80000000LL;
3471 #endif
3472 pMem->flags = MEM_Int;
3473 testcase( pMem->u.i<0 );
3474 return 4;
3475 }
3476 case 5: { /* 6-byte signed integer */
3477 /* EVIDENCE-OF: R-50385-09674 Value is a big-endian 48-bit
3478 ** twos-complement integer. */
3479 pMem->u.i = FOUR_BYTE_UINT(buf+2) + (((i64)1)<<32)*TWO_BYTE_INT(buf);
3480 pMem->flags = MEM_Int;
3481 testcase( pMem->u.i<0 );
3482 return 6;
3483 }
3484 case 6: /* 8-byte signed integer */
3485 case 7: { /* IEEE floating point */
3486 /* These use local variables, so do them in a separate routine
3487 ** to avoid having to move the frame pointer in the common case */
3488 return serialGet(buf,serial_type,pMem);
3489 }
3490 case 8: /* Integer 0 */
3491 case 9: { /* Integer 1 */
3492 /* EVIDENCE-OF: R-12976-22893 Value is the integer 0. */
3493 /* EVIDENCE-OF: R-18143-12121 Value is the integer 1. */
3494 pMem->u.i = serial_type-8;
3495 pMem->flags = MEM_Int;
3496 return 0;
3497 }
3498 default: {
3499 /* EVIDENCE-OF: R-14606-31564 Value is a BLOB that is (N-12)/2 bytes in
3500 ** length.
3501 ** EVIDENCE-OF: R-28401-00140 Value is a string in the text encoding and
3502 ** (N-13)/2 bytes in length. */
3503 static const u16 aFlag[] = { MEM_Blob|MEM_Ephem, MEM_Str|MEM_Ephem };
3504 pMem->z = (char *)buf;
3505 pMem->n = (serial_type-12)/2;
3506 pMem->flags = aFlag[serial_type&1];
3507 return pMem->n;
3508 }
3509 }
3510 return 0;
3511 }
3512 /*
3513 ** This routine is used to allocate sufficient space for an UnpackedRecord
3514 ** structure large enough to be used with sqlite3VdbeRecordUnpack() if
3515 ** the first argument is a pointer to KeyInfo structure pKeyInfo.
3516 **
3517 ** The space is either allocated using sqlite3DbMallocRaw() or from within
3518 ** the unaligned buffer passed via the second and third arguments (presumably
3519 ** stack space). If the former, then *ppFree is set to a pointer that should
3520 ** be eventually freed by the caller using sqlite3DbFree(). Or, if the
3521 ** allocation comes from the pSpace/szSpace buffer, *ppFree is set to NULL
3522 ** before returning.
3523 **
3524 ** If an OOM error occurs, NULL is returned.
3525 */
sqlite3VdbeAllocUnpackedRecord(KeyInfo * pKeyInfo)3526 UnpackedRecord *sqlite3VdbeAllocUnpackedRecord(
3527 KeyInfo *pKeyInfo /* Description of the record */
3528 ){
3529 UnpackedRecord *p; /* Unpacked record to return */
3530 int nByte; /* Number of bytes required for *p */
3531 nByte = ROUND8(sizeof(UnpackedRecord)) + sizeof(Mem)*(pKeyInfo->nField+1);
3532 p = (UnpackedRecord *)sqlite3DbMallocRaw(pKeyInfo->db, nByte);
3533 if( !p ) return 0;
3534 p->aMem = (Mem*)&((char*)p)[ROUND8(sizeof(UnpackedRecord))];
3535 assert( pKeyInfo->aSortOrder!=0 );
3536 p->pKeyInfo = pKeyInfo;
3537 p->nField = pKeyInfo->nField + 1;
3538 return p;
3539 }
3540
3541 /*
3542 ** Given the nKey-byte encoding of a record in pKey[], populate the
3543 ** UnpackedRecord structure indicated by the fourth argument with the
3544 ** contents of the decoded record.
3545 */
sqlite3VdbeRecordUnpack(KeyInfo * pKeyInfo,int nKey,const void * pKey,UnpackedRecord * p)3546 void sqlite3VdbeRecordUnpack(
3547 KeyInfo *pKeyInfo, /* Information about the record format */
3548 int nKey, /* Size of the binary record */
3549 const void *pKey, /* The binary record */
3550 UnpackedRecord *p /* Populate this structure before returning. */
3551 ){
3552 const unsigned char *aKey = (const unsigned char *)pKey;
3553 int d;
3554 u32 idx; /* Offset in aKey[] to read from */
3555 u16 u; /* Unsigned loop counter */
3556 u32 szHdr;
3557 Mem *pMem = p->aMem;
3558
3559 p->default_rc = 0;
3560 assert( EIGHT_BYTE_ALIGNMENT(pMem) );
3561 idx = getVarint32(aKey, szHdr);
3562 d = szHdr;
3563 u = 0;
3564 while( idx<szHdr && d<=nKey ){
3565 u32 serial_type;
3566
3567 idx += getVarint32(&aKey[idx], serial_type);
3568 pMem->enc = pKeyInfo->enc;
3569 pMem->db = pKeyInfo->db;
3570 /* pMem->flags = 0; // sqlite3VdbeSerialGet() will set this for us */
3571 pMem->szMalloc = 0;
3572 pMem->z = 0;
3573 d += sqlite3VdbeSerialGet(&aKey[d], serial_type, pMem);
3574 pMem++;
3575 if( (++u)>=p->nField ) break;
3576 }
3577 assert( u<=pKeyInfo->nField + 1 );
3578 p->nField = u;
3579 }
3580
3581 #ifdef SQLITE_DEBUG
3582 /*
3583 ** This function compares two index or table record keys in the same way
3584 ** as the sqlite3VdbeRecordCompare() routine. Unlike VdbeRecordCompare(),
3585 ** this function deserializes and compares values using the
3586 ** sqlite3VdbeSerialGet() and sqlite3MemCompare() functions. It is used
3587 ** in assert() statements to ensure that the optimized code in
3588 ** sqlite3VdbeRecordCompare() returns results with these two primitives.
3589 **
3590 ** Return true if the result of comparison is equivalent to desiredResult.
3591 ** Return false if there is a disagreement.
3592 */
vdbeRecordCompareDebug(int nKey1,const void * pKey1,const UnpackedRecord * pPKey2,int desiredResult)3593 static int vdbeRecordCompareDebug(
3594 int nKey1, const void *pKey1, /* Left key */
3595 const UnpackedRecord *pPKey2, /* Right key */
3596 int desiredResult /* Correct answer */
3597 ){
3598 u32 d1; /* Offset into aKey[] of next data element */
3599 u32 idx1; /* Offset into aKey[] of next header element */
3600 u32 szHdr1; /* Number of bytes in header */
3601 int i = 0;
3602 int rc = 0;
3603 const unsigned char *aKey1 = (const unsigned char *)pKey1;
3604 KeyInfo *pKeyInfo;
3605 Mem mem1;
3606
3607 pKeyInfo = pPKey2->pKeyInfo;
3608 if( pKeyInfo->db==0 ) return 1;
3609 mem1.enc = pKeyInfo->enc;
3610 mem1.db = pKeyInfo->db;
3611 /* mem1.flags = 0; // Will be initialized by sqlite3VdbeSerialGet() */
3612 VVA_ONLY( mem1.szMalloc = 0; ) /* Only needed by assert() statements */
3613
3614 /* Compilers may complain that mem1.u.i is potentially uninitialized.
3615 ** We could initialize it, as shown here, to silence those complaints.
3616 ** But in fact, mem1.u.i will never actually be used uninitialized, and doing
3617 ** the unnecessary initialization has a measurable negative performance
3618 ** impact, since this routine is a very high runner. And so, we choose
3619 ** to ignore the compiler warnings and leave this variable uninitialized.
3620 */
3621 /* mem1.u.i = 0; // not needed, here to silence compiler warning */
3622
3623 idx1 = getVarint32(aKey1, szHdr1);
3624 if( szHdr1>98307 ) return SQLITE_CORRUPT;
3625 d1 = szHdr1;
3626 assert( pKeyInfo->nField+pKeyInfo->nXField>=pPKey2->nField || CORRUPT_DB );
3627 assert( pKeyInfo->aSortOrder!=0 );
3628 assert( pKeyInfo->nField>0 );
3629 assert( idx1<=szHdr1 || CORRUPT_DB );
3630 do{
3631 u32 serial_type1;
3632
3633 /* Read the serial types for the next element in each key. */
3634 idx1 += getVarint32( aKey1+idx1, serial_type1 );
3635
3636 /* Verify that there is enough key space remaining to avoid
3637 ** a buffer overread. The "d1+serial_type1+2" subexpression will
3638 ** always be greater than or equal to the amount of required key space.
3639 ** Use that approximation to avoid the more expensive call to
3640 ** sqlite3VdbeSerialTypeLen() in the common case.
3641 */
3642 if( d1+serial_type1+2>(u32)nKey1
3643 && d1+sqlite3VdbeSerialTypeLen(serial_type1)>(u32)nKey1
3644 ){
3645 break;
3646 }
3647
3648 /* Extract the values to be compared.
3649 */
3650 d1 += sqlite3VdbeSerialGet(&aKey1[d1], serial_type1, &mem1);
3651
3652 /* Do the comparison
3653 */
3654 rc = sqlite3MemCompare(&mem1, &pPKey2->aMem[i], pKeyInfo->aColl[i]);
3655 if( rc!=0 ){
3656 assert( mem1.szMalloc==0 ); /* See comment below */
3657 if( pKeyInfo->aSortOrder[i] ){
3658 rc = -rc; /* Invert the result for DESC sort order. */
3659 }
3660 goto debugCompareEnd;
3661 }
3662 i++;
3663 }while( idx1<szHdr1 && i<pPKey2->nField );
3664
3665 /* No memory allocation is ever used on mem1. Prove this using
3666 ** the following assert(). If the assert() fails, it indicates a
3667 ** memory leak and a need to call sqlite3VdbeMemRelease(&mem1).
3668 */
3669 assert( mem1.szMalloc==0 );
3670
3671 /* rc==0 here means that one of the keys ran out of fields and
3672 ** all the fields up to that point were equal. Return the default_rc
3673 ** value. */
3674 rc = pPKey2->default_rc;
3675
3676 debugCompareEnd:
3677 if( desiredResult==0 && rc==0 ) return 1;
3678 if( desiredResult<0 && rc<0 ) return 1;
3679 if( desiredResult>0 && rc>0 ) return 1;
3680 if( CORRUPT_DB ) return 1;
3681 if( pKeyInfo->db->mallocFailed ) return 1;
3682 return 0;
3683 }
3684 #endif
3685
3686 #ifdef SQLITE_DEBUG
3687 /*
3688 ** Count the number of fields (a.k.a. columns) in the record given by
3689 ** pKey,nKey. The verify that this count is less than or equal to the
3690 ** limit given by pKeyInfo->nField + pKeyInfo->nXField.
3691 **
3692 ** If this constraint is not satisfied, it means that the high-speed
3693 ** vdbeRecordCompareInt() and vdbeRecordCompareString() routines will
3694 ** not work correctly. If this assert() ever fires, it probably means
3695 ** that the KeyInfo.nField or KeyInfo.nXField values were computed
3696 ** incorrectly.
3697 */
vdbeAssertFieldCountWithinLimits(int nKey,const void * pKey,const KeyInfo * pKeyInfo)3698 static void vdbeAssertFieldCountWithinLimits(
3699 int nKey, const void *pKey, /* The record to verify */
3700 const KeyInfo *pKeyInfo /* Compare size with this KeyInfo */
3701 ){
3702 int nField = 0;
3703 u32 szHdr;
3704 u32 idx;
3705 u32 notUsed;
3706 const unsigned char *aKey = (const unsigned char*)pKey;
3707
3708 if( CORRUPT_DB ) return;
3709 idx = getVarint32(aKey, szHdr);
3710 assert( nKey>=0 );
3711 assert( szHdr<=(u32)nKey );
3712 while( idx<szHdr ){
3713 idx += getVarint32(aKey+idx, notUsed);
3714 nField++;
3715 }
3716 assert( nField <= pKeyInfo->nField+pKeyInfo->nXField );
3717 }
3718 #else
3719 # define vdbeAssertFieldCountWithinLimits(A,B,C)
3720 #endif
3721
3722 /*
3723 ** Both *pMem1 and *pMem2 contain string values. Compare the two values
3724 ** using the collation sequence pColl. As usual, return a negative , zero
3725 ** or positive value if *pMem1 is less than, equal to or greater than
3726 ** *pMem2, respectively. Similar in spirit to "rc = (*pMem1) - (*pMem2);".
3727 */
vdbeCompareMemString(const Mem * pMem1,const Mem * pMem2,const CollSeq * pColl,u8 * prcErr)3728 static int vdbeCompareMemString(
3729 const Mem *pMem1,
3730 const Mem *pMem2,
3731 const CollSeq *pColl,
3732 u8 *prcErr /* If an OOM occurs, set to SQLITE_NOMEM */
3733 ){
3734 if( pMem1->enc==pColl->enc ){
3735 /* The strings are already in the correct encoding. Call the
3736 ** comparison function directly */
3737 return pColl->xCmp(pColl->pUser,pMem1->n,pMem1->z,pMem2->n,pMem2->z);
3738 }else{
3739 int rc;
3740 const void *v1, *v2;
3741 Mem c1;
3742 Mem c2;
3743 sqlite3VdbeMemInit(&c1, pMem1->db, MEM_Null);
3744 sqlite3VdbeMemInit(&c2, pMem1->db, MEM_Null);
3745 sqlite3VdbeMemShallowCopy(&c1, pMem1, MEM_Ephem);
3746 sqlite3VdbeMemShallowCopy(&c2, pMem2, MEM_Ephem);
3747 v1 = sqlite3ValueText((sqlite3_value*)&c1, pColl->enc);
3748 v2 = sqlite3ValueText((sqlite3_value*)&c2, pColl->enc);
3749 if( (v1==0 || v2==0) ){
3750 if( prcErr ) *prcErr = SQLITE_NOMEM_BKPT;
3751 rc = 0;
3752 }else{
3753 rc = pColl->xCmp(pColl->pUser, c1.n, v1, c2.n, v2);
3754 }
3755 sqlite3VdbeMemRelease(&c1);
3756 sqlite3VdbeMemRelease(&c2);
3757 return rc;
3758 }
3759 }
3760
3761 /*
3762 ** The input pBlob is guaranteed to be a Blob that is not marked
3763 ** with MEM_Zero. Return true if it could be a zero-blob.
3764 */
isAllZero(const char * z,int n)3765 static int isAllZero(const char *z, int n){
3766 int i;
3767 for(i=0; i<n; i++){
3768 if( z[i] ) return 0;
3769 }
3770 return 1;
3771 }
3772
3773 /*
3774 ** Compare two blobs. Return negative, zero, or positive if the first
3775 ** is less than, equal to, or greater than the second, respectively.
3776 ** If one blob is a prefix of the other, then the shorter is the lessor.
3777 */
sqlite3BlobCompare(const Mem * pB1,const Mem * pB2)3778 static SQLITE_NOINLINE int sqlite3BlobCompare(const Mem *pB1, const Mem *pB2){
3779 int c;
3780 int n1 = pB1->n;
3781 int n2 = pB2->n;
3782
3783 /* It is possible to have a Blob value that has some non-zero content
3784 ** followed by zero content. But that only comes up for Blobs formed
3785 ** by the OP_MakeRecord opcode, and such Blobs never get passed into
3786 ** sqlite3MemCompare(). */
3787 assert( (pB1->flags & MEM_Zero)==0 || n1==0 );
3788 assert( (pB2->flags & MEM_Zero)==0 || n2==0 );
3789
3790 if( (pB1->flags|pB2->flags) & MEM_Zero ){
3791 if( pB1->flags & pB2->flags & MEM_Zero ){
3792 return pB1->u.nZero - pB2->u.nZero;
3793 }else if( pB1->flags & MEM_Zero ){
3794 if( !isAllZero(pB2->z, pB2->n) ) return -1;
3795 return pB1->u.nZero - n2;
3796 }else{
3797 if( !isAllZero(pB1->z, pB1->n) ) return +1;
3798 return n1 - pB2->u.nZero;
3799 }
3800 }
3801 c = memcmp(pB1->z, pB2->z, n1>n2 ? n2 : n1);
3802 if( c ) return c;
3803 return n1 - n2;
3804 }
3805
3806 /*
3807 ** Do a comparison between a 64-bit signed integer and a 64-bit floating-point
3808 ** number. Return negative, zero, or positive if the first (i64) is less than,
3809 ** equal to, or greater than the second (double).
3810 */
sqlite3IntFloatCompare(i64 i,double r)3811 static int sqlite3IntFloatCompare(i64 i, double r){
3812 if( sizeof(LONGDOUBLE_TYPE)>8 ){
3813 LONGDOUBLE_TYPE x = (LONGDOUBLE_TYPE)i;
3814 if( x<r ) return -1;
3815 if( x>r ) return +1;
3816 return 0;
3817 }else{
3818 i64 y;
3819 double s;
3820 if( r<-9223372036854775808.0 ) return +1;
3821 if( r>9223372036854775807.0 ) return -1;
3822 y = (i64)r;
3823 if( i<y ) return -1;
3824 if( i>y ){
3825 if( y==SMALLEST_INT64 && r>0.0 ) return -1;
3826 return +1;
3827 }
3828 s = (double)i;
3829 if( s<r ) return -1;
3830 if( s>r ) return +1;
3831 return 0;
3832 }
3833 }
3834
3835 /*
3836 ** Compare the values contained by the two memory cells, returning
3837 ** negative, zero or positive if pMem1 is less than, equal to, or greater
3838 ** than pMem2. Sorting order is NULL's first, followed by numbers (integers
3839 ** and reals) sorted numerically, followed by text ordered by the collating
3840 ** sequence pColl and finally blob's ordered by memcmp().
3841 **
3842 ** Two NULL values are considered equal by this function.
3843 */
sqlite3MemCompare(const Mem * pMem1,const Mem * pMem2,const CollSeq * pColl)3844 int sqlite3MemCompare(const Mem *pMem1, const Mem *pMem2, const CollSeq *pColl){
3845 int f1, f2;
3846 int combined_flags;
3847
3848 f1 = pMem1->flags;
3849 f2 = pMem2->flags;
3850 combined_flags = f1|f2;
3851 assert( (combined_flags & MEM_RowSet)==0 );
3852
3853 /* If one value is NULL, it is less than the other. If both values
3854 ** are NULL, return 0.
3855 */
3856 if( combined_flags&MEM_Null ){
3857 return (f2&MEM_Null) - (f1&MEM_Null);
3858 }
3859
3860 /* At least one of the two values is a number
3861 */
3862 if( combined_flags&(MEM_Int|MEM_Real) ){
3863 if( (f1 & f2 & MEM_Int)!=0 ){
3864 if( pMem1->u.i < pMem2->u.i ) return -1;
3865 if( pMem1->u.i > pMem2->u.i ) return +1;
3866 return 0;
3867 }
3868 if( (f1 & f2 & MEM_Real)!=0 ){
3869 if( pMem1->u.r < pMem2->u.r ) return -1;
3870 if( pMem1->u.r > pMem2->u.r ) return +1;
3871 return 0;
3872 }
3873 if( (f1&MEM_Int)!=0 ){
3874 if( (f2&MEM_Real)!=0 ){
3875 return sqlite3IntFloatCompare(pMem1->u.i, pMem2->u.r);
3876 }else{
3877 return -1;
3878 }
3879 }
3880 if( (f1&MEM_Real)!=0 ){
3881 if( (f2&MEM_Int)!=0 ){
3882 return -sqlite3IntFloatCompare(pMem2->u.i, pMem1->u.r);
3883 }else{
3884 return -1;
3885 }
3886 }
3887 return +1;
3888 }
3889
3890 /* If one value is a string and the other is a blob, the string is less.
3891 ** If both are strings, compare using the collating functions.
3892 */
3893 if( combined_flags&MEM_Str ){
3894 if( (f1 & MEM_Str)==0 ){
3895 return 1;
3896 }
3897 if( (f2 & MEM_Str)==0 ){
3898 return -1;
3899 }
3900
3901 assert( pMem1->enc==pMem2->enc || pMem1->db->mallocFailed );
3902 assert( pMem1->enc==SQLITE_UTF8 ||
3903 pMem1->enc==SQLITE_UTF16LE || pMem1->enc==SQLITE_UTF16BE );
3904
3905 /* The collation sequence must be defined at this point, even if
3906 ** the user deletes the collation sequence after the vdbe program is
3907 ** compiled (this was not always the case).
3908 */
3909 assert( !pColl || pColl->xCmp );
3910
3911 if( pColl ){
3912 return vdbeCompareMemString(pMem1, pMem2, pColl, 0);
3913 }
3914 /* If a NULL pointer was passed as the collate function, fall through
3915 ** to the blob case and use memcmp(). */
3916 }
3917
3918 /* Both values must be blobs. Compare using memcmp(). */
3919 return sqlite3BlobCompare(pMem1, pMem2);
3920 }
3921
3922
3923 /*
3924 ** The first argument passed to this function is a serial-type that
3925 ** corresponds to an integer - all values between 1 and 9 inclusive
3926 ** except 7. The second points to a buffer containing an integer value
3927 ** serialized according to serial_type. This function deserializes
3928 ** and returns the value.
3929 */
vdbeRecordDecodeInt(u32 serial_type,const u8 * aKey)3930 static i64 vdbeRecordDecodeInt(u32 serial_type, const u8 *aKey){
3931 u32 y;
3932 assert( CORRUPT_DB || (serial_type>=1 && serial_type<=9 && serial_type!=7) );
3933 switch( serial_type ){
3934 case 0:
3935 case 1:
3936 testcase( aKey[0]&0x80 );
3937 return ONE_BYTE_INT(aKey);
3938 case 2:
3939 testcase( aKey[0]&0x80 );
3940 return TWO_BYTE_INT(aKey);
3941 case 3:
3942 testcase( aKey[0]&0x80 );
3943 return THREE_BYTE_INT(aKey);
3944 case 4: {
3945 testcase( aKey[0]&0x80 );
3946 y = FOUR_BYTE_UINT(aKey);
3947 return (i64)*(int*)&y;
3948 }
3949 case 5: {
3950 testcase( aKey[0]&0x80 );
3951 return FOUR_BYTE_UINT(aKey+2) + (((i64)1)<<32)*TWO_BYTE_INT(aKey);
3952 }
3953 case 6: {
3954 u64 x = FOUR_BYTE_UINT(aKey);
3955 testcase( aKey[0]&0x80 );
3956 x = (x<<32) | FOUR_BYTE_UINT(aKey+4);
3957 return (i64)*(i64*)&x;
3958 }
3959 }
3960
3961 return (serial_type - 8);
3962 }
3963
3964 /*
3965 ** This function compares the two table rows or index records
3966 ** specified by {nKey1, pKey1} and pPKey2. It returns a negative, zero
3967 ** or positive integer if key1 is less than, equal to or
3968 ** greater than key2. The {nKey1, pKey1} key must be a blob
3969 ** created by the OP_MakeRecord opcode of the VDBE. The pPKey2
3970 ** key must be a parsed key such as obtained from
3971 ** sqlite3VdbeParseRecord.
3972 **
3973 ** If argument bSkip is non-zero, it is assumed that the caller has already
3974 ** determined that the first fields of the keys are equal.
3975 **
3976 ** Key1 and Key2 do not have to contain the same number of fields. If all
3977 ** fields that appear in both keys are equal, then pPKey2->default_rc is
3978 ** returned.
3979 **
3980 ** If database corruption is discovered, set pPKey2->errCode to
3981 ** SQLITE_CORRUPT and return 0. If an OOM error is encountered,
3982 ** pPKey2->errCode is set to SQLITE_NOMEM and, if it is not NULL, the
3983 ** malloc-failed flag set on database handle (pPKey2->pKeyInfo->db).
3984 */
sqlite3VdbeRecordCompareWithSkip(int nKey1,const void * pKey1,UnpackedRecord * pPKey2,int bSkip)3985 int sqlite3VdbeRecordCompareWithSkip(
3986 int nKey1, const void *pKey1, /* Left key */
3987 UnpackedRecord *pPKey2, /* Right key */
3988 int bSkip /* If true, skip the first field */
3989 ){
3990 u32 d1; /* Offset into aKey[] of next data element */
3991 int i; /* Index of next field to compare */
3992 u32 szHdr1; /* Size of record header in bytes */
3993 u32 idx1; /* Offset of first type in header */
3994 int rc = 0; /* Return value */
3995 Mem *pRhs = pPKey2->aMem; /* Next field of pPKey2 to compare */
3996 KeyInfo *pKeyInfo = pPKey2->pKeyInfo;
3997 const unsigned char *aKey1 = (const unsigned char *)pKey1;
3998 Mem mem1;
3999
4000 /* If bSkip is true, then the caller has already determined that the first
4001 ** two elements in the keys are equal. Fix the various stack variables so
4002 ** that this routine begins comparing at the second field. */
4003 if( bSkip ){
4004 u32 s1;
4005 idx1 = 1 + getVarint32(&aKey1[1], s1);
4006 szHdr1 = aKey1[0];
4007 d1 = szHdr1 + sqlite3VdbeSerialTypeLen(s1);
4008 i = 1;
4009 pRhs++;
4010 }else{
4011 idx1 = getVarint32(aKey1, szHdr1);
4012 d1 = szHdr1;
4013 if( d1>(unsigned)nKey1 ){
4014 pPKey2->errCode = (u8)SQLITE_CORRUPT_BKPT;
4015 return 0; /* Corruption */
4016 }
4017 i = 0;
4018 }
4019
4020 VVA_ONLY( mem1.szMalloc = 0; ) /* Only needed by assert() statements */
4021 assert( pPKey2->pKeyInfo->nField+pPKey2->pKeyInfo->nXField>=pPKey2->nField
4022 || CORRUPT_DB );
4023 assert( pPKey2->pKeyInfo->aSortOrder!=0 );
4024 assert( pPKey2->pKeyInfo->nField>0 );
4025 assert( idx1<=szHdr1 || CORRUPT_DB );
4026 do{
4027 u32 serial_type;
4028
4029 /* RHS is an integer */
4030 if( pRhs->flags & MEM_Int ){
4031 serial_type = aKey1[idx1];
4032 testcase( serial_type==12 );
4033 if( serial_type>=10 ){
4034 rc = +1;
4035 }else if( serial_type==0 ){
4036 rc = -1;
4037 }else if( serial_type==7 ){
4038 sqlite3VdbeSerialGet(&aKey1[d1], serial_type, &mem1);
4039 rc = -sqlite3IntFloatCompare(pRhs->u.i, mem1.u.r);
4040 }else{
4041 i64 lhs = vdbeRecordDecodeInt(serial_type, &aKey1[d1]);
4042 i64 rhs = pRhs->u.i;
4043 if( lhs<rhs ){
4044 rc = -1;
4045 }else if( lhs>rhs ){
4046 rc = +1;
4047 }
4048 }
4049 }
4050
4051 /* RHS is real */
4052 else if( pRhs->flags & MEM_Real ){
4053 serial_type = aKey1[idx1];
4054 if( serial_type>=10 ){
4055 /* Serial types 12 or greater are strings and blobs (greater than
4056 ** numbers). Types 10 and 11 are currently "reserved for future
4057 ** use", so it doesn't really matter what the results of comparing
4058 ** them to numberic values are. */
4059 rc = +1;
4060 }else if( serial_type==0 ){
4061 rc = -1;
4062 }else{
4063 sqlite3VdbeSerialGet(&aKey1[d1], serial_type, &mem1);
4064 if( serial_type==7 ){
4065 if( mem1.u.r<pRhs->u.r ){
4066 rc = -1;
4067 }else if( mem1.u.r>pRhs->u.r ){
4068 rc = +1;
4069 }
4070 }else{
4071 rc = sqlite3IntFloatCompare(mem1.u.i, pRhs->u.r);
4072 }
4073 }
4074 }
4075
4076 /* RHS is a string */
4077 else if( pRhs->flags & MEM_Str ){
4078 getVarint32(&aKey1[idx1], serial_type);
4079 testcase( serial_type==12 );
4080 if( serial_type<12 ){
4081 rc = -1;
4082 }else if( !(serial_type & 0x01) ){
4083 rc = +1;
4084 }else{
4085 mem1.n = (serial_type - 12) / 2;
4086 testcase( (d1+mem1.n)==(unsigned)nKey1 );
4087 testcase( (d1+mem1.n+1)==(unsigned)nKey1 );
4088 if( (d1+mem1.n) > (unsigned)nKey1 ){
4089 pPKey2->errCode = (u8)SQLITE_CORRUPT_BKPT;
4090 return 0; /* Corruption */
4091 }else if( pKeyInfo->aColl[i] ){
4092 mem1.enc = pKeyInfo->enc;
4093 mem1.db = pKeyInfo->db;
4094 mem1.flags = MEM_Str;
4095 mem1.z = (char*)&aKey1[d1];
4096 rc = vdbeCompareMemString(
4097 &mem1, pRhs, pKeyInfo->aColl[i], &pPKey2->errCode
4098 );
4099 }else{
4100 int nCmp = MIN(mem1.n, pRhs->n);
4101 rc = memcmp(&aKey1[d1], pRhs->z, nCmp);
4102 if( rc==0 ) rc = mem1.n - pRhs->n;
4103 }
4104 }
4105 }
4106
4107 /* RHS is a blob */
4108 else if( pRhs->flags & MEM_Blob ){
4109 assert( (pRhs->flags & MEM_Zero)==0 || pRhs->n==0 );
4110 getVarint32(&aKey1[idx1], serial_type);
4111 testcase( serial_type==12 );
4112 if( serial_type<12 || (serial_type & 0x01) ){
4113 rc = -1;
4114 }else{
4115 int nStr = (serial_type - 12) / 2;
4116 testcase( (d1+nStr)==(unsigned)nKey1 );
4117 testcase( (d1+nStr+1)==(unsigned)nKey1 );
4118 if( (d1+nStr) > (unsigned)nKey1 ){
4119 pPKey2->errCode = (u8)SQLITE_CORRUPT_BKPT;
4120 return 0; /* Corruption */
4121 }else if( pRhs->flags & MEM_Zero ){
4122 if( !isAllZero((const char*)&aKey1[d1],nStr) ){
4123 rc = 1;
4124 }else{
4125 rc = nStr - pRhs->u.nZero;
4126 }
4127 }else{
4128 int nCmp = MIN(nStr, pRhs->n);
4129 rc = memcmp(&aKey1[d1], pRhs->z, nCmp);
4130 if( rc==0 ) rc = nStr - pRhs->n;
4131 }
4132 }
4133 }
4134
4135 /* RHS is null */
4136 else{
4137 serial_type = aKey1[idx1];
4138 rc = (serial_type!=0);
4139 }
4140
4141 if( rc!=0 ){
4142 if( pKeyInfo->aSortOrder[i] ){
4143 rc = -rc;
4144 }
4145 assert( vdbeRecordCompareDebug(nKey1, pKey1, pPKey2, rc) );
4146 assert( mem1.szMalloc==0 ); /* See comment below */
4147 return rc;
4148 }
4149
4150 i++;
4151 pRhs++;
4152 d1 += sqlite3VdbeSerialTypeLen(serial_type);
4153 idx1 += sqlite3VarintLen(serial_type);
4154 }while( idx1<(unsigned)szHdr1 && i<pPKey2->nField && d1<=(unsigned)nKey1 );
4155
4156 /* No memory allocation is ever used on mem1. Prove this using
4157 ** the following assert(). If the assert() fails, it indicates a
4158 ** memory leak and a need to call sqlite3VdbeMemRelease(&mem1). */
4159 assert( mem1.szMalloc==0 );
4160
4161 /* rc==0 here means that one or both of the keys ran out of fields and
4162 ** all the fields up to that point were equal. Return the default_rc
4163 ** value. */
4164 assert( CORRUPT_DB
4165 || vdbeRecordCompareDebug(nKey1, pKey1, pPKey2, pPKey2->default_rc)
4166 || pKeyInfo->db->mallocFailed
4167 );
4168 pPKey2->eqSeen = 1;
4169 return pPKey2->default_rc;
4170 }
sqlite3VdbeRecordCompare(int nKey1,const void * pKey1,UnpackedRecord * pPKey2)4171 int sqlite3VdbeRecordCompare(
4172 int nKey1, const void *pKey1, /* Left key */
4173 UnpackedRecord *pPKey2 /* Right key */
4174 ){
4175 return sqlite3VdbeRecordCompareWithSkip(nKey1, pKey1, pPKey2, 0);
4176 }
4177
4178
4179 /*
4180 ** This function is an optimized version of sqlite3VdbeRecordCompare()
4181 ** that (a) the first field of pPKey2 is an integer, and (b) the
4182 ** size-of-header varint at the start of (pKey1/nKey1) fits in a single
4183 ** byte (i.e. is less than 128).
4184 **
4185 ** To avoid concerns about buffer overreads, this routine is only used
4186 ** on schemas where the maximum valid header size is 63 bytes or less.
4187 */
vdbeRecordCompareInt(int nKey1,const void * pKey1,UnpackedRecord * pPKey2)4188 static int vdbeRecordCompareInt(
4189 int nKey1, const void *pKey1, /* Left key */
4190 UnpackedRecord *pPKey2 /* Right key */
4191 ){
4192 const u8 *aKey = &((const u8*)pKey1)[*(const u8*)pKey1 & 0x3F];
4193 int serial_type = ((const u8*)pKey1)[1];
4194 int res;
4195 u32 y;
4196 u64 x;
4197 i64 v;
4198 i64 lhs;
4199
4200 vdbeAssertFieldCountWithinLimits(nKey1, pKey1, pPKey2->pKeyInfo);
4201 assert( (*(u8*)pKey1)<=0x3F || CORRUPT_DB );
4202 switch( serial_type ){
4203 case 1: { /* 1-byte signed integer */
4204 lhs = ONE_BYTE_INT(aKey);
4205 testcase( lhs<0 );
4206 break;
4207 }
4208 case 2: { /* 2-byte signed integer */
4209 lhs = TWO_BYTE_INT(aKey);
4210 testcase( lhs<0 );
4211 break;
4212 }
4213 case 3: { /* 3-byte signed integer */
4214 lhs = THREE_BYTE_INT(aKey);
4215 testcase( lhs<0 );
4216 break;
4217 }
4218 case 4: { /* 4-byte signed integer */
4219 y = FOUR_BYTE_UINT(aKey);
4220 lhs = (i64)*(int*)&y;
4221 testcase( lhs<0 );
4222 break;
4223 }
4224 case 5: { /* 6-byte signed integer */
4225 lhs = FOUR_BYTE_UINT(aKey+2) + (((i64)1)<<32)*TWO_BYTE_INT(aKey);
4226 testcase( lhs<0 );
4227 break;
4228 }
4229 case 6: { /* 8-byte signed integer */
4230 x = FOUR_BYTE_UINT(aKey);
4231 x = (x<<32) | FOUR_BYTE_UINT(aKey+4);
4232 lhs = *(i64*)&x;
4233 testcase( lhs<0 );
4234 break;
4235 }
4236 case 8:
4237 lhs = 0;
4238 break;
4239 case 9:
4240 lhs = 1;
4241 break;
4242
4243 /* This case could be removed without changing the results of running
4244 ** this code. Including it causes gcc to generate a faster switch
4245 ** statement (since the range of switch targets now starts at zero and
4246 ** is contiguous) but does not cause any duplicate code to be generated
4247 ** (as gcc is clever enough to combine the two like cases). Other
4248 ** compilers might be similar. */
4249 case 0: case 7:
4250 return sqlite3VdbeRecordCompare(nKey1, pKey1, pPKey2);
4251
4252 default:
4253 return sqlite3VdbeRecordCompare(nKey1, pKey1, pPKey2);
4254 }
4255
4256 v = pPKey2->aMem[0].u.i;
4257 if( v>lhs ){
4258 res = pPKey2->r1;
4259 }else if( v<lhs ){
4260 res = pPKey2->r2;
4261 }else if( pPKey2->nField>1 ){
4262 /* The first fields of the two keys are equal. Compare the trailing
4263 ** fields. */
4264 res = sqlite3VdbeRecordCompareWithSkip(nKey1, pKey1, pPKey2, 1);
4265 }else{
4266 /* The first fields of the two keys are equal and there are no trailing
4267 ** fields. Return pPKey2->default_rc in this case. */
4268 res = pPKey2->default_rc;
4269 pPKey2->eqSeen = 1;
4270 }
4271
4272 assert( vdbeRecordCompareDebug(nKey1, pKey1, pPKey2, res) );
4273 return res;
4274 }
4275
4276 /*
4277 ** This function is an optimized version of sqlite3VdbeRecordCompare()
4278 ** that (a) the first field of pPKey2 is a string, that (b) the first field
4279 ** uses the collation sequence BINARY and (c) that the size-of-header varint
4280 ** at the start of (pKey1/nKey1) fits in a single byte.
4281 */
vdbeRecordCompareString(int nKey1,const void * pKey1,UnpackedRecord * pPKey2)4282 static int vdbeRecordCompareString(
4283 int nKey1, const void *pKey1, /* Left key */
4284 UnpackedRecord *pPKey2 /* Right key */
4285 ){
4286 const u8 *aKey1 = (const u8*)pKey1;
4287 int serial_type;
4288 int res;
4289
4290 assert( pPKey2->aMem[0].flags & MEM_Str );
4291 vdbeAssertFieldCountWithinLimits(nKey1, pKey1, pPKey2->pKeyInfo);
4292 getVarint32(&aKey1[1], serial_type);
4293 if( serial_type<12 ){
4294 res = pPKey2->r1; /* (pKey1/nKey1) is a number or a null */
4295 }else if( !(serial_type & 0x01) ){
4296 res = pPKey2->r2; /* (pKey1/nKey1) is a blob */
4297 }else{
4298 int nCmp;
4299 int nStr;
4300 int szHdr = aKey1[0];
4301
4302 nStr = (serial_type-12) / 2;
4303 if( (szHdr + nStr) > nKey1 ){
4304 pPKey2->errCode = (u8)SQLITE_CORRUPT_BKPT;
4305 return 0; /* Corruption */
4306 }
4307 nCmp = MIN( pPKey2->aMem[0].n, nStr );
4308 res = memcmp(&aKey1[szHdr], pPKey2->aMem[0].z, nCmp);
4309
4310 if( res==0 ){
4311 res = nStr - pPKey2->aMem[0].n;
4312 if( res==0 ){
4313 if( pPKey2->nField>1 ){
4314 res = sqlite3VdbeRecordCompareWithSkip(nKey1, pKey1, pPKey2, 1);
4315 }else{
4316 res = pPKey2->default_rc;
4317 pPKey2->eqSeen = 1;
4318 }
4319 }else if( res>0 ){
4320 res = pPKey2->r2;
4321 }else{
4322 res = pPKey2->r1;
4323 }
4324 }else if( res>0 ){
4325 res = pPKey2->r2;
4326 }else{
4327 res = pPKey2->r1;
4328 }
4329 }
4330
4331 assert( vdbeRecordCompareDebug(nKey1, pKey1, pPKey2, res)
4332 || CORRUPT_DB
4333 || pPKey2->pKeyInfo->db->mallocFailed
4334 );
4335 return res;
4336 }
4337
4338 /*
4339 ** Return a pointer to an sqlite3VdbeRecordCompare() compatible function
4340 ** suitable for comparing serialized records to the unpacked record passed
4341 ** as the only argument.
4342 */
sqlite3VdbeFindCompare(UnpackedRecord * p)4343 RecordCompare sqlite3VdbeFindCompare(UnpackedRecord *p){
4344 /* varintRecordCompareInt() and varintRecordCompareString() both assume
4345 ** that the size-of-header varint that occurs at the start of each record
4346 ** fits in a single byte (i.e. is 127 or less). varintRecordCompareInt()
4347 ** also assumes that it is safe to overread a buffer by at least the
4348 ** maximum possible legal header size plus 8 bytes. Because there is
4349 ** guaranteed to be at least 74 (but not 136) bytes of padding following each
4350 ** buffer passed to varintRecordCompareInt() this makes it convenient to
4351 ** limit the size of the header to 64 bytes in cases where the first field
4352 ** is an integer.
4353 **
4354 ** The easiest way to enforce this limit is to consider only records with
4355 ** 13 fields or less. If the first field is an integer, the maximum legal
4356 ** header size is (12*5 + 1 + 1) bytes. */
4357 if( (p->pKeyInfo->nField + p->pKeyInfo->nXField)<=13 ){
4358 int flags = p->aMem[0].flags;
4359 if( p->pKeyInfo->aSortOrder[0] ){
4360 p->r1 = 1;
4361 p->r2 = -1;
4362 }else{
4363 p->r1 = -1;
4364 p->r2 = 1;
4365 }
4366 if( (flags & MEM_Int) ){
4367 return vdbeRecordCompareInt;
4368 }
4369 testcase( flags & MEM_Real );
4370 testcase( flags & MEM_Null );
4371 testcase( flags & MEM_Blob );
4372 if( (flags & (MEM_Real|MEM_Null|MEM_Blob))==0 && p->pKeyInfo->aColl[0]==0 ){
4373 assert( flags & MEM_Str );
4374 return vdbeRecordCompareString;
4375 }
4376 }
4377
4378 return sqlite3VdbeRecordCompare;
4379 }
4380
4381 /*
4382 ** pCur points at an index entry created using the OP_MakeRecord opcode.
4383 ** Read the rowid (the last field in the record) and store it in *rowid.
4384 ** Return SQLITE_OK if everything works, or an error code otherwise.
4385 **
4386 ** pCur might be pointing to text obtained from a corrupt database file.
4387 ** So the content cannot be trusted. Do appropriate checks on the content.
4388 */
sqlite3VdbeIdxRowid(sqlite3 * db,BtCursor * pCur,i64 * rowid)4389 int sqlite3VdbeIdxRowid(sqlite3 *db, BtCursor *pCur, i64 *rowid){
4390 i64 nCellKey = 0;
4391 int rc;
4392 u32 szHdr; /* Size of the header */
4393 u32 typeRowid; /* Serial type of the rowid */
4394 u32 lenRowid; /* Size of the rowid */
4395 Mem m, v;
4396
4397 /* Get the size of the index entry. Only indices entries of less
4398 ** than 2GiB are support - anything large must be database corruption.
4399 ** Any corruption is detected in sqlite3BtreeParseCellPtr(), though, so
4400 ** this code can safely assume that nCellKey is 32-bits
4401 */
4402 assert( sqlite3BtreeCursorIsValid(pCur) );
4403 nCellKey = sqlite3BtreePayloadSize(pCur);
4404 assert( (nCellKey & SQLITE_MAX_U32)==(u64)nCellKey );
4405
4406 /* Read in the complete content of the index entry */
4407 sqlite3VdbeMemInit(&m, db, 0);
4408 rc = sqlite3VdbeMemFromBtree(pCur, 0, (u32)nCellKey, &m);
4409 if( rc ){
4410 return rc;
4411 }
4412
4413 /* The index entry must begin with a header size */
4414 (void)getVarint32((u8*)m.z, szHdr);
4415 testcase( szHdr==3 );
4416 testcase( szHdr==m.n );
4417 if( unlikely(szHdr<3 || (int)szHdr>m.n) ){
4418 goto idx_rowid_corruption;
4419 }
4420
4421 /* The last field of the index should be an integer - the ROWID.
4422 ** Verify that the last entry really is an integer. */
4423 (void)getVarint32((u8*)&m.z[szHdr-1], typeRowid);
4424 testcase( typeRowid==1 );
4425 testcase( typeRowid==2 );
4426 testcase( typeRowid==3 );
4427 testcase( typeRowid==4 );
4428 testcase( typeRowid==5 );
4429 testcase( typeRowid==6 );
4430 testcase( typeRowid==8 );
4431 testcase( typeRowid==9 );
4432 if( unlikely(typeRowid<1 || typeRowid>9 || typeRowid==7) ){
4433 goto idx_rowid_corruption;
4434 }
4435 lenRowid = sqlite3SmallTypeSizes[typeRowid];
4436 testcase( (u32)m.n==szHdr+lenRowid );
4437 if( unlikely((u32)m.n<szHdr+lenRowid) ){
4438 goto idx_rowid_corruption;
4439 }
4440
4441 /* Fetch the integer off the end of the index record */
4442 sqlite3VdbeSerialGet((u8*)&m.z[m.n-lenRowid], typeRowid, &v);
4443 *rowid = v.u.i;
4444 sqlite3VdbeMemRelease(&m);
4445 return SQLITE_OK;
4446
4447 /* Jump here if database corruption is detected after m has been
4448 ** allocated. Free the m object and return SQLITE_CORRUPT. */
4449 idx_rowid_corruption:
4450 testcase( m.szMalloc!=0 );
4451 sqlite3VdbeMemRelease(&m);
4452 return SQLITE_CORRUPT_BKPT;
4453 }
4454
4455 /*
4456 ** Compare the key of the index entry that cursor pC is pointing to against
4457 ** the key string in pUnpacked. Write into *pRes a number
4458 ** that is negative, zero, or positive if pC is less than, equal to,
4459 ** or greater than pUnpacked. Return SQLITE_OK on success.
4460 **
4461 ** pUnpacked is either created without a rowid or is truncated so that it
4462 ** omits the rowid at the end. The rowid at the end of the index entry
4463 ** is ignored as well. Hence, this routine only compares the prefixes
4464 ** of the keys prior to the final rowid, not the entire key.
4465 */
sqlite3VdbeIdxKeyCompare(sqlite3 * db,VdbeCursor * pC,UnpackedRecord * pUnpacked,int * res)4466 int sqlite3VdbeIdxKeyCompare(
4467 sqlite3 *db, /* Database connection */
4468 VdbeCursor *pC, /* The cursor to compare against */
4469 UnpackedRecord *pUnpacked, /* Unpacked version of key */
4470 int *res /* Write the comparison result here */
4471 ){
4472 i64 nCellKey = 0;
4473 int rc;
4474 BtCursor *pCur;
4475 Mem m;
4476
4477 assert( pC->eCurType==CURTYPE_BTREE );
4478 pCur = pC->uc.pCursor;
4479 assert( sqlite3BtreeCursorIsValid(pCur) );
4480 nCellKey = sqlite3BtreePayloadSize(pCur);
4481 /* nCellKey will always be between 0 and 0xffffffff because of the way
4482 ** that btreeParseCellPtr() and sqlite3GetVarint32() are implemented */
4483 if( nCellKey<=0 || nCellKey>0x7fffffff ){
4484 *res = 0;
4485 return SQLITE_CORRUPT_BKPT;
4486 }
4487 sqlite3VdbeMemInit(&m, db, 0);
4488 rc = sqlite3VdbeMemFromBtree(pCur, 0, (u32)nCellKey, &m);
4489 if( rc ){
4490 return rc;
4491 }
4492 *res = sqlite3VdbeRecordCompare(m.n, m.z, pUnpacked);
4493 sqlite3VdbeMemRelease(&m);
4494 return SQLITE_OK;
4495 }
4496
4497 /*
4498 ** This routine sets the value to be returned by subsequent calls to
4499 ** sqlite3_changes() on the database handle 'db'.
4500 */
sqlite3VdbeSetChanges(sqlite3 * db,int nChange)4501 void sqlite3VdbeSetChanges(sqlite3 *db, int nChange){
4502 assert( sqlite3_mutex_held(db->mutex) );
4503 db->nChange = nChange;
4504 db->nTotalChange += nChange;
4505 }
4506
4507 /*
4508 ** Set a flag in the vdbe to update the change counter when it is finalised
4509 ** or reset.
4510 */
sqlite3VdbeCountChanges(Vdbe * v)4511 void sqlite3VdbeCountChanges(Vdbe *v){
4512 v->changeCntOn = 1;
4513 }
4514
4515 /*
4516 ** Mark every prepared statement associated with a database connection
4517 ** as expired.
4518 **
4519 ** An expired statement means that recompilation of the statement is
4520 ** recommend. Statements expire when things happen that make their
4521 ** programs obsolete. Removing user-defined functions or collating
4522 ** sequences, or changing an authorization function are the types of
4523 ** things that make prepared statements obsolete.
4524 */
sqlite3ExpirePreparedStatements(sqlite3 * db)4525 void sqlite3ExpirePreparedStatements(sqlite3 *db){
4526 Vdbe *p;
4527 for(p = db->pVdbe; p; p=p->pNext){
4528 p->expired = 1;
4529 }
4530 }
4531
4532 /*
4533 ** Return the database associated with the Vdbe.
4534 */
sqlite3VdbeDb(Vdbe * v)4535 sqlite3 *sqlite3VdbeDb(Vdbe *v){
4536 return v->db;
4537 }
4538
4539 /*
4540 ** Return the SQLITE_PREPARE flags for a Vdbe.
4541 */
sqlite3VdbePrepareFlags(Vdbe * v)4542 u8 sqlite3VdbePrepareFlags(Vdbe *v){
4543 return v->prepFlags;
4544 }
4545
4546 /*
4547 ** Return a pointer to an sqlite3_value structure containing the value bound
4548 ** parameter iVar of VM v. Except, if the value is an SQL NULL, return
4549 ** 0 instead. Unless it is NULL, apply affinity aff (one of the SQLITE_AFF_*
4550 ** constants) to the value before returning it.
4551 **
4552 ** The returned value must be freed by the caller using sqlite3ValueFree().
4553 */
sqlite3VdbeGetBoundValue(Vdbe * v,int iVar,u8 aff)4554 sqlite3_value *sqlite3VdbeGetBoundValue(Vdbe *v, int iVar, u8 aff){
4555 assert( iVar>0 );
4556 if( v ){
4557 Mem *pMem = &v->aVar[iVar-1];
4558 assert( (v->db->flags & SQLITE_EnableQPSG)==0 );
4559 if( 0==(pMem->flags & MEM_Null) ){
4560 sqlite3_value *pRet = sqlite3ValueNew(v->db);
4561 if( pRet ){
4562 sqlite3VdbeMemCopy((Mem *)pRet, pMem);
4563 sqlite3ValueApplyAffinity(pRet, aff, SQLITE_UTF8);
4564 }
4565 return pRet;
4566 }
4567 }
4568 return 0;
4569 }
4570
4571 /*
4572 ** Configure SQL variable iVar so that binding a new value to it signals
4573 ** to sqlite3_reoptimize() that re-preparing the statement may result
4574 ** in a better query plan.
4575 */
sqlite3VdbeSetVarmask(Vdbe * v,int iVar)4576 void sqlite3VdbeSetVarmask(Vdbe *v, int iVar){
4577 assert( iVar>0 );
4578 assert( (v->db->flags & SQLITE_EnableQPSG)==0 );
4579 if( iVar>=32 ){
4580 v->expmask |= 0x80000000;
4581 }else{
4582 v->expmask |= ((u32)1 << (iVar-1));
4583 }
4584 }
4585
4586 /*
4587 ** Cause a function to throw an error if it was call from OP_PureFunc
4588 ** rather than OP_Function.
4589 **
4590 ** OP_PureFunc means that the function must be deterministic, and should
4591 ** throw an error if it is given inputs that would make it non-deterministic.
4592 ** This routine is invoked by date/time functions that use non-deterministic
4593 ** features such as 'now'.
4594 */
sqlite3NotPureFunc(sqlite3_context * pCtx)4595 int sqlite3NotPureFunc(sqlite3_context *pCtx){
4596 #ifdef SQLITE_ENABLE_STAT3_OR_STAT4
4597 if( pCtx->pVdbe==0 ) return 1;
4598 #endif
4599 if( pCtx->pVdbe->aOp[pCtx->iOp].opcode==OP_PureFunc ){
4600 sqlite3_result_error(pCtx,
4601 "non-deterministic function in index expression or CHECK constraint",
4602 -1);
4603 return 0;
4604 }
4605 return 1;
4606 }
4607
4608 #ifndef SQLITE_OMIT_VIRTUALTABLE
4609 /*
4610 ** Transfer error message text from an sqlite3_vtab.zErrMsg (text stored
4611 ** in memory obtained from sqlite3_malloc) into a Vdbe.zErrMsg (text stored
4612 ** in memory obtained from sqlite3DbMalloc).
4613 */
sqlite3VtabImportErrmsg(Vdbe * p,sqlite3_vtab * pVtab)4614 void sqlite3VtabImportErrmsg(Vdbe *p, sqlite3_vtab *pVtab){
4615 if( pVtab->zErrMsg ){
4616 sqlite3 *db = p->db;
4617 sqlite3DbFree(db, p->zErrMsg);
4618 p->zErrMsg = sqlite3DbStrDup(db, pVtab->zErrMsg);
4619 sqlite3_free(pVtab->zErrMsg);
4620 pVtab->zErrMsg = 0;
4621 }
4622 }
4623 #endif /* SQLITE_OMIT_VIRTUALTABLE */
4624
4625 #ifdef SQLITE_ENABLE_PREUPDATE_HOOK
4626
4627 /*
4628 ** If the second argument is not NULL, release any allocations associated
4629 ** with the memory cells in the p->aMem[] array. Also free the UnpackedRecord
4630 ** structure itself, using sqlite3DbFree().
4631 **
4632 ** This function is used to free UnpackedRecord structures allocated by
4633 ** the vdbeUnpackRecord() function found in vdbeapi.c.
4634 */
vdbeFreeUnpacked(sqlite3 * db,int nField,UnpackedRecord * p)4635 static void vdbeFreeUnpacked(sqlite3 *db, int nField, UnpackedRecord *p){
4636 if( p ){
4637 int i;
4638 for(i=0; i<nField; i++){
4639 Mem *pMem = &p->aMem[i];
4640 if( pMem->zMalloc ) sqlite3VdbeMemRelease(pMem);
4641 }
4642 sqlite3DbFreeNN(db, p);
4643 }
4644 }
4645 #endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
4646
4647 #ifdef SQLITE_ENABLE_PREUPDATE_HOOK
4648 /*
4649 ** Invoke the pre-update hook. If this is an UPDATE or DELETE pre-update call,
4650 ** then cursor passed as the second argument should point to the row about
4651 ** to be update or deleted. If the application calls sqlite3_preupdate_old(),
4652 ** the required value will be read from the row the cursor points to.
4653 */
sqlite3VdbePreUpdateHook(Vdbe * v,VdbeCursor * pCsr,int op,const char * zDb,Table * pTab,i64 iKey1,int iReg)4654 void sqlite3VdbePreUpdateHook(
4655 Vdbe *v, /* Vdbe pre-update hook is invoked by */
4656 VdbeCursor *pCsr, /* Cursor to grab old.* values from */
4657 int op, /* SQLITE_INSERT, UPDATE or DELETE */
4658 const char *zDb, /* Database name */
4659 Table *pTab, /* Modified table */
4660 i64 iKey1, /* Initial key value */
4661 int iReg /* Register for new.* record */
4662 ){
4663 sqlite3 *db = v->db;
4664 i64 iKey2;
4665 PreUpdate preupdate;
4666 const char *zTbl = pTab->zName;
4667 static const u8 fakeSortOrder = 0;
4668
4669 assert( db->pPreUpdate==0 );
4670 memset(&preupdate, 0, sizeof(PreUpdate));
4671 if( HasRowid(pTab)==0 ){
4672 iKey1 = iKey2 = 0;
4673 preupdate.pPk = sqlite3PrimaryKeyIndex(pTab);
4674 }else{
4675 if( op==SQLITE_UPDATE ){
4676 iKey2 = v->aMem[iReg].u.i;
4677 }else{
4678 iKey2 = iKey1;
4679 }
4680 }
4681
4682 assert( pCsr->nField==pTab->nCol
4683 || (pCsr->nField==pTab->nCol+1 && op==SQLITE_DELETE && iReg==-1)
4684 );
4685
4686 preupdate.v = v;
4687 preupdate.pCsr = pCsr;
4688 preupdate.op = op;
4689 preupdate.iNewReg = iReg;
4690 preupdate.keyinfo.db = db;
4691 preupdate.keyinfo.enc = ENC(db);
4692 preupdate.keyinfo.nField = pTab->nCol;
4693 preupdate.keyinfo.aSortOrder = (u8*)&fakeSortOrder;
4694 preupdate.iKey1 = iKey1;
4695 preupdate.iKey2 = iKey2;
4696 preupdate.pTab = pTab;
4697
4698 db->pPreUpdate = &preupdate;
4699 db->xPreUpdateCallback(db->pPreUpdateArg, db, op, zDb, zTbl, iKey1, iKey2);
4700 db->pPreUpdate = 0;
4701 sqlite3DbFree(db, preupdate.aRecord);
4702 vdbeFreeUnpacked(db, preupdate.keyinfo.nField+1, preupdate.pUnpacked);
4703 vdbeFreeUnpacked(db, preupdate.keyinfo.nField+1, preupdate.pNewUnpacked);
4704 if( preupdate.aNew ){
4705 int i;
4706 for(i=0; i<pCsr->nField; i++){
4707 sqlite3VdbeMemRelease(&preupdate.aNew[i]);
4708 }
4709 sqlite3DbFreeNN(db, preupdate.aNew);
4710 }
4711 }
4712 #endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
4713