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1/*
2** 2001 September 15
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 routines used for analyzing expressions and
13** for generating VDBE code that evaluates expressions in SQLite.
14**
15** $Id: expr.c,v 1.313 2007/09/18 15:55:07 drh Exp $
16*/
17#include "sqliteInt.h"
18#include <ctype.h>
19
20/*
21** Return the 'affinity' of the expression pExpr if any.
22**
23** If pExpr is a column, a reference to a column via an 'AS' alias,
24** or a sub-select with a column as the return value, then the
25** affinity of that column is returned. Otherwise, 0x00 is returned,
26** indicating no affinity for the expression.
27**
28** i.e. the WHERE clause expresssions in the following statements all
29** have an affinity:
30**
31** CREATE TABLE t1(a);
32** SELECT * FROM t1 WHERE a;
33** SELECT a AS b FROM t1 WHERE b;
34** SELECT * FROM t1 WHERE (select a from t1);
35*/
36char sqlite3ExprAffinity(Expr *pExpr){
37 int op = pExpr->op;
38 if( op==TK_SELECT ){
39 return sqlite3ExprAffinity(pExpr->pSelect->pEList->a[0].pExpr);
40 }
41#ifndef SQLITE_OMIT_CAST
42 if( op==TK_CAST ){
43 return sqlite3AffinityType(&pExpr->token);
44 }
45#endif
46 return pExpr->affinity;
47}
48
49/*
50** Set the collating sequence for expression pExpr to be the collating
51** sequence named by pToken. Return a pointer to the revised expression.
52** The collating sequence is marked as "explicit" using the EP_ExpCollate
53** flag. An explicit collating sequence will override implicit
54** collating sequences.
55*/
56Expr *sqlite3ExprSetColl(Parse *pParse, Expr *pExpr, Token *pName){
57 CollSeq *pColl;
58 if( pExpr==0 ) return 0;
59 pColl = sqlite3LocateCollSeq(pParse, (char*)pName->z, pName->n);
60 if( pColl ){
61 pExpr->pColl = pColl;
62 pExpr->flags |= EP_ExpCollate;
63 }
64 return pExpr;
65}
66
67/*
68** Return the default collation sequence for the expression pExpr. If
69** there is no default collation type, return 0.
70*/
71CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr){
72 CollSeq *pColl = 0;
73 if( pExpr ){
74 int op;
75 pColl = pExpr->pColl;
76 op = pExpr->op;
77 if( (op==TK_CAST || op==TK_UPLUS) && !pColl ){
78 return sqlite3ExprCollSeq(pParse, pExpr->pLeft);
79 }
80 }
81 if( sqlite3CheckCollSeq(pParse, pColl) ){
82 pColl = 0;
83 }
84 return pColl;
85}
86
87/*
88** pExpr is an operand of a comparison operator. aff2 is the
89** type affinity of the other operand. This routine returns the
90** type affinity that should be used for the comparison operator.
91*/
92char sqlite3CompareAffinity(Expr *pExpr, char aff2){
93 char aff1 = sqlite3ExprAffinity(pExpr);
94 if( aff1 && aff2 ){
95 /* Both sides of the comparison are columns. If one has numeric
96 ** affinity, use that. Otherwise use no affinity.
97 */
98 if( sqlite3IsNumericAffinity(aff1) || sqlite3IsNumericAffinity(aff2) ){
99 return SQLITE_AFF_NUMERIC;
100 }else{
101 return SQLITE_AFF_NONE;
102 }
103 }else if( !aff1 && !aff2 ){
104 /* Neither side of the comparison is a column. Compare the
105 ** results directly.
106 */
107 return SQLITE_AFF_NONE;
108 }else{
109 /* One side is a column, the other is not. Use the columns affinity. */
110 assert( aff1==0 || aff2==0 );
111 return (aff1 + aff2);
112 }
113}
114
115/*
116** pExpr is a comparison operator. Return the type affinity that should
117** be applied to both operands prior to doing the comparison.
118*/
119static char comparisonAffinity(Expr *pExpr){
120 char aff;
121 assert( pExpr->op==TK_EQ || pExpr->op==TK_IN || pExpr->op==TK_LT ||
122 pExpr->op==TK_GT || pExpr->op==TK_GE || pExpr->op==TK_LE ||
123 pExpr->op==TK_NE );
124 assert( pExpr->pLeft );
125 aff = sqlite3ExprAffinity(pExpr->pLeft);
126 if( pExpr->pRight ){
127 aff = sqlite3CompareAffinity(pExpr->pRight, aff);
128 }
129 else if( pExpr->pSelect ){
130 aff = sqlite3CompareAffinity(pExpr->pSelect->pEList->a[0].pExpr, aff);
131 }
132 else if( !aff ){
133 aff = SQLITE_AFF_NONE;
134 }
135 return aff;
136}
137
138/*
139** pExpr is a comparison expression, eg. '=', '<', IN(...) etc.
140** idx_affinity is the affinity of an indexed column. Return true
141** if the index with affinity idx_affinity may be used to implement
142** the comparison in pExpr.
143*/
144int sqlite3IndexAffinityOk(Expr *pExpr, char idx_affinity){
145 char aff = comparisonAffinity(pExpr);
146 switch( aff ){
147 case SQLITE_AFF_NONE:
148 return 1;
149 case SQLITE_AFF_TEXT:
150 return idx_affinity==SQLITE_AFF_TEXT;
151 default:
152 return sqlite3IsNumericAffinity(idx_affinity);
153 }
154}
155
156/*
157** Return the P1 value that should be used for a binary comparison
158** opcode (OP_Eq, OP_Ge etc.) used to compare pExpr1 and pExpr2.
159** If jumpIfNull is true, then set the low byte of the returned
160** P1 value to tell the opcode to jump if either expression
161** evaluates to NULL.
162*/
163static int binaryCompareP1(Expr *pExpr1, Expr *pExpr2, int jumpIfNull){
164 char aff = sqlite3ExprAffinity(pExpr2);
165 return ((int)sqlite3CompareAffinity(pExpr1, aff))+(jumpIfNull?0x100:0);
166}
167
168/*
169** Return a pointer to the collation sequence that should be used by
170** a binary comparison operator comparing pLeft and pRight.
171**
172** If the left hand expression has a collating sequence type, then it is
173** used. Otherwise the collation sequence for the right hand expression
174** is used, or the default (BINARY) if neither expression has a collating
175** type.
176**
177** Argument pRight (but not pLeft) may be a null pointer. In this case,
178** it is not considered.
179*/
180CollSeq *sqlite3BinaryCompareCollSeq(
181 Parse *pParse,
182 Expr *pLeft,
183 Expr *pRight
184){
185 CollSeq *pColl;
186 assert( pLeft );
187 if( pLeft->flags & EP_ExpCollate ){
188 assert( pLeft->pColl );
189 pColl = pLeft->pColl;
190 }else if( pRight && pRight->flags & EP_ExpCollate ){
191 assert( pRight->pColl );
192 pColl = pRight->pColl;
193 }else{
194 pColl = sqlite3ExprCollSeq(pParse, pLeft);
195 if( !pColl ){
196 pColl = sqlite3ExprCollSeq(pParse, pRight);
197 }
198 }
199 return pColl;
200}
201
202/*
203** Generate code for a comparison operator.
204*/
205static int codeCompare(
206 Parse *pParse, /* The parsing (and code generating) context */
207 Expr *pLeft, /* The left operand */
208 Expr *pRight, /* The right operand */
209 int opcode, /* The comparison opcode */
210 int dest, /* Jump here if true. */
211 int jumpIfNull /* If true, jump if either operand is NULL */
212){
213 int p1 = binaryCompareP1(pLeft, pRight, jumpIfNull);
214 CollSeq *p3 = sqlite3BinaryCompareCollSeq(pParse, pLeft, pRight);
215 return sqlite3VdbeOp3(pParse->pVdbe, opcode, p1, dest, (void*)p3, P3_COLLSEQ);
216}
217
218/*
219** Construct a new expression node and return a pointer to it. Memory
220** for this node is obtained from sqlite3_malloc(). The calling function
221** is responsible for making sure the node eventually gets freed.
222*/
223Expr *sqlite3Expr(
224 sqlite3 *db, /* Handle for sqlite3DbMallocZero() (may be null) */
225 int op, /* Expression opcode */
226 Expr *pLeft, /* Left operand */
227 Expr *pRight, /* Right operand */
228 const Token *pToken /* Argument token */
229){
230 Expr *pNew;
231 pNew = sqlite3DbMallocZero(db, sizeof(Expr));
232 if( pNew==0 ){
233 /* When malloc fails, delete pLeft and pRight. Expressions passed to
234 ** this function must always be allocated with sqlite3Expr() for this
235 ** reason.
236 */
237 sqlite3ExprDelete(pLeft);
238 sqlite3ExprDelete(pRight);
239 return 0;
240 }
241 pNew->op = op;
242 pNew->pLeft = pLeft;
243 pNew->pRight = pRight;
244 pNew->iAgg = -1;
245 if( pToken ){
246 assert( pToken->dyn==0 );
247 pNew->span = pNew->token = *pToken;
248 }else if( pLeft ){
249 if( pRight ){
250 sqlite3ExprSpan(pNew, &pLeft->span, &pRight->span);
251 if( pRight->flags & EP_ExpCollate ){
252 pNew->flags |= EP_ExpCollate;
253 pNew->pColl = pRight->pColl;
254 }
255 }
256 if( pLeft->flags & EP_ExpCollate ){
257 pNew->flags |= EP_ExpCollate;
258 pNew->pColl = pLeft->pColl;
259 }
260 }
261
262 sqlite3ExprSetHeight(pNew);
263 return pNew;
264}
265
266/*
267** Works like sqlite3Expr() except that it takes an extra Parse*
268** argument and notifies the associated connection object if malloc fails.
269*/
270Expr *sqlite3PExpr(
271 Parse *pParse, /* Parsing context */
272 int op, /* Expression opcode */
273 Expr *pLeft, /* Left operand */
274 Expr *pRight, /* Right operand */
275 const Token *pToken /* Argument token */
276){
277 return sqlite3Expr(pParse->db, op, pLeft, pRight, pToken);
278}
279
280/*
281** When doing a nested parse, you can include terms in an expression
282** that look like this: #0 #1 #2 ... These terms refer to elements
283** on the stack. "#0" means the top of the stack.
284** "#1" means the next down on the stack. And so forth.
285**
286** This routine is called by the parser to deal with on of those terms.
287** It immediately generates code to store the value in a memory location.
288** The returns an expression that will code to extract the value from
289** that memory location as needed.
290*/
291Expr *sqlite3RegisterExpr(Parse *pParse, Token *pToken){
292 Vdbe *v = pParse->pVdbe;
293 Expr *p;
294 int depth;
295 if( pParse->nested==0 ){
296 sqlite3ErrorMsg(pParse, "near \"%T\": syntax error", pToken);
297 return sqlite3PExpr(pParse, TK_NULL, 0, 0, 0);
298 }
299 if( v==0 ) return 0;
300 p = sqlite3PExpr(pParse, TK_REGISTER, 0, 0, pToken);
301 if( p==0 ){
302 return 0; /* Malloc failed */
303 }
304 depth = atoi((char*)&pToken->z[1]);
305 p->iTable = pParse->nMem++;
306 sqlite3VdbeAddOp(v, OP_Dup, depth, 0);
307 sqlite3VdbeAddOp(v, OP_MemStore, p->iTable, 1);
308 return p;
309}
310
311/*
312** Join two expressions using an AND operator. If either expression is
313** NULL, then just return the other expression.
314*/
315Expr *sqlite3ExprAnd(sqlite3 *db, Expr *pLeft, Expr *pRight){
316 if( pLeft==0 ){
317 return pRight;
318 }else if( pRight==0 ){
319 return pLeft;
320 }else{
321 return sqlite3Expr(db, TK_AND, pLeft, pRight, 0);
322 }
323}
324
325/*
326** Set the Expr.span field of the given expression to span all
327** text between the two given tokens.
328*/
329void sqlite3ExprSpan(Expr *pExpr, Token *pLeft, Token *pRight){
330 assert( pRight!=0 );
331 assert( pLeft!=0 );
332 if( pExpr && pRight->z && pLeft->z ){
333 assert( pLeft->dyn==0 || pLeft->z[pLeft->n]==0 );
334 if( pLeft->dyn==0 && pRight->dyn==0 ){
335 pExpr->span.z = pLeft->z;
336 pExpr->span.n = pRight->n + (pRight->z - pLeft->z);
337 }else{
338 pExpr->span.z = 0;
339 }
340 }
341}
342
343/*
344** Construct a new expression node for a function with multiple
345** arguments.
346*/
347Expr *sqlite3ExprFunction(Parse *pParse, ExprList *pList, Token *pToken){
348 Expr *pNew;
349 assert( pToken );
350 pNew = sqlite3DbMallocZero(pParse->db, sizeof(Expr) );
351 if( pNew==0 ){
352 sqlite3ExprListDelete(pList); /* Avoid leaking memory when malloc fails */
353 return 0;
354 }
355 pNew->op = TK_FUNCTION;
356 pNew->pList = pList;
357 assert( pToken->dyn==0 );
358 pNew->token = *pToken;
359 pNew->span = pNew->token;
360
361 sqlite3ExprSetHeight(pNew);
362 return pNew;
363}
364
365/*
366** Assign a variable number to an expression that encodes a wildcard
367** in the original SQL statement.
368**
369** Wildcards consisting of a single "?" are assigned the next sequential
370** variable number.
371**
372** Wildcards of the form "?nnn" are assigned the number "nnn". We make
373** sure "nnn" is not too be to avoid a denial of service attack when
374** the SQL statement comes from an external source.
375**
376** Wildcards of the form ":aaa" or "$aaa" are assigned the same number
377** as the previous instance of the same wildcard. Or if this is the first
378** instance of the wildcard, the next sequenial variable number is
379** assigned.
380*/
381void sqlite3ExprAssignVarNumber(Parse *pParse, Expr *pExpr){
382 Token *pToken;
383 sqlite3 *db = pParse->db;
384
385 if( pExpr==0 ) return;
386 pToken = &pExpr->token;
387 assert( pToken->n>=1 );
388 assert( pToken->z!=0 );
389 assert( pToken->z[0]!=0 );
390 if( pToken->n==1 ){
391 /* Wildcard of the form "?". Assign the next variable number */
392 pExpr->iTable = ++pParse->nVar;
393 }else if( pToken->z[0]=='?' ){
394 /* Wildcard of the form "?nnn". Convert "nnn" to an integer and
395 ** use it as the variable number */
396 int i;
397 pExpr->iTable = i = atoi((char*)&pToken->z[1]);
398 if( i<1 || i>SQLITE_MAX_VARIABLE_NUMBER ){
399 sqlite3ErrorMsg(pParse, "variable number must be between ?1 and ?%d",
400 SQLITE_MAX_VARIABLE_NUMBER);
401 }
402 if( i>pParse->nVar ){
403 pParse->nVar = i;
404 }
405 }else{
406 /* Wildcards of the form ":aaa" or "$aaa". Reuse the same variable
407 ** number as the prior appearance of the same name, or if the name
408 ** has never appeared before, reuse the same variable number
409 */
410 int i, n;
411 n = pToken->n;
412 for(i=0; i<pParse->nVarExpr; i++){
413 Expr *pE;
414 if( (pE = pParse->apVarExpr[i])!=0
415 && pE->token.n==n
416 && memcmp(pE->token.z, pToken->z, n)==0 ){
417 pExpr->iTable = pE->iTable;
418 break;
419 }
420 }
421 if( i>=pParse->nVarExpr ){
422 pExpr->iTable = ++pParse->nVar;
423 if( pParse->nVarExpr>=pParse->nVarExprAlloc-1 ){
424 pParse->nVarExprAlloc += pParse->nVarExprAlloc + 10;
425 pParse->apVarExpr =
426 sqlite3DbReallocOrFree(
427 db,
428 pParse->apVarExpr,
429 pParse->nVarExprAlloc*sizeof(pParse->apVarExpr[0])
430 );
431 }
432 if( !db->mallocFailed ){
433 assert( pParse->apVarExpr!=0 );
434 pParse->apVarExpr[pParse->nVarExpr++] = pExpr;
435 }
436 }
437 }
438 if( !pParse->nErr && pParse->nVar>SQLITE_MAX_VARIABLE_NUMBER ){
439 sqlite3ErrorMsg(pParse, "too many SQL variables");
440 }
441}
442
443/*
444** Recursively delete an expression tree.
445*/
446void sqlite3ExprDelete(Expr *p){
447 if( p==0 ) return;
448 if( p->span.dyn ) sqlite3_free((char*)p->span.z);
449 if( p->token.dyn ) sqlite3_free((char*)p->token.z);
450 sqlite3ExprDelete(p->pLeft);
451 sqlite3ExprDelete(p->pRight);
452 sqlite3ExprListDelete(p->pList);
453 sqlite3SelectDelete(p->pSelect);
454 sqlite3_free(p);
455}
456
457/*
458** The Expr.token field might be a string literal that is quoted.
459** If so, remove the quotation marks.
460*/
461void sqlite3DequoteExpr(sqlite3 *db, Expr *p){
462 if( ExprHasAnyProperty(p, EP_Dequoted) ){
463 return;
464 }
465 ExprSetProperty(p, EP_Dequoted);
466 if( p->token.dyn==0 ){
467 sqlite3TokenCopy(db, &p->token, &p->token);
468 }
469 sqlite3Dequote((char*)p->token.z);
470}
471
472
473/*
474** The following group of routines make deep copies of expressions,
475** expression lists, ID lists, and select statements. The copies can
476** be deleted (by being passed to their respective ...Delete() routines)
477** without effecting the originals.
478**
479** The expression list, ID, and source lists return by sqlite3ExprListDup(),
480** sqlite3IdListDup(), and sqlite3SrcListDup() can not be further expanded
481** by subsequent calls to sqlite*ListAppend() routines.
482**
483** Any tables that the SrcList might point to are not duplicated.
484*/
485Expr *sqlite3ExprDup(sqlite3 *db, Expr *p){
486 Expr *pNew;
487 if( p==0 ) return 0;
488 pNew = sqlite3DbMallocRaw(db, sizeof(*p) );
489 if( pNew==0 ) return 0;
490 memcpy(pNew, p, sizeof(*pNew));
491 if( p->token.z!=0 ){
492 pNew->token.z = (u8*)sqlite3DbStrNDup(db, (char*)p->token.z, p->token.n);
493 pNew->token.dyn = 1;
494 }else{
495 assert( pNew->token.z==0 );
496 }
497 pNew->span.z = 0;
498 pNew->pLeft = sqlite3ExprDup(db, p->pLeft);
499 pNew->pRight = sqlite3ExprDup(db, p->pRight);
500 pNew->pList = sqlite3ExprListDup(db, p->pList);
501 pNew->pSelect = sqlite3SelectDup(db, p->pSelect);
502 return pNew;
503}
504void sqlite3TokenCopy(sqlite3 *db, Token *pTo, Token *pFrom){
505 if( pTo->dyn ) sqlite3_free((char*)pTo->z);
506 if( pFrom->z ){
507 pTo->n = pFrom->n;
508 pTo->z = (u8*)sqlite3DbStrNDup(db, (char*)pFrom->z, pFrom->n);
509 pTo->dyn = 1;
510 }else{
511 pTo->z = 0;
512 }
513}
514ExprList *sqlite3ExprListDup(sqlite3 *db, ExprList *p){
515 ExprList *pNew;
516 struct ExprList_item *pItem, *pOldItem;
517 int i;
518 if( p==0 ) return 0;
519 pNew = sqlite3DbMallocRaw(db, sizeof(*pNew) );
520 if( pNew==0 ) return 0;
521 pNew->iECursor = 0;
522 pNew->nExpr = pNew->nAlloc = p->nExpr;
523 pNew->a = pItem = sqlite3DbMallocRaw(db, p->nExpr*sizeof(p->a[0]) );
524 if( pItem==0 ){
525 sqlite3_free(pNew);
526 return 0;
527 }
528 pOldItem = p->a;
529 for(i=0; i<p->nExpr; i++, pItem++, pOldItem++){
530 Expr *pNewExpr, *pOldExpr;
531 pItem->pExpr = pNewExpr = sqlite3ExprDup(db, pOldExpr = pOldItem->pExpr);
532 if( pOldExpr->span.z!=0 && pNewExpr ){
533 /* Always make a copy of the span for top-level expressions in the
534 ** expression list. The logic in SELECT processing that determines
535 ** the names of columns in the result set needs this information */
536 sqlite3TokenCopy(db, &pNewExpr->span, &pOldExpr->span);
537 }
538 assert( pNewExpr==0 || pNewExpr->span.z!=0
539 || pOldExpr->span.z==0
540 || db->mallocFailed );
541 pItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
542 pItem->sortOrder = pOldItem->sortOrder;
543 pItem->isAgg = pOldItem->isAgg;
544 pItem->done = 0;
545 }
546 return pNew;
547}
548
549/*
550** If cursors, triggers, views and subqueries are all omitted from
551** the build, then none of the following routines, except for
552** sqlite3SelectDup(), can be called. sqlite3SelectDup() is sometimes
553** called with a NULL argument.
554*/
555#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_TRIGGER) \
556 || !defined(SQLITE_OMIT_SUBQUERY)
557SrcList *sqlite3SrcListDup(sqlite3 *db, SrcList *p){
558 SrcList *pNew;
559 int i;
560 int nByte;
561 if( p==0 ) return 0;
562 nByte = sizeof(*p) + (p->nSrc>0 ? sizeof(p->a[0]) * (p->nSrc-1) : 0);
563 pNew = sqlite3DbMallocRaw(db, nByte );
564 if( pNew==0 ) return 0;
565 pNew->nSrc = pNew->nAlloc = p->nSrc;
566 for(i=0; i<p->nSrc; i++){
567 struct SrcList_item *pNewItem = &pNew->a[i];
568 struct SrcList_item *pOldItem = &p->a[i];
569 Table *pTab;
570 pNewItem->zDatabase = sqlite3DbStrDup(db, pOldItem->zDatabase);
571 pNewItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
572 pNewItem->zAlias = sqlite3DbStrDup(db, pOldItem->zAlias);
573 pNewItem->jointype = pOldItem->jointype;
574 pNewItem->iCursor = pOldItem->iCursor;
575 pNewItem->isPopulated = pOldItem->isPopulated;
576 pTab = pNewItem->pTab = pOldItem->pTab;
577 if( pTab ){
578 pTab->nRef++;
579 }
580 pNewItem->pSelect = sqlite3SelectDup(db, pOldItem->pSelect);
581 pNewItem->pOn = sqlite3ExprDup(db, pOldItem->pOn);
582 pNewItem->pUsing = sqlite3IdListDup(db, pOldItem->pUsing);
583 pNewItem->colUsed = pOldItem->colUsed;
584 }
585 return pNew;
586}
587IdList *sqlite3IdListDup(sqlite3 *db, IdList *p){
588 IdList *pNew;
589 int i;
590 if( p==0 ) return 0;
591 pNew = sqlite3DbMallocRaw(db, sizeof(*pNew) );
592 if( pNew==0 ) return 0;
593 pNew->nId = pNew->nAlloc = p->nId;
594 pNew->a = sqlite3DbMallocRaw(db, p->nId*sizeof(p->a[0]) );
595 if( pNew->a==0 ){
596 sqlite3_free(pNew);
597 return 0;
598 }
599 for(i=0; i<p->nId; i++){
600 struct IdList_item *pNewItem = &pNew->a[i];
601 struct IdList_item *pOldItem = &p->a[i];
602 pNewItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
603 pNewItem->idx = pOldItem->idx;
604 }
605 return pNew;
606}
607Select *sqlite3SelectDup(sqlite3 *db, Select *p){
608 Select *pNew;
609 if( p==0 ) return 0;
610 pNew = sqlite3DbMallocRaw(db, sizeof(*p) );
611 if( pNew==0 ) return 0;
612 pNew->isDistinct = p->isDistinct;
613 pNew->pEList = sqlite3ExprListDup(db, p->pEList);
614 pNew->pSrc = sqlite3SrcListDup(db, p->pSrc);
615 pNew->pWhere = sqlite3ExprDup(db, p->pWhere);
616 pNew->pGroupBy = sqlite3ExprListDup(db, p->pGroupBy);
617 pNew->pHaving = sqlite3ExprDup(db, p->pHaving);
618 pNew->pOrderBy = sqlite3ExprListDup(db, p->pOrderBy);
619 pNew->op = p->op;
620 pNew->pPrior = sqlite3SelectDup(db, p->pPrior);
621 pNew->pLimit = sqlite3ExprDup(db, p->pLimit);
622 pNew->pOffset = sqlite3ExprDup(db, p->pOffset);
623 pNew->iLimit = -1;
624 pNew->iOffset = -1;
625 pNew->isResolved = p->isResolved;
626 pNew->isAgg = p->isAgg;
627 pNew->usesEphm = 0;
628 pNew->disallowOrderBy = 0;
629 pNew->pRightmost = 0;
630 pNew->addrOpenEphm[0] = -1;
631 pNew->addrOpenEphm[1] = -1;
632 pNew->addrOpenEphm[2] = -1;
633 return pNew;
634}
635#else
636Select *sqlite3SelectDup(sqlite3 *db, Select *p){
637 assert( p==0 );
638 return 0;
639}
640#endif
641
642
643/*
644** Add a new element to the end of an expression list. If pList is
645** initially NULL, then create a new expression list.
646*/
647ExprList *sqlite3ExprListAppend(
648 Parse *pParse, /* Parsing context */
649 ExprList *pList, /* List to which to append. Might be NULL */
650 Expr *pExpr, /* Expression to be appended */
651 Token *pName /* AS keyword for the expression */
652){
653 sqlite3 *db = pParse->db;
654 if( pList==0 ){
655 pList = sqlite3DbMallocZero(db, sizeof(ExprList) );
656 if( pList==0 ){
657 goto no_mem;
658 }
659 assert( pList->nAlloc==0 );
660 }
661 if( pList->nAlloc<=pList->nExpr ){
662 struct ExprList_item *a;
663 int n = pList->nAlloc*2 + 4;
664 a = sqlite3DbRealloc(db, pList->a, n*sizeof(pList->a[0]));
665 if( a==0 ){
666 goto no_mem;
667 }
668 pList->a = a;
669 pList->nAlloc = n;
670 }
671 assert( pList->a!=0 );
672 if( pExpr || pName ){
673 struct ExprList_item *pItem = &pList->a[pList->nExpr++];
674 memset(pItem, 0, sizeof(*pItem));
675 pItem->zName = sqlite3NameFromToken(db, pName);
676 pItem->pExpr = pExpr;
677 }
678 return pList;
679
680no_mem:
681 /* Avoid leaking memory if malloc has failed. */
682 sqlite3ExprDelete(pExpr);
683 sqlite3ExprListDelete(pList);
684 return 0;
685}
686
687/*
688** If the expression list pEList contains more than iLimit elements,
689** leave an error message in pParse.
690*/
691void sqlite3ExprListCheckLength(
692 Parse *pParse,
693 ExprList *pEList,
694 int iLimit,
695 const char *zObject
696){
697 if( pEList && pEList->nExpr>iLimit ){
698 sqlite3ErrorMsg(pParse, "too many columns in %s", zObject);
699 }
700}
701
702
703#if defined(SQLITE_TEST) || SQLITE_MAX_EXPR_DEPTH>0
704/* The following three functions, heightOfExpr(), heightOfExprList()
705** and heightOfSelect(), are used to determine the maximum height
706** of any expression tree referenced by the structure passed as the
707** first argument.
708**
709** If this maximum height is greater than the current value pointed
710** to by pnHeight, the second parameter, then set *pnHeight to that
711** value.
712*/
713static void heightOfExpr(Expr *p, int *pnHeight){
714 if( p ){
715 if( p->nHeight>*pnHeight ){
716 *pnHeight = p->nHeight;
717 }
718 }
719}
720static void heightOfExprList(ExprList *p, int *pnHeight){
721 if( p ){
722 int i;
723 for(i=0; i<p->nExpr; i++){
724 heightOfExpr(p->a[i].pExpr, pnHeight);
725 }
726 }
727}
728static void heightOfSelect(Select *p, int *pnHeight){
729 if( p ){
730 heightOfExpr(p->pWhere, pnHeight);
731 heightOfExpr(p->pHaving, pnHeight);
732 heightOfExpr(p->pLimit, pnHeight);
733 heightOfExpr(p->pOffset, pnHeight);
734 heightOfExprList(p->pEList, pnHeight);
735 heightOfExprList(p->pGroupBy, pnHeight);
736 heightOfExprList(p->pOrderBy, pnHeight);
737 heightOfSelect(p->pPrior, pnHeight);
738 }
739}
740
741/*
742** Set the Expr.nHeight variable in the structure passed as an
743** argument. An expression with no children, Expr.pList or
744** Expr.pSelect member has a height of 1. Any other expression
745** has a height equal to the maximum height of any other
746** referenced Expr plus one.
747*/
748void sqlite3ExprSetHeight(Expr *p){
749 int nHeight = 0;
750 heightOfExpr(p->pLeft, &nHeight);
751 heightOfExpr(p->pRight, &nHeight);
752 heightOfExprList(p->pList, &nHeight);
753 heightOfSelect(p->pSelect, &nHeight);
754 p->nHeight = nHeight + 1;
755}
756
757/*
758** Return the maximum height of any expression tree referenced
759** by the select statement passed as an argument.
760*/
761int sqlite3SelectExprHeight(Select *p){
762 int nHeight = 0;
763 heightOfSelect(p, &nHeight);
764 return nHeight;
765}
766#endif
767
768/*
769** Delete an entire expression list.
770*/
771void sqlite3ExprListDelete(ExprList *pList){
772 int i;
773 struct ExprList_item *pItem;
774 if( pList==0 ) return;
775 assert( pList->a!=0 || (pList->nExpr==0 && pList->nAlloc==0) );
776 assert( pList->nExpr<=pList->nAlloc );
777 for(pItem=pList->a, i=0; i<pList->nExpr; i++, pItem++){
778 sqlite3ExprDelete(pItem->pExpr);
779 sqlite3_free(pItem->zName);
780 }
781 sqlite3_free(pList->a);
782 sqlite3_free(pList);
783}
784
785/*
786** Walk an expression tree. Call xFunc for each node visited.
787**
788** The return value from xFunc determines whether the tree walk continues.
789** 0 means continue walking the tree. 1 means do not walk children
790** of the current node but continue with siblings. 2 means abandon
791** the tree walk completely.
792**
793** The return value from this routine is 1 to abandon the tree walk
794** and 0 to continue.
795**
796** NOTICE: This routine does *not* descend into subqueries.
797*/
798static int walkExprList(ExprList *, int (*)(void *, Expr*), void *);
799static int walkExprTree(Expr *pExpr, int (*xFunc)(void*,Expr*), void *pArg){
800 int rc;
801 if( pExpr==0 ) return 0;
802 rc = (*xFunc)(pArg, pExpr);
803 if( rc==0 ){
804 if( walkExprTree(pExpr->pLeft, xFunc, pArg) ) return 1;
805 if( walkExprTree(pExpr->pRight, xFunc, pArg) ) return 1;
806 if( walkExprList(pExpr->pList, xFunc, pArg) ) return 1;
807 }
808 return rc>1;
809}
810
811/*
812** Call walkExprTree() for every expression in list p.
813*/
814static int walkExprList(ExprList *p, int (*xFunc)(void *, Expr*), void *pArg){
815 int i;
816 struct ExprList_item *pItem;
817 if( !p ) return 0;
818 for(i=p->nExpr, pItem=p->a; i>0; i--, pItem++){
819 if( walkExprTree(pItem->pExpr, xFunc, pArg) ) return 1;
820 }
821 return 0;
822}
823
824/*
825** Call walkExprTree() for every expression in Select p, not including
826** expressions that are part of sub-selects in any FROM clause or the LIMIT
827** or OFFSET expressions..
828*/
829static int walkSelectExpr(Select *p, int (*xFunc)(void *, Expr*), void *pArg){
830 walkExprList(p->pEList, xFunc, pArg);
831 walkExprTree(p->pWhere, xFunc, pArg);
832 walkExprList(p->pGroupBy, xFunc, pArg);
833 walkExprTree(p->pHaving, xFunc, pArg);
834 walkExprList(p->pOrderBy, xFunc, pArg);
835 if( p->pPrior ){
836 walkSelectExpr(p->pPrior, xFunc, pArg);
837 }
838 return 0;
839}
840
841
842/*
843** This routine is designed as an xFunc for walkExprTree().
844**
845** pArg is really a pointer to an integer. If we can tell by looking
846** at pExpr that the expression that contains pExpr is not a constant
847** expression, then set *pArg to 0 and return 2 to abandon the tree walk.
848** If pExpr does does not disqualify the expression from being a constant
849** then do nothing.
850**
851** After walking the whole tree, if no nodes are found that disqualify
852** the expression as constant, then we assume the whole expression
853** is constant. See sqlite3ExprIsConstant() for additional information.
854*/
855static int exprNodeIsConstant(void *pArg, Expr *pExpr){
856 int *pN = (int*)pArg;
857
858 /* If *pArg is 3 then any term of the expression that comes from
859 ** the ON or USING clauses of a join disqualifies the expression
860 ** from being considered constant. */
861 if( (*pN)==3 && ExprHasAnyProperty(pExpr, EP_FromJoin) ){
862 *pN = 0;
863 return 2;
864 }
865
866 switch( pExpr->op ){
867 /* Consider functions to be constant if all their arguments are constant
868 ** and *pArg==2 */
869 case TK_FUNCTION:
870 if( (*pN)==2 ) return 0;
871 /* Fall through */
872 case TK_ID:
873 case TK_COLUMN:
874 case TK_DOT:
875 case TK_AGG_FUNCTION:
876 case TK_AGG_COLUMN:
877#ifndef SQLITE_OMIT_SUBQUERY
878 case TK_SELECT:
879 case TK_EXISTS:
880#endif
881 *pN = 0;
882 return 2;
883 case TK_IN:
884 if( pExpr->pSelect ){
885 *pN = 0;
886 return 2;
887 }
888 default:
889 return 0;
890 }
891}
892
893/*
894** Walk an expression tree. Return 1 if the expression is constant
895** and 0 if it involves variables or function calls.
896**
897** For the purposes of this function, a double-quoted string (ex: "abc")
898** is considered a variable but a single-quoted string (ex: 'abc') is
899** a constant.
900*/
901int sqlite3ExprIsConstant(Expr *p){
902 int isConst = 1;
903 walkExprTree(p, exprNodeIsConstant, &isConst);
904 return isConst;
905}
906
907/*
908** Walk an expression tree. Return 1 if the expression is constant
909** that does no originate from the ON or USING clauses of a join.
910** Return 0 if it involves variables or function calls or terms from
911** an ON or USING clause.
912*/
913int sqlite3ExprIsConstantNotJoin(Expr *p){
914 int isConst = 3;
915 walkExprTree(p, exprNodeIsConstant, &isConst);
916 return isConst!=0;
917}
918
919/*
920** Walk an expression tree. Return 1 if the expression is constant
921** or a function call with constant arguments. Return and 0 if there
922** are any variables.
923**
924** For the purposes of this function, a double-quoted string (ex: "abc")
925** is considered a variable but a single-quoted string (ex: 'abc') is
926** a constant.
927*/
928int sqlite3ExprIsConstantOrFunction(Expr *p){
929 int isConst = 2;
930 walkExprTree(p, exprNodeIsConstant, &isConst);
931 return isConst!=0;
932}
933
934/*
935** If the expression p codes a constant integer that is small enough
936** to fit in a 32-bit integer, return 1 and put the value of the integer
937** in *pValue. If the expression is not an integer or if it is too big
938** to fit in a signed 32-bit integer, return 0 and leave *pValue unchanged.
939*/
940int sqlite3ExprIsInteger(Expr *p, int *pValue){
941 switch( p->op ){
942 case TK_INTEGER: {
943 if( sqlite3GetInt32((char*)p->token.z, pValue) ){
944 return 1;
945 }
946 break;
947 }
948 case TK_UPLUS: {
949 return sqlite3ExprIsInteger(p->pLeft, pValue);
950 }
951 case TK_UMINUS: {
952 int v;
953 if( sqlite3ExprIsInteger(p->pLeft, &v) ){
954 *pValue = -v;
955 return 1;
956 }
957 break;
958 }
959 default: break;
960 }
961 return 0;
962}
963
964/*
965** Return TRUE if the given string is a row-id column name.
966*/
967int sqlite3IsRowid(const char *z){
968 if( sqlite3StrICmp(z, "_ROWID_")==0 ) return 1;
969 if( sqlite3StrICmp(z, "ROWID")==0 ) return 1;
970 if( sqlite3StrICmp(z, "OID")==0 ) return 1;
971 return 0;
972}
973
974/*
975** Given the name of a column of the form X.Y.Z or Y.Z or just Z, look up
976** that name in the set of source tables in pSrcList and make the pExpr
977** expression node refer back to that source column. The following changes
978** are made to pExpr:
979**
980** pExpr->iDb Set the index in db->aDb[] of the database holding
981** the table.
982** pExpr->iTable Set to the cursor number for the table obtained
983** from pSrcList.
984** pExpr->iColumn Set to the column number within the table.
985** pExpr->op Set to TK_COLUMN.
986** pExpr->pLeft Any expression this points to is deleted
987** pExpr->pRight Any expression this points to is deleted.
988**
989** The pDbToken is the name of the database (the "X"). This value may be
990** NULL meaning that name is of the form Y.Z or Z. Any available database
991** can be used. The pTableToken is the name of the table (the "Y"). This
992** value can be NULL if pDbToken is also NULL. If pTableToken is NULL it
993** means that the form of the name is Z and that columns from any table
994** can be used.
995**
996** If the name cannot be resolved unambiguously, leave an error message
997** in pParse and return non-zero. Return zero on success.
998*/
999static int lookupName(
1000 Parse *pParse, /* The parsing context */
1001 Token *pDbToken, /* Name of the database containing table, or NULL */
1002 Token *pTableToken, /* Name of table containing column, or NULL */
1003 Token *pColumnToken, /* Name of the column. */
1004 NameContext *pNC, /* The name context used to resolve the name */
1005 Expr *pExpr /* Make this EXPR node point to the selected column */
1006){
1007 char *zDb = 0; /* Name of the database. The "X" in X.Y.Z */
1008 char *zTab = 0; /* Name of the table. The "Y" in X.Y.Z or Y.Z */
1009 char *zCol = 0; /* Name of the column. The "Z" */
1010 int i, j; /* Loop counters */
1011 int cnt = 0; /* Number of matching column names */
1012 int cntTab = 0; /* Number of matching table names */
1013 sqlite3 *db = pParse->db; /* The database */
1014 struct SrcList_item *pItem; /* Use for looping over pSrcList items */
1015 struct SrcList_item *pMatch = 0; /* The matching pSrcList item */
1016 NameContext *pTopNC = pNC; /* First namecontext in the list */
1017 Schema *pSchema = 0; /* Schema of the expression */
1018
1019 assert( pColumnToken && pColumnToken->z ); /* The Z in X.Y.Z cannot be NULL */
1020 zDb = sqlite3NameFromToken(db, pDbToken);
1021 zTab = sqlite3NameFromToken(db, pTableToken);
1022 zCol = sqlite3NameFromToken(db, pColumnToken);
1023 if( db->mallocFailed ){
1024 goto lookupname_end;
1025 }
1026
1027 pExpr->iTable = -1;
1028 while( pNC && cnt==0 ){
1029 ExprList *pEList;
1030 SrcList *pSrcList = pNC->pSrcList;
1031
1032 if( pSrcList ){
1033 for(i=0, pItem=pSrcList->a; i<pSrcList->nSrc; i++, pItem++){
1034 Table *pTab;
1035 int iDb;
1036 Column *pCol;
1037
1038 pTab = pItem->pTab;
1039 assert( pTab!=0 );
1040 iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
1041 assert( pTab->nCol>0 );
1042 if( zTab ){
1043 if( pItem->zAlias ){
1044 char *zTabName = pItem->zAlias;
1045 if( sqlite3StrICmp(zTabName, zTab)!=0 ) continue;
1046 }else{
1047 char *zTabName = pTab->zName;
1048 if( zTabName==0 || sqlite3StrICmp(zTabName, zTab)!=0 ) continue;
1049 if( zDb!=0 && sqlite3StrICmp(db->aDb[iDb].zName, zDb)!=0 ){
1050 continue;
1051 }
1052 }
1053 }
1054 if( 0==(cntTab++) ){
1055 pExpr->iTable = pItem->iCursor;
1056 pSchema = pTab->pSchema;
1057 pMatch = pItem;
1058 }
1059 for(j=0, pCol=pTab->aCol; j<pTab->nCol; j++, pCol++){
1060 if( sqlite3StrICmp(pCol->zName, zCol)==0 ){
1061 const char *zColl = pTab->aCol[j].zColl;
1062 IdList *pUsing;
1063 cnt++;
1064 pExpr->iTable = pItem->iCursor;
1065 pMatch = pItem;
1066 pSchema = pTab->pSchema;
1067 /* Substitute the rowid (column -1) for the INTEGER PRIMARY KEY */
1068 pExpr->iColumn = j==pTab->iPKey ? -1 : j;
1069 pExpr->affinity = pTab->aCol[j].affinity;
1070 if( (pExpr->flags & EP_ExpCollate)==0 ){
1071 pExpr->pColl = sqlite3FindCollSeq(db, ENC(db), zColl,-1, 0);
1072 }
1073 if( i<pSrcList->nSrc-1 ){
1074 if( pItem[1].jointype & JT_NATURAL ){
1075 /* If this match occurred in the left table of a natural join,
1076 ** then skip the right table to avoid a duplicate match */
1077 pItem++;
1078 i++;
1079 }else if( (pUsing = pItem[1].pUsing)!=0 ){
1080 /* If this match occurs on a column that is in the USING clause
1081 ** of a join, skip the search of the right table of the join
1082 ** to avoid a duplicate match there. */
1083 int k;
1084 for(k=0; k<pUsing->nId; k++){
1085 if( sqlite3StrICmp(pUsing->a[k].zName, zCol)==0 ){
1086 pItem++;
1087 i++;
1088 break;
1089 }
1090 }
1091 }
1092 }
1093 break;
1094 }
1095 }
1096 }
1097 }
1098
1099#ifndef SQLITE_OMIT_TRIGGER
1100 /* If we have not already resolved the name, then maybe
1101 ** it is a new.* or old.* trigger argument reference
1102 */
1103 if( zDb==0 && zTab!=0 && cnt==0 && pParse->trigStack!=0 ){
1104 TriggerStack *pTriggerStack = pParse->trigStack;
1105 Table *pTab = 0;
1106 if( pTriggerStack->newIdx != -1 && sqlite3StrICmp("new", zTab) == 0 ){
1107 pExpr->iTable = pTriggerStack->newIdx;
1108 assert( pTriggerStack->pTab );
1109 pTab = pTriggerStack->pTab;
1110 }else if( pTriggerStack->oldIdx != -1 && sqlite3StrICmp("old", zTab)==0 ){
1111 pExpr->iTable = pTriggerStack->oldIdx;
1112 assert( pTriggerStack->pTab );
1113 pTab = pTriggerStack->pTab;
1114 }
1115
1116 if( pTab ){
1117 int iCol;
1118 Column *pCol = pTab->aCol;
1119
1120 pSchema = pTab->pSchema;
1121 cntTab++;
1122 for(iCol=0; iCol < pTab->nCol; iCol++, pCol++) {
1123 if( sqlite3StrICmp(pCol->zName, zCol)==0 ){
1124 const char *zColl = pTab->aCol[iCol].zColl;
1125 cnt++;
1126 pExpr->iColumn = iCol==pTab->iPKey ? -1 : iCol;
1127 pExpr->affinity = pTab->aCol[iCol].affinity;
1128 if( (pExpr->flags & EP_ExpCollate)==0 ){
1129 pExpr->pColl = sqlite3FindCollSeq(db, ENC(db), zColl,-1, 0);
1130 }
1131 pExpr->pTab = pTab;
1132 break;
1133 }
1134 }
1135 }
1136 }
1137#endif /* !defined(SQLITE_OMIT_TRIGGER) */
1138
1139 /*
1140 ** Perhaps the name is a reference to the ROWID
1141 */
1142 if( cnt==0 && cntTab==1 && sqlite3IsRowid(zCol) ){
1143 cnt = 1;
1144 pExpr->iColumn = -1;
1145 pExpr->affinity = SQLITE_AFF_INTEGER;
1146 }
1147
1148 /*
1149 ** If the input is of the form Z (not Y.Z or X.Y.Z) then the name Z
1150 ** might refer to an result-set alias. This happens, for example, when
1151 ** we are resolving names in the WHERE clause of the following command:
1152 **
1153 ** SELECT a+b AS x FROM table WHERE x<10;
1154 **
1155 ** In cases like this, replace pExpr with a copy of the expression that
1156 ** forms the result set entry ("a+b" in the example) and return immediately.
1157 ** Note that the expression in the result set should have already been
1158 ** resolved by the time the WHERE clause is resolved.
1159 */
1160 if( cnt==0 && (pEList = pNC->pEList)!=0 && zTab==0 ){
1161 for(j=0; j<pEList->nExpr; j++){
1162 char *zAs = pEList->a[j].zName;
1163 if( zAs!=0 && sqlite3StrICmp(zAs, zCol)==0 ){
1164 Expr *pDup, *pOrig;
1165 assert( pExpr->pLeft==0 && pExpr->pRight==0 );
1166 assert( pExpr->pList==0 );
1167 assert( pExpr->pSelect==0 );
1168 pOrig = pEList->a[j].pExpr;
1169 if( !pNC->allowAgg && ExprHasProperty(pOrig, EP_Agg) ){
1170 sqlite3ErrorMsg(pParse, "misuse of aliased aggregate %s", zAs);
1171 sqlite3_free(zCol);
1172 return 2;
1173 }
1174 pDup = sqlite3ExprDup(db, pOrig);
1175 if( pExpr->flags & EP_ExpCollate ){
1176 pDup->pColl = pExpr->pColl;
1177 pDup->flags |= EP_ExpCollate;
1178 }
1179 if( pExpr->span.dyn ) sqlite3_free((char*)pExpr->span.z);
1180 if( pExpr->token.dyn ) sqlite3_free((char*)pExpr->token.z);
1181 memcpy(pExpr, pDup, sizeof(*pExpr));
1182 sqlite3_free(pDup);
1183 cnt = 1;
1184 pMatch = 0;
1185 assert( zTab==0 && zDb==0 );
1186 goto lookupname_end_2;
1187 }
1188 }
1189 }
1190
1191 /* Advance to the next name context. The loop will exit when either
1192 ** we have a match (cnt>0) or when we run out of name contexts.
1193 */
1194 if( cnt==0 ){
1195 pNC = pNC->pNext;
1196 }
1197 }
1198
1199 /*
1200 ** If X and Y are NULL (in other words if only the column name Z is
1201 ** supplied) and the value of Z is enclosed in double-quotes, then
1202 ** Z is a string literal if it doesn't match any column names. In that
1203 ** case, we need to return right away and not make any changes to
1204 ** pExpr.
1205 **
1206 ** Because no reference was made to outer contexts, the pNC->nRef
1207 ** fields are not changed in any context.
1208 */
1209 if( cnt==0 && zTab==0 && pColumnToken->z[0]=='"' ){
1210 sqlite3_free(zCol);
1211 return 0;
1212 }
1213
1214 /*
1215 ** cnt==0 means there was not match. cnt>1 means there were two or
1216 ** more matches. Either way, we have an error.
1217 */
1218 if( cnt!=1 ){
1219 char *z = 0;
1220 char *zErr;
1221 zErr = cnt==0 ? "no such column: %s" : "ambiguous column name: %s";
1222 if( zDb ){
1223 sqlite3SetString(&z, zDb, ".", zTab, ".", zCol, (char*)0);
1224 }else if( zTab ){
1225 sqlite3SetString(&z, zTab, ".", zCol, (char*)0);
1226 }else{
1227 z = sqlite3StrDup(zCol);
1228 }
1229 if( z ){
1230 sqlite3ErrorMsg(pParse, zErr, z);
1231 sqlite3_free(z);
1232 pTopNC->nErr++;
1233 }else{
1234 db->mallocFailed = 1;
1235 }
1236 }
1237
1238 /* If a column from a table in pSrcList is referenced, then record
1239 ** this fact in the pSrcList.a[].colUsed bitmask. Column 0 causes
1240 ** bit 0 to be set. Column 1 sets bit 1. And so forth. If the
1241 ** column number is greater than the number of bits in the bitmask
1242 ** then set the high-order bit of the bitmask.
1243 */
1244 if( pExpr->iColumn>=0 && pMatch!=0 ){
1245 int n = pExpr->iColumn;
1246 if( n>=sizeof(Bitmask)*8 ){
1247 n = sizeof(Bitmask)*8-1;
1248 }
1249 assert( pMatch->iCursor==pExpr->iTable );
1250 pMatch->colUsed |= ((Bitmask)1)<<n;
1251 }
1252
1253lookupname_end:
1254 /* Clean up and return
1255 */
1256 sqlite3_free(zDb);
1257 sqlite3_free(zTab);
1258 sqlite3ExprDelete(pExpr->pLeft);
1259 pExpr->pLeft = 0;
1260 sqlite3ExprDelete(pExpr->pRight);
1261 pExpr->pRight = 0;
1262 pExpr->op = TK_COLUMN;
1263lookupname_end_2:
1264 sqlite3_free(zCol);
1265 if( cnt==1 ){
1266 assert( pNC!=0 );
1267 sqlite3AuthRead(pParse, pExpr, pSchema, pNC->pSrcList);
1268 if( pMatch && !pMatch->pSelect ){
1269 pExpr->pTab = pMatch->pTab;
1270 }
1271 /* Increment the nRef value on all name contexts from TopNC up to
1272 ** the point where the name matched. */
1273 for(;;){
1274 assert( pTopNC!=0 );
1275 pTopNC->nRef++;
1276 if( pTopNC==pNC ) break;
1277 pTopNC = pTopNC->pNext;
1278 }
1279 return 0;
1280 } else {
1281 return 1;
1282 }
1283}
1284
1285/*
1286** This routine is designed as an xFunc for walkExprTree().
1287**
1288** Resolve symbolic names into TK_COLUMN operators for the current
1289** node in the expression tree. Return 0 to continue the search down
1290** the tree or 2 to abort the tree walk.
1291**
1292** This routine also does error checking and name resolution for
1293** function names. The operator for aggregate functions is changed
1294** to TK_AGG_FUNCTION.
1295*/
1296static int nameResolverStep(void *pArg, Expr *pExpr){
1297 NameContext *pNC = (NameContext*)pArg;
1298 Parse *pParse;
1299
1300 if( pExpr==0 ) return 1;
1301 assert( pNC!=0 );
1302 pParse = pNC->pParse;
1303
1304 if( ExprHasAnyProperty(pExpr, EP_Resolved) ) return 1;
1305 ExprSetProperty(pExpr, EP_Resolved);
1306#ifndef NDEBUG
1307 if( pNC->pSrcList && pNC->pSrcList->nAlloc>0 ){
1308 SrcList *pSrcList = pNC->pSrcList;
1309 int i;
1310 for(i=0; i<pNC->pSrcList->nSrc; i++){
1311 assert( pSrcList->a[i].iCursor>=0 && pSrcList->a[i].iCursor<pParse->nTab);
1312 }
1313 }
1314#endif
1315 switch( pExpr->op ){
1316 /* Double-quoted strings (ex: "abc") are used as identifiers if
1317 ** possible. Otherwise they remain as strings. Single-quoted
1318 ** strings (ex: 'abc') are always string literals.
1319 */
1320 case TK_STRING: {
1321 if( pExpr->token.z[0]=='\'' ) break;
1322 /* Fall thru into the TK_ID case if this is a double-quoted string */
1323 }
1324 /* A lone identifier is the name of a column.
1325 */
1326 case TK_ID: {
1327 lookupName(pParse, 0, 0, &pExpr->token, pNC, pExpr);
1328 return 1;
1329 }
1330
1331 /* A table name and column name: ID.ID
1332 ** Or a database, table and column: ID.ID.ID
1333 */
1334 case TK_DOT: {
1335 Token *pColumn;
1336 Token *pTable;
1337 Token *pDb;
1338 Expr *pRight;
1339
1340 /* if( pSrcList==0 ) break; */
1341 pRight = pExpr->pRight;
1342 if( pRight->op==TK_ID ){
1343 pDb = 0;
1344 pTable = &pExpr->pLeft->token;
1345 pColumn = &pRight->token;
1346 }else{
1347 assert( pRight->op==TK_DOT );
1348 pDb = &pExpr->pLeft->token;
1349 pTable = &pRight->pLeft->token;
1350 pColumn = &pRight->pRight->token;
1351 }
1352 lookupName(pParse, pDb, pTable, pColumn, pNC, pExpr);
1353 return 1;
1354 }
1355
1356 /* Resolve function names
1357 */
1358 case TK_CONST_FUNC:
1359 case TK_FUNCTION: {
1360 ExprList *pList = pExpr->pList; /* The argument list */
1361 int n = pList ? pList->nExpr : 0; /* Number of arguments */
1362 int no_such_func = 0; /* True if no such function exists */
1363 int wrong_num_args = 0; /* True if wrong number of arguments */
1364 int is_agg = 0; /* True if is an aggregate function */
1365 int i;
1366 int auth; /* Authorization to use the function */
1367 int nId; /* Number of characters in function name */
1368 const char *zId; /* The function name. */
1369 FuncDef *pDef; /* Information about the function */
1370 int enc = ENC(pParse->db); /* The database encoding */
1371
1372 zId = (char*)pExpr->token.z;
1373 nId = pExpr->token.n;
1374 pDef = sqlite3FindFunction(pParse->db, zId, nId, n, enc, 0);
1375 if( pDef==0 ){
1376 pDef = sqlite3FindFunction(pParse->db, zId, nId, -1, enc, 0);
1377 if( pDef==0 ){
1378 no_such_func = 1;
1379 }else{
1380 wrong_num_args = 1;
1381 }
1382 }else{
1383 is_agg = pDef->xFunc==0;
1384 }
1385#ifndef SQLITE_OMIT_AUTHORIZATION
1386 if( pDef ){
1387 auth = sqlite3AuthCheck(pParse, SQLITE_FUNCTION, 0, pDef->zName, 0);
1388 if( auth!=SQLITE_OK ){
1389 if( auth==SQLITE_DENY ){
1390 sqlite3ErrorMsg(pParse, "not authorized to use function: %s",
1391 pDef->zName);
1392 pNC->nErr++;
1393 }
1394 pExpr->op = TK_NULL;
1395 return 1;
1396 }
1397 }
1398#endif
1399 if( is_agg && !pNC->allowAgg ){
1400 sqlite3ErrorMsg(pParse, "misuse of aggregate function %.*s()", nId,zId);
1401 pNC->nErr++;
1402 is_agg = 0;
1403 }else if( no_such_func ){
1404 sqlite3ErrorMsg(pParse, "no such function: %.*s", nId, zId);
1405 pNC->nErr++;
1406 }else if( wrong_num_args ){
1407 sqlite3ErrorMsg(pParse,"wrong number of arguments to function %.*s()",
1408 nId, zId);
1409 pNC->nErr++;
1410 }
1411 if( is_agg ){
1412 pExpr->op = TK_AGG_FUNCTION;
1413 pNC->hasAgg = 1;
1414 }
1415 if( is_agg ) pNC->allowAgg = 0;
1416 for(i=0; pNC->nErr==0 && i<n; i++){
1417 walkExprTree(pList->a[i].pExpr, nameResolverStep, pNC);
1418 }
1419 if( is_agg ) pNC->allowAgg = 1;
1420 /* FIX ME: Compute pExpr->affinity based on the expected return
1421 ** type of the function
1422 */
1423 return is_agg;
1424 }
1425#ifndef SQLITE_OMIT_SUBQUERY
1426 case TK_SELECT:
1427 case TK_EXISTS:
1428#endif
1429 case TK_IN: {
1430 if( pExpr->pSelect ){
1431 int nRef = pNC->nRef;
1432#ifndef SQLITE_OMIT_CHECK
1433 if( pNC->isCheck ){
1434 sqlite3ErrorMsg(pParse,"subqueries prohibited in CHECK constraints");
1435 }
1436#endif
1437 sqlite3SelectResolve(pParse, pExpr->pSelect, pNC);
1438 assert( pNC->nRef>=nRef );
1439 if( nRef!=pNC->nRef ){
1440 ExprSetProperty(pExpr, EP_VarSelect);
1441 }
1442 }
1443 break;
1444 }
1445#ifndef SQLITE_OMIT_CHECK
1446 case TK_VARIABLE: {
1447 if( pNC->isCheck ){
1448 sqlite3ErrorMsg(pParse,"parameters prohibited in CHECK constraints");
1449 }
1450 break;
1451 }
1452#endif
1453 }
1454 return 0;
1455}
1456
1457/*
1458** This routine walks an expression tree and resolves references to
1459** table columns. Nodes of the form ID.ID or ID resolve into an
1460** index to the table in the table list and a column offset. The
1461** Expr.opcode for such nodes is changed to TK_COLUMN. The Expr.iTable
1462** value is changed to the index of the referenced table in pTabList
1463** plus the "base" value. The base value will ultimately become the
1464** VDBE cursor number for a cursor that is pointing into the referenced
1465** table. The Expr.iColumn value is changed to the index of the column
1466** of the referenced table. The Expr.iColumn value for the special
1467** ROWID column is -1. Any INTEGER PRIMARY KEY column is tried as an
1468** alias for ROWID.
1469**
1470** Also resolve function names and check the functions for proper
1471** usage. Make sure all function names are recognized and all functions
1472** have the correct number of arguments. Leave an error message
1473** in pParse->zErrMsg if anything is amiss. Return the number of errors.
1474**
1475** If the expression contains aggregate functions then set the EP_Agg
1476** property on the expression.
1477*/
1478int sqlite3ExprResolveNames(
1479 NameContext *pNC, /* Namespace to resolve expressions in. */
1480 Expr *pExpr /* The expression to be analyzed. */
1481){
1482 int savedHasAgg;
1483 if( pExpr==0 ) return 0;
1484#if defined(SQLITE_TEST) || SQLITE_MAX_EXPR_DEPTH>0
1485 if( (pExpr->nHeight+pNC->pParse->nHeight)>SQLITE_MAX_EXPR_DEPTH ){
1486 sqlite3ErrorMsg(pNC->pParse,
1487 "Expression tree is too large (maximum depth %d)",
1488 SQLITE_MAX_EXPR_DEPTH
1489 );
1490 return 1;
1491 }
1492 pNC->pParse->nHeight += pExpr->nHeight;
1493#endif
1494 savedHasAgg = pNC->hasAgg;
1495 pNC->hasAgg = 0;
1496 walkExprTree(pExpr, nameResolverStep, pNC);
1497#if defined(SQLITE_TEST) || SQLITE_MAX_EXPR_DEPTH>0
1498 pNC->pParse->nHeight -= pExpr->nHeight;
1499#endif
1500 if( pNC->nErr>0 ){
1501 ExprSetProperty(pExpr, EP_Error);
1502 }
1503 if( pNC->hasAgg ){
1504 ExprSetProperty(pExpr, EP_Agg);
1505 }else if( savedHasAgg ){
1506 pNC->hasAgg = 1;
1507 }
1508 return ExprHasProperty(pExpr, EP_Error);
1509}
1510
1511/*
1512** A pointer instance of this structure is used to pass information
1513** through walkExprTree into codeSubqueryStep().
1514*/
1515typedef struct QueryCoder QueryCoder;
1516struct QueryCoder {
1517 Parse *pParse; /* The parsing context */
1518 NameContext *pNC; /* Namespace of first enclosing query */
1519};
1520
1521
1522/*
1523** Generate code for scalar subqueries used as an expression
1524** and IN operators. Examples:
1525**
1526** (SELECT a FROM b) -- subquery
1527** EXISTS (SELECT a FROM b) -- EXISTS subquery
1528** x IN (4,5,11) -- IN operator with list on right-hand side
1529** x IN (SELECT a FROM b) -- IN operator with subquery on the right
1530**
1531** The pExpr parameter describes the expression that contains the IN
1532** operator or subquery.
1533*/
1534#ifndef SQLITE_OMIT_SUBQUERY
1535void sqlite3CodeSubselect(Parse *pParse, Expr *pExpr){
1536 int testAddr = 0; /* One-time test address */
1537 Vdbe *v = sqlite3GetVdbe(pParse);
1538 if( v==0 ) return;
1539
1540
1541 /* This code must be run in its entirety every time it is encountered
1542 ** if any of the following is true:
1543 **
1544 ** * The right-hand side is a correlated subquery
1545 ** * The right-hand side is an expression list containing variables
1546 ** * We are inside a trigger
1547 **
1548 ** If all of the above are false, then we can run this code just once
1549 ** save the results, and reuse the same result on subsequent invocations.
1550 */
1551 if( !ExprHasAnyProperty(pExpr, EP_VarSelect) && !pParse->trigStack ){
1552 int mem = pParse->nMem++;
1553 sqlite3VdbeAddOp(v, OP_MemLoad, mem, 0);
1554 testAddr = sqlite3VdbeAddOp(v, OP_If, 0, 0);
1555 assert( testAddr>0 || pParse->db->mallocFailed );
1556 sqlite3VdbeAddOp(v, OP_MemInt, 1, mem);
1557 }
1558
1559 switch( pExpr->op ){
1560 case TK_IN: {
1561 char affinity;
1562 KeyInfo keyInfo;
1563 int addr; /* Address of OP_OpenEphemeral instruction */
1564
1565 affinity = sqlite3ExprAffinity(pExpr->pLeft);
1566
1567 /* Whether this is an 'x IN(SELECT...)' or an 'x IN(<exprlist>)'
1568 ** expression it is handled the same way. A virtual table is
1569 ** filled with single-field index keys representing the results
1570 ** from the SELECT or the <exprlist>.
1571 **
1572 ** If the 'x' expression is a column value, or the SELECT...
1573 ** statement returns a column value, then the affinity of that
1574 ** column is used to build the index keys. If both 'x' and the
1575 ** SELECT... statement are columns, then numeric affinity is used
1576 ** if either column has NUMERIC or INTEGER affinity. If neither
1577 ** 'x' nor the SELECT... statement are columns, then numeric affinity
1578 ** is used.
1579 */
1580 pExpr->iTable = pParse->nTab++;
1581 addr = sqlite3VdbeAddOp(v, OP_OpenEphemeral, pExpr->iTable, 0);
1582 memset(&keyInfo, 0, sizeof(keyInfo));
1583 keyInfo.nField = 1;
1584 sqlite3VdbeAddOp(v, OP_SetNumColumns, pExpr->iTable, 1);
1585
1586 if( pExpr->pSelect ){
1587 /* Case 1: expr IN (SELECT ...)
1588 **
1589 ** Generate code to write the results of the select into the temporary
1590 ** table allocated and opened above.
1591 */
1592 int iParm = pExpr->iTable + (((int)affinity)<<16);
1593 ExprList *pEList;
1594 assert( (pExpr->iTable&0x0000FFFF)==pExpr->iTable );
1595 if( sqlite3Select(pParse, pExpr->pSelect, SRT_Set, iParm, 0, 0, 0, 0) ){
1596 return;
1597 }
1598 pEList = pExpr->pSelect->pEList;
1599 if( pEList && pEList->nExpr>0 ){
1600 keyInfo.aColl[0] = sqlite3BinaryCompareCollSeq(pParse, pExpr->pLeft,
1601 pEList->a[0].pExpr);
1602 }
1603 }else if( pExpr->pList ){
1604 /* Case 2: expr IN (exprlist)
1605 **
1606 ** For each expression, build an index key from the evaluation and
1607 ** store it in the temporary table. If <expr> is a column, then use
1608 ** that columns affinity when building index keys. If <expr> is not
1609 ** a column, use numeric affinity.
1610 */
1611 int i;
1612 ExprList *pList = pExpr->pList;
1613 struct ExprList_item *pItem;
1614
1615 if( !affinity ){
1616 affinity = SQLITE_AFF_NONE;
1617 }
1618 keyInfo.aColl[0] = pExpr->pLeft->pColl;
1619
1620 /* Loop through each expression in <exprlist>. */
1621 for(i=pList->nExpr, pItem=pList->a; i>0; i--, pItem++){
1622 Expr *pE2 = pItem->pExpr;
1623
1624 /* If the expression is not constant then we will need to
1625 ** disable the test that was generated above that makes sure
1626 ** this code only executes once. Because for a non-constant
1627 ** expression we need to rerun this code each time.
1628 */
1629 if( testAddr>0 && !sqlite3ExprIsConstant(pE2) ){
1630 sqlite3VdbeChangeToNoop(v, testAddr-1, 3);
1631 testAddr = 0;
1632 }
1633
1634 /* Evaluate the expression and insert it into the temp table */
1635 sqlite3ExprCode(pParse, pE2);
1636 sqlite3VdbeOp3(v, OP_MakeRecord, 1, 0, &affinity, 1);
1637 sqlite3VdbeAddOp(v, OP_IdxInsert, pExpr->iTable, 0);
1638 }
1639 }
1640 sqlite3VdbeChangeP3(v, addr, (void *)&keyInfo, P3_KEYINFO);
1641 break;
1642 }
1643
1644 case TK_EXISTS:
1645 case TK_SELECT: {
1646 /* This has to be a scalar SELECT. Generate code to put the
1647 ** value of this select in a memory cell and record the number
1648 ** of the memory cell in iColumn.
1649 */
1650 static const Token one = { (u8*)"1", 0, 1 };
1651 Select *pSel;
1652 int iMem;
1653 int sop;
1654
1655 pExpr->iColumn = iMem = pParse->nMem++;
1656 pSel = pExpr->pSelect;
1657 if( pExpr->op==TK_SELECT ){
1658 sop = SRT_Mem;
1659 sqlite3VdbeAddOp(v, OP_MemNull, iMem, 0);
1660 VdbeComment((v, "# Init subquery result"));
1661 }else{
1662 sop = SRT_Exists;
1663 sqlite3VdbeAddOp(v, OP_MemInt, 0, iMem);
1664 VdbeComment((v, "# Init EXISTS result"));
1665 }
1666 sqlite3ExprDelete(pSel->pLimit);
1667 pSel->pLimit = sqlite3PExpr(pParse, TK_INTEGER, 0, 0, &one);
1668 if( sqlite3Select(pParse, pSel, sop, iMem, 0, 0, 0, 0) ){
1669 return;
1670 }
1671 break;
1672 }
1673 }
1674
1675 if( testAddr ){
1676 sqlite3VdbeJumpHere(v, testAddr);
1677 }
1678
1679 return;
1680}
1681#endif /* SQLITE_OMIT_SUBQUERY */
1682
1683/*
1684** Generate an instruction that will put the integer describe by
1685** text z[0..n-1] on the stack.
1686*/
1687static void codeInteger(Vdbe *v, const char *z, int n){
1688 assert( z || v==0 || sqlite3VdbeDb(v)->mallocFailed );
1689 if( z ){
1690 int i;
1691 if( sqlite3GetInt32(z, &i) ){
1692 sqlite3VdbeAddOp(v, OP_Integer, i, 0);
1693 }else if( sqlite3FitsIn64Bits(z) ){
1694 sqlite3VdbeOp3(v, OP_Int64, 0, 0, z, n);
1695 }else{
1696 sqlite3VdbeOp3(v, OP_Real, 0, 0, z, n);
1697 }
1698 }
1699}
1700
1701
1702/*
1703** Generate code that will extract the iColumn-th column from
1704** table pTab and push that column value on the stack. There
1705** is an open cursor to pTab in iTable. If iColumn<0 then
1706** code is generated that extracts the rowid.
1707*/
1708void sqlite3ExprCodeGetColumn(Vdbe *v, Table *pTab, int iColumn, int iTable){
1709 if( iColumn<0 ){
1710 int op = (pTab && IsVirtual(pTab)) ? OP_VRowid : OP_Rowid;
1711 sqlite3VdbeAddOp(v, op, iTable, 0);
1712 }else if( pTab==0 ){
1713 sqlite3VdbeAddOp(v, OP_Column, iTable, iColumn);
1714 }else{
1715 int op = IsVirtual(pTab) ? OP_VColumn : OP_Column;
1716 sqlite3VdbeAddOp(v, op, iTable, iColumn);
1717 sqlite3ColumnDefault(v, pTab, iColumn);
1718#ifndef SQLITE_OMIT_FLOATING_POINT
1719 if( pTab->aCol[iColumn].affinity==SQLITE_AFF_REAL ){
1720 sqlite3VdbeAddOp(v, OP_RealAffinity, 0, 0);
1721 }
1722#endif
1723 }
1724}
1725
1726/*
1727** Generate code into the current Vdbe to evaluate the given
1728** expression and leave the result on the top of stack.
1729**
1730** This code depends on the fact that certain token values (ex: TK_EQ)
1731** are the same as opcode values (ex: OP_Eq) that implement the corresponding
1732** operation. Special comments in vdbe.c and the mkopcodeh.awk script in
1733** the make process cause these values to align. Assert()s in the code
1734** below verify that the numbers are aligned correctly.
1735*/
1736void sqlite3ExprCode(Parse *pParse, Expr *pExpr){
1737 Vdbe *v = pParse->pVdbe;
1738 int op;
1739 int stackChng = 1; /* Amount of change to stack depth */
1740
1741 if( v==0 ) return;
1742 if( pExpr==0 ){
1743 sqlite3VdbeAddOp(v, OP_Null, 0, 0);
1744 return;
1745 }
1746 op = pExpr->op;
1747 switch( op ){
1748 case TK_AGG_COLUMN: {
1749 AggInfo *pAggInfo = pExpr->pAggInfo;
1750 struct AggInfo_col *pCol = &pAggInfo->aCol[pExpr->iAgg];
1751 if( !pAggInfo->directMode ){
1752 sqlite3VdbeAddOp(v, OP_MemLoad, pCol->iMem, 0);
1753 break;
1754 }else if( pAggInfo->useSortingIdx ){
1755 sqlite3VdbeAddOp(v, OP_Column, pAggInfo->sortingIdx,
1756 pCol->iSorterColumn);
1757 break;
1758 }
1759 /* Otherwise, fall thru into the TK_COLUMN case */
1760 }
1761 case TK_COLUMN: {
1762 if( pExpr->iTable<0 ){
1763 /* This only happens when coding check constraints */
1764 assert( pParse->ckOffset>0 );
1765 sqlite3VdbeAddOp(v, OP_Dup, pParse->ckOffset-pExpr->iColumn-1, 1);
1766 }else{
1767 sqlite3ExprCodeGetColumn(v, pExpr->pTab, pExpr->iColumn, pExpr->iTable);
1768 }
1769 break;
1770 }
1771 case TK_INTEGER: {
1772 codeInteger(v, (char*)pExpr->token.z, pExpr->token.n);
1773 break;
1774 }
1775 case TK_FLOAT:
1776 case TK_STRING: {
1777 assert( TK_FLOAT==OP_Real );
1778 assert( TK_STRING==OP_String8 );
1779 sqlite3DequoteExpr(pParse->db, pExpr);
1780 sqlite3VdbeOp3(v, op, 0, 0, (char*)pExpr->token.z, pExpr->token.n);
1781 break;
1782 }
1783 case TK_NULL: {
1784 sqlite3VdbeAddOp(v, OP_Null, 0, 0);
1785 break;
1786 }
1787#ifndef SQLITE_OMIT_BLOB_LITERAL
1788 case TK_BLOB: {
1789 int n;
1790 const char *z;
1791 assert( TK_BLOB==OP_HexBlob );
1792 n = pExpr->token.n - 3;
1793 z = (char*)pExpr->token.z + 2;
1794 assert( n>=0 );
1795 if( n==0 ){
1796 z = "";
1797 }
1798 sqlite3VdbeOp3(v, op, 0, 0, z, n);
1799 break;
1800 }
1801#endif
1802 case TK_VARIABLE: {
1803 sqlite3VdbeAddOp(v, OP_Variable, pExpr->iTable, 0);
1804 if( pExpr->token.n>1 ){
1805 sqlite3VdbeChangeP3(v, -1, (char*)pExpr->token.z, pExpr->token.n);
1806 }
1807 break;
1808 }
1809 case TK_REGISTER: {
1810 sqlite3VdbeAddOp(v, OP_MemLoad, pExpr->iTable, 0);
1811 break;
1812 }
1813#ifndef SQLITE_OMIT_CAST
1814 case TK_CAST: {
1815 /* Expressions of the form: CAST(pLeft AS token) */
1816 int aff, to_op;
1817 sqlite3ExprCode(pParse, pExpr->pLeft);
1818 aff = sqlite3AffinityType(&pExpr->token);
1819 to_op = aff - SQLITE_AFF_TEXT + OP_ToText;
1820 assert( to_op==OP_ToText || aff!=SQLITE_AFF_TEXT );
1821 assert( to_op==OP_ToBlob || aff!=SQLITE_AFF_NONE );
1822 assert( to_op==OP_ToNumeric || aff!=SQLITE_AFF_NUMERIC );
1823 assert( to_op==OP_ToInt || aff!=SQLITE_AFF_INTEGER );
1824 assert( to_op==OP_ToReal || aff!=SQLITE_AFF_REAL );
1825 sqlite3VdbeAddOp(v, to_op, 0, 0);
1826 stackChng = 0;
1827 break;
1828 }
1829#endif /* SQLITE_OMIT_CAST */
1830 case TK_LT:
1831 case TK_LE:
1832 case TK_GT:
1833 case TK_GE:
1834 case TK_NE:
1835 case TK_EQ: {
1836 assert( TK_LT==OP_Lt );
1837 assert( TK_LE==OP_Le );
1838 assert( TK_GT==OP_Gt );
1839 assert( TK_GE==OP_Ge );
1840 assert( TK_EQ==OP_Eq );
1841 assert( TK_NE==OP_Ne );
1842 sqlite3ExprCode(pParse, pExpr->pLeft);
1843 sqlite3ExprCode(pParse, pExpr->pRight);
1844 codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op, 0, 0);
1845 stackChng = -1;
1846 break;
1847 }
1848 case TK_AND:
1849 case TK_OR:
1850 case TK_PLUS:
1851 case TK_STAR:
1852 case TK_MINUS:
1853 case TK_REM:
1854 case TK_BITAND:
1855 case TK_BITOR:
1856 case TK_SLASH:
1857 case TK_LSHIFT:
1858 case TK_RSHIFT:
1859 case TK_CONCAT: {
1860 assert( TK_AND==OP_And );
1861 assert( TK_OR==OP_Or );
1862 assert( TK_PLUS==OP_Add );
1863 assert( TK_MINUS==OP_Subtract );
1864 assert( TK_REM==OP_Remainder );
1865 assert( TK_BITAND==OP_BitAnd );
1866 assert( TK_BITOR==OP_BitOr );
1867 assert( TK_SLASH==OP_Divide );
1868 assert( TK_LSHIFT==OP_ShiftLeft );
1869 assert( TK_RSHIFT==OP_ShiftRight );
1870 assert( TK_CONCAT==OP_Concat );
1871 sqlite3ExprCode(pParse, pExpr->pLeft);
1872 sqlite3ExprCode(pParse, pExpr->pRight);
1873 sqlite3VdbeAddOp(v, op, 0, 0);
1874 stackChng = -1;
1875 break;
1876 }
1877 case TK_UMINUS: {
1878 Expr *pLeft = pExpr->pLeft;
1879 assert( pLeft );
1880 if( pLeft->op==TK_FLOAT || pLeft->op==TK_INTEGER ){
1881 Token *p = &pLeft->token;
1882 char *z = sqlite3MPrintf(pParse->db, "-%.*s", p->n, p->z);
1883 if( pLeft->op==TK_FLOAT ){
1884 sqlite3VdbeOp3(v, OP_Real, 0, 0, z, p->n+1);
1885 }else{
1886 codeInteger(v, z, p->n+1);
1887 }
1888 sqlite3_free(z);
1889 break;
1890 }
1891 /* Fall through into TK_NOT */
1892 }
1893 case TK_BITNOT:
1894 case TK_NOT: {
1895 assert( TK_BITNOT==OP_BitNot );
1896 assert( TK_NOT==OP_Not );
1897 sqlite3ExprCode(pParse, pExpr->pLeft);
1898 sqlite3VdbeAddOp(v, op, 0, 0);
1899 stackChng = 0;
1900 break;
1901 }
1902 case TK_ISNULL:
1903 case TK_NOTNULL: {
1904 int dest;
1905 assert( TK_ISNULL==OP_IsNull );
1906 assert( TK_NOTNULL==OP_NotNull );
1907 sqlite3VdbeAddOp(v, OP_Integer, 1, 0);
1908 sqlite3ExprCode(pParse, pExpr->pLeft);
1909 dest = sqlite3VdbeCurrentAddr(v) + 2;
1910 sqlite3VdbeAddOp(v, op, 1, dest);
1911 sqlite3VdbeAddOp(v, OP_AddImm, -1, 0);
1912 stackChng = 0;
1913 break;
1914 }
1915 case TK_AGG_FUNCTION: {
1916 AggInfo *pInfo = pExpr->pAggInfo;
1917 if( pInfo==0 ){
1918 sqlite3ErrorMsg(pParse, "misuse of aggregate: %T",
1919 &pExpr->span);
1920 }else{
1921 sqlite3VdbeAddOp(v, OP_MemLoad, pInfo->aFunc[pExpr->iAgg].iMem, 0);
1922 }
1923 break;
1924 }
1925 case TK_CONST_FUNC:
1926 case TK_FUNCTION: {
1927 ExprList *pList = pExpr->pList;
1928 int nExpr = pList ? pList->nExpr : 0;
1929 FuncDef *pDef;
1930 int nId;
1931 const char *zId;
1932 int constMask = 0;
1933 int i;
1934 sqlite3 *db = pParse->db;
1935 u8 enc = ENC(db);
1936 CollSeq *pColl = 0;
1937
1938 zId = (char*)pExpr->token.z;
1939 nId = pExpr->token.n;
1940 pDef = sqlite3FindFunction(pParse->db, zId, nId, nExpr, enc, 0);
1941 assert( pDef!=0 );
1942 nExpr = sqlite3ExprCodeExprList(pParse, pList);
1943#ifndef SQLITE_OMIT_VIRTUALTABLE
1944 /* Possibly overload the function if the first argument is
1945 ** a virtual table column.
1946 **
1947 ** For infix functions (LIKE, GLOB, REGEXP, and MATCH) use the
1948 ** second argument, not the first, as the argument to test to
1949 ** see if it is a column in a virtual table. This is done because
1950 ** the left operand of infix functions (the operand we want to
1951 ** control overloading) ends up as the second argument to the
1952 ** function. The expression "A glob B" is equivalent to
1953 ** "glob(B,A). We want to use the A in "A glob B" to test
1954 ** for function overloading. But we use the B term in "glob(B,A)".
1955 */
1956 if( nExpr>=2 && (pExpr->flags & EP_InfixFunc) ){
1957 pDef = sqlite3VtabOverloadFunction(db, pDef, nExpr, pList->a[1].pExpr);
1958 }else if( nExpr>0 ){
1959 pDef = sqlite3VtabOverloadFunction(db, pDef, nExpr, pList->a[0].pExpr);
1960 }
1961#endif
1962 for(i=0; i<nExpr && i<32; i++){
1963 if( sqlite3ExprIsConstant(pList->a[i].pExpr) ){
1964 constMask |= (1<<i);
1965 }
1966 if( pDef->needCollSeq && !pColl ){
1967 pColl = sqlite3ExprCollSeq(pParse, pList->a[i].pExpr);
1968 }
1969 }
1970 if( pDef->needCollSeq ){
1971 if( !pColl ) pColl = pParse->db->pDfltColl;
1972 sqlite3VdbeOp3(v, OP_CollSeq, 0, 0, (char *)pColl, P3_COLLSEQ);
1973 }
1974 sqlite3VdbeOp3(v, OP_Function, constMask, nExpr, (char*)pDef, P3_FUNCDEF);
1975 stackChng = 1-nExpr;
1976 break;
1977 }
1978#ifndef SQLITE_OMIT_SUBQUERY
1979 case TK_EXISTS:
1980 case TK_SELECT: {
1981 if( pExpr->iColumn==0 ){
1982 sqlite3CodeSubselect(pParse, pExpr);
1983 }
1984 sqlite3VdbeAddOp(v, OP_MemLoad, pExpr->iColumn, 0);
1985 VdbeComment((v, "# load subquery result"));
1986 break;
1987 }
1988 case TK_IN: {
1989 int addr;
1990 char affinity;
1991 int ckOffset = pParse->ckOffset;
1992 sqlite3CodeSubselect(pParse, pExpr);
1993
1994 /* Figure out the affinity to use to create a key from the results
1995 ** of the expression. affinityStr stores a static string suitable for
1996 ** P3 of OP_MakeRecord.
1997 */
1998 affinity = comparisonAffinity(pExpr);
1999
2000 sqlite3VdbeAddOp(v, OP_Integer, 1, 0);
2001 pParse->ckOffset = (ckOffset ? (ckOffset+1) : 0);
2002
2003 /* Code the <expr> from "<expr> IN (...)". The temporary table
2004 ** pExpr->iTable contains the values that make up the (...) set.
2005 */
2006 sqlite3ExprCode(pParse, pExpr->pLeft);
2007 addr = sqlite3VdbeCurrentAddr(v);
2008 sqlite3VdbeAddOp(v, OP_NotNull, -1, addr+4); /* addr + 0 */
2009 sqlite3VdbeAddOp(v, OP_Pop, 2, 0);
2010 sqlite3VdbeAddOp(v, OP_Null, 0, 0);
2011 sqlite3VdbeAddOp(v, OP_Goto, 0, addr+7);
2012 sqlite3VdbeOp3(v, OP_MakeRecord, 1, 0, &affinity, 1); /* addr + 4 */
2013 sqlite3VdbeAddOp(v, OP_Found, pExpr->iTable, addr+7);
2014 sqlite3VdbeAddOp(v, OP_AddImm, -1, 0); /* addr + 6 */
2015
2016 break;
2017 }
2018#endif
2019 case TK_BETWEEN: {
2020 Expr *pLeft = pExpr->pLeft;
2021 struct ExprList_item *pLItem = pExpr->pList->a;
2022 Expr *pRight = pLItem->pExpr;
2023 sqlite3ExprCode(pParse, pLeft);
2024 sqlite3VdbeAddOp(v, OP_Dup, 0, 0);
2025 sqlite3ExprCode(pParse, pRight);
2026 codeCompare(pParse, pLeft, pRight, OP_Ge, 0, 0);
2027 sqlite3VdbeAddOp(v, OP_Pull, 1, 0);
2028 pLItem++;
2029 pRight = pLItem->pExpr;
2030 sqlite3ExprCode(pParse, pRight);
2031 codeCompare(pParse, pLeft, pRight, OP_Le, 0, 0);
2032 sqlite3VdbeAddOp(v, OP_And, 0, 0);
2033 break;
2034 }
2035 case TK_UPLUS: {
2036 sqlite3ExprCode(pParse, pExpr->pLeft);
2037 stackChng = 0;
2038 break;
2039 }
2040 case TK_CASE: {
2041 int expr_end_label;
2042 int jumpInst;
2043 int nExpr;
2044 int i;
2045 ExprList *pEList;
2046 struct ExprList_item *aListelem;
2047
2048 assert(pExpr->pList);
2049 assert((pExpr->pList->nExpr % 2) == 0);
2050 assert(pExpr->pList->nExpr > 0);
2051 pEList = pExpr->pList;
2052 aListelem = pEList->a;
2053 nExpr = pEList->nExpr;
2054 expr_end_label = sqlite3VdbeMakeLabel(v);
2055 if( pExpr->pLeft ){
2056 sqlite3ExprCode(pParse, pExpr->pLeft);
2057 }
2058 for(i=0; i<nExpr; i=i+2){
2059 sqlite3ExprCode(pParse, aListelem[i].pExpr);
2060 if( pExpr->pLeft ){
2061 sqlite3VdbeAddOp(v, OP_Dup, 1, 1);
2062 jumpInst = codeCompare(pParse, pExpr->pLeft, aListelem[i].pExpr,
2063 OP_Ne, 0, 1);
2064 sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
2065 }else{
2066 jumpInst = sqlite3VdbeAddOp(v, OP_IfNot, 1, 0);
2067 }
2068 sqlite3ExprCode(pParse, aListelem[i+1].pExpr);
2069 sqlite3VdbeAddOp(v, OP_Goto, 0, expr_end_label);
2070 sqlite3VdbeJumpHere(v, jumpInst);
2071 }
2072 if( pExpr->pLeft ){
2073 sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
2074 }
2075 if( pExpr->pRight ){
2076 sqlite3ExprCode(pParse, pExpr->pRight);
2077 }else{
2078 sqlite3VdbeAddOp(v, OP_Null, 0, 0);
2079 }
2080 sqlite3VdbeResolveLabel(v, expr_end_label);
2081 break;
2082 }
2083#ifndef SQLITE_OMIT_TRIGGER
2084 case TK_RAISE: {
2085 if( !pParse->trigStack ){
2086 sqlite3ErrorMsg(pParse,
2087 "RAISE() may only be used within a trigger-program");
2088 return;
2089 }
2090 if( pExpr->iColumn!=OE_Ignore ){
2091 assert( pExpr->iColumn==OE_Rollback ||
2092 pExpr->iColumn == OE_Abort ||
2093 pExpr->iColumn == OE_Fail );
2094 sqlite3DequoteExpr(pParse->db, pExpr);
2095 sqlite3VdbeOp3(v, OP_Halt, SQLITE_CONSTRAINT, pExpr->iColumn,
2096 (char*)pExpr->token.z, pExpr->token.n);
2097 } else {
2098 assert( pExpr->iColumn == OE_Ignore );
2099 sqlite3VdbeAddOp(v, OP_ContextPop, 0, 0);
2100 sqlite3VdbeAddOp(v, OP_Goto, 0, pParse->trigStack->ignoreJump);
2101 VdbeComment((v, "# raise(IGNORE)"));
2102 }
2103 stackChng = 0;
2104 break;
2105 }
2106#endif
2107 }
2108
2109 if( pParse->ckOffset ){
2110 pParse->ckOffset += stackChng;
2111 assert( pParse->ckOffset );
2112 }
2113}
2114
2115#ifndef SQLITE_OMIT_TRIGGER
2116/*
2117** Generate code that evalutes the given expression and leaves the result
2118** on the stack. See also sqlite3ExprCode().
2119**
2120** This routine might also cache the result and modify the pExpr tree
2121** so that it will make use of the cached result on subsequent evaluations
2122** rather than evaluate the whole expression again. Trivial expressions are
2123** not cached. If the expression is cached, its result is stored in a
2124** memory location.
2125*/
2126void sqlite3ExprCodeAndCache(Parse *pParse, Expr *pExpr){
2127 Vdbe *v = pParse->pVdbe;
2128 int iMem;
2129 int addr1, addr2;
2130 if( v==0 ) return;
2131 addr1 = sqlite3VdbeCurrentAddr(v);
2132 sqlite3ExprCode(pParse, pExpr);
2133 addr2 = sqlite3VdbeCurrentAddr(v);
2134 if( addr2>addr1+1 || sqlite3VdbeGetOp(v, addr1)->opcode==OP_Function ){
2135 iMem = pExpr->iTable = pParse->nMem++;
2136 sqlite3VdbeAddOp(v, OP_MemStore, iMem, 0);
2137 pExpr->op = TK_REGISTER;
2138 }
2139}
2140#endif
2141
2142/*
2143** Generate code that pushes the value of every element of the given
2144** expression list onto the stack.
2145**
2146** Return the number of elements pushed onto the stack.
2147*/
2148int sqlite3ExprCodeExprList(
2149 Parse *pParse, /* Parsing context */
2150 ExprList *pList /* The expression list to be coded */
2151){
2152 struct ExprList_item *pItem;
2153 int i, n;
2154 if( pList==0 ) return 0;
2155 n = pList->nExpr;
2156 for(pItem=pList->a, i=n; i>0; i--, pItem++){
2157 sqlite3ExprCode(pParse, pItem->pExpr);
2158 }
2159 return n;
2160}
2161
2162/*
2163** Generate code for a boolean expression such that a jump is made
2164** to the label "dest" if the expression is true but execution
2165** continues straight thru if the expression is false.
2166**
2167** If the expression evaluates to NULL (neither true nor false), then
2168** take the jump if the jumpIfNull flag is true.
2169**
2170** This code depends on the fact that certain token values (ex: TK_EQ)
2171** are the same as opcode values (ex: OP_Eq) that implement the corresponding
2172** operation. Special comments in vdbe.c and the mkopcodeh.awk script in
2173** the make process cause these values to align. Assert()s in the code
2174** below verify that the numbers are aligned correctly.
2175*/
2176void sqlite3ExprIfTrue(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
2177 Vdbe *v = pParse->pVdbe;
2178 int op = 0;
2179 int ckOffset = pParse->ckOffset;
2180 if( v==0 || pExpr==0 ) return;
2181 op = pExpr->op;
2182 switch( op ){
2183 case TK_AND: {
2184 int d2 = sqlite3VdbeMakeLabel(v);
2185 sqlite3ExprIfFalse(pParse, pExpr->pLeft, d2, !jumpIfNull);
2186 sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);
2187 sqlite3VdbeResolveLabel(v, d2);
2188 break;
2189 }
2190 case TK_OR: {
2191 sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);
2192 sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);
2193 break;
2194 }
2195 case TK_NOT: {
2196 sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);
2197 break;
2198 }
2199 case TK_LT:
2200 case TK_LE:
2201 case TK_GT:
2202 case TK_GE:
2203 case TK_NE:
2204 case TK_EQ: {
2205 assert( TK_LT==OP_Lt );
2206 assert( TK_LE==OP_Le );
2207 assert( TK_GT==OP_Gt );
2208 assert( TK_GE==OP_Ge );
2209 assert( TK_EQ==OP_Eq );
2210 assert( TK_NE==OP_Ne );
2211 sqlite3ExprCode(pParse, pExpr->pLeft);
2212 sqlite3ExprCode(pParse, pExpr->pRight);
2213 codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op, dest, jumpIfNull);
2214 break;
2215 }
2216 case TK_ISNULL:
2217 case TK_NOTNULL: {
2218 assert( TK_ISNULL==OP_IsNull );
2219 assert( TK_NOTNULL==OP_NotNull );
2220 sqlite3ExprCode(pParse, pExpr->pLeft);
2221 sqlite3VdbeAddOp(v, op, 1, dest);
2222 break;
2223 }
2224 case TK_BETWEEN: {
2225 /* The expression "x BETWEEN y AND z" is implemented as:
2226 **
2227 ** 1 IF (x < y) GOTO 3
2228 ** 2 IF (x <= z) GOTO <dest>
2229 ** 3 ...
2230 */
2231 int addr;
2232 Expr *pLeft = pExpr->pLeft;
2233 Expr *pRight = pExpr->pList->a[0].pExpr;
2234 sqlite3ExprCode(pParse, pLeft);
2235 sqlite3VdbeAddOp(v, OP_Dup, 0, 0);
2236 sqlite3ExprCode(pParse, pRight);
2237 addr = codeCompare(pParse, pLeft, pRight, OP_Lt, 0, !jumpIfNull);
2238
2239 pRight = pExpr->pList->a[1].pExpr;
2240 sqlite3ExprCode(pParse, pRight);
2241 codeCompare(pParse, pLeft, pRight, OP_Le, dest, jumpIfNull);
2242
2243 sqlite3VdbeAddOp(v, OP_Integer, 0, 0);
2244 sqlite3VdbeJumpHere(v, addr);
2245 sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
2246 break;
2247 }
2248 default: {
2249 sqlite3ExprCode(pParse, pExpr);
2250 sqlite3VdbeAddOp(v, OP_If, jumpIfNull, dest);
2251 break;
2252 }
2253 }
2254 pParse->ckOffset = ckOffset;
2255}
2256
2257/*
2258** Generate code for a boolean expression such that a jump is made
2259** to the label "dest" if the expression is false but execution
2260** continues straight thru if the expression is true.
2261**
2262** If the expression evaluates to NULL (neither true nor false) then
2263** jump if jumpIfNull is true or fall through if jumpIfNull is false.
2264*/
2265void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
2266 Vdbe *v = pParse->pVdbe;
2267 int op = 0;
2268 int ckOffset = pParse->ckOffset;
2269 if( v==0 || pExpr==0 ) return;
2270
2271 /* The value of pExpr->op and op are related as follows:
2272 **
2273 ** pExpr->op op
2274 ** --------- ----------
2275 ** TK_ISNULL OP_NotNull
2276 ** TK_NOTNULL OP_IsNull
2277 ** TK_NE OP_Eq
2278 ** TK_EQ OP_Ne
2279 ** TK_GT OP_Le
2280 ** TK_LE OP_Gt
2281 ** TK_GE OP_Lt
2282 ** TK_LT OP_Ge
2283 **
2284 ** For other values of pExpr->op, op is undefined and unused.
2285 ** The value of TK_ and OP_ constants are arranged such that we
2286 ** can compute the mapping above using the following expression.
2287 ** Assert()s verify that the computation is correct.
2288 */
2289 op = ((pExpr->op+(TK_ISNULL&1))^1)-(TK_ISNULL&1);
2290
2291 /* Verify correct alignment of TK_ and OP_ constants
2292 */
2293 assert( pExpr->op!=TK_ISNULL || op==OP_NotNull );
2294 assert( pExpr->op!=TK_NOTNULL || op==OP_IsNull );
2295 assert( pExpr->op!=TK_NE || op==OP_Eq );
2296 assert( pExpr->op!=TK_EQ || op==OP_Ne );
2297 assert( pExpr->op!=TK_LT || op==OP_Ge );
2298 assert( pExpr->op!=TK_LE || op==OP_Gt );
2299 assert( pExpr->op!=TK_GT || op==OP_Le );
2300 assert( pExpr->op!=TK_GE || op==OP_Lt );
2301
2302 switch( pExpr->op ){
2303 case TK_AND: {
2304 sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);
2305 sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
2306 break;
2307 }
2308 case TK_OR: {
2309 int d2 = sqlite3VdbeMakeLabel(v);
2310 sqlite3ExprIfTrue(pParse, pExpr->pLeft, d2, !jumpIfNull);
2311 sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
2312 sqlite3VdbeResolveLabel(v, d2);
2313 break;
2314 }
2315 case TK_NOT: {
2316 sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);
2317 break;
2318 }
2319 case TK_LT:
2320 case TK_LE:
2321 case TK_GT:
2322 case TK_GE:
2323 case TK_NE:
2324 case TK_EQ: {
2325 sqlite3ExprCode(pParse, pExpr->pLeft);
2326 sqlite3ExprCode(pParse, pExpr->pRight);
2327 codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op, dest, jumpIfNull);
2328 break;
2329 }
2330 case TK_ISNULL:
2331 case TK_NOTNULL: {
2332 sqlite3ExprCode(pParse, pExpr->pLeft);
2333 sqlite3VdbeAddOp(v, op, 1, dest);
2334 break;
2335 }
2336 case TK_BETWEEN: {
2337 /* The expression is "x BETWEEN y AND z". It is implemented as:
2338 **
2339 ** 1 IF (x >= y) GOTO 3
2340 ** 2 GOTO <dest>
2341 ** 3 IF (x > z) GOTO <dest>
2342 */
2343 int addr;
2344 Expr *pLeft = pExpr->pLeft;
2345 Expr *pRight = pExpr->pList->a[0].pExpr;
2346 sqlite3ExprCode(pParse, pLeft);
2347 sqlite3VdbeAddOp(v, OP_Dup, 0, 0);
2348 sqlite3ExprCode(pParse, pRight);
2349 addr = sqlite3VdbeCurrentAddr(v);
2350 codeCompare(pParse, pLeft, pRight, OP_Ge, addr+3, !jumpIfNull);
2351
2352 sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
2353 sqlite3VdbeAddOp(v, OP_Goto, 0, dest);
2354 pRight = pExpr->pList->a[1].pExpr;
2355 sqlite3ExprCode(pParse, pRight);
2356 codeCompare(pParse, pLeft, pRight, OP_Gt, dest, jumpIfNull);
2357 break;
2358 }
2359 default: {
2360 sqlite3ExprCode(pParse, pExpr);
2361 sqlite3VdbeAddOp(v, OP_IfNot, jumpIfNull, dest);
2362 break;
2363 }
2364 }
2365 pParse->ckOffset = ckOffset;
2366}
2367
2368/*
2369** Do a deep comparison of two expression trees. Return TRUE (non-zero)
2370** if they are identical and return FALSE if they differ in any way.
2371**
2372** Sometimes this routine will return FALSE even if the two expressions
2373** really are equivalent. If we cannot prove that the expressions are
2374** identical, we return FALSE just to be safe. So if this routine
2375** returns false, then you do not really know for certain if the two
2376** expressions are the same. But if you get a TRUE return, then you
2377** can be sure the expressions are the same. In the places where
2378** this routine is used, it does not hurt to get an extra FALSE - that
2379** just might result in some slightly slower code. But returning
2380** an incorrect TRUE could lead to a malfunction.
2381*/
2382int sqlite3ExprCompare(Expr *pA, Expr *pB){
2383 int i;
2384 if( pA==0||pB==0 ){
2385 return pB==pA;
2386 }
2387 if( pA->op!=pB->op ) return 0;
2388 if( (pA->flags & EP_Distinct)!=(pB->flags & EP_Distinct) ) return 0;
2389 if( !sqlite3ExprCompare(pA->pLeft, pB->pLeft) ) return 0;
2390 if( !sqlite3ExprCompare(pA->pRight, pB->pRight) ) return 0;
2391 if( pA->pList ){
2392 if( pB->pList==0 ) return 0;
2393 if( pA->pList->nExpr!=pB->pList->nExpr ) return 0;
2394 for(i=0; i<pA->pList->nExpr; i++){
2395 if( !sqlite3ExprCompare(pA->pList->a[i].pExpr, pB->pList->a[i].pExpr) ){
2396 return 0;
2397 }
2398 }
2399 }else if( pB->pList ){
2400 return 0;
2401 }
2402 if( pA->pSelect || pB->pSelect ) return 0;
2403 if( pA->iTable!=pB->iTable || pA->iColumn!=pB->iColumn ) return 0;
2404 if( pA->op!=TK_COLUMN && pA->token.z ){
2405 if( pB->token.z==0 ) return 0;
2406 if( pB->token.n!=pA->token.n ) return 0;
2407 if( sqlite3StrNICmp((char*)pA->token.z,(char*)pB->token.z,pB->token.n)!=0 ){
2408 return 0;
2409 }
2410 }
2411 return 1;
2412}
2413
2414
2415/*
2416** Add a new element to the pAggInfo->aCol[] array. Return the index of
2417** the new element. Return a negative number if malloc fails.
2418*/
2419static int addAggInfoColumn(sqlite3 *db, AggInfo *pInfo){
2420 int i;
2421 pInfo->aCol = sqlite3ArrayAllocate(
2422 db,
2423 pInfo->aCol,
2424 sizeof(pInfo->aCol[0]),
2425 3,
2426 &pInfo->nColumn,
2427 &pInfo->nColumnAlloc,
2428 &i
2429 );
2430 return i;
2431}
2432
2433/*
2434** Add a new element to the pAggInfo->aFunc[] array. Return the index of
2435** the new element. Return a negative number if malloc fails.
2436*/
2437static int addAggInfoFunc(sqlite3 *db, AggInfo *pInfo){
2438 int i;
2439 pInfo->aFunc = sqlite3ArrayAllocate(
2440 db,
2441 pInfo->aFunc,
2442 sizeof(pInfo->aFunc[0]),
2443 3,
2444 &pInfo->nFunc,
2445 &pInfo->nFuncAlloc,
2446 &i
2447 );
2448 return i;
2449}
2450
2451/*
2452** This is an xFunc for walkExprTree() used to implement
2453** sqlite3ExprAnalyzeAggregates(). See sqlite3ExprAnalyzeAggregates
2454** for additional information.
2455**
2456** This routine analyzes the aggregate function at pExpr.
2457*/
2458static int analyzeAggregate(void *pArg, Expr *pExpr){
2459 int i;
2460 NameContext *pNC = (NameContext *)pArg;
2461 Parse *pParse = pNC->pParse;
2462 SrcList *pSrcList = pNC->pSrcList;
2463 AggInfo *pAggInfo = pNC->pAggInfo;
2464
2465 switch( pExpr->op ){
2466 case TK_AGG_COLUMN:
2467 case TK_COLUMN: {
2468 /* Check to see if the column is in one of the tables in the FROM
2469 ** clause of the aggregate query */
2470 if( pSrcList ){
2471 struct SrcList_item *pItem = pSrcList->a;
2472 for(i=0; i<pSrcList->nSrc; i++, pItem++){
2473 struct AggInfo_col *pCol;
2474 if( pExpr->iTable==pItem->iCursor ){
2475 /* If we reach this point, it means that pExpr refers to a table
2476 ** that is in the FROM clause of the aggregate query.
2477 **
2478 ** Make an entry for the column in pAggInfo->aCol[] if there
2479 ** is not an entry there already.
2480 */
2481 int k;
2482 pCol = pAggInfo->aCol;
2483 for(k=0; k<pAggInfo->nColumn; k++, pCol++){
2484 if( pCol->iTable==pExpr->iTable &&
2485 pCol->iColumn==pExpr->iColumn ){
2486 break;
2487 }
2488 }
2489 if( (k>=pAggInfo->nColumn)
2490 && (k = addAggInfoColumn(pParse->db, pAggInfo))>=0
2491 ){
2492 pCol = &pAggInfo->aCol[k];
2493 pCol->pTab = pExpr->pTab;
2494 pCol->iTable = pExpr->iTable;
2495 pCol->iColumn = pExpr->iColumn;
2496 pCol->iMem = pParse->nMem++;
2497 pCol->iSorterColumn = -1;
2498 pCol->pExpr = pExpr;
2499 if( pAggInfo->pGroupBy ){
2500 int j, n;
2501 ExprList *pGB = pAggInfo->pGroupBy;
2502 struct ExprList_item *pTerm = pGB->a;
2503 n = pGB->nExpr;
2504 for(j=0; j<n; j++, pTerm++){
2505 Expr *pE = pTerm->pExpr;
2506 if( pE->op==TK_COLUMN && pE->iTable==pExpr->iTable &&
2507 pE->iColumn==pExpr->iColumn ){
2508 pCol->iSorterColumn = j;
2509 break;
2510 }
2511 }
2512 }
2513 if( pCol->iSorterColumn<0 ){
2514 pCol->iSorterColumn = pAggInfo->nSortingColumn++;
2515 }
2516 }
2517 /* There is now an entry for pExpr in pAggInfo->aCol[] (either
2518 ** because it was there before or because we just created it).
2519 ** Convert the pExpr to be a TK_AGG_COLUMN referring to that
2520 ** pAggInfo->aCol[] entry.
2521 */
2522 pExpr->pAggInfo = pAggInfo;
2523 pExpr->op = TK_AGG_COLUMN;
2524 pExpr->iAgg = k;
2525 break;
2526 } /* endif pExpr->iTable==pItem->iCursor */
2527 } /* end loop over pSrcList */
2528 }
2529 return 1;
2530 }
2531 case TK_AGG_FUNCTION: {
2532 /* The pNC->nDepth==0 test causes aggregate functions in subqueries
2533 ** to be ignored */
2534 if( pNC->nDepth==0 ){
2535 /* Check to see if pExpr is a duplicate of another aggregate
2536 ** function that is already in the pAggInfo structure
2537 */
2538 struct AggInfo_func *pItem = pAggInfo->aFunc;
2539 for(i=0; i<pAggInfo->nFunc; i++, pItem++){
2540 if( sqlite3ExprCompare(pItem->pExpr, pExpr) ){
2541 break;
2542 }
2543 }
2544 if( i>=pAggInfo->nFunc ){
2545 /* pExpr is original. Make a new entry in pAggInfo->aFunc[]
2546 */
2547 u8 enc = ENC(pParse->db);
2548 i = addAggInfoFunc(pParse->db, pAggInfo);
2549 if( i>=0 ){
2550 pItem = &pAggInfo->aFunc[i];
2551 pItem->pExpr = pExpr;
2552 pItem->iMem = pParse->nMem++;
2553 pItem->pFunc = sqlite3FindFunction(pParse->db,
2554 (char*)pExpr->token.z, pExpr->token.n,
2555 pExpr->pList ? pExpr->pList->nExpr : 0, enc, 0);
2556 if( pExpr->flags & EP_Distinct ){
2557 pItem->iDistinct = pParse->nTab++;
2558 }else{
2559 pItem->iDistinct = -1;
2560 }
2561 }
2562 }
2563 /* Make pExpr point to the appropriate pAggInfo->aFunc[] entry
2564 */
2565 pExpr->iAgg = i;
2566 pExpr->pAggInfo = pAggInfo;
2567 return 1;
2568 }
2569 }
2570 }
2571
2572 /* Recursively walk subqueries looking for TK_COLUMN nodes that need
2573 ** to be changed to TK_AGG_COLUMN. But increment nDepth so that
2574 ** TK_AGG_FUNCTION nodes in subqueries will be unchanged.
2575 */
2576 if( pExpr->pSelect ){
2577 pNC->nDepth++;
2578 walkSelectExpr(pExpr->pSelect, analyzeAggregate, pNC);
2579 pNC->nDepth--;
2580 }
2581 return 0;
2582}
2583
2584/*
2585** Analyze the given expression looking for aggregate functions and
2586** for variables that need to be added to the pParse->aAgg[] array.
2587** Make additional entries to the pParse->aAgg[] array as necessary.
2588**
2589** This routine should only be called after the expression has been
2590** analyzed by sqlite3ExprResolveNames().
2591**
2592** If errors are seen, leave an error message in zErrMsg and return
2593** the number of errors.
2594*/
2595int sqlite3ExprAnalyzeAggregates(NameContext *pNC, Expr *pExpr){
2596 int nErr = pNC->pParse->nErr;
2597 walkExprTree(pExpr, analyzeAggregate, pNC);
2598 return pNC->pParse->nErr - nErr;
2599}
2600
2601/*
2602** Call sqlite3ExprAnalyzeAggregates() for every expression in an
2603** expression list. Return the number of errors.
2604**
2605** If an error is found, the analysis is cut short.
2606*/
2607int sqlite3ExprAnalyzeAggList(NameContext *pNC, ExprList *pList){
2608 struct ExprList_item *pItem;
2609 int i;
2610 int nErr = 0;
2611 if( pList ){
2612 for(pItem=pList->a, i=0; nErr==0 && i<pList->nExpr; i++, pItem++){
2613 nErr += sqlite3ExprAnalyzeAggregates(pNC, pItem->pExpr);
2614 }
2615 }
2616 return nErr;
2617}
generated by cgit v1.1 at 2024-12-24 01:30:10 +0000