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: #include "sqliteInt.h"
16:
17: /*
18: ** Return the 'affinity' of the expression pExpr if any.
19: **
20: ** If pExpr is a column, a reference to a column via an 'AS' alias,
21: ** or a sub-select with a column as the return value, then the
22: ** affinity of that column is returned. Otherwise, 0x00 is returned,
23: ** indicating no affinity for the expression.
24: **
25: ** i.e. the WHERE clause expresssions in the following statements all
26: ** have an affinity:
27: **
28: ** CREATE TABLE t1(a);
29: ** SELECT * FROM t1 WHERE a;
30: ** SELECT a AS b FROM t1 WHERE b;
31: ** SELECT * FROM t1 WHERE (select a from t1);
32: */
33: char sqlite3ExprAffinity(Expr *pExpr){
34: int op = pExpr->op;
35: if( op==TK_SELECT ){
36: assert( pExpr->flags&EP_xIsSelect );
37: return sqlite3ExprAffinity(pExpr->x.pSelect->pEList->a[0].pExpr);
38: }
39: #ifndef SQLITE_OMIT_CAST
40: if( op==TK_CAST ){
41: assert( !ExprHasProperty(pExpr, EP_IntValue) );
42: return sqlite3AffinityType(pExpr->u.zToken);
43: }
44: #endif
45: if( (op==TK_AGG_COLUMN || op==TK_COLUMN || op==TK_REGISTER)
46: && pExpr->pTab!=0
47: ){
48: /* op==TK_REGISTER && pExpr->pTab!=0 happens when pExpr was originally
49: ** a TK_COLUMN but was previously evaluated and cached in a register */
50: int j = pExpr->iColumn;
51: if( j<0 ) return SQLITE_AFF_INTEGER;
52: assert( pExpr->pTab && j<pExpr->pTab->nCol );
53: return pExpr->pTab->aCol[j].affinity;
54: }
55: return pExpr->affinity;
56: }
57:
58: /*
59: ** Set the explicit collating sequence for an expression to the
60: ** collating sequence supplied in the second argument.
61: */
62: Expr *sqlite3ExprSetColl(Expr *pExpr, CollSeq *pColl){
63: if( pExpr && pColl ){
64: pExpr->pColl = pColl;
65: pExpr->flags |= EP_ExpCollate;
66: }
67: return pExpr;
68: }
69:
70: /*
71: ** Set the collating sequence for expression pExpr to be the collating
72: ** sequence named by pToken. Return a pointer to the revised expression.
73: ** The collating sequence is marked as "explicit" using the EP_ExpCollate
74: ** flag. An explicit collating sequence will override implicit
75: ** collating sequences.
76: */
77: Expr *sqlite3ExprSetCollByToken(Parse *pParse, Expr *pExpr, Token *pCollName){
78: char *zColl = 0; /* Dequoted name of collation sequence */
79: CollSeq *pColl;
80: sqlite3 *db = pParse->db;
81: zColl = sqlite3NameFromToken(db, pCollName);
82: pColl = sqlite3LocateCollSeq(pParse, zColl);
83: sqlite3ExprSetColl(pExpr, pColl);
84: sqlite3DbFree(db, zColl);
85: return pExpr;
86: }
87:
88: /*
89: ** Return the default collation sequence for the expression pExpr. If
90: ** there is no default collation type, return 0.
91: */
92: CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr){
93: CollSeq *pColl = 0;
94: Expr *p = pExpr;
95: while( p ){
96: int op;
97: pColl = p->pColl;
98: if( pColl ) break;
99: op = p->op;
100: if( p->pTab!=0 && (
101: op==TK_AGG_COLUMN || op==TK_COLUMN || op==TK_REGISTER || op==TK_TRIGGER
102: )){
103: /* op==TK_REGISTER && p->pTab!=0 happens when pExpr was originally
104: ** a TK_COLUMN but was previously evaluated and cached in a register */
105: const char *zColl;
106: int j = p->iColumn;
107: if( j>=0 ){
108: sqlite3 *db = pParse->db;
109: zColl = p->pTab->aCol[j].zColl;
110: pColl = sqlite3FindCollSeq(db, ENC(db), zColl, 0);
111: pExpr->pColl = pColl;
112: }
113: break;
114: }
115: if( op!=TK_CAST && op!=TK_UPLUS ){
116: break;
117: }
118: p = p->pLeft;
119: }
120: if( sqlite3CheckCollSeq(pParse, pColl) ){
121: pColl = 0;
122: }
123: return pColl;
124: }
125:
126: /*
127: ** pExpr is an operand of a comparison operator. aff2 is the
128: ** type affinity of the other operand. This routine returns the
129: ** type affinity that should be used for the comparison operator.
130: */
131: char sqlite3CompareAffinity(Expr *pExpr, char aff2){
132: char aff1 = sqlite3ExprAffinity(pExpr);
133: if( aff1 && aff2 ){
134: /* Both sides of the comparison are columns. If one has numeric
135: ** affinity, use that. Otherwise use no affinity.
136: */
137: if( sqlite3IsNumericAffinity(aff1) || sqlite3IsNumericAffinity(aff2) ){
138: return SQLITE_AFF_NUMERIC;
139: }else{
140: return SQLITE_AFF_NONE;
141: }
142: }else if( !aff1 && !aff2 ){
143: /* Neither side of the comparison is a column. Compare the
144: ** results directly.
145: */
146: return SQLITE_AFF_NONE;
147: }else{
148: /* One side is a column, the other is not. Use the columns affinity. */
149: assert( aff1==0 || aff2==0 );
150: return (aff1 + aff2);
151: }
152: }
153:
154: /*
155: ** pExpr is a comparison operator. Return the type affinity that should
156: ** be applied to both operands prior to doing the comparison.
157: */
158: static char comparisonAffinity(Expr *pExpr){
159: char aff;
160: assert( pExpr->op==TK_EQ || pExpr->op==TK_IN || pExpr->op==TK_LT ||
161: pExpr->op==TK_GT || pExpr->op==TK_GE || pExpr->op==TK_LE ||
162: pExpr->op==TK_NE || pExpr->op==TK_IS || pExpr->op==TK_ISNOT );
163: assert( pExpr->pLeft );
164: aff = sqlite3ExprAffinity(pExpr->pLeft);
165: if( pExpr->pRight ){
166: aff = sqlite3CompareAffinity(pExpr->pRight, aff);
167: }else if( ExprHasProperty(pExpr, EP_xIsSelect) ){
168: aff = sqlite3CompareAffinity(pExpr->x.pSelect->pEList->a[0].pExpr, aff);
169: }else if( !aff ){
170: aff = SQLITE_AFF_NONE;
171: }
172: return aff;
173: }
174:
175: /*
176: ** pExpr is a comparison expression, eg. '=', '<', IN(...) etc.
177: ** idx_affinity is the affinity of an indexed column. Return true
178: ** if the index with affinity idx_affinity may be used to implement
179: ** the comparison in pExpr.
180: */
181: int sqlite3IndexAffinityOk(Expr *pExpr, char idx_affinity){
182: char aff = comparisonAffinity(pExpr);
183: switch( aff ){
184: case SQLITE_AFF_NONE:
185: return 1;
186: case SQLITE_AFF_TEXT:
187: return idx_affinity==SQLITE_AFF_TEXT;
188: default:
189: return sqlite3IsNumericAffinity(idx_affinity);
190: }
191: }
192:
193: /*
194: ** Return the P5 value that should be used for a binary comparison
195: ** opcode (OP_Eq, OP_Ge etc.) used to compare pExpr1 and pExpr2.
196: */
197: static u8 binaryCompareP5(Expr *pExpr1, Expr *pExpr2, int jumpIfNull){
198: u8 aff = (char)sqlite3ExprAffinity(pExpr2);
199: aff = (u8)sqlite3CompareAffinity(pExpr1, aff) | (u8)jumpIfNull;
200: return aff;
201: }
202:
203: /*
204: ** Return a pointer to the collation sequence that should be used by
205: ** a binary comparison operator comparing pLeft and pRight.
206: **
207: ** If the left hand expression has a collating sequence type, then it is
208: ** used. Otherwise the collation sequence for the right hand expression
209: ** is used, or the default (BINARY) if neither expression has a collating
210: ** type.
211: **
212: ** Argument pRight (but not pLeft) may be a null pointer. In this case,
213: ** it is not considered.
214: */
215: CollSeq *sqlite3BinaryCompareCollSeq(
216: Parse *pParse,
217: Expr *pLeft,
218: Expr *pRight
219: ){
220: CollSeq *pColl;
221: assert( pLeft );
222: if( pLeft->flags & EP_ExpCollate ){
223: assert( pLeft->pColl );
224: pColl = pLeft->pColl;
225: }else if( pRight && pRight->flags & EP_ExpCollate ){
226: assert( pRight->pColl );
227: pColl = pRight->pColl;
228: }else{
229: pColl = sqlite3ExprCollSeq(pParse, pLeft);
230: if( !pColl ){
231: pColl = sqlite3ExprCollSeq(pParse, pRight);
232: }
233: }
234: return pColl;
235: }
236:
237: /*
238: ** Generate code for a comparison operator.
239: */
240: static int codeCompare(
241: Parse *pParse, /* The parsing (and code generating) context */
242: Expr *pLeft, /* The left operand */
243: Expr *pRight, /* The right operand */
244: int opcode, /* The comparison opcode */
245: int in1, int in2, /* Register holding operands */
246: int dest, /* Jump here if true. */
247: int jumpIfNull /* If true, jump if either operand is NULL */
248: ){
249: int p5;
250: int addr;
251: CollSeq *p4;
252:
253: p4 = sqlite3BinaryCompareCollSeq(pParse, pLeft, pRight);
254: p5 = binaryCompareP5(pLeft, pRight, jumpIfNull);
255: addr = sqlite3VdbeAddOp4(pParse->pVdbe, opcode, in2, dest, in1,
256: (void*)p4, P4_COLLSEQ);
257: sqlite3VdbeChangeP5(pParse->pVdbe, (u8)p5);
258: return addr;
259: }
260:
261: #if SQLITE_MAX_EXPR_DEPTH>0
262: /*
263: ** Check that argument nHeight is less than or equal to the maximum
264: ** expression depth allowed. If it is not, leave an error message in
265: ** pParse.
266: */
267: int sqlite3ExprCheckHeight(Parse *pParse, int nHeight){
268: int rc = SQLITE_OK;
269: int mxHeight = pParse->db->aLimit[SQLITE_LIMIT_EXPR_DEPTH];
270: if( nHeight>mxHeight ){
271: sqlite3ErrorMsg(pParse,
272: "Expression tree is too large (maximum depth %d)", mxHeight
273: );
274: rc = SQLITE_ERROR;
275: }
276: return rc;
277: }
278:
279: /* The following three functions, heightOfExpr(), heightOfExprList()
280: ** and heightOfSelect(), are used to determine the maximum height
281: ** of any expression tree referenced by the structure passed as the
282: ** first argument.
283: **
284: ** If this maximum height is greater than the current value pointed
285: ** to by pnHeight, the second parameter, then set *pnHeight to that
286: ** value.
287: */
288: static void heightOfExpr(Expr *p, int *pnHeight){
289: if( p ){
290: if( p->nHeight>*pnHeight ){
291: *pnHeight = p->nHeight;
292: }
293: }
294: }
295: static void heightOfExprList(ExprList *p, int *pnHeight){
296: if( p ){
297: int i;
298: for(i=0; i<p->nExpr; i++){
299: heightOfExpr(p->a[i].pExpr, pnHeight);
300: }
301: }
302: }
303: static void heightOfSelect(Select *p, int *pnHeight){
304: if( p ){
305: heightOfExpr(p->pWhere, pnHeight);
306: heightOfExpr(p->pHaving, pnHeight);
307: heightOfExpr(p->pLimit, pnHeight);
308: heightOfExpr(p->pOffset, pnHeight);
309: heightOfExprList(p->pEList, pnHeight);
310: heightOfExprList(p->pGroupBy, pnHeight);
311: heightOfExprList(p->pOrderBy, pnHeight);
312: heightOfSelect(p->pPrior, pnHeight);
313: }
314: }
315:
316: /*
317: ** Set the Expr.nHeight variable in the structure passed as an
318: ** argument. An expression with no children, Expr.pList or
319: ** Expr.pSelect member has a height of 1. Any other expression
320: ** has a height equal to the maximum height of any other
321: ** referenced Expr plus one.
322: */
323: static void exprSetHeight(Expr *p){
324: int nHeight = 0;
325: heightOfExpr(p->pLeft, &nHeight);
326: heightOfExpr(p->pRight, &nHeight);
327: if( ExprHasProperty(p, EP_xIsSelect) ){
328: heightOfSelect(p->x.pSelect, &nHeight);
329: }else{
330: heightOfExprList(p->x.pList, &nHeight);
331: }
332: p->nHeight = nHeight + 1;
333: }
334:
335: /*
336: ** Set the Expr.nHeight variable using the exprSetHeight() function. If
337: ** the height is greater than the maximum allowed expression depth,
338: ** leave an error in pParse.
339: */
340: void sqlite3ExprSetHeight(Parse *pParse, Expr *p){
341: exprSetHeight(p);
342: sqlite3ExprCheckHeight(pParse, p->nHeight);
343: }
344:
345: /*
346: ** Return the maximum height of any expression tree referenced
347: ** by the select statement passed as an argument.
348: */
349: int sqlite3SelectExprHeight(Select *p){
350: int nHeight = 0;
351: heightOfSelect(p, &nHeight);
352: return nHeight;
353: }
354: #else
355: #define exprSetHeight(y)
356: #endif /* SQLITE_MAX_EXPR_DEPTH>0 */
357:
358: /*
359: ** This routine is the core allocator for Expr nodes.
360: **
361: ** Construct a new expression node and return a pointer to it. Memory
362: ** for this node and for the pToken argument is a single allocation
363: ** obtained from sqlite3DbMalloc(). The calling function
364: ** is responsible for making sure the node eventually gets freed.
365: **
366: ** If dequote is true, then the token (if it exists) is dequoted.
367: ** If dequote is false, no dequoting is performance. The deQuote
368: ** parameter is ignored if pToken is NULL or if the token does not
369: ** appear to be quoted. If the quotes were of the form "..." (double-quotes)
370: ** then the EP_DblQuoted flag is set on the expression node.
371: **
372: ** Special case: If op==TK_INTEGER and pToken points to a string that
373: ** can be translated into a 32-bit integer, then the token is not
374: ** stored in u.zToken. Instead, the integer values is written
375: ** into u.iValue and the EP_IntValue flag is set. No extra storage
376: ** is allocated to hold the integer text and the dequote flag is ignored.
377: */
378: Expr *sqlite3ExprAlloc(
379: sqlite3 *db, /* Handle for sqlite3DbMallocZero() (may be null) */
380: int op, /* Expression opcode */
381: const Token *pToken, /* Token argument. Might be NULL */
382: int dequote /* True to dequote */
383: ){
384: Expr *pNew;
385: int nExtra = 0;
386: int iValue = 0;
387:
388: if( pToken ){
389: if( op!=TK_INTEGER || pToken->z==0
390: || sqlite3GetInt32(pToken->z, &iValue)==0 ){
391: nExtra = pToken->n+1;
392: assert( iValue>=0 );
393: }
394: }
395: pNew = sqlite3DbMallocZero(db, sizeof(Expr)+nExtra);
396: if( pNew ){
397: pNew->op = (u8)op;
398: pNew->iAgg = -1;
399: if( pToken ){
400: if( nExtra==0 ){
401: pNew->flags |= EP_IntValue;
402: pNew->u.iValue = iValue;
403: }else{
404: int c;
405: pNew->u.zToken = (char*)&pNew[1];
406: assert( pToken->z!=0 || pToken->n==0 );
407: if( pToken->n ) memcpy(pNew->u.zToken, pToken->z, pToken->n);
408: pNew->u.zToken[pToken->n] = 0;
409: if( dequote && nExtra>=3
410: && ((c = pToken->z[0])=='\'' || c=='"' || c=='[' || c=='`') ){
411: sqlite3Dequote(pNew->u.zToken);
412: if( c=='"' ) pNew->flags |= EP_DblQuoted;
413: }
414: }
415: }
416: #if SQLITE_MAX_EXPR_DEPTH>0
417: pNew->nHeight = 1;
418: #endif
419: }
420: return pNew;
421: }
422:
423: /*
424: ** Allocate a new expression node from a zero-terminated token that has
425: ** already been dequoted.
426: */
427: Expr *sqlite3Expr(
428: sqlite3 *db, /* Handle for sqlite3DbMallocZero() (may be null) */
429: int op, /* Expression opcode */
430: const char *zToken /* Token argument. Might be NULL */
431: ){
432: Token x;
433: x.z = zToken;
434: x.n = zToken ? sqlite3Strlen30(zToken) : 0;
435: return sqlite3ExprAlloc(db, op, &x, 0);
436: }
437:
438: /*
439: ** Attach subtrees pLeft and pRight to the Expr node pRoot.
440: **
441: ** If pRoot==NULL that means that a memory allocation error has occurred.
442: ** In that case, delete the subtrees pLeft and pRight.
443: */
444: void sqlite3ExprAttachSubtrees(
445: sqlite3 *db,
446: Expr *pRoot,
447: Expr *pLeft,
448: Expr *pRight
449: ){
450: if( pRoot==0 ){
451: assert( db->mallocFailed );
452: sqlite3ExprDelete(db, pLeft);
453: sqlite3ExprDelete(db, pRight);
454: }else{
455: if( pRight ){
456: pRoot->pRight = pRight;
457: if( pRight->flags & EP_ExpCollate ){
458: pRoot->flags |= EP_ExpCollate;
459: pRoot->pColl = pRight->pColl;
460: }
461: }
462: if( pLeft ){
463: pRoot->pLeft = pLeft;
464: if( pLeft->flags & EP_ExpCollate ){
465: pRoot->flags |= EP_ExpCollate;
466: pRoot->pColl = pLeft->pColl;
467: }
468: }
469: exprSetHeight(pRoot);
470: }
471: }
472:
473: /*
474: ** Allocate a Expr node which joins as many as two subtrees.
475: **
476: ** One or both of the subtrees can be NULL. Return a pointer to the new
477: ** Expr node. Or, if an OOM error occurs, set pParse->db->mallocFailed,
478: ** free the subtrees and return NULL.
479: */
480: Expr *sqlite3PExpr(
481: Parse *pParse, /* Parsing context */
482: int op, /* Expression opcode */
483: Expr *pLeft, /* Left operand */
484: Expr *pRight, /* Right operand */
485: const Token *pToken /* Argument token */
486: ){
487: Expr *p = sqlite3ExprAlloc(pParse->db, op, pToken, 1);
488: sqlite3ExprAttachSubtrees(pParse->db, p, pLeft, pRight);
489: if( p ) {
490: sqlite3ExprCheckHeight(pParse, p->nHeight);
491: }
492: return p;
493: }
494:
495: /*
496: ** Join two expressions using an AND operator. If either expression is
497: ** NULL, then just return the other expression.
498: */
499: Expr *sqlite3ExprAnd(sqlite3 *db, Expr *pLeft, Expr *pRight){
500: if( pLeft==0 ){
501: return pRight;
502: }else if( pRight==0 ){
503: return pLeft;
504: }else{
505: Expr *pNew = sqlite3ExprAlloc(db, TK_AND, 0, 0);
506: sqlite3ExprAttachSubtrees(db, pNew, pLeft, pRight);
507: return pNew;
508: }
509: }
510:
511: /*
512: ** Construct a new expression node for a function with multiple
513: ** arguments.
514: */
515: Expr *sqlite3ExprFunction(Parse *pParse, ExprList *pList, Token *pToken){
516: Expr *pNew;
517: sqlite3 *db = pParse->db;
518: assert( pToken );
519: pNew = sqlite3ExprAlloc(db, TK_FUNCTION, pToken, 1);
520: if( pNew==0 ){
521: sqlite3ExprListDelete(db, pList); /* Avoid memory leak when malloc fails */
522: return 0;
523: }
524: pNew->x.pList = pList;
525: assert( !ExprHasProperty(pNew, EP_xIsSelect) );
526: sqlite3ExprSetHeight(pParse, pNew);
527: return pNew;
528: }
529:
530: /*
531: ** Assign a variable number to an expression that encodes a wildcard
532: ** in the original SQL statement.
533: **
534: ** Wildcards consisting of a single "?" are assigned the next sequential
535: ** variable number.
536: **
537: ** Wildcards of the form "?nnn" are assigned the number "nnn". We make
538: ** sure "nnn" is not too be to avoid a denial of service attack when
539: ** the SQL statement comes from an external source.
540: **
541: ** Wildcards of the form ":aaa", "@aaa", or "$aaa" are assigned the same number
542: ** as the previous instance of the same wildcard. Or if this is the first
543: ** instance of the wildcard, the next sequenial variable number is
544: ** assigned.
545: */
546: void sqlite3ExprAssignVarNumber(Parse *pParse, Expr *pExpr){
547: sqlite3 *db = pParse->db;
548: const char *z;
549:
550: if( pExpr==0 ) return;
551: assert( !ExprHasAnyProperty(pExpr, EP_IntValue|EP_Reduced|EP_TokenOnly) );
552: z = pExpr->u.zToken;
553: assert( z!=0 );
554: assert( z[0]!=0 );
555: if( z[1]==0 ){
556: /* Wildcard of the form "?". Assign the next variable number */
557: assert( z[0]=='?' );
558: pExpr->iColumn = (ynVar)(++pParse->nVar);
559: }else{
560: ynVar x = 0;
561: u32 n = sqlite3Strlen30(z);
562: if( z[0]=='?' ){
563: /* Wildcard of the form "?nnn". Convert "nnn" to an integer and
564: ** use it as the variable number */
565: i64 i;
566: int bOk = 0==sqlite3Atoi64(&z[1], &i, n-1, SQLITE_UTF8);
567: pExpr->iColumn = x = (ynVar)i;
568: testcase( i==0 );
569: testcase( i==1 );
570: testcase( i==db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]-1 );
571: testcase( i==db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] );
572: if( bOk==0 || i<1 || i>db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ){
573: sqlite3ErrorMsg(pParse, "variable number must be between ?1 and ?%d",
574: db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]);
575: x = 0;
576: }
577: if( i>pParse->nVar ){
578: pParse->nVar = (int)i;
579: }
580: }else{
581: /* Wildcards like ":aaa", "$aaa" or "@aaa". Reuse the same variable
582: ** number as the prior appearance of the same name, or if the name
583: ** has never appeared before, reuse the same variable number
584: */
585: ynVar i;
586: for(i=0; i<pParse->nzVar; i++){
587: if( pParse->azVar[i] && memcmp(pParse->azVar[i],z,n+1)==0 ){
588: pExpr->iColumn = x = (ynVar)i+1;
589: break;
590: }
591: }
592: if( x==0 ) x = pExpr->iColumn = (ynVar)(++pParse->nVar);
593: }
594: if( x>0 ){
595: if( x>pParse->nzVar ){
596: char **a;
597: a = sqlite3DbRealloc(db, pParse->azVar, x*sizeof(a[0]));
598: if( a==0 ) return; /* Error reported through db->mallocFailed */
599: pParse->azVar = a;
600: memset(&a[pParse->nzVar], 0, (x-pParse->nzVar)*sizeof(a[0]));
601: pParse->nzVar = x;
602: }
603: if( z[0]!='?' || pParse->azVar[x-1]==0 ){
604: sqlite3DbFree(db, pParse->azVar[x-1]);
605: pParse->azVar[x-1] = sqlite3DbStrNDup(db, z, n);
606: }
607: }
608: }
609: if( !pParse->nErr && pParse->nVar>db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ){
610: sqlite3ErrorMsg(pParse, "too many SQL variables");
611: }
612: }
613:
614: /*
615: ** Recursively delete an expression tree.
616: */
617: void sqlite3ExprDelete(sqlite3 *db, Expr *p){
618: if( p==0 ) return;
619: /* Sanity check: Assert that the IntValue is non-negative if it exists */
620: assert( !ExprHasProperty(p, EP_IntValue) || p->u.iValue>=0 );
621: if( !ExprHasAnyProperty(p, EP_TokenOnly) ){
622: sqlite3ExprDelete(db, p->pLeft);
623: sqlite3ExprDelete(db, p->pRight);
624: if( !ExprHasProperty(p, EP_Reduced) && (p->flags2 & EP2_MallocedToken)!=0 ){
625: sqlite3DbFree(db, p->u.zToken);
626: }
627: if( ExprHasProperty(p, EP_xIsSelect) ){
628: sqlite3SelectDelete(db, p->x.pSelect);
629: }else{
630: sqlite3ExprListDelete(db, p->x.pList);
631: }
632: }
633: if( !ExprHasProperty(p, EP_Static) ){
634: sqlite3DbFree(db, p);
635: }
636: }
637:
638: /*
639: ** Return the number of bytes allocated for the expression structure
640: ** passed as the first argument. This is always one of EXPR_FULLSIZE,
641: ** EXPR_REDUCEDSIZE or EXPR_TOKENONLYSIZE.
642: */
643: static int exprStructSize(Expr *p){
644: if( ExprHasProperty(p, EP_TokenOnly) ) return EXPR_TOKENONLYSIZE;
645: if( ExprHasProperty(p, EP_Reduced) ) return EXPR_REDUCEDSIZE;
646: return EXPR_FULLSIZE;
647: }
648:
649: /*
650: ** The dupedExpr*Size() routines each return the number of bytes required
651: ** to store a copy of an expression or expression tree. They differ in
652: ** how much of the tree is measured.
653: **
654: ** dupedExprStructSize() Size of only the Expr structure
655: ** dupedExprNodeSize() Size of Expr + space for token
656: ** dupedExprSize() Expr + token + subtree components
657: **
658: ***************************************************************************
659: **
660: ** The dupedExprStructSize() function returns two values OR-ed together:
661: ** (1) the space required for a copy of the Expr structure only and
662: ** (2) the EP_xxx flags that indicate what the structure size should be.
663: ** The return values is always one of:
664: **
665: ** EXPR_FULLSIZE
666: ** EXPR_REDUCEDSIZE | EP_Reduced
667: ** EXPR_TOKENONLYSIZE | EP_TokenOnly
668: **
669: ** The size of the structure can be found by masking the return value
670: ** of this routine with 0xfff. The flags can be found by masking the
671: ** return value with EP_Reduced|EP_TokenOnly.
672: **
673: ** Note that with flags==EXPRDUP_REDUCE, this routines works on full-size
674: ** (unreduced) Expr objects as they or originally constructed by the parser.
675: ** During expression analysis, extra information is computed and moved into
676: ** later parts of teh Expr object and that extra information might get chopped
677: ** off if the expression is reduced. Note also that it does not work to
678: ** make a EXPRDUP_REDUCE copy of a reduced expression. It is only legal
679: ** to reduce a pristine expression tree from the parser. The implementation
680: ** of dupedExprStructSize() contain multiple assert() statements that attempt
681: ** to enforce this constraint.
682: */
683: static int dupedExprStructSize(Expr *p, int flags){
684: int nSize;
685: assert( flags==EXPRDUP_REDUCE || flags==0 ); /* Only one flag value allowed */
686: if( 0==(flags&EXPRDUP_REDUCE) ){
687: nSize = EXPR_FULLSIZE;
688: }else{
689: assert( !ExprHasAnyProperty(p, EP_TokenOnly|EP_Reduced) );
690: assert( !ExprHasProperty(p, EP_FromJoin) );
691: assert( (p->flags2 & EP2_MallocedToken)==0 );
692: assert( (p->flags2 & EP2_Irreducible)==0 );
693: if( p->pLeft || p->pRight || p->pColl || p->x.pList ){
694: nSize = EXPR_REDUCEDSIZE | EP_Reduced;
695: }else{
696: nSize = EXPR_TOKENONLYSIZE | EP_TokenOnly;
697: }
698: }
699: return nSize;
700: }
701:
702: /*
703: ** This function returns the space in bytes required to store the copy
704: ** of the Expr structure and a copy of the Expr.u.zToken string (if that
705: ** string is defined.)
706: */
707: static int dupedExprNodeSize(Expr *p, int flags){
708: int nByte = dupedExprStructSize(p, flags) & 0xfff;
709: if( !ExprHasProperty(p, EP_IntValue) && p->u.zToken ){
710: nByte += sqlite3Strlen30(p->u.zToken)+1;
711: }
712: return ROUND8(nByte);
713: }
714:
715: /*
716: ** Return the number of bytes required to create a duplicate of the
717: ** expression passed as the first argument. The second argument is a
718: ** mask containing EXPRDUP_XXX flags.
719: **
720: ** The value returned includes space to create a copy of the Expr struct
721: ** itself and the buffer referred to by Expr.u.zToken, if any.
722: **
723: ** If the EXPRDUP_REDUCE flag is set, then the return value includes
724: ** space to duplicate all Expr nodes in the tree formed by Expr.pLeft
725: ** and Expr.pRight variables (but not for any structures pointed to or
726: ** descended from the Expr.x.pList or Expr.x.pSelect variables).
727: */
728: static int dupedExprSize(Expr *p, int flags){
729: int nByte = 0;
730: if( p ){
731: nByte = dupedExprNodeSize(p, flags);
732: if( flags&EXPRDUP_REDUCE ){
733: nByte += dupedExprSize(p->pLeft, flags) + dupedExprSize(p->pRight, flags);
734: }
735: }
736: return nByte;
737: }
738:
739: /*
740: ** This function is similar to sqlite3ExprDup(), except that if pzBuffer
741: ** is not NULL then *pzBuffer is assumed to point to a buffer large enough
742: ** to store the copy of expression p, the copies of p->u.zToken
743: ** (if applicable), and the copies of the p->pLeft and p->pRight expressions,
744: ** if any. Before returning, *pzBuffer is set to the first byte passed the
745: ** portion of the buffer copied into by this function.
746: */
747: static Expr *exprDup(sqlite3 *db, Expr *p, int flags, u8 **pzBuffer){
748: Expr *pNew = 0; /* Value to return */
749: if( p ){
750: const int isReduced = (flags&EXPRDUP_REDUCE);
751: u8 *zAlloc;
752: u32 staticFlag = 0;
753:
754: assert( pzBuffer==0 || isReduced );
755:
756: /* Figure out where to write the new Expr structure. */
757: if( pzBuffer ){
758: zAlloc = *pzBuffer;
759: staticFlag = EP_Static;
760: }else{
761: zAlloc = sqlite3DbMallocRaw(db, dupedExprSize(p, flags));
762: }
763: pNew = (Expr *)zAlloc;
764:
765: if( pNew ){
766: /* Set nNewSize to the size allocated for the structure pointed to
767: ** by pNew. This is either EXPR_FULLSIZE, EXPR_REDUCEDSIZE or
768: ** EXPR_TOKENONLYSIZE. nToken is set to the number of bytes consumed
769: ** by the copy of the p->u.zToken string (if any).
770: */
771: const unsigned nStructSize = dupedExprStructSize(p, flags);
772: const int nNewSize = nStructSize & 0xfff;
773: int nToken;
774: if( !ExprHasProperty(p, EP_IntValue) && p->u.zToken ){
775: nToken = sqlite3Strlen30(p->u.zToken) + 1;
776: }else{
777: nToken = 0;
778: }
779: if( isReduced ){
780: assert( ExprHasProperty(p, EP_Reduced)==0 );
781: memcpy(zAlloc, p, nNewSize);
782: }else{
783: int nSize = exprStructSize(p);
784: memcpy(zAlloc, p, nSize);
785: memset(&zAlloc[nSize], 0, EXPR_FULLSIZE-nSize);
786: }
787:
788: /* Set the EP_Reduced, EP_TokenOnly, and EP_Static flags appropriately. */
789: pNew->flags &= ~(EP_Reduced|EP_TokenOnly|EP_Static);
790: pNew->flags |= nStructSize & (EP_Reduced|EP_TokenOnly);
791: pNew->flags |= staticFlag;
792:
793: /* Copy the p->u.zToken string, if any. */
794: if( nToken ){
795: char *zToken = pNew->u.zToken = (char*)&zAlloc[nNewSize];
796: memcpy(zToken, p->u.zToken, nToken);
797: }
798:
799: if( 0==((p->flags|pNew->flags) & EP_TokenOnly) ){
800: /* Fill in the pNew->x.pSelect or pNew->x.pList member. */
801: if( ExprHasProperty(p, EP_xIsSelect) ){
802: pNew->x.pSelect = sqlite3SelectDup(db, p->x.pSelect, isReduced);
803: }else{
804: pNew->x.pList = sqlite3ExprListDup(db, p->x.pList, isReduced);
805: }
806: }
807:
808: /* Fill in pNew->pLeft and pNew->pRight. */
809: if( ExprHasAnyProperty(pNew, EP_Reduced|EP_TokenOnly) ){
810: zAlloc += dupedExprNodeSize(p, flags);
811: if( ExprHasProperty(pNew, EP_Reduced) ){
812: pNew->pLeft = exprDup(db, p->pLeft, EXPRDUP_REDUCE, &zAlloc);
813: pNew->pRight = exprDup(db, p->pRight, EXPRDUP_REDUCE, &zAlloc);
814: }
815: if( pzBuffer ){
816: *pzBuffer = zAlloc;
817: }
818: }else{
819: pNew->flags2 = 0;
820: if( !ExprHasAnyProperty(p, EP_TokenOnly) ){
821: pNew->pLeft = sqlite3ExprDup(db, p->pLeft, 0);
822: pNew->pRight = sqlite3ExprDup(db, p->pRight, 0);
823: }
824: }
825:
826: }
827: }
828: return pNew;
829: }
830:
831: /*
832: ** The following group of routines make deep copies of expressions,
833: ** expression lists, ID lists, and select statements. The copies can
834: ** be deleted (by being passed to their respective ...Delete() routines)
835: ** without effecting the originals.
836: **
837: ** The expression list, ID, and source lists return by sqlite3ExprListDup(),
838: ** sqlite3IdListDup(), and sqlite3SrcListDup() can not be further expanded
839: ** by subsequent calls to sqlite*ListAppend() routines.
840: **
841: ** Any tables that the SrcList might point to are not duplicated.
842: **
843: ** The flags parameter contains a combination of the EXPRDUP_XXX flags.
844: ** If the EXPRDUP_REDUCE flag is set, then the structure returned is a
845: ** truncated version of the usual Expr structure that will be stored as
846: ** part of the in-memory representation of the database schema.
847: */
848: Expr *sqlite3ExprDup(sqlite3 *db, Expr *p, int flags){
849: return exprDup(db, p, flags, 0);
850: }
851: ExprList *sqlite3ExprListDup(sqlite3 *db, ExprList *p, int flags){
852: ExprList *pNew;
853: struct ExprList_item *pItem, *pOldItem;
854: int i;
855: if( p==0 ) return 0;
856: pNew = sqlite3DbMallocRaw(db, sizeof(*pNew) );
857: if( pNew==0 ) return 0;
858: pNew->iECursor = 0;
859: pNew->nExpr = pNew->nAlloc = p->nExpr;
860: pNew->a = pItem = sqlite3DbMallocRaw(db, p->nExpr*sizeof(p->a[0]) );
861: if( pItem==0 ){
862: sqlite3DbFree(db, pNew);
863: return 0;
864: }
865: pOldItem = p->a;
866: for(i=0; i<p->nExpr; i++, pItem++, pOldItem++){
867: Expr *pOldExpr = pOldItem->pExpr;
868: pItem->pExpr = sqlite3ExprDup(db, pOldExpr, flags);
869: pItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
870: pItem->zSpan = sqlite3DbStrDup(db, pOldItem->zSpan);
871: pItem->sortOrder = pOldItem->sortOrder;
872: pItem->done = 0;
873: pItem->iOrderByCol = pOldItem->iOrderByCol;
874: pItem->iAlias = pOldItem->iAlias;
875: }
876: return pNew;
877: }
878:
879: /*
880: ** If cursors, triggers, views and subqueries are all omitted from
881: ** the build, then none of the following routines, except for
882: ** sqlite3SelectDup(), can be called. sqlite3SelectDup() is sometimes
883: ** called with a NULL argument.
884: */
885: #if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_TRIGGER) \
886: || !defined(SQLITE_OMIT_SUBQUERY)
887: SrcList *sqlite3SrcListDup(sqlite3 *db, SrcList *p, int flags){
888: SrcList *pNew;
889: int i;
890: int nByte;
891: if( p==0 ) return 0;
892: nByte = sizeof(*p) + (p->nSrc>0 ? sizeof(p->a[0]) * (p->nSrc-1) : 0);
893: pNew = sqlite3DbMallocRaw(db, nByte );
894: if( pNew==0 ) return 0;
895: pNew->nSrc = pNew->nAlloc = p->nSrc;
896: for(i=0; i<p->nSrc; i++){
897: struct SrcList_item *pNewItem = &pNew->a[i];
898: struct SrcList_item *pOldItem = &p->a[i];
899: Table *pTab;
900: pNewItem->zDatabase = sqlite3DbStrDup(db, pOldItem->zDatabase);
901: pNewItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
902: pNewItem->zAlias = sqlite3DbStrDup(db, pOldItem->zAlias);
903: pNewItem->jointype = pOldItem->jointype;
904: pNewItem->iCursor = pOldItem->iCursor;
905: pNewItem->addrFillSub = pOldItem->addrFillSub;
906: pNewItem->regReturn = pOldItem->regReturn;
907: pNewItem->isCorrelated = pOldItem->isCorrelated;
908: pNewItem->zIndex = sqlite3DbStrDup(db, pOldItem->zIndex);
909: pNewItem->notIndexed = pOldItem->notIndexed;
910: pNewItem->pIndex = pOldItem->pIndex;
911: pTab = pNewItem->pTab = pOldItem->pTab;
912: if( pTab ){
913: pTab->nRef++;
914: }
915: pNewItem->pSelect = sqlite3SelectDup(db, pOldItem->pSelect, flags);
916: pNewItem->pOn = sqlite3ExprDup(db, pOldItem->pOn, flags);
917: pNewItem->pUsing = sqlite3IdListDup(db, pOldItem->pUsing);
918: pNewItem->colUsed = pOldItem->colUsed;
919: }
920: return pNew;
921: }
922: IdList *sqlite3IdListDup(sqlite3 *db, IdList *p){
923: IdList *pNew;
924: int i;
925: if( p==0 ) return 0;
926: pNew = sqlite3DbMallocRaw(db, sizeof(*pNew) );
927: if( pNew==0 ) return 0;
928: pNew->nId = pNew->nAlloc = p->nId;
929: pNew->a = sqlite3DbMallocRaw(db, p->nId*sizeof(p->a[0]) );
930: if( pNew->a==0 ){
931: sqlite3DbFree(db, pNew);
932: return 0;
933: }
934: for(i=0; i<p->nId; i++){
935: struct IdList_item *pNewItem = &pNew->a[i];
936: struct IdList_item *pOldItem = &p->a[i];
937: pNewItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
938: pNewItem->idx = pOldItem->idx;
939: }
940: return pNew;
941: }
942: Select *sqlite3SelectDup(sqlite3 *db, Select *p, int flags){
943: Select *pNew, *pPrior;
944: if( p==0 ) return 0;
945: pNew = sqlite3DbMallocRaw(db, sizeof(*p) );
946: if( pNew==0 ) return 0;
947: pNew->pEList = sqlite3ExprListDup(db, p->pEList, flags);
948: pNew->pSrc = sqlite3SrcListDup(db, p->pSrc, flags);
949: pNew->pWhere = sqlite3ExprDup(db, p->pWhere, flags);
950: pNew->pGroupBy = sqlite3ExprListDup(db, p->pGroupBy, flags);
951: pNew->pHaving = sqlite3ExprDup(db, p->pHaving, flags);
952: pNew->pOrderBy = sqlite3ExprListDup(db, p->pOrderBy, flags);
953: pNew->op = p->op;
954: pNew->pPrior = pPrior = sqlite3SelectDup(db, p->pPrior, flags);
955: if( pPrior ) pPrior->pNext = pNew;
956: pNew->pNext = 0;
957: pNew->pLimit = sqlite3ExprDup(db, p->pLimit, flags);
958: pNew->pOffset = sqlite3ExprDup(db, p->pOffset, flags);
959: pNew->iLimit = 0;
960: pNew->iOffset = 0;
961: pNew->selFlags = p->selFlags & ~SF_UsesEphemeral;
962: pNew->pRightmost = 0;
963: pNew->addrOpenEphm[0] = -1;
964: pNew->addrOpenEphm[1] = -1;
965: pNew->addrOpenEphm[2] = -1;
966: return pNew;
967: }
968: #else
969: Select *sqlite3SelectDup(sqlite3 *db, Select *p, int flags){
970: assert( p==0 );
971: return 0;
972: }
973: #endif
974:
975:
976: /*
977: ** Add a new element to the end of an expression list. If pList is
978: ** initially NULL, then create a new expression list.
979: **
980: ** If a memory allocation error occurs, the entire list is freed and
981: ** NULL is returned. If non-NULL is returned, then it is guaranteed
982: ** that the new entry was successfully appended.
983: */
984: ExprList *sqlite3ExprListAppend(
985: Parse *pParse, /* Parsing context */
986: ExprList *pList, /* List to which to append. Might be NULL */
987: Expr *pExpr /* Expression to be appended. Might be NULL */
988: ){
989: sqlite3 *db = pParse->db;
990: if( pList==0 ){
991: pList = sqlite3DbMallocZero(db, sizeof(ExprList) );
992: if( pList==0 ){
993: goto no_mem;
994: }
995: assert( pList->nAlloc==0 );
996: }
997: if( pList->nAlloc<=pList->nExpr ){
998: struct ExprList_item *a;
999: int n = pList->nAlloc*2 + 4;
1000: a = sqlite3DbRealloc(db, pList->a, n*sizeof(pList->a[0]));
1001: if( a==0 ){
1002: goto no_mem;
1003: }
1004: pList->a = a;
1005: pList->nAlloc = sqlite3DbMallocSize(db, a)/sizeof(a[0]);
1006: }
1007: assert( pList->a!=0 );
1008: if( 1 ){
1009: struct ExprList_item *pItem = &pList->a[pList->nExpr++];
1010: memset(pItem, 0, sizeof(*pItem));
1011: pItem->pExpr = pExpr;
1012: }
1013: return pList;
1014:
1015: no_mem:
1016: /* Avoid leaking memory if malloc has failed. */
1017: sqlite3ExprDelete(db, pExpr);
1018: sqlite3ExprListDelete(db, pList);
1019: return 0;
1020: }
1021:
1022: /*
1023: ** Set the ExprList.a[].zName element of the most recently added item
1024: ** on the expression list.
1025: **
1026: ** pList might be NULL following an OOM error. But pName should never be
1027: ** NULL. If a memory allocation fails, the pParse->db->mallocFailed flag
1028: ** is set.
1029: */
1030: void sqlite3ExprListSetName(
1031: Parse *pParse, /* Parsing context */
1032: ExprList *pList, /* List to which to add the span. */
1033: Token *pName, /* Name to be added */
1034: int dequote /* True to cause the name to be dequoted */
1035: ){
1036: assert( pList!=0 || pParse->db->mallocFailed!=0 );
1037: if( pList ){
1038: struct ExprList_item *pItem;
1039: assert( pList->nExpr>0 );
1040: pItem = &pList->a[pList->nExpr-1];
1041: assert( pItem->zName==0 );
1042: pItem->zName = sqlite3DbStrNDup(pParse->db, pName->z, pName->n);
1043: if( dequote && pItem->zName ) sqlite3Dequote(pItem->zName);
1044: }
1045: }
1046:
1047: /*
1048: ** Set the ExprList.a[].zSpan element of the most recently added item
1049: ** on the expression list.
1050: **
1051: ** pList might be NULL following an OOM error. But pSpan should never be
1052: ** NULL. If a memory allocation fails, the pParse->db->mallocFailed flag
1053: ** is set.
1054: */
1055: void sqlite3ExprListSetSpan(
1056: Parse *pParse, /* Parsing context */
1057: ExprList *pList, /* List to which to add the span. */
1058: ExprSpan *pSpan /* The span to be added */
1059: ){
1060: sqlite3 *db = pParse->db;
1061: assert( pList!=0 || db->mallocFailed!=0 );
1062: if( pList ){
1063: struct ExprList_item *pItem = &pList->a[pList->nExpr-1];
1064: assert( pList->nExpr>0 );
1065: assert( db->mallocFailed || pItem->pExpr==pSpan->pExpr );
1066: sqlite3DbFree(db, pItem->zSpan);
1067: pItem->zSpan = sqlite3DbStrNDup(db, (char*)pSpan->zStart,
1068: (int)(pSpan->zEnd - pSpan->zStart));
1069: }
1070: }
1071:
1072: /*
1073: ** If the expression list pEList contains more than iLimit elements,
1074: ** leave an error message in pParse.
1075: */
1076: void sqlite3ExprListCheckLength(
1077: Parse *pParse,
1078: ExprList *pEList,
1079: const char *zObject
1080: ){
1081: int mx = pParse->db->aLimit[SQLITE_LIMIT_COLUMN];
1082: testcase( pEList && pEList->nExpr==mx );
1083: testcase( pEList && pEList->nExpr==mx+1 );
1084: if( pEList && pEList->nExpr>mx ){
1085: sqlite3ErrorMsg(pParse, "too many columns in %s", zObject);
1086: }
1087: }
1088:
1089: /*
1090: ** Delete an entire expression list.
1091: */
1092: void sqlite3ExprListDelete(sqlite3 *db, ExprList *pList){
1093: int i;
1094: struct ExprList_item *pItem;
1095: if( pList==0 ) return;
1096: assert( pList->a!=0 || (pList->nExpr==0 && pList->nAlloc==0) );
1097: assert( pList->nExpr<=pList->nAlloc );
1098: for(pItem=pList->a, i=0; i<pList->nExpr; i++, pItem++){
1099: sqlite3ExprDelete(db, pItem->pExpr);
1100: sqlite3DbFree(db, pItem->zName);
1101: sqlite3DbFree(db, pItem->zSpan);
1102: }
1103: sqlite3DbFree(db, pList->a);
1104: sqlite3DbFree(db, pList);
1105: }
1106:
1107: /*
1108: ** These routines are Walker callbacks. Walker.u.pi is a pointer
1109: ** to an integer. These routines are checking an expression to see
1110: ** if it is a constant. Set *Walker.u.pi to 0 if the expression is
1111: ** not constant.
1112: **
1113: ** These callback routines are used to implement the following:
1114: **
1115: ** sqlite3ExprIsConstant()
1116: ** sqlite3ExprIsConstantNotJoin()
1117: ** sqlite3ExprIsConstantOrFunction()
1118: **
1119: */
1120: static int exprNodeIsConstant(Walker *pWalker, Expr *pExpr){
1121:
1122: /* If pWalker->u.i is 3 then any term of the expression that comes from
1123: ** the ON or USING clauses of a join disqualifies the expression
1124: ** from being considered constant. */
1125: if( pWalker->u.i==3 && ExprHasAnyProperty(pExpr, EP_FromJoin) ){
1126: pWalker->u.i = 0;
1127: return WRC_Abort;
1128: }
1129:
1130: switch( pExpr->op ){
1131: /* Consider functions to be constant if all their arguments are constant
1132: ** and pWalker->u.i==2 */
1133: case TK_FUNCTION:
1134: if( pWalker->u.i==2 ) return 0;
1135: /* Fall through */
1136: case TK_ID:
1137: case TK_COLUMN:
1138: case TK_AGG_FUNCTION:
1139: case TK_AGG_COLUMN:
1140: testcase( pExpr->op==TK_ID );
1141: testcase( pExpr->op==TK_COLUMN );
1142: testcase( pExpr->op==TK_AGG_FUNCTION );
1143: testcase( pExpr->op==TK_AGG_COLUMN );
1144: pWalker->u.i = 0;
1145: return WRC_Abort;
1146: default:
1147: testcase( pExpr->op==TK_SELECT ); /* selectNodeIsConstant will disallow */
1148: testcase( pExpr->op==TK_EXISTS ); /* selectNodeIsConstant will disallow */
1149: return WRC_Continue;
1150: }
1151: }
1152: static int selectNodeIsConstant(Walker *pWalker, Select *NotUsed){
1153: UNUSED_PARAMETER(NotUsed);
1154: pWalker->u.i = 0;
1155: return WRC_Abort;
1156: }
1157: static int exprIsConst(Expr *p, int initFlag){
1158: Walker w;
1159: w.u.i = initFlag;
1160: w.xExprCallback = exprNodeIsConstant;
1161: w.xSelectCallback = selectNodeIsConstant;
1162: sqlite3WalkExpr(&w, p);
1163: return w.u.i;
1164: }
1165:
1166: /*
1167: ** Walk an expression tree. Return 1 if the expression is constant
1168: ** and 0 if it involves variables or function calls.
1169: **
1170: ** For the purposes of this function, a double-quoted string (ex: "abc")
1171: ** is considered a variable but a single-quoted string (ex: 'abc') is
1172: ** a constant.
1173: */
1174: int sqlite3ExprIsConstant(Expr *p){
1175: return exprIsConst(p, 1);
1176: }
1177:
1178: /*
1179: ** Walk an expression tree. Return 1 if the expression is constant
1180: ** that does no originate from the ON or USING clauses of a join.
1181: ** Return 0 if it involves variables or function calls or terms from
1182: ** an ON or USING clause.
1183: */
1184: int sqlite3ExprIsConstantNotJoin(Expr *p){
1185: return exprIsConst(p, 3);
1186: }
1187:
1188: /*
1189: ** Walk an expression tree. Return 1 if the expression is constant
1190: ** or a function call with constant arguments. Return and 0 if there
1191: ** are any variables.
1192: **
1193: ** For the purposes of this function, a double-quoted string (ex: "abc")
1194: ** is considered a variable but a single-quoted string (ex: 'abc') is
1195: ** a constant.
1196: */
1197: int sqlite3ExprIsConstantOrFunction(Expr *p){
1198: return exprIsConst(p, 2);
1199: }
1200:
1201: /*
1202: ** If the expression p codes a constant integer that is small enough
1203: ** to fit in a 32-bit integer, return 1 and put the value of the integer
1204: ** in *pValue. If the expression is not an integer or if it is too big
1205: ** to fit in a signed 32-bit integer, return 0 and leave *pValue unchanged.
1206: */
1207: int sqlite3ExprIsInteger(Expr *p, int *pValue){
1208: int rc = 0;
1209:
1210: /* If an expression is an integer literal that fits in a signed 32-bit
1211: ** integer, then the EP_IntValue flag will have already been set */
1212: assert( p->op!=TK_INTEGER || (p->flags & EP_IntValue)!=0
1213: || sqlite3GetInt32(p->u.zToken, &rc)==0 );
1214:
1215: if( p->flags & EP_IntValue ){
1216: *pValue = p->u.iValue;
1217: return 1;
1218: }
1219: switch( p->op ){
1220: case TK_UPLUS: {
1221: rc = sqlite3ExprIsInteger(p->pLeft, pValue);
1222: break;
1223: }
1224: case TK_UMINUS: {
1225: int v;
1226: if( sqlite3ExprIsInteger(p->pLeft, &v) ){
1227: *pValue = -v;
1228: rc = 1;
1229: }
1230: break;
1231: }
1232: default: break;
1233: }
1234: return rc;
1235: }
1236:
1237: /*
1238: ** Return FALSE if there is no chance that the expression can be NULL.
1239: **
1240: ** If the expression might be NULL or if the expression is too complex
1241: ** to tell return TRUE.
1242: **
1243: ** This routine is used as an optimization, to skip OP_IsNull opcodes
1244: ** when we know that a value cannot be NULL. Hence, a false positive
1245: ** (returning TRUE when in fact the expression can never be NULL) might
1246: ** be a small performance hit but is otherwise harmless. On the other
1247: ** hand, a false negative (returning FALSE when the result could be NULL)
1248: ** will likely result in an incorrect answer. So when in doubt, return
1249: ** TRUE.
1250: */
1251: int sqlite3ExprCanBeNull(const Expr *p){
1252: u8 op;
1253: while( p->op==TK_UPLUS || p->op==TK_UMINUS ){ p = p->pLeft; }
1254: op = p->op;
1255: if( op==TK_REGISTER ) op = p->op2;
1256: switch( op ){
1257: case TK_INTEGER:
1258: case TK_STRING:
1259: case TK_FLOAT:
1260: case TK_BLOB:
1261: return 0;
1262: default:
1263: return 1;
1264: }
1265: }
1266:
1267: /*
1268: ** Generate an OP_IsNull instruction that tests register iReg and jumps
1269: ** to location iDest if the value in iReg is NULL. The value in iReg
1270: ** was computed by pExpr. If we can look at pExpr at compile-time and
1271: ** determine that it can never generate a NULL, then the OP_IsNull operation
1272: ** can be omitted.
1273: */
1274: void sqlite3ExprCodeIsNullJump(
1275: Vdbe *v, /* The VDBE under construction */
1276: const Expr *pExpr, /* Only generate OP_IsNull if this expr can be NULL */
1277: int iReg, /* Test the value in this register for NULL */
1278: int iDest /* Jump here if the value is null */
1279: ){
1280: if( sqlite3ExprCanBeNull(pExpr) ){
1281: sqlite3VdbeAddOp2(v, OP_IsNull, iReg, iDest);
1282: }
1283: }
1284:
1285: /*
1286: ** Return TRUE if the given expression is a constant which would be
1287: ** unchanged by OP_Affinity with the affinity given in the second
1288: ** argument.
1289: **
1290: ** This routine is used to determine if the OP_Affinity operation
1291: ** can be omitted. When in doubt return FALSE. A false negative
1292: ** is harmless. A false positive, however, can result in the wrong
1293: ** answer.
1294: */
1295: int sqlite3ExprNeedsNoAffinityChange(const Expr *p, char aff){
1296: u8 op;
1297: if( aff==SQLITE_AFF_NONE ) return 1;
1298: while( p->op==TK_UPLUS || p->op==TK_UMINUS ){ p = p->pLeft; }
1299: op = p->op;
1300: if( op==TK_REGISTER ) op = p->op2;
1301: switch( op ){
1302: case TK_INTEGER: {
1303: return aff==SQLITE_AFF_INTEGER || aff==SQLITE_AFF_NUMERIC;
1304: }
1305: case TK_FLOAT: {
1306: return aff==SQLITE_AFF_REAL || aff==SQLITE_AFF_NUMERIC;
1307: }
1308: case TK_STRING: {
1309: return aff==SQLITE_AFF_TEXT;
1310: }
1311: case TK_BLOB: {
1312: return 1;
1313: }
1314: case TK_COLUMN: {
1315: assert( p->iTable>=0 ); /* p cannot be part of a CHECK constraint */
1316: return p->iColumn<0
1317: && (aff==SQLITE_AFF_INTEGER || aff==SQLITE_AFF_NUMERIC);
1318: }
1319: default: {
1320: return 0;
1321: }
1322: }
1323: }
1324:
1325: /*
1326: ** Return TRUE if the given string is a row-id column name.
1327: */
1328: int sqlite3IsRowid(const char *z){
1329: if( sqlite3StrICmp(z, "_ROWID_")==0 ) return 1;
1330: if( sqlite3StrICmp(z, "ROWID")==0 ) return 1;
1331: if( sqlite3StrICmp(z, "OID")==0 ) return 1;
1332: return 0;
1333: }
1334:
1335: /*
1336: ** Return true if we are able to the IN operator optimization on a
1337: ** query of the form
1338: **
1339: ** x IN (SELECT ...)
1340: **
1341: ** Where the SELECT... clause is as specified by the parameter to this
1342: ** routine.
1343: **
1344: ** The Select object passed in has already been preprocessed and no
1345: ** errors have been found.
1346: */
1347: #ifndef SQLITE_OMIT_SUBQUERY
1348: static int isCandidateForInOpt(Select *p){
1349: SrcList *pSrc;
1350: ExprList *pEList;
1351: Table *pTab;
1352: if( p==0 ) return 0; /* right-hand side of IN is SELECT */
1353: if( p->pPrior ) return 0; /* Not a compound SELECT */
1354: if( p->selFlags & (SF_Distinct|SF_Aggregate) ){
1355: testcase( (p->selFlags & (SF_Distinct|SF_Aggregate))==SF_Distinct );
1356: testcase( (p->selFlags & (SF_Distinct|SF_Aggregate))==SF_Aggregate );
1357: return 0; /* No DISTINCT keyword and no aggregate functions */
1358: }
1359: assert( p->pGroupBy==0 ); /* Has no GROUP BY clause */
1360: if( p->pLimit ) return 0; /* Has no LIMIT clause */
1361: assert( p->pOffset==0 ); /* No LIMIT means no OFFSET */
1362: if( p->pWhere ) return 0; /* Has no WHERE clause */
1363: pSrc = p->pSrc;
1364: assert( pSrc!=0 );
1365: if( pSrc->nSrc!=1 ) return 0; /* Single term in FROM clause */
1366: if( pSrc->a[0].pSelect ) return 0; /* FROM is not a subquery or view */
1367: pTab = pSrc->a[0].pTab;
1368: if( NEVER(pTab==0) ) return 0;
1369: assert( pTab->pSelect==0 ); /* FROM clause is not a view */
1370: if( IsVirtual(pTab) ) return 0; /* FROM clause not a virtual table */
1371: pEList = p->pEList;
1372: if( pEList->nExpr!=1 ) return 0; /* One column in the result set */
1373: if( pEList->a[0].pExpr->op!=TK_COLUMN ) return 0; /* Result is a column */
1374: return 1;
1375: }
1376: #endif /* SQLITE_OMIT_SUBQUERY */
1377:
1378: /*
1379: ** Code an OP_Once instruction and allocate space for its flag. Return the
1380: ** address of the new instruction.
1381: */
1382: int sqlite3CodeOnce(Parse *pParse){
1383: Vdbe *v = sqlite3GetVdbe(pParse); /* Virtual machine being coded */
1384: return sqlite3VdbeAddOp1(v, OP_Once, pParse->nOnce++);
1385: }
1386:
1387: /*
1388: ** This function is used by the implementation of the IN (...) operator.
1389: ** It's job is to find or create a b-tree structure that may be used
1390: ** either to test for membership of the (...) set or to iterate through
1391: ** its members, skipping duplicates.
1392: **
1393: ** The index of the cursor opened on the b-tree (database table, database index
1394: ** or ephermal table) is stored in pX->iTable before this function returns.
1395: ** The returned value of this function indicates the b-tree type, as follows:
1396: **
1397: ** IN_INDEX_ROWID - The cursor was opened on a database table.
1398: ** IN_INDEX_INDEX - The cursor was opened on a database index.
1399: ** IN_INDEX_EPH - The cursor was opened on a specially created and
1400: ** populated epheremal table.
1401: **
1402: ** An existing b-tree may only be used if the SELECT is of the simple
1403: ** form:
1404: **
1405: ** SELECT <column> FROM <table>
1406: **
1407: ** If the prNotFound parameter is 0, then the b-tree will be used to iterate
1408: ** through the set members, skipping any duplicates. In this case an
1409: ** epheremal table must be used unless the selected <column> is guaranteed
1410: ** to be unique - either because it is an INTEGER PRIMARY KEY or it
1411: ** has a UNIQUE constraint or UNIQUE index.
1412: **
1413: ** If the prNotFound parameter is not 0, then the b-tree will be used
1414: ** for fast set membership tests. In this case an epheremal table must
1415: ** be used unless <column> is an INTEGER PRIMARY KEY or an index can
1416: ** be found with <column> as its left-most column.
1417: **
1418: ** When the b-tree is being used for membership tests, the calling function
1419: ** needs to know whether or not the structure contains an SQL NULL
1420: ** value in order to correctly evaluate expressions like "X IN (Y, Z)".
1421: ** If there is any chance that the (...) might contain a NULL value at
1422: ** runtime, then a register is allocated and the register number written
1423: ** to *prNotFound. If there is no chance that the (...) contains a
1424: ** NULL value, then *prNotFound is left unchanged.
1425: **
1426: ** If a register is allocated and its location stored in *prNotFound, then
1427: ** its initial value is NULL. If the (...) does not remain constant
1428: ** for the duration of the query (i.e. the SELECT within the (...)
1429: ** is a correlated subquery) then the value of the allocated register is
1430: ** reset to NULL each time the subquery is rerun. This allows the
1431: ** caller to use vdbe code equivalent to the following:
1432: **
1433: ** if( register==NULL ){
1434: ** has_null = <test if data structure contains null>
1435: ** register = 1
1436: ** }
1437: **
1438: ** in order to avoid running the <test if data structure contains null>
1439: ** test more often than is necessary.
1440: */
1441: #ifndef SQLITE_OMIT_SUBQUERY
1442: int sqlite3FindInIndex(Parse *pParse, Expr *pX, int *prNotFound){
1443: Select *p; /* SELECT to the right of IN operator */
1444: int eType = 0; /* Type of RHS table. IN_INDEX_* */
1445: int iTab = pParse->nTab++; /* Cursor of the RHS table */
1446: int mustBeUnique = (prNotFound==0); /* True if RHS must be unique */
1447: Vdbe *v = sqlite3GetVdbe(pParse); /* Virtual machine being coded */
1448:
1449: assert( pX->op==TK_IN );
1450:
1451: /* Check to see if an existing table or index can be used to
1452: ** satisfy the query. This is preferable to generating a new
1453: ** ephemeral table.
1454: */
1455: p = (ExprHasProperty(pX, EP_xIsSelect) ? pX->x.pSelect : 0);
1456: if( ALWAYS(pParse->nErr==0) && isCandidateForInOpt(p) ){
1457: sqlite3 *db = pParse->db; /* Database connection */
1458: Table *pTab; /* Table <table>. */
1459: Expr *pExpr; /* Expression <column> */
1460: int iCol; /* Index of column <column> */
1461: int iDb; /* Database idx for pTab */
1462:
1463: assert( p ); /* Because of isCandidateForInOpt(p) */
1464: assert( p->pEList!=0 ); /* Because of isCandidateForInOpt(p) */
1465: assert( p->pEList->a[0].pExpr!=0 ); /* Because of isCandidateForInOpt(p) */
1466: assert( p->pSrc!=0 ); /* Because of isCandidateForInOpt(p) */
1467: pTab = p->pSrc->a[0].pTab;
1468: pExpr = p->pEList->a[0].pExpr;
1469: iCol = pExpr->iColumn;
1470:
1471: /* Code an OP_VerifyCookie and OP_TableLock for <table>. */
1472: iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
1473: sqlite3CodeVerifySchema(pParse, iDb);
1474: sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
1475:
1476: /* This function is only called from two places. In both cases the vdbe
1477: ** has already been allocated. So assume sqlite3GetVdbe() is always
1478: ** successful here.
1479: */
1480: assert(v);
1481: if( iCol<0 ){
1482: int iAddr;
1483:
1484: iAddr = sqlite3CodeOnce(pParse);
1485:
1486: sqlite3OpenTable(pParse, iTab, iDb, pTab, OP_OpenRead);
1487: eType = IN_INDEX_ROWID;
1488:
1489: sqlite3VdbeJumpHere(v, iAddr);
1490: }else{
1491: Index *pIdx; /* Iterator variable */
1492:
1493: /* The collation sequence used by the comparison. If an index is to
1494: ** be used in place of a temp-table, it must be ordered according
1495: ** to this collation sequence. */
1496: CollSeq *pReq = sqlite3BinaryCompareCollSeq(pParse, pX->pLeft, pExpr);
1497:
1498: /* Check that the affinity that will be used to perform the
1499: ** comparison is the same as the affinity of the column. If
1500: ** it is not, it is not possible to use any index.
1501: */
1502: char aff = comparisonAffinity(pX);
1503: int affinity_ok = (pTab->aCol[iCol].affinity==aff||aff==SQLITE_AFF_NONE);
1504:
1505: for(pIdx=pTab->pIndex; pIdx && eType==0 && affinity_ok; pIdx=pIdx->pNext){
1506: if( (pIdx->aiColumn[0]==iCol)
1507: && sqlite3FindCollSeq(db, ENC(db), pIdx->azColl[0], 0)==pReq
1508: && (!mustBeUnique || (pIdx->nColumn==1 && pIdx->onError!=OE_None))
1509: ){
1510: int iAddr;
1511: char *pKey;
1512:
1513: pKey = (char *)sqlite3IndexKeyinfo(pParse, pIdx);
1514: iAddr = sqlite3CodeOnce(pParse);
1515:
1516: sqlite3VdbeAddOp4(v, OP_OpenRead, iTab, pIdx->tnum, iDb,
1517: pKey,P4_KEYINFO_HANDOFF);
1518: VdbeComment((v, "%s", pIdx->zName));
1519: eType = IN_INDEX_INDEX;
1520:
1521: sqlite3VdbeJumpHere(v, iAddr);
1522: if( prNotFound && !pTab->aCol[iCol].notNull ){
1523: *prNotFound = ++pParse->nMem;
1524: sqlite3VdbeAddOp2(v, OP_Null, 0, *prNotFound);
1525: }
1526: }
1527: }
1528: }
1529: }
1530:
1531: if( eType==0 ){
1532: /* Could not found an existing table or index to use as the RHS b-tree.
1533: ** We will have to generate an ephemeral table to do the job.
1534: */
1535: double savedNQueryLoop = pParse->nQueryLoop;
1536: int rMayHaveNull = 0;
1537: eType = IN_INDEX_EPH;
1538: if( prNotFound ){
1539: *prNotFound = rMayHaveNull = ++pParse->nMem;
1540: sqlite3VdbeAddOp2(v, OP_Null, 0, *prNotFound);
1541: }else{
1542: testcase( pParse->nQueryLoop>(double)1 );
1543: pParse->nQueryLoop = (double)1;
1544: if( pX->pLeft->iColumn<0 && !ExprHasAnyProperty(pX, EP_xIsSelect) ){
1545: eType = IN_INDEX_ROWID;
1546: }
1547: }
1548: sqlite3CodeSubselect(pParse, pX, rMayHaveNull, eType==IN_INDEX_ROWID);
1549: pParse->nQueryLoop = savedNQueryLoop;
1550: }else{
1551: pX->iTable = iTab;
1552: }
1553: return eType;
1554: }
1555: #endif
1556:
1557: /*
1558: ** Generate code for scalar subqueries used as a subquery expression, EXISTS,
1559: ** or IN operators. Examples:
1560: **
1561: ** (SELECT a FROM b) -- subquery
1562: ** EXISTS (SELECT a FROM b) -- EXISTS subquery
1563: ** x IN (4,5,11) -- IN operator with list on right-hand side
1564: ** x IN (SELECT a FROM b) -- IN operator with subquery on the right
1565: **
1566: ** The pExpr parameter describes the expression that contains the IN
1567: ** operator or subquery.
1568: **
1569: ** If parameter isRowid is non-zero, then expression pExpr is guaranteed
1570: ** to be of the form "<rowid> IN (?, ?, ?)", where <rowid> is a reference
1571: ** to some integer key column of a table B-Tree. In this case, use an
1572: ** intkey B-Tree to store the set of IN(...) values instead of the usual
1573: ** (slower) variable length keys B-Tree.
1574: **
1575: ** If rMayHaveNull is non-zero, that means that the operation is an IN
1576: ** (not a SELECT or EXISTS) and that the RHS might contains NULLs.
1577: ** Furthermore, the IN is in a WHERE clause and that we really want
1578: ** to iterate over the RHS of the IN operator in order to quickly locate
1579: ** all corresponding LHS elements. All this routine does is initialize
1580: ** the register given by rMayHaveNull to NULL. Calling routines will take
1581: ** care of changing this register value to non-NULL if the RHS is NULL-free.
1582: **
1583: ** If rMayHaveNull is zero, that means that the subquery is being used
1584: ** for membership testing only. There is no need to initialize any
1585: ** registers to indicate the presense or absence of NULLs on the RHS.
1586: **
1587: ** For a SELECT or EXISTS operator, return the register that holds the
1588: ** result. For IN operators or if an error occurs, the return value is 0.
1589: */
1590: #ifndef SQLITE_OMIT_SUBQUERY
1591: int sqlite3CodeSubselect(
1592: Parse *pParse, /* Parsing context */
1593: Expr *pExpr, /* The IN, SELECT, or EXISTS operator */
1594: int rMayHaveNull, /* Register that records whether NULLs exist in RHS */
1595: int isRowid /* If true, LHS of IN operator is a rowid */
1596: ){
1597: int testAddr = -1; /* One-time test address */
1598: int rReg = 0; /* Register storing resulting */
1599: Vdbe *v = sqlite3GetVdbe(pParse);
1600: if( NEVER(v==0) ) return 0;
1601: sqlite3ExprCachePush(pParse);
1602:
1603: /* This code must be run in its entirety every time it is encountered
1604: ** if any of the following is true:
1605: **
1606: ** * The right-hand side is a correlated subquery
1607: ** * The right-hand side is an expression list containing variables
1608: ** * We are inside a trigger
1609: **
1610: ** If all of the above are false, then we can run this code just once
1611: ** save the results, and reuse the same result on subsequent invocations.
1612: */
1613: if( !ExprHasAnyProperty(pExpr, EP_VarSelect) ){
1614: testAddr = sqlite3CodeOnce(pParse);
1615: }
1616:
1617: #ifndef SQLITE_OMIT_EXPLAIN
1618: if( pParse->explain==2 ){
1619: char *zMsg = sqlite3MPrintf(
1620: pParse->db, "EXECUTE %s%s SUBQUERY %d", testAddr>=0?"":"CORRELATED ",
1621: pExpr->op==TK_IN?"LIST":"SCALAR", pParse->iNextSelectId
1622: );
1623: sqlite3VdbeAddOp4(v, OP_Explain, pParse->iSelectId, 0, 0, zMsg, P4_DYNAMIC);
1624: }
1625: #endif
1626:
1627: switch( pExpr->op ){
1628: case TK_IN: {
1629: char affinity; /* Affinity of the LHS of the IN */
1630: KeyInfo keyInfo; /* Keyinfo for the generated table */
1631: int addr; /* Address of OP_OpenEphemeral instruction */
1632: Expr *pLeft = pExpr->pLeft; /* the LHS of the IN operator */
1633:
1634: if( rMayHaveNull ){
1635: sqlite3VdbeAddOp2(v, OP_Null, 0, rMayHaveNull);
1636: }
1637:
1638: affinity = sqlite3ExprAffinity(pLeft);
1639:
1640: /* Whether this is an 'x IN(SELECT...)' or an 'x IN(<exprlist>)'
1641: ** expression it is handled the same way. An ephemeral table is
1642: ** filled with single-field index keys representing the results
1643: ** from the SELECT or the <exprlist>.
1644: **
1645: ** If the 'x' expression is a column value, or the SELECT...
1646: ** statement returns a column value, then the affinity of that
1647: ** column is used to build the index keys. If both 'x' and the
1648: ** SELECT... statement are columns, then numeric affinity is used
1649: ** if either column has NUMERIC or INTEGER affinity. If neither
1650: ** 'x' nor the SELECT... statement are columns, then numeric affinity
1651: ** is used.
1652: */
1653: pExpr->iTable = pParse->nTab++;
1654: addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pExpr->iTable, !isRowid);
1655: if( rMayHaveNull==0 ) sqlite3VdbeChangeP5(v, BTREE_UNORDERED);
1656: memset(&keyInfo, 0, sizeof(keyInfo));
1657: keyInfo.nField = 1;
1658:
1659: if( ExprHasProperty(pExpr, EP_xIsSelect) ){
1660: /* Case 1: expr IN (SELECT ...)
1661: **
1662: ** Generate code to write the results of the select into the temporary
1663: ** table allocated and opened above.
1664: */
1665: SelectDest dest;
1666: ExprList *pEList;
1667:
1668: assert( !isRowid );
1669: sqlite3SelectDestInit(&dest, SRT_Set, pExpr->iTable);
1670: dest.affinity = (u8)affinity;
1671: assert( (pExpr->iTable&0x0000FFFF)==pExpr->iTable );
1672: pExpr->x.pSelect->iLimit = 0;
1673: if( sqlite3Select(pParse, pExpr->x.pSelect, &dest) ){
1674: return 0;
1675: }
1676: pEList = pExpr->x.pSelect->pEList;
1677: if( ALWAYS(pEList!=0 && pEList->nExpr>0) ){
1678: keyInfo.aColl[0] = sqlite3BinaryCompareCollSeq(pParse, pExpr->pLeft,
1679: pEList->a[0].pExpr);
1680: }
1681: }else if( ALWAYS(pExpr->x.pList!=0) ){
1682: /* Case 2: expr IN (exprlist)
1683: **
1684: ** For each expression, build an index key from the evaluation and
1685: ** store it in the temporary table. If <expr> is a column, then use
1686: ** that columns affinity when building index keys. If <expr> is not
1687: ** a column, use numeric affinity.
1688: */
1689: int i;
1690: ExprList *pList = pExpr->x.pList;
1691: struct ExprList_item *pItem;
1692: int r1, r2, r3;
1693:
1694: if( !affinity ){
1695: affinity = SQLITE_AFF_NONE;
1696: }
1697: keyInfo.aColl[0] = sqlite3ExprCollSeq(pParse, pExpr->pLeft);
1698:
1699: /* Loop through each expression in <exprlist>. */
1700: r1 = sqlite3GetTempReg(pParse);
1701: r2 = sqlite3GetTempReg(pParse);
1702: sqlite3VdbeAddOp2(v, OP_Null, 0, r2);
1703: for(i=pList->nExpr, pItem=pList->a; i>0; i--, pItem++){
1704: Expr *pE2 = pItem->pExpr;
1705: int iValToIns;
1706:
1707: /* If the expression is not constant then we will need to
1708: ** disable the test that was generated above that makes sure
1709: ** this code only executes once. Because for a non-constant
1710: ** expression we need to rerun this code each time.
1711: */
1712: if( testAddr>=0 && !sqlite3ExprIsConstant(pE2) ){
1713: sqlite3VdbeChangeToNoop(v, testAddr);
1714: testAddr = -1;
1715: }
1716:
1717: /* Evaluate the expression and insert it into the temp table */
1718: if( isRowid && sqlite3ExprIsInteger(pE2, &iValToIns) ){
1719: sqlite3VdbeAddOp3(v, OP_InsertInt, pExpr->iTable, r2, iValToIns);
1720: }else{
1721: r3 = sqlite3ExprCodeTarget(pParse, pE2, r1);
1722: if( isRowid ){
1723: sqlite3VdbeAddOp2(v, OP_MustBeInt, r3,
1724: sqlite3VdbeCurrentAddr(v)+2);
1725: sqlite3VdbeAddOp3(v, OP_Insert, pExpr->iTable, r2, r3);
1726: }else{
1727: sqlite3VdbeAddOp4(v, OP_MakeRecord, r3, 1, r2, &affinity, 1);
1728: sqlite3ExprCacheAffinityChange(pParse, r3, 1);
1729: sqlite3VdbeAddOp2(v, OP_IdxInsert, pExpr->iTable, r2);
1730: }
1731: }
1732: }
1733: sqlite3ReleaseTempReg(pParse, r1);
1734: sqlite3ReleaseTempReg(pParse, r2);
1735: }
1736: if( !isRowid ){
1737: sqlite3VdbeChangeP4(v, addr, (void *)&keyInfo, P4_KEYINFO);
1738: }
1739: break;
1740: }
1741:
1742: case TK_EXISTS:
1743: case TK_SELECT:
1744: default: {
1745: /* If this has to be a scalar SELECT. Generate code to put the
1746: ** value of this select in a memory cell and record the number
1747: ** of the memory cell in iColumn. If this is an EXISTS, write
1748: ** an integer 0 (not exists) or 1 (exists) into a memory cell
1749: ** and record that memory cell in iColumn.
1750: */
1751: Select *pSel; /* SELECT statement to encode */
1752: SelectDest dest; /* How to deal with SELECt result */
1753:
1754: testcase( pExpr->op==TK_EXISTS );
1755: testcase( pExpr->op==TK_SELECT );
1756: assert( pExpr->op==TK_EXISTS || pExpr->op==TK_SELECT );
1757:
1758: assert( ExprHasProperty(pExpr, EP_xIsSelect) );
1759: pSel = pExpr->x.pSelect;
1760: sqlite3SelectDestInit(&dest, 0, ++pParse->nMem);
1761: if( pExpr->op==TK_SELECT ){
1762: dest.eDest = SRT_Mem;
1763: sqlite3VdbeAddOp2(v, OP_Null, 0, dest.iParm);
1764: VdbeComment((v, "Init subquery result"));
1765: }else{
1766: dest.eDest = SRT_Exists;
1767: sqlite3VdbeAddOp2(v, OP_Integer, 0, dest.iParm);
1768: VdbeComment((v, "Init EXISTS result"));
1769: }
1770: sqlite3ExprDelete(pParse->db, pSel->pLimit);
1771: pSel->pLimit = sqlite3PExpr(pParse, TK_INTEGER, 0, 0,
1772: &sqlite3IntTokens[1]);
1773: pSel->iLimit = 0;
1774: if( sqlite3Select(pParse, pSel, &dest) ){
1775: return 0;
1776: }
1777: rReg = dest.iParm;
1778: ExprSetIrreducible(pExpr);
1779: break;
1780: }
1781: }
1782:
1783: if( testAddr>=0 ){
1784: sqlite3VdbeJumpHere(v, testAddr);
1785: }
1786: sqlite3ExprCachePop(pParse, 1);
1787:
1788: return rReg;
1789: }
1790: #endif /* SQLITE_OMIT_SUBQUERY */
1791:
1792: #ifndef SQLITE_OMIT_SUBQUERY
1793: /*
1794: ** Generate code for an IN expression.
1795: **
1796: ** x IN (SELECT ...)
1797: ** x IN (value, value, ...)
1798: **
1799: ** The left-hand side (LHS) is a scalar expression. The right-hand side (RHS)
1800: ** is an array of zero or more values. The expression is true if the LHS is
1801: ** contained within the RHS. The value of the expression is unknown (NULL)
1802: ** if the LHS is NULL or if the LHS is not contained within the RHS and the
1803: ** RHS contains one or more NULL values.
1804: **
1805: ** This routine generates code will jump to destIfFalse if the LHS is not
1806: ** contained within the RHS. If due to NULLs we cannot determine if the LHS
1807: ** is contained in the RHS then jump to destIfNull. If the LHS is contained
1808: ** within the RHS then fall through.
1809: */
1810: static void sqlite3ExprCodeIN(
1811: Parse *pParse, /* Parsing and code generating context */
1812: Expr *pExpr, /* The IN expression */
1813: int destIfFalse, /* Jump here if LHS is not contained in the RHS */
1814: int destIfNull /* Jump here if the results are unknown due to NULLs */
1815: ){
1816: int rRhsHasNull = 0; /* Register that is true if RHS contains NULL values */
1817: char affinity; /* Comparison affinity to use */
1818: int eType; /* Type of the RHS */
1819: int r1; /* Temporary use register */
1820: Vdbe *v; /* Statement under construction */
1821:
1822: /* Compute the RHS. After this step, the table with cursor
1823: ** pExpr->iTable will contains the values that make up the RHS.
1824: */
1825: v = pParse->pVdbe;
1826: assert( v!=0 ); /* OOM detected prior to this routine */
1827: VdbeNoopComment((v, "begin IN expr"));
1828: eType = sqlite3FindInIndex(pParse, pExpr, &rRhsHasNull);
1829:
1830: /* Figure out the affinity to use to create a key from the results
1831: ** of the expression. affinityStr stores a static string suitable for
1832: ** P4 of OP_MakeRecord.
1833: */
1834: affinity = comparisonAffinity(pExpr);
1835:
1836: /* Code the LHS, the <expr> from "<expr> IN (...)".
1837: */
1838: sqlite3ExprCachePush(pParse);
1839: r1 = sqlite3GetTempReg(pParse);
1840: sqlite3ExprCode(pParse, pExpr->pLeft, r1);
1841:
1842: /* If the LHS is NULL, then the result is either false or NULL depending
1843: ** on whether the RHS is empty or not, respectively.
1844: */
1845: if( destIfNull==destIfFalse ){
1846: /* Shortcut for the common case where the false and NULL outcomes are
1847: ** the same. */
1848: sqlite3VdbeAddOp2(v, OP_IsNull, r1, destIfNull);
1849: }else{
1850: int addr1 = sqlite3VdbeAddOp1(v, OP_NotNull, r1);
1851: sqlite3VdbeAddOp2(v, OP_Rewind, pExpr->iTable, destIfFalse);
1852: sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfNull);
1853: sqlite3VdbeJumpHere(v, addr1);
1854: }
1855:
1856: if( eType==IN_INDEX_ROWID ){
1857: /* In this case, the RHS is the ROWID of table b-tree
1858: */
1859: sqlite3VdbeAddOp2(v, OP_MustBeInt, r1, destIfFalse);
1860: sqlite3VdbeAddOp3(v, OP_NotExists, pExpr->iTable, destIfFalse, r1);
1861: }else{
1862: /* In this case, the RHS is an index b-tree.
1863: */
1864: sqlite3VdbeAddOp4(v, OP_Affinity, r1, 1, 0, &affinity, 1);
1865:
1866: /* If the set membership test fails, then the result of the
1867: ** "x IN (...)" expression must be either 0 or NULL. If the set
1868: ** contains no NULL values, then the result is 0. If the set
1869: ** contains one or more NULL values, then the result of the
1870: ** expression is also NULL.
1871: */
1872: if( rRhsHasNull==0 || destIfFalse==destIfNull ){
1873: /* This branch runs if it is known at compile time that the RHS
1874: ** cannot contain NULL values. This happens as the result
1875: ** of a "NOT NULL" constraint in the database schema.
1876: **
1877: ** Also run this branch if NULL is equivalent to FALSE
1878: ** for this particular IN operator.
1879: */
1880: sqlite3VdbeAddOp4Int(v, OP_NotFound, pExpr->iTable, destIfFalse, r1, 1);
1881:
1882: }else{
1883: /* In this branch, the RHS of the IN might contain a NULL and
1884: ** the presence of a NULL on the RHS makes a difference in the
1885: ** outcome.
1886: */
1887: int j1, j2, j3;
1888:
1889: /* First check to see if the LHS is contained in the RHS. If so,
1890: ** then the presence of NULLs in the RHS does not matter, so jump
1891: ** over all of the code that follows.
1892: */
1893: j1 = sqlite3VdbeAddOp4Int(v, OP_Found, pExpr->iTable, 0, r1, 1);
1894:
1895: /* Here we begin generating code that runs if the LHS is not
1896: ** contained within the RHS. Generate additional code that
1897: ** tests the RHS for NULLs. If the RHS contains a NULL then
1898: ** jump to destIfNull. If there are no NULLs in the RHS then
1899: ** jump to destIfFalse.
1900: */
1901: j2 = sqlite3VdbeAddOp1(v, OP_NotNull, rRhsHasNull);
1902: j3 = sqlite3VdbeAddOp4Int(v, OP_Found, pExpr->iTable, 0, rRhsHasNull, 1);
1903: sqlite3VdbeAddOp2(v, OP_Integer, -1, rRhsHasNull);
1904: sqlite3VdbeJumpHere(v, j3);
1905: sqlite3VdbeAddOp2(v, OP_AddImm, rRhsHasNull, 1);
1906: sqlite3VdbeJumpHere(v, j2);
1907:
1908: /* Jump to the appropriate target depending on whether or not
1909: ** the RHS contains a NULL
1910: */
1911: sqlite3VdbeAddOp2(v, OP_If, rRhsHasNull, destIfNull);
1912: sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfFalse);
1913:
1914: /* The OP_Found at the top of this branch jumps here when true,
1915: ** causing the overall IN expression evaluation to fall through.
1916: */
1917: sqlite3VdbeJumpHere(v, j1);
1918: }
1919: }
1920: sqlite3ReleaseTempReg(pParse, r1);
1921: sqlite3ExprCachePop(pParse, 1);
1922: VdbeComment((v, "end IN expr"));
1923: }
1924: #endif /* SQLITE_OMIT_SUBQUERY */
1925:
1926: /*
1927: ** Duplicate an 8-byte value
1928: */
1929: static char *dup8bytes(Vdbe *v, const char *in){
1930: char *out = sqlite3DbMallocRaw(sqlite3VdbeDb(v), 8);
1931: if( out ){
1932: memcpy(out, in, 8);
1933: }
1934: return out;
1935: }
1936:
1937: #ifndef SQLITE_OMIT_FLOATING_POINT
1938: /*
1939: ** Generate an instruction that will put the floating point
1940: ** value described by z[0..n-1] into register iMem.
1941: **
1942: ** The z[] string will probably not be zero-terminated. But the
1943: ** z[n] character is guaranteed to be something that does not look
1944: ** like the continuation of the number.
1945: */
1946: static void codeReal(Vdbe *v, const char *z, int negateFlag, int iMem){
1947: if( ALWAYS(z!=0) ){
1948: double value;
1949: char *zV;
1950: sqlite3AtoF(z, &value, sqlite3Strlen30(z), SQLITE_UTF8);
1951: assert( !sqlite3IsNaN(value) ); /* The new AtoF never returns NaN */
1952: if( negateFlag ) value = -value;
1953: zV = dup8bytes(v, (char*)&value);
1954: sqlite3VdbeAddOp4(v, OP_Real, 0, iMem, 0, zV, P4_REAL);
1955: }
1956: }
1957: #endif
1958:
1959:
1960: /*
1961: ** Generate an instruction that will put the integer describe by
1962: ** text z[0..n-1] into register iMem.
1963: **
1964: ** Expr.u.zToken is always UTF8 and zero-terminated.
1965: */
1966: static void codeInteger(Parse *pParse, Expr *pExpr, int negFlag, int iMem){
1967: Vdbe *v = pParse->pVdbe;
1968: if( pExpr->flags & EP_IntValue ){
1969: int i = pExpr->u.iValue;
1970: assert( i>=0 );
1971: if( negFlag ) i = -i;
1972: sqlite3VdbeAddOp2(v, OP_Integer, i, iMem);
1973: }else{
1974: int c;
1975: i64 value;
1976: const char *z = pExpr->u.zToken;
1977: assert( z!=0 );
1978: c = sqlite3Atoi64(z, &value, sqlite3Strlen30(z), SQLITE_UTF8);
1979: if( c==0 || (c==2 && negFlag) ){
1980: char *zV;
1981: if( negFlag ){ value = c==2 ? SMALLEST_INT64 : -value; }
1982: zV = dup8bytes(v, (char*)&value);
1983: sqlite3VdbeAddOp4(v, OP_Int64, 0, iMem, 0, zV, P4_INT64);
1984: }else{
1985: #ifdef SQLITE_OMIT_FLOATING_POINT
1986: sqlite3ErrorMsg(pParse, "oversized integer: %s%s", negFlag ? "-" : "", z);
1987: #else
1988: codeReal(v, z, negFlag, iMem);
1989: #endif
1990: }
1991: }
1992: }
1993:
1994: /*
1995: ** Clear a cache entry.
1996: */
1997: static void cacheEntryClear(Parse *pParse, struct yColCache *p){
1998: if( p->tempReg ){
1999: if( pParse->nTempReg<ArraySize(pParse->aTempReg) ){
2000: pParse->aTempReg[pParse->nTempReg++] = p->iReg;
2001: }
2002: p->tempReg = 0;
2003: }
2004: }
2005:
2006:
2007: /*
2008: ** Record in the column cache that a particular column from a
2009: ** particular table is stored in a particular register.
2010: */
2011: void sqlite3ExprCacheStore(Parse *pParse, int iTab, int iCol, int iReg){
2012: int i;
2013: int minLru;
2014: int idxLru;
2015: struct yColCache *p;
2016:
2017: assert( iReg>0 ); /* Register numbers are always positive */
2018: assert( iCol>=-1 && iCol<32768 ); /* Finite column numbers */
2019:
2020: /* The SQLITE_ColumnCache flag disables the column cache. This is used
2021: ** for testing only - to verify that SQLite always gets the same answer
2022: ** with and without the column cache.
2023: */
2024: if( pParse->db->flags & SQLITE_ColumnCache ) return;
2025:
2026: /* First replace any existing entry.
2027: **
2028: ** Actually, the way the column cache is currently used, we are guaranteed
2029: ** that the object will never already be in cache. Verify this guarantee.
2030: */
2031: #ifndef NDEBUG
2032: for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
2033: #if 0 /* This code wold remove the entry from the cache if it existed */
2034: if( p->iReg && p->iTable==iTab && p->iColumn==iCol ){
2035: cacheEntryClear(pParse, p);
2036: p->iLevel = pParse->iCacheLevel;
2037: p->iReg = iReg;
2038: p->lru = pParse->iCacheCnt++;
2039: return;
2040: }
2041: #endif
2042: assert( p->iReg==0 || p->iTable!=iTab || p->iColumn!=iCol );
2043: }
2044: #endif
2045:
2046: /* Find an empty slot and replace it */
2047: for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
2048: if( p->iReg==0 ){
2049: p->iLevel = pParse->iCacheLevel;
2050: p->iTable = iTab;
2051: p->iColumn = iCol;
2052: p->iReg = iReg;
2053: p->tempReg = 0;
2054: p->lru = pParse->iCacheCnt++;
2055: return;
2056: }
2057: }
2058:
2059: /* Replace the last recently used */
2060: minLru = 0x7fffffff;
2061: idxLru = -1;
2062: for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
2063: if( p->lru<minLru ){
2064: idxLru = i;
2065: minLru = p->lru;
2066: }
2067: }
2068: if( ALWAYS(idxLru>=0) ){
2069: p = &pParse->aColCache[idxLru];
2070: p->iLevel = pParse->iCacheLevel;
2071: p->iTable = iTab;
2072: p->iColumn = iCol;
2073: p->iReg = iReg;
2074: p->tempReg = 0;
2075: p->lru = pParse->iCacheCnt++;
2076: return;
2077: }
2078: }
2079:
2080: /*
2081: ** Indicate that registers between iReg..iReg+nReg-1 are being overwritten.
2082: ** Purge the range of registers from the column cache.
2083: */
2084: void sqlite3ExprCacheRemove(Parse *pParse, int iReg, int nReg){
2085: int i;
2086: int iLast = iReg + nReg - 1;
2087: struct yColCache *p;
2088: for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
2089: int r = p->iReg;
2090: if( r>=iReg && r<=iLast ){
2091: cacheEntryClear(pParse, p);
2092: p->iReg = 0;
2093: }
2094: }
2095: }
2096:
2097: /*
2098: ** Remember the current column cache context. Any new entries added
2099: ** added to the column cache after this call are removed when the
2100: ** corresponding pop occurs.
2101: */
2102: void sqlite3ExprCachePush(Parse *pParse){
2103: pParse->iCacheLevel++;
2104: }
2105:
2106: /*
2107: ** Remove from the column cache any entries that were added since the
2108: ** the previous N Push operations. In other words, restore the cache
2109: ** to the state it was in N Pushes ago.
2110: */
2111: void sqlite3ExprCachePop(Parse *pParse, int N){
2112: int i;
2113: struct yColCache *p;
2114: assert( N>0 );
2115: assert( pParse->iCacheLevel>=N );
2116: pParse->iCacheLevel -= N;
2117: for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
2118: if( p->iReg && p->iLevel>pParse->iCacheLevel ){
2119: cacheEntryClear(pParse, p);
2120: p->iReg = 0;
2121: }
2122: }
2123: }
2124:
2125: /*
2126: ** When a cached column is reused, make sure that its register is
2127: ** no longer available as a temp register. ticket #3879: that same
2128: ** register might be in the cache in multiple places, so be sure to
2129: ** get them all.
2130: */
2131: static void sqlite3ExprCachePinRegister(Parse *pParse, int iReg){
2132: int i;
2133: struct yColCache *p;
2134: for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
2135: if( p->iReg==iReg ){
2136: p->tempReg = 0;
2137: }
2138: }
2139: }
2140:
2141: /*
2142: ** Generate code to extract the value of the iCol-th column of a table.
2143: */
2144: void sqlite3ExprCodeGetColumnOfTable(
2145: Vdbe *v, /* The VDBE under construction */
2146: Table *pTab, /* The table containing the value */
2147: int iTabCur, /* The cursor for this table */
2148: int iCol, /* Index of the column to extract */
2149: int regOut /* Extract the valud into this register */
2150: ){
2151: if( iCol<0 || iCol==pTab->iPKey ){
2152: sqlite3VdbeAddOp2(v, OP_Rowid, iTabCur, regOut);
2153: }else{
2154: int op = IsVirtual(pTab) ? OP_VColumn : OP_Column;
2155: sqlite3VdbeAddOp3(v, op, iTabCur, iCol, regOut);
2156: }
2157: if( iCol>=0 ){
2158: sqlite3ColumnDefault(v, pTab, iCol, regOut);
2159: }
2160: }
2161:
2162: /*
2163: ** Generate code that will extract the iColumn-th column from
2164: ** table pTab and store the column value in a register. An effort
2165: ** is made to store the column value in register iReg, but this is
2166: ** not guaranteed. The location of the column value is returned.
2167: **
2168: ** There must be an open cursor to pTab in iTable when this routine
2169: ** is called. If iColumn<0 then code is generated that extracts the rowid.
2170: */
2171: int sqlite3ExprCodeGetColumn(
2172: Parse *pParse, /* Parsing and code generating context */
2173: Table *pTab, /* Description of the table we are reading from */
2174: int iColumn, /* Index of the table column */
2175: int iTable, /* The cursor pointing to the table */
2176: int iReg /* Store results here */
2177: ){
2178: Vdbe *v = pParse->pVdbe;
2179: int i;
2180: struct yColCache *p;
2181:
2182: for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
2183: if( p->iReg>0 && p->iTable==iTable && p->iColumn==iColumn ){
2184: p->lru = pParse->iCacheCnt++;
2185: sqlite3ExprCachePinRegister(pParse, p->iReg);
2186: return p->iReg;
2187: }
2188: }
2189: assert( v!=0 );
2190: sqlite3ExprCodeGetColumnOfTable(v, pTab, iTable, iColumn, iReg);
2191: sqlite3ExprCacheStore(pParse, iTable, iColumn, iReg);
2192: return iReg;
2193: }
2194:
2195: /*
2196: ** Clear all column cache entries.
2197: */
2198: void sqlite3ExprCacheClear(Parse *pParse){
2199: int i;
2200: struct yColCache *p;
2201:
2202: for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
2203: if( p->iReg ){
2204: cacheEntryClear(pParse, p);
2205: p->iReg = 0;
2206: }
2207: }
2208: }
2209:
2210: /*
2211: ** Record the fact that an affinity change has occurred on iCount
2212: ** registers starting with iStart.
2213: */
2214: void sqlite3ExprCacheAffinityChange(Parse *pParse, int iStart, int iCount){
2215: sqlite3ExprCacheRemove(pParse, iStart, iCount);
2216: }
2217:
2218: /*
2219: ** Generate code to move content from registers iFrom...iFrom+nReg-1
2220: ** over to iTo..iTo+nReg-1. Keep the column cache up-to-date.
2221: */
2222: void sqlite3ExprCodeMove(Parse *pParse, int iFrom, int iTo, int nReg){
2223: int i;
2224: struct yColCache *p;
2225: if( NEVER(iFrom==iTo) ) return;
2226: sqlite3VdbeAddOp3(pParse->pVdbe, OP_Move, iFrom, iTo, nReg);
2227: for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
2228: int x = p->iReg;
2229: if( x>=iFrom && x<iFrom+nReg ){
2230: p->iReg += iTo-iFrom;
2231: }
2232: }
2233: }
2234:
2235: /*
2236: ** Generate code to copy content from registers iFrom...iFrom+nReg-1
2237: ** over to iTo..iTo+nReg-1.
2238: */
2239: void sqlite3ExprCodeCopy(Parse *pParse, int iFrom, int iTo, int nReg){
2240: int i;
2241: if( NEVER(iFrom==iTo) ) return;
2242: for(i=0; i<nReg; i++){
2243: sqlite3VdbeAddOp2(pParse->pVdbe, OP_Copy, iFrom+i, iTo+i);
2244: }
2245: }
2246:
2247: #if defined(SQLITE_DEBUG) || defined(SQLITE_COVERAGE_TEST)
2248: /*
2249: ** Return true if any register in the range iFrom..iTo (inclusive)
2250: ** is used as part of the column cache.
2251: **
2252: ** This routine is used within assert() and testcase() macros only
2253: ** and does not appear in a normal build.
2254: */
2255: static int usedAsColumnCache(Parse *pParse, int iFrom, int iTo){
2256: int i;
2257: struct yColCache *p;
2258: for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
2259: int r = p->iReg;
2260: if( r>=iFrom && r<=iTo ) return 1; /*NO_TEST*/
2261: }
2262: return 0;
2263: }
2264: #endif /* SQLITE_DEBUG || SQLITE_COVERAGE_TEST */
2265:
2266: /*
2267: ** Generate code into the current Vdbe to evaluate the given
2268: ** expression. Attempt to store the results in register "target".
2269: ** Return the register where results are stored.
2270: **
2271: ** With this routine, there is no guarantee that results will
2272: ** be stored in target. The result might be stored in some other
2273: ** register if it is convenient to do so. The calling function
2274: ** must check the return code and move the results to the desired
2275: ** register.
2276: */
2277: int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){
2278: Vdbe *v = pParse->pVdbe; /* The VM under construction */
2279: int op; /* The opcode being coded */
2280: int inReg = target; /* Results stored in register inReg */
2281: int regFree1 = 0; /* If non-zero free this temporary register */
2282: int regFree2 = 0; /* If non-zero free this temporary register */
2283: int r1, r2, r3, r4; /* Various register numbers */
2284: sqlite3 *db = pParse->db; /* The database connection */
2285:
2286: assert( target>0 && target<=pParse->nMem );
2287: if( v==0 ){
2288: assert( pParse->db->mallocFailed );
2289: return 0;
2290: }
2291:
2292: if( pExpr==0 ){
2293: op = TK_NULL;
2294: }else{
2295: op = pExpr->op;
2296: }
2297: switch( op ){
2298: case TK_AGG_COLUMN: {
2299: AggInfo *pAggInfo = pExpr->pAggInfo;
2300: struct AggInfo_col *pCol = &pAggInfo->aCol[pExpr->iAgg];
2301: if( !pAggInfo->directMode ){
2302: assert( pCol->iMem>0 );
2303: inReg = pCol->iMem;
2304: break;
2305: }else if( pAggInfo->useSortingIdx ){
2306: sqlite3VdbeAddOp3(v, OP_Column, pAggInfo->sortingIdxPTab,
2307: pCol->iSorterColumn, target);
2308: break;
2309: }
2310: /* Otherwise, fall thru into the TK_COLUMN case */
2311: }
2312: case TK_COLUMN: {
2313: if( pExpr->iTable<0 ){
2314: /* This only happens when coding check constraints */
2315: assert( pParse->ckBase>0 );
2316: inReg = pExpr->iColumn + pParse->ckBase;
2317: }else{
2318: inReg = sqlite3ExprCodeGetColumn(pParse, pExpr->pTab,
2319: pExpr->iColumn, pExpr->iTable, target);
2320: }
2321: break;
2322: }
2323: case TK_INTEGER: {
2324: codeInteger(pParse, pExpr, 0, target);
2325: break;
2326: }
2327: #ifndef SQLITE_OMIT_FLOATING_POINT
2328: case TK_FLOAT: {
2329: assert( !ExprHasProperty(pExpr, EP_IntValue) );
2330: codeReal(v, pExpr->u.zToken, 0, target);
2331: break;
2332: }
2333: #endif
2334: case TK_STRING: {
2335: assert( !ExprHasProperty(pExpr, EP_IntValue) );
2336: sqlite3VdbeAddOp4(v, OP_String8, 0, target, 0, pExpr->u.zToken, 0);
2337: break;
2338: }
2339: case TK_NULL: {
2340: sqlite3VdbeAddOp2(v, OP_Null, 0, target);
2341: break;
2342: }
2343: #ifndef SQLITE_OMIT_BLOB_LITERAL
2344: case TK_BLOB: {
2345: int n;
2346: const char *z;
2347: char *zBlob;
2348: assert( !ExprHasProperty(pExpr, EP_IntValue) );
2349: assert( pExpr->u.zToken[0]=='x' || pExpr->u.zToken[0]=='X' );
2350: assert( pExpr->u.zToken[1]=='\'' );
2351: z = &pExpr->u.zToken[2];
2352: n = sqlite3Strlen30(z) - 1;
2353: assert( z[n]=='\'' );
2354: zBlob = sqlite3HexToBlob(sqlite3VdbeDb(v), z, n);
2355: sqlite3VdbeAddOp4(v, OP_Blob, n/2, target, 0, zBlob, P4_DYNAMIC);
2356: break;
2357: }
2358: #endif
2359: case TK_VARIABLE: {
2360: assert( !ExprHasProperty(pExpr, EP_IntValue) );
2361: assert( pExpr->u.zToken!=0 );
2362: assert( pExpr->u.zToken[0]!=0 );
2363: sqlite3VdbeAddOp2(v, OP_Variable, pExpr->iColumn, target);
2364: if( pExpr->u.zToken[1]!=0 ){
2365: assert( pExpr->u.zToken[0]=='?'
2366: || strcmp(pExpr->u.zToken, pParse->azVar[pExpr->iColumn-1])==0 );
2367: sqlite3VdbeChangeP4(v, -1, pParse->azVar[pExpr->iColumn-1], P4_STATIC);
2368: }
2369: break;
2370: }
2371: case TK_REGISTER: {
2372: inReg = pExpr->iTable;
2373: break;
2374: }
2375: case TK_AS: {
2376: inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
2377: break;
2378: }
2379: #ifndef SQLITE_OMIT_CAST
2380: case TK_CAST: {
2381: /* Expressions of the form: CAST(pLeft AS token) */
2382: int aff, to_op;
2383: inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
2384: assert( !ExprHasProperty(pExpr, EP_IntValue) );
2385: aff = sqlite3AffinityType(pExpr->u.zToken);
2386: to_op = aff - SQLITE_AFF_TEXT + OP_ToText;
2387: assert( to_op==OP_ToText || aff!=SQLITE_AFF_TEXT );
2388: assert( to_op==OP_ToBlob || aff!=SQLITE_AFF_NONE );
2389: assert( to_op==OP_ToNumeric || aff!=SQLITE_AFF_NUMERIC );
2390: assert( to_op==OP_ToInt || aff!=SQLITE_AFF_INTEGER );
2391: assert( to_op==OP_ToReal || aff!=SQLITE_AFF_REAL );
2392: testcase( to_op==OP_ToText );
2393: testcase( to_op==OP_ToBlob );
2394: testcase( to_op==OP_ToNumeric );
2395: testcase( to_op==OP_ToInt );
2396: testcase( to_op==OP_ToReal );
2397: if( inReg!=target ){
2398: sqlite3VdbeAddOp2(v, OP_SCopy, inReg, target);
2399: inReg = target;
2400: }
2401: sqlite3VdbeAddOp1(v, to_op, inReg);
2402: testcase( usedAsColumnCache(pParse, inReg, inReg) );
2403: sqlite3ExprCacheAffinityChange(pParse, inReg, 1);
2404: break;
2405: }
2406: #endif /* SQLITE_OMIT_CAST */
2407: case TK_LT:
2408: case TK_LE:
2409: case TK_GT:
2410: case TK_GE:
2411: case TK_NE:
2412: case TK_EQ: {
2413: assert( TK_LT==OP_Lt );
2414: assert( TK_LE==OP_Le );
2415: assert( TK_GT==OP_Gt );
2416: assert( TK_GE==OP_Ge );
2417: assert( TK_EQ==OP_Eq );
2418: assert( TK_NE==OP_Ne );
2419: testcase( op==TK_LT );
2420: testcase( op==TK_LE );
2421: testcase( op==TK_GT );
2422: testcase( op==TK_GE );
2423: testcase( op==TK_EQ );
2424: testcase( op==TK_NE );
2425: r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
2426: r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2);
2427: codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
2428: r1, r2, inReg, SQLITE_STOREP2);
2429: testcase( regFree1==0 );
2430: testcase( regFree2==0 );
2431: break;
2432: }
2433: case TK_IS:
2434: case TK_ISNOT: {
2435: testcase( op==TK_IS );
2436: testcase( op==TK_ISNOT );
2437: r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
2438: r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2);
2439: op = (op==TK_IS) ? TK_EQ : TK_NE;
2440: codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
2441: r1, r2, inReg, SQLITE_STOREP2 | SQLITE_NULLEQ);
2442: testcase( regFree1==0 );
2443: testcase( regFree2==0 );
2444: break;
2445: }
2446: case TK_AND:
2447: case TK_OR:
2448: case TK_PLUS:
2449: case TK_STAR:
2450: case TK_MINUS:
2451: case TK_REM:
2452: case TK_BITAND:
2453: case TK_BITOR:
2454: case TK_SLASH:
2455: case TK_LSHIFT:
2456: case TK_RSHIFT:
2457: case TK_CONCAT: {
2458: assert( TK_AND==OP_And );
2459: assert( TK_OR==OP_Or );
2460: assert( TK_PLUS==OP_Add );
2461: assert( TK_MINUS==OP_Subtract );
2462: assert( TK_REM==OP_Remainder );
2463: assert( TK_BITAND==OP_BitAnd );
2464: assert( TK_BITOR==OP_BitOr );
2465: assert( TK_SLASH==OP_Divide );
2466: assert( TK_LSHIFT==OP_ShiftLeft );
2467: assert( TK_RSHIFT==OP_ShiftRight );
2468: assert( TK_CONCAT==OP_Concat );
2469: testcase( op==TK_AND );
2470: testcase( op==TK_OR );
2471: testcase( op==TK_PLUS );
2472: testcase( op==TK_MINUS );
2473: testcase( op==TK_REM );
2474: testcase( op==TK_BITAND );
2475: testcase( op==TK_BITOR );
2476: testcase( op==TK_SLASH );
2477: testcase( op==TK_LSHIFT );
2478: testcase( op==TK_RSHIFT );
2479: testcase( op==TK_CONCAT );
2480: r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
2481: r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2);
2482: sqlite3VdbeAddOp3(v, op, r2, r1, target);
2483: testcase( regFree1==0 );
2484: testcase( regFree2==0 );
2485: break;
2486: }
2487: case TK_UMINUS: {
2488: Expr *pLeft = pExpr->pLeft;
2489: assert( pLeft );
2490: if( pLeft->op==TK_INTEGER ){
2491: codeInteger(pParse, pLeft, 1, target);
2492: #ifndef SQLITE_OMIT_FLOATING_POINT
2493: }else if( pLeft->op==TK_FLOAT ){
2494: assert( !ExprHasProperty(pExpr, EP_IntValue) );
2495: codeReal(v, pLeft->u.zToken, 1, target);
2496: #endif
2497: }else{
2498: regFree1 = r1 = sqlite3GetTempReg(pParse);
2499: sqlite3VdbeAddOp2(v, OP_Integer, 0, r1);
2500: r2 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free2);
2501: sqlite3VdbeAddOp3(v, OP_Subtract, r2, r1, target);
2502: testcase( regFree2==0 );
2503: }
2504: inReg = target;
2505: break;
2506: }
2507: case TK_BITNOT:
2508: case TK_NOT: {
2509: assert( TK_BITNOT==OP_BitNot );
2510: assert( TK_NOT==OP_Not );
2511: testcase( op==TK_BITNOT );
2512: testcase( op==TK_NOT );
2513: r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
2514: testcase( regFree1==0 );
2515: inReg = target;
2516: sqlite3VdbeAddOp2(v, op, r1, inReg);
2517: break;
2518: }
2519: case TK_ISNULL:
2520: case TK_NOTNULL: {
2521: int addr;
2522: assert( TK_ISNULL==OP_IsNull );
2523: assert( TK_NOTNULL==OP_NotNull );
2524: testcase( op==TK_ISNULL );
2525: testcase( op==TK_NOTNULL );
2526: sqlite3VdbeAddOp2(v, OP_Integer, 1, target);
2527: r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
2528: testcase( regFree1==0 );
2529: addr = sqlite3VdbeAddOp1(v, op, r1);
2530: sqlite3VdbeAddOp2(v, OP_AddImm, target, -1);
2531: sqlite3VdbeJumpHere(v, addr);
2532: break;
2533: }
2534: case TK_AGG_FUNCTION: {
2535: AggInfo *pInfo = pExpr->pAggInfo;
2536: if( pInfo==0 ){
2537: assert( !ExprHasProperty(pExpr, EP_IntValue) );
2538: sqlite3ErrorMsg(pParse, "misuse of aggregate: %s()", pExpr->u.zToken);
2539: }else{
2540: inReg = pInfo->aFunc[pExpr->iAgg].iMem;
2541: }
2542: break;
2543: }
2544: case TK_CONST_FUNC:
2545: case TK_FUNCTION: {
2546: ExprList *pFarg; /* List of function arguments */
2547: int nFarg; /* Number of function arguments */
2548: FuncDef *pDef; /* The function definition object */
2549: int nId; /* Length of the function name in bytes */
2550: const char *zId; /* The function name */
2551: int constMask = 0; /* Mask of function arguments that are constant */
2552: int i; /* Loop counter */
2553: u8 enc = ENC(db); /* The text encoding used by this database */
2554: CollSeq *pColl = 0; /* A collating sequence */
2555:
2556: assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
2557: testcase( op==TK_CONST_FUNC );
2558: testcase( op==TK_FUNCTION );
2559: if( ExprHasAnyProperty(pExpr, EP_TokenOnly) ){
2560: pFarg = 0;
2561: }else{
2562: pFarg = pExpr->x.pList;
2563: }
2564: nFarg = pFarg ? pFarg->nExpr : 0;
2565: assert( !ExprHasProperty(pExpr, EP_IntValue) );
2566: zId = pExpr->u.zToken;
2567: nId = sqlite3Strlen30(zId);
2568: pDef = sqlite3FindFunction(db, zId, nId, nFarg, enc, 0);
2569: if( pDef==0 ){
2570: sqlite3ErrorMsg(pParse, "unknown function: %.*s()", nId, zId);
2571: break;
2572: }
2573:
2574: /* Attempt a direct implementation of the built-in COALESCE() and
2575: ** IFNULL() functions. This avoids unnecessary evalation of
2576: ** arguments past the first non-NULL argument.
2577: */
2578: if( pDef->flags & SQLITE_FUNC_COALESCE ){
2579: int endCoalesce = sqlite3VdbeMakeLabel(v);
2580: assert( nFarg>=2 );
2581: sqlite3ExprCode(pParse, pFarg->a[0].pExpr, target);
2582: for(i=1; i<nFarg; i++){
2583: sqlite3VdbeAddOp2(v, OP_NotNull, target, endCoalesce);
2584: sqlite3ExprCacheRemove(pParse, target, 1);
2585: sqlite3ExprCachePush(pParse);
2586: sqlite3ExprCode(pParse, pFarg->a[i].pExpr, target);
2587: sqlite3ExprCachePop(pParse, 1);
2588: }
2589: sqlite3VdbeResolveLabel(v, endCoalesce);
2590: break;
2591: }
2592:
2593:
2594: if( pFarg ){
2595: r1 = sqlite3GetTempRange(pParse, nFarg);
2596: sqlite3ExprCachePush(pParse); /* Ticket 2ea2425d34be */
2597: sqlite3ExprCodeExprList(pParse, pFarg, r1, 1);
2598: sqlite3ExprCachePop(pParse, 1); /* Ticket 2ea2425d34be */
2599: }else{
2600: r1 = 0;
2601: }
2602: #ifndef SQLITE_OMIT_VIRTUALTABLE
2603: /* Possibly overload the function if the first argument is
2604: ** a virtual table column.
2605: **
2606: ** For infix functions (LIKE, GLOB, REGEXP, and MATCH) use the
2607: ** second argument, not the first, as the argument to test to
2608: ** see if it is a column in a virtual table. This is done because
2609: ** the left operand of infix functions (the operand we want to
2610: ** control overloading) ends up as the second argument to the
2611: ** function. The expression "A glob B" is equivalent to
2612: ** "glob(B,A). We want to use the A in "A glob B" to test
2613: ** for function overloading. But we use the B term in "glob(B,A)".
2614: */
2615: if( nFarg>=2 && (pExpr->flags & EP_InfixFunc) ){
2616: pDef = sqlite3VtabOverloadFunction(db, pDef, nFarg, pFarg->a[1].pExpr);
2617: }else if( nFarg>0 ){
2618: pDef = sqlite3VtabOverloadFunction(db, pDef, nFarg, pFarg->a[0].pExpr);
2619: }
2620: #endif
2621: for(i=0; i<nFarg; i++){
2622: if( i<32 && sqlite3ExprIsConstant(pFarg->a[i].pExpr) ){
2623: constMask |= (1<<i);
2624: }
2625: if( (pDef->flags & SQLITE_FUNC_NEEDCOLL)!=0 && !pColl ){
2626: pColl = sqlite3ExprCollSeq(pParse, pFarg->a[i].pExpr);
2627: }
2628: }
2629: if( pDef->flags & SQLITE_FUNC_NEEDCOLL ){
2630: if( !pColl ) pColl = db->pDfltColl;
2631: sqlite3VdbeAddOp4(v, OP_CollSeq, 0, 0, 0, (char *)pColl, P4_COLLSEQ);
2632: }
2633: sqlite3VdbeAddOp4(v, OP_Function, constMask, r1, target,
2634: (char*)pDef, P4_FUNCDEF);
2635: sqlite3VdbeChangeP5(v, (u8)nFarg);
2636: if( nFarg ){
2637: sqlite3ReleaseTempRange(pParse, r1, nFarg);
2638: }
2639: break;
2640: }
2641: #ifndef SQLITE_OMIT_SUBQUERY
2642: case TK_EXISTS:
2643: case TK_SELECT: {
2644: testcase( op==TK_EXISTS );
2645: testcase( op==TK_SELECT );
2646: inReg = sqlite3CodeSubselect(pParse, pExpr, 0, 0);
2647: break;
2648: }
2649: case TK_IN: {
2650: int destIfFalse = sqlite3VdbeMakeLabel(v);
2651: int destIfNull = sqlite3VdbeMakeLabel(v);
2652: sqlite3VdbeAddOp2(v, OP_Null, 0, target);
2653: sqlite3ExprCodeIN(pParse, pExpr, destIfFalse, destIfNull);
2654: sqlite3VdbeAddOp2(v, OP_Integer, 1, target);
2655: sqlite3VdbeResolveLabel(v, destIfFalse);
2656: sqlite3VdbeAddOp2(v, OP_AddImm, target, 0);
2657: sqlite3VdbeResolveLabel(v, destIfNull);
2658: break;
2659: }
2660: #endif /* SQLITE_OMIT_SUBQUERY */
2661:
2662:
2663: /*
2664: ** x BETWEEN y AND z
2665: **
2666: ** This is equivalent to
2667: **
2668: ** x>=y AND x<=z
2669: **
2670: ** X is stored in pExpr->pLeft.
2671: ** Y is stored in pExpr->pList->a[0].pExpr.
2672: ** Z is stored in pExpr->pList->a[1].pExpr.
2673: */
2674: case TK_BETWEEN: {
2675: Expr *pLeft = pExpr->pLeft;
2676: struct ExprList_item *pLItem = pExpr->x.pList->a;
2677: Expr *pRight = pLItem->pExpr;
2678:
2679: r1 = sqlite3ExprCodeTemp(pParse, pLeft, ®Free1);
2680: r2 = sqlite3ExprCodeTemp(pParse, pRight, ®Free2);
2681: testcase( regFree1==0 );
2682: testcase( regFree2==0 );
2683: r3 = sqlite3GetTempReg(pParse);
2684: r4 = sqlite3GetTempReg(pParse);
2685: codeCompare(pParse, pLeft, pRight, OP_Ge,
2686: r1, r2, r3, SQLITE_STOREP2);
2687: pLItem++;
2688: pRight = pLItem->pExpr;
2689: sqlite3ReleaseTempReg(pParse, regFree2);
2690: r2 = sqlite3ExprCodeTemp(pParse, pRight, ®Free2);
2691: testcase( regFree2==0 );
2692: codeCompare(pParse, pLeft, pRight, OP_Le, r1, r2, r4, SQLITE_STOREP2);
2693: sqlite3VdbeAddOp3(v, OP_And, r3, r4, target);
2694: sqlite3ReleaseTempReg(pParse, r3);
2695: sqlite3ReleaseTempReg(pParse, r4);
2696: break;
2697: }
2698: case TK_UPLUS: {
2699: inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
2700: break;
2701: }
2702:
2703: case TK_TRIGGER: {
2704: /* If the opcode is TK_TRIGGER, then the expression is a reference
2705: ** to a column in the new.* or old.* pseudo-tables available to
2706: ** trigger programs. In this case Expr.iTable is set to 1 for the
2707: ** new.* pseudo-table, or 0 for the old.* pseudo-table. Expr.iColumn
2708: ** is set to the column of the pseudo-table to read, or to -1 to
2709: ** read the rowid field.
2710: **
2711: ** The expression is implemented using an OP_Param opcode. The p1
2712: ** parameter is set to 0 for an old.rowid reference, or to (i+1)
2713: ** to reference another column of the old.* pseudo-table, where
2714: ** i is the index of the column. For a new.rowid reference, p1 is
2715: ** set to (n+1), where n is the number of columns in each pseudo-table.
2716: ** For a reference to any other column in the new.* pseudo-table, p1
2717: ** is set to (n+2+i), where n and i are as defined previously. For
2718: ** example, if the table on which triggers are being fired is
2719: ** declared as:
2720: **
2721: ** CREATE TABLE t1(a, b);
2722: **
2723: ** Then p1 is interpreted as follows:
2724: **
2725: ** p1==0 -> old.rowid p1==3 -> new.rowid
2726: ** p1==1 -> old.a p1==4 -> new.a
2727: ** p1==2 -> old.b p1==5 -> new.b
2728: */
2729: Table *pTab = pExpr->pTab;
2730: int p1 = pExpr->iTable * (pTab->nCol+1) + 1 + pExpr->iColumn;
2731:
2732: assert( pExpr->iTable==0 || pExpr->iTable==1 );
2733: assert( pExpr->iColumn>=-1 && pExpr->iColumn<pTab->nCol );
2734: assert( pTab->iPKey<0 || pExpr->iColumn!=pTab->iPKey );
2735: assert( p1>=0 && p1<(pTab->nCol*2+2) );
2736:
2737: sqlite3VdbeAddOp2(v, OP_Param, p1, target);
2738: VdbeComment((v, "%s.%s -> $%d",
2739: (pExpr->iTable ? "new" : "old"),
2740: (pExpr->iColumn<0 ? "rowid" : pExpr->pTab->aCol[pExpr->iColumn].zName),
2741: target
2742: ));
2743:
2744: #ifndef SQLITE_OMIT_FLOATING_POINT
2745: /* If the column has REAL affinity, it may currently be stored as an
2746: ** integer. Use OP_RealAffinity to make sure it is really real. */
2747: if( pExpr->iColumn>=0
2748: && pTab->aCol[pExpr->iColumn].affinity==SQLITE_AFF_REAL
2749: ){
2750: sqlite3VdbeAddOp1(v, OP_RealAffinity, target);
2751: }
2752: #endif
2753: break;
2754: }
2755:
2756:
2757: /*
2758: ** Form A:
2759: ** CASE x WHEN e1 THEN r1 WHEN e2 THEN r2 ... WHEN eN THEN rN ELSE y END
2760: **
2761: ** Form B:
2762: ** CASE WHEN e1 THEN r1 WHEN e2 THEN r2 ... WHEN eN THEN rN ELSE y END
2763: **
2764: ** Form A is can be transformed into the equivalent form B as follows:
2765: ** CASE WHEN x=e1 THEN r1 WHEN x=e2 THEN r2 ...
2766: ** WHEN x=eN THEN rN ELSE y END
2767: **
2768: ** X (if it exists) is in pExpr->pLeft.
2769: ** Y is in pExpr->pRight. The Y is also optional. If there is no
2770: ** ELSE clause and no other term matches, then the result of the
2771: ** exprssion is NULL.
2772: ** Ei is in pExpr->pList->a[i*2] and Ri is pExpr->pList->a[i*2+1].
2773: **
2774: ** The result of the expression is the Ri for the first matching Ei,
2775: ** or if there is no matching Ei, the ELSE term Y, or if there is
2776: ** no ELSE term, NULL.
2777: */
2778: default: assert( op==TK_CASE ); {
2779: int endLabel; /* GOTO label for end of CASE stmt */
2780: int nextCase; /* GOTO label for next WHEN clause */
2781: int nExpr; /* 2x number of WHEN terms */
2782: int i; /* Loop counter */
2783: ExprList *pEList; /* List of WHEN terms */
2784: struct ExprList_item *aListelem; /* Array of WHEN terms */
2785: Expr opCompare; /* The X==Ei expression */
2786: Expr cacheX; /* Cached expression X */
2787: Expr *pX; /* The X expression */
2788: Expr *pTest = 0; /* X==Ei (form A) or just Ei (form B) */
2789: VVA_ONLY( int iCacheLevel = pParse->iCacheLevel; )
2790:
2791: assert( !ExprHasProperty(pExpr, EP_xIsSelect) && pExpr->x.pList );
2792: assert((pExpr->x.pList->nExpr % 2) == 0);
2793: assert(pExpr->x.pList->nExpr > 0);
2794: pEList = pExpr->x.pList;
2795: aListelem = pEList->a;
2796: nExpr = pEList->nExpr;
2797: endLabel = sqlite3VdbeMakeLabel(v);
2798: if( (pX = pExpr->pLeft)!=0 ){
2799: cacheX = *pX;
2800: testcase( pX->op==TK_COLUMN );
2801: testcase( pX->op==TK_REGISTER );
2802: cacheX.iTable = sqlite3ExprCodeTemp(pParse, pX, ®Free1);
2803: testcase( regFree1==0 );
2804: cacheX.op = TK_REGISTER;
2805: opCompare.op = TK_EQ;
2806: opCompare.pLeft = &cacheX;
2807: pTest = &opCompare;
2808: /* Ticket b351d95f9cd5ef17e9d9dbae18f5ca8611190001:
2809: ** The value in regFree1 might get SCopy-ed into the file result.
2810: ** So make sure that the regFree1 register is not reused for other
2811: ** purposes and possibly overwritten. */
2812: regFree1 = 0;
2813: }
2814: for(i=0; i<nExpr; i=i+2){
2815: sqlite3ExprCachePush(pParse);
2816: if( pX ){
2817: assert( pTest!=0 );
2818: opCompare.pRight = aListelem[i].pExpr;
2819: }else{
2820: pTest = aListelem[i].pExpr;
2821: }
2822: nextCase = sqlite3VdbeMakeLabel(v);
2823: testcase( pTest->op==TK_COLUMN );
2824: sqlite3ExprIfFalse(pParse, pTest, nextCase, SQLITE_JUMPIFNULL);
2825: testcase( aListelem[i+1].pExpr->op==TK_COLUMN );
2826: testcase( aListelem[i+1].pExpr->op==TK_REGISTER );
2827: sqlite3ExprCode(pParse, aListelem[i+1].pExpr, target);
2828: sqlite3VdbeAddOp2(v, OP_Goto, 0, endLabel);
2829: sqlite3ExprCachePop(pParse, 1);
2830: sqlite3VdbeResolveLabel(v, nextCase);
2831: }
2832: if( pExpr->pRight ){
2833: sqlite3ExprCachePush(pParse);
2834: sqlite3ExprCode(pParse, pExpr->pRight, target);
2835: sqlite3ExprCachePop(pParse, 1);
2836: }else{
2837: sqlite3VdbeAddOp2(v, OP_Null, 0, target);
2838: }
2839: assert( db->mallocFailed || pParse->nErr>0
2840: || pParse->iCacheLevel==iCacheLevel );
2841: sqlite3VdbeResolveLabel(v, endLabel);
2842: break;
2843: }
2844: #ifndef SQLITE_OMIT_TRIGGER
2845: case TK_RAISE: {
2846: assert( pExpr->affinity==OE_Rollback
2847: || pExpr->affinity==OE_Abort
2848: || pExpr->affinity==OE_Fail
2849: || pExpr->affinity==OE_Ignore
2850: );
2851: if( !pParse->pTriggerTab ){
2852: sqlite3ErrorMsg(pParse,
2853: "RAISE() may only be used within a trigger-program");
2854: return 0;
2855: }
2856: if( pExpr->affinity==OE_Abort ){
2857: sqlite3MayAbort(pParse);
2858: }
2859: assert( !ExprHasProperty(pExpr, EP_IntValue) );
2860: if( pExpr->affinity==OE_Ignore ){
2861: sqlite3VdbeAddOp4(
2862: v, OP_Halt, SQLITE_OK, OE_Ignore, 0, pExpr->u.zToken,0);
2863: }else{
2864: sqlite3HaltConstraint(pParse, pExpr->affinity, pExpr->u.zToken, 0);
2865: }
2866:
2867: break;
2868: }
2869: #endif
2870: }
2871: sqlite3ReleaseTempReg(pParse, regFree1);
2872: sqlite3ReleaseTempReg(pParse, regFree2);
2873: return inReg;
2874: }
2875:
2876: /*
2877: ** Generate code to evaluate an expression and store the results
2878: ** into a register. Return the register number where the results
2879: ** are stored.
2880: **
2881: ** If the register is a temporary register that can be deallocated,
2882: ** then write its number into *pReg. If the result register is not
2883: ** a temporary, then set *pReg to zero.
2884: */
2885: int sqlite3ExprCodeTemp(Parse *pParse, Expr *pExpr, int *pReg){
2886: int r1 = sqlite3GetTempReg(pParse);
2887: int r2 = sqlite3ExprCodeTarget(pParse, pExpr, r1);
2888: if( r2==r1 ){
2889: *pReg = r1;
2890: }else{
2891: sqlite3ReleaseTempReg(pParse, r1);
2892: *pReg = 0;
2893: }
2894: return r2;
2895: }
2896:
2897: /*
2898: ** Generate code that will evaluate expression pExpr and store the
2899: ** results in register target. The results are guaranteed to appear
2900: ** in register target.
2901: */
2902: int sqlite3ExprCode(Parse *pParse, Expr *pExpr, int target){
2903: int inReg;
2904:
2905: assert( target>0 && target<=pParse->nMem );
2906: if( pExpr && pExpr->op==TK_REGISTER ){
2907: sqlite3VdbeAddOp2(pParse->pVdbe, OP_Copy, pExpr->iTable, target);
2908: }else{
2909: inReg = sqlite3ExprCodeTarget(pParse, pExpr, target);
2910: assert( pParse->pVdbe || pParse->db->mallocFailed );
2911: if( inReg!=target && pParse->pVdbe ){
2912: sqlite3VdbeAddOp2(pParse->pVdbe, OP_SCopy, inReg, target);
2913: }
2914: }
2915: return target;
2916: }
2917:
2918: /*
2919: ** Generate code that evalutes the given expression and puts the result
2920: ** in register target.
2921: **
2922: ** Also make a copy of the expression results into another "cache" register
2923: ** and modify the expression so that the next time it is evaluated,
2924: ** the result is a copy of the cache register.
2925: **
2926: ** This routine is used for expressions that are used multiple
2927: ** times. They are evaluated once and the results of the expression
2928: ** are reused.
2929: */
2930: int sqlite3ExprCodeAndCache(Parse *pParse, Expr *pExpr, int target){
2931: Vdbe *v = pParse->pVdbe;
2932: int inReg;
2933: inReg = sqlite3ExprCode(pParse, pExpr, target);
2934: assert( target>0 );
2935: /* This routine is called for terms to INSERT or UPDATE. And the only
2936: ** other place where expressions can be converted into TK_REGISTER is
2937: ** in WHERE clause processing. So as currently implemented, there is
2938: ** no way for a TK_REGISTER to exist here. But it seems prudent to
2939: ** keep the ALWAYS() in case the conditions above change with future
2940: ** modifications or enhancements. */
2941: if( ALWAYS(pExpr->op!=TK_REGISTER) ){
2942: int iMem;
2943: iMem = ++pParse->nMem;
2944: sqlite3VdbeAddOp2(v, OP_Copy, inReg, iMem);
2945: pExpr->iTable = iMem;
2946: pExpr->op2 = pExpr->op;
2947: pExpr->op = TK_REGISTER;
2948: }
2949: return inReg;
2950: }
2951:
2952: #if defined(SQLITE_ENABLE_TREE_EXPLAIN)
2953: /*
2954: ** Generate a human-readable explanation of an expression tree.
2955: */
2956: void sqlite3ExplainExpr(Vdbe *pOut, Expr *pExpr){
2957: int op; /* The opcode being coded */
2958: const char *zBinOp = 0; /* Binary operator */
2959: const char *zUniOp = 0; /* Unary operator */
2960: if( pExpr==0 ){
2961: op = TK_NULL;
2962: }else{
2963: op = pExpr->op;
2964: }
2965: switch( op ){
2966: case TK_AGG_COLUMN: {
2967: sqlite3ExplainPrintf(pOut, "AGG{%d:%d}",
2968: pExpr->iTable, pExpr->iColumn);
2969: break;
2970: }
2971: case TK_COLUMN: {
2972: if( pExpr->iTable<0 ){
2973: /* This only happens when coding check constraints */
2974: sqlite3ExplainPrintf(pOut, "COLUMN(%d)", pExpr->iColumn);
2975: }else{
2976: sqlite3ExplainPrintf(pOut, "{%d:%d}",
2977: pExpr->iTable, pExpr->iColumn);
2978: }
2979: break;
2980: }
2981: case TK_INTEGER: {
2982: if( pExpr->flags & EP_IntValue ){
2983: sqlite3ExplainPrintf(pOut, "%d", pExpr->u.iValue);
2984: }else{
2985: sqlite3ExplainPrintf(pOut, "%s", pExpr->u.zToken);
2986: }
2987: break;
2988: }
2989: #ifndef SQLITE_OMIT_FLOATING_POINT
2990: case TK_FLOAT: {
2991: sqlite3ExplainPrintf(pOut,"%s", pExpr->u.zToken);
2992: break;
2993: }
2994: #endif
2995: case TK_STRING: {
2996: sqlite3ExplainPrintf(pOut,"%Q", pExpr->u.zToken);
2997: break;
2998: }
2999: case TK_NULL: {
3000: sqlite3ExplainPrintf(pOut,"NULL");
3001: break;
3002: }
3003: #ifndef SQLITE_OMIT_BLOB_LITERAL
3004: case TK_BLOB: {
3005: sqlite3ExplainPrintf(pOut,"%s", pExpr->u.zToken);
3006: break;
3007: }
3008: #endif
3009: case TK_VARIABLE: {
3010: sqlite3ExplainPrintf(pOut,"VARIABLE(%s,%d)",
3011: pExpr->u.zToken, pExpr->iColumn);
3012: break;
3013: }
3014: case TK_REGISTER: {
3015: sqlite3ExplainPrintf(pOut,"REGISTER(%d)", pExpr->iTable);
3016: break;
3017: }
3018: case TK_AS: {
3019: sqlite3ExplainExpr(pOut, pExpr->pLeft);
3020: break;
3021: }
3022: #ifndef SQLITE_OMIT_CAST
3023: case TK_CAST: {
3024: /* Expressions of the form: CAST(pLeft AS token) */
3025: const char *zAff = "unk";
3026: switch( sqlite3AffinityType(pExpr->u.zToken) ){
3027: case SQLITE_AFF_TEXT: zAff = "TEXT"; break;
3028: case SQLITE_AFF_NONE: zAff = "NONE"; break;
3029: case SQLITE_AFF_NUMERIC: zAff = "NUMERIC"; break;
3030: case SQLITE_AFF_INTEGER: zAff = "INTEGER"; break;
3031: case SQLITE_AFF_REAL: zAff = "REAL"; break;
3032: }
3033: sqlite3ExplainPrintf(pOut, "CAST-%s(", zAff);
3034: sqlite3ExplainExpr(pOut, pExpr->pLeft);
3035: sqlite3ExplainPrintf(pOut, ")");
3036: break;
3037: }
3038: #endif /* SQLITE_OMIT_CAST */
3039: case TK_LT: zBinOp = "LT"; break;
3040: case TK_LE: zBinOp = "LE"; break;
3041: case TK_GT: zBinOp = "GT"; break;
3042: case TK_GE: zBinOp = "GE"; break;
3043: case TK_NE: zBinOp = "NE"; break;
3044: case TK_EQ: zBinOp = "EQ"; break;
3045: case TK_IS: zBinOp = "IS"; break;
3046: case TK_ISNOT: zBinOp = "ISNOT"; break;
3047: case TK_AND: zBinOp = "AND"; break;
3048: case TK_OR: zBinOp = "OR"; break;
3049: case TK_PLUS: zBinOp = "ADD"; break;
3050: case TK_STAR: zBinOp = "MUL"; break;
3051: case TK_MINUS: zBinOp = "SUB"; break;
3052: case TK_REM: zBinOp = "REM"; break;
3053: case TK_BITAND: zBinOp = "BITAND"; break;
3054: case TK_BITOR: zBinOp = "BITOR"; break;
3055: case TK_SLASH: zBinOp = "DIV"; break;
3056: case TK_LSHIFT: zBinOp = "LSHIFT"; break;
3057: case TK_RSHIFT: zBinOp = "RSHIFT"; break;
3058: case TK_CONCAT: zBinOp = "CONCAT"; break;
3059:
3060: case TK_UMINUS: zUniOp = "UMINUS"; break;
3061: case TK_UPLUS: zUniOp = "UPLUS"; break;
3062: case TK_BITNOT: zUniOp = "BITNOT"; break;
3063: case TK_NOT: zUniOp = "NOT"; break;
3064: case TK_ISNULL: zUniOp = "ISNULL"; break;
3065: case TK_NOTNULL: zUniOp = "NOTNULL"; break;
3066:
3067: case TK_AGG_FUNCTION:
3068: case TK_CONST_FUNC:
3069: case TK_FUNCTION: {
3070: ExprList *pFarg; /* List of function arguments */
3071: if( ExprHasAnyProperty(pExpr, EP_TokenOnly) ){
3072: pFarg = 0;
3073: }else{
3074: pFarg = pExpr->x.pList;
3075: }
3076: sqlite3ExplainPrintf(pOut, "%sFUNCTION:%s(",
3077: op==TK_AGG_FUNCTION ? "AGG_" : "",
3078: pExpr->u.zToken);
3079: if( pFarg ){
3080: sqlite3ExplainExprList(pOut, pFarg);
3081: }
3082: sqlite3ExplainPrintf(pOut, ")");
3083: break;
3084: }
3085: #ifndef SQLITE_OMIT_SUBQUERY
3086: case TK_EXISTS: {
3087: sqlite3ExplainPrintf(pOut, "EXISTS(");
3088: sqlite3ExplainSelect(pOut, pExpr->x.pSelect);
3089: sqlite3ExplainPrintf(pOut,")");
3090: break;
3091: }
3092: case TK_SELECT: {
3093: sqlite3ExplainPrintf(pOut, "(");
3094: sqlite3ExplainSelect(pOut, pExpr->x.pSelect);
3095: sqlite3ExplainPrintf(pOut, ")");
3096: break;
3097: }
3098: case TK_IN: {
3099: sqlite3ExplainPrintf(pOut, "IN(");
3100: sqlite3ExplainExpr(pOut, pExpr->pLeft);
3101: sqlite3ExplainPrintf(pOut, ",");
3102: if( ExprHasProperty(pExpr, EP_xIsSelect) ){
3103: sqlite3ExplainSelect(pOut, pExpr->x.pSelect);
3104: }else{
3105: sqlite3ExplainExprList(pOut, pExpr->x.pList);
3106: }
3107: sqlite3ExplainPrintf(pOut, ")");
3108: break;
3109: }
3110: #endif /* SQLITE_OMIT_SUBQUERY */
3111:
3112: /*
3113: ** x BETWEEN y AND z
3114: **
3115: ** This is equivalent to
3116: **
3117: ** x>=y AND x<=z
3118: **
3119: ** X is stored in pExpr->pLeft.
3120: ** Y is stored in pExpr->pList->a[0].pExpr.
3121: ** Z is stored in pExpr->pList->a[1].pExpr.
3122: */
3123: case TK_BETWEEN: {
3124: Expr *pX = pExpr->pLeft;
3125: Expr *pY = pExpr->x.pList->a[0].pExpr;
3126: Expr *pZ = pExpr->x.pList->a[1].pExpr;
3127: sqlite3ExplainPrintf(pOut, "BETWEEN(");
3128: sqlite3ExplainExpr(pOut, pX);
3129: sqlite3ExplainPrintf(pOut, ",");
3130: sqlite3ExplainExpr(pOut, pY);
3131: sqlite3ExplainPrintf(pOut, ",");
3132: sqlite3ExplainExpr(pOut, pZ);
3133: sqlite3ExplainPrintf(pOut, ")");
3134: break;
3135: }
3136: case TK_TRIGGER: {
3137: /* If the opcode is TK_TRIGGER, then the expression is a reference
3138: ** to a column in the new.* or old.* pseudo-tables available to
3139: ** trigger programs. In this case Expr.iTable is set to 1 for the
3140: ** new.* pseudo-table, or 0 for the old.* pseudo-table. Expr.iColumn
3141: ** is set to the column of the pseudo-table to read, or to -1 to
3142: ** read the rowid field.
3143: */
3144: sqlite3ExplainPrintf(pOut, "%s(%d)",
3145: pExpr->iTable ? "NEW" : "OLD", pExpr->iColumn);
3146: break;
3147: }
3148: case TK_CASE: {
3149: sqlite3ExplainPrintf(pOut, "CASE(");
3150: sqlite3ExplainExpr(pOut, pExpr->pLeft);
3151: sqlite3ExplainPrintf(pOut, ",");
3152: sqlite3ExplainExprList(pOut, pExpr->x.pList);
3153: break;
3154: }
3155: #ifndef SQLITE_OMIT_TRIGGER
3156: case TK_RAISE: {
3157: const char *zType = "unk";
3158: switch( pExpr->affinity ){
3159: case OE_Rollback: zType = "rollback"; break;
3160: case OE_Abort: zType = "abort"; break;
3161: case OE_Fail: zType = "fail"; break;
3162: case OE_Ignore: zType = "ignore"; break;
3163: }
3164: sqlite3ExplainPrintf(pOut, "RAISE-%s(%s)", zType, pExpr->u.zToken);
3165: break;
3166: }
3167: #endif
3168: }
3169: if( zBinOp ){
3170: sqlite3ExplainPrintf(pOut,"%s(", zBinOp);
3171: sqlite3ExplainExpr(pOut, pExpr->pLeft);
3172: sqlite3ExplainPrintf(pOut,",");
3173: sqlite3ExplainExpr(pOut, pExpr->pRight);
3174: sqlite3ExplainPrintf(pOut,")");
3175: }else if( zUniOp ){
3176: sqlite3ExplainPrintf(pOut,"%s(", zUniOp);
3177: sqlite3ExplainExpr(pOut, pExpr->pLeft);
3178: sqlite3ExplainPrintf(pOut,")");
3179: }
3180: }
3181: #endif /* defined(SQLITE_ENABLE_TREE_EXPLAIN) */
3182:
3183: #if defined(SQLITE_ENABLE_TREE_EXPLAIN)
3184: /*
3185: ** Generate a human-readable explanation of an expression list.
3186: */
3187: void sqlite3ExplainExprList(Vdbe *pOut, ExprList *pList){
3188: int i;
3189: if( pList==0 || pList->nExpr==0 ){
3190: sqlite3ExplainPrintf(pOut, "(empty-list)");
3191: return;
3192: }else if( pList->nExpr==1 ){
3193: sqlite3ExplainExpr(pOut, pList->a[0].pExpr);
3194: }else{
3195: sqlite3ExplainPush(pOut);
3196: for(i=0; i<pList->nExpr; i++){
3197: sqlite3ExplainPrintf(pOut, "item[%d] = ", i);
3198: sqlite3ExplainPush(pOut);
3199: sqlite3ExplainExpr(pOut, pList->a[i].pExpr);
3200: sqlite3ExplainPop(pOut);
3201: if( i<pList->nExpr-1 ){
3202: sqlite3ExplainNL(pOut);
3203: }
3204: }
3205: sqlite3ExplainPop(pOut);
3206: }
3207: }
3208: #endif /* SQLITE_DEBUG */
3209:
3210: /*
3211: ** Return TRUE if pExpr is an constant expression that is appropriate
3212: ** for factoring out of a loop. Appropriate expressions are:
3213: **
3214: ** * Any expression that evaluates to two or more opcodes.
3215: **
3216: ** * Any OP_Integer, OP_Real, OP_String, OP_Blob, OP_Null,
3217: ** or OP_Variable that does not need to be placed in a
3218: ** specific register.
3219: **
3220: ** There is no point in factoring out single-instruction constant
3221: ** expressions that need to be placed in a particular register.
3222: ** We could factor them out, but then we would end up adding an
3223: ** OP_SCopy instruction to move the value into the correct register
3224: ** later. We might as well just use the original instruction and
3225: ** avoid the OP_SCopy.
3226: */
3227: static int isAppropriateForFactoring(Expr *p){
3228: if( !sqlite3ExprIsConstantNotJoin(p) ){
3229: return 0; /* Only constant expressions are appropriate for factoring */
3230: }
3231: if( (p->flags & EP_FixedDest)==0 ){
3232: return 1; /* Any constant without a fixed destination is appropriate */
3233: }
3234: while( p->op==TK_UPLUS ) p = p->pLeft;
3235: switch( p->op ){
3236: #ifndef SQLITE_OMIT_BLOB_LITERAL
3237: case TK_BLOB:
3238: #endif
3239: case TK_VARIABLE:
3240: case TK_INTEGER:
3241: case TK_FLOAT:
3242: case TK_NULL:
3243: case TK_STRING: {
3244: testcase( p->op==TK_BLOB );
3245: testcase( p->op==TK_VARIABLE );
3246: testcase( p->op==TK_INTEGER );
3247: testcase( p->op==TK_FLOAT );
3248: testcase( p->op==TK_NULL );
3249: testcase( p->op==TK_STRING );
3250: /* Single-instruction constants with a fixed destination are
3251: ** better done in-line. If we factor them, they will just end
3252: ** up generating an OP_SCopy to move the value to the destination
3253: ** register. */
3254: return 0;
3255: }
3256: case TK_UMINUS: {
3257: if( p->pLeft->op==TK_FLOAT || p->pLeft->op==TK_INTEGER ){
3258: return 0;
3259: }
3260: break;
3261: }
3262: default: {
3263: break;
3264: }
3265: }
3266: return 1;
3267: }
3268:
3269: /*
3270: ** If pExpr is a constant expression that is appropriate for
3271: ** factoring out of a loop, then evaluate the expression
3272: ** into a register and convert the expression into a TK_REGISTER
3273: ** expression.
3274: */
3275: static int evalConstExpr(Walker *pWalker, Expr *pExpr){
3276: Parse *pParse = pWalker->pParse;
3277: switch( pExpr->op ){
3278: case TK_IN:
3279: case TK_REGISTER: {
3280: return WRC_Prune;
3281: }
3282: case TK_FUNCTION:
3283: case TK_AGG_FUNCTION:
3284: case TK_CONST_FUNC: {
3285: /* The arguments to a function have a fixed destination.
3286: ** Mark them this way to avoid generated unneeded OP_SCopy
3287: ** instructions.
3288: */
3289: ExprList *pList = pExpr->x.pList;
3290: assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
3291: if( pList ){
3292: int i = pList->nExpr;
3293: struct ExprList_item *pItem = pList->a;
3294: for(; i>0; i--, pItem++){
3295: if( ALWAYS(pItem->pExpr) ) pItem->pExpr->flags |= EP_FixedDest;
3296: }
3297: }
3298: break;
3299: }
3300: }
3301: if( isAppropriateForFactoring(pExpr) ){
3302: int r1 = ++pParse->nMem;
3303: int r2;
3304: r2 = sqlite3ExprCodeTarget(pParse, pExpr, r1);
3305: if( NEVER(r1!=r2) ) sqlite3ReleaseTempReg(pParse, r1);
3306: pExpr->op2 = pExpr->op;
3307: pExpr->op = TK_REGISTER;
3308: pExpr->iTable = r2;
3309: return WRC_Prune;
3310: }
3311: return WRC_Continue;
3312: }
3313:
3314: /*
3315: ** Preevaluate constant subexpressions within pExpr and store the
3316: ** results in registers. Modify pExpr so that the constant subexpresions
3317: ** are TK_REGISTER opcodes that refer to the precomputed values.
3318: **
3319: ** This routine is a no-op if the jump to the cookie-check code has
3320: ** already occur. Since the cookie-check jump is generated prior to
3321: ** any other serious processing, this check ensures that there is no
3322: ** way to accidently bypass the constant initializations.
3323: **
3324: ** This routine is also a no-op if the SQLITE_FactorOutConst optimization
3325: ** is disabled via the sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS)
3326: ** interface. This allows test logic to verify that the same answer is
3327: ** obtained for queries regardless of whether or not constants are
3328: ** precomputed into registers or if they are inserted in-line.
3329: */
3330: void sqlite3ExprCodeConstants(Parse *pParse, Expr *pExpr){
3331: Walker w;
3332: if( pParse->cookieGoto ) return;
3333: if( (pParse->db->flags & SQLITE_FactorOutConst)!=0 ) return;
3334: w.xExprCallback = evalConstExpr;
3335: w.xSelectCallback = 0;
3336: w.pParse = pParse;
3337: sqlite3WalkExpr(&w, pExpr);
3338: }
3339:
3340:
3341: /*
3342: ** Generate code that pushes the value of every element of the given
3343: ** expression list into a sequence of registers beginning at target.
3344: **
3345: ** Return the number of elements evaluated.
3346: */
3347: int sqlite3ExprCodeExprList(
3348: Parse *pParse, /* Parsing context */
3349: ExprList *pList, /* The expression list to be coded */
3350: int target, /* Where to write results */
3351: int doHardCopy /* Make a hard copy of every element */
3352: ){
3353: struct ExprList_item *pItem;
3354: int i, n;
3355: assert( pList!=0 );
3356: assert( target>0 );
3357: assert( pParse->pVdbe!=0 ); /* Never gets this far otherwise */
3358: n = pList->nExpr;
3359: for(pItem=pList->a, i=0; i<n; i++, pItem++){
3360: Expr *pExpr = pItem->pExpr;
3361: int inReg = sqlite3ExprCodeTarget(pParse, pExpr, target+i);
3362: if( inReg!=target+i ){
3363: sqlite3VdbeAddOp2(pParse->pVdbe, doHardCopy ? OP_Copy : OP_SCopy,
3364: inReg, target+i);
3365: }
3366: }
3367: return n;
3368: }
3369:
3370: /*
3371: ** Generate code for a BETWEEN operator.
3372: **
3373: ** x BETWEEN y AND z
3374: **
3375: ** The above is equivalent to
3376: **
3377: ** x>=y AND x<=z
3378: **
3379: ** Code it as such, taking care to do the common subexpression
3380: ** elementation of x.
3381: */
3382: static void exprCodeBetween(
3383: Parse *pParse, /* Parsing and code generating context */
3384: Expr *pExpr, /* The BETWEEN expression */
3385: int dest, /* Jump here if the jump is taken */
3386: int jumpIfTrue, /* Take the jump if the BETWEEN is true */
3387: int jumpIfNull /* Take the jump if the BETWEEN is NULL */
3388: ){
3389: Expr exprAnd; /* The AND operator in x>=y AND x<=z */
3390: Expr compLeft; /* The x>=y term */
3391: Expr compRight; /* The x<=z term */
3392: Expr exprX; /* The x subexpression */
3393: int regFree1 = 0; /* Temporary use register */
3394:
3395: assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
3396: exprX = *pExpr->pLeft;
3397: exprAnd.op = TK_AND;
3398: exprAnd.pLeft = &compLeft;
3399: exprAnd.pRight = &compRight;
3400: compLeft.op = TK_GE;
3401: compLeft.pLeft = &exprX;
3402: compLeft.pRight = pExpr->x.pList->a[0].pExpr;
3403: compRight.op = TK_LE;
3404: compRight.pLeft = &exprX;
3405: compRight.pRight = pExpr->x.pList->a[1].pExpr;
3406: exprX.iTable = sqlite3ExprCodeTemp(pParse, &exprX, ®Free1);
3407: exprX.op = TK_REGISTER;
3408: if( jumpIfTrue ){
3409: sqlite3ExprIfTrue(pParse, &exprAnd, dest, jumpIfNull);
3410: }else{
3411: sqlite3ExprIfFalse(pParse, &exprAnd, dest, jumpIfNull);
3412: }
3413: sqlite3ReleaseTempReg(pParse, regFree1);
3414:
3415: /* Ensure adequate test coverage */
3416: testcase( jumpIfTrue==0 && jumpIfNull==0 && regFree1==0 );
3417: testcase( jumpIfTrue==0 && jumpIfNull==0 && regFree1!=0 );
3418: testcase( jumpIfTrue==0 && jumpIfNull!=0 && regFree1==0 );
3419: testcase( jumpIfTrue==0 && jumpIfNull!=0 && regFree1!=0 );
3420: testcase( jumpIfTrue!=0 && jumpIfNull==0 && regFree1==0 );
3421: testcase( jumpIfTrue!=0 && jumpIfNull==0 && regFree1!=0 );
3422: testcase( jumpIfTrue!=0 && jumpIfNull!=0 && regFree1==0 );
3423: testcase( jumpIfTrue!=0 && jumpIfNull!=0 && regFree1!=0 );
3424: }
3425:
3426: /*
3427: ** Generate code for a boolean expression such that a jump is made
3428: ** to the label "dest" if the expression is true but execution
3429: ** continues straight thru if the expression is false.
3430: **
3431: ** If the expression evaluates to NULL (neither true nor false), then
3432: ** take the jump if the jumpIfNull flag is SQLITE_JUMPIFNULL.
3433: **
3434: ** This code depends on the fact that certain token values (ex: TK_EQ)
3435: ** are the same as opcode values (ex: OP_Eq) that implement the corresponding
3436: ** operation. Special comments in vdbe.c and the mkopcodeh.awk script in
3437: ** the make process cause these values to align. Assert()s in the code
3438: ** below verify that the numbers are aligned correctly.
3439: */
3440: void sqlite3ExprIfTrue(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
3441: Vdbe *v = pParse->pVdbe;
3442: int op = 0;
3443: int regFree1 = 0;
3444: int regFree2 = 0;
3445: int r1, r2;
3446:
3447: assert( jumpIfNull==SQLITE_JUMPIFNULL || jumpIfNull==0 );
3448: if( NEVER(v==0) ) return; /* Existance of VDBE checked by caller */
3449: if( NEVER(pExpr==0) ) return; /* No way this can happen */
3450: op = pExpr->op;
3451: switch( op ){
3452: case TK_AND: {
3453: int d2 = sqlite3VdbeMakeLabel(v);
3454: testcase( jumpIfNull==0 );
3455: sqlite3ExprCachePush(pParse);
3456: sqlite3ExprIfFalse(pParse, pExpr->pLeft, d2,jumpIfNull^SQLITE_JUMPIFNULL);
3457: sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);
3458: sqlite3VdbeResolveLabel(v, d2);
3459: sqlite3ExprCachePop(pParse, 1);
3460: break;
3461: }
3462: case TK_OR: {
3463: testcase( jumpIfNull==0 );
3464: sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);
3465: sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);
3466: break;
3467: }
3468: case TK_NOT: {
3469: testcase( jumpIfNull==0 );
3470: sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);
3471: break;
3472: }
3473: case TK_LT:
3474: case TK_LE:
3475: case TK_GT:
3476: case TK_GE:
3477: case TK_NE:
3478: case TK_EQ: {
3479: assert( TK_LT==OP_Lt );
3480: assert( TK_LE==OP_Le );
3481: assert( TK_GT==OP_Gt );
3482: assert( TK_GE==OP_Ge );
3483: assert( TK_EQ==OP_Eq );
3484: assert( TK_NE==OP_Ne );
3485: testcase( op==TK_LT );
3486: testcase( op==TK_LE );
3487: testcase( op==TK_GT );
3488: testcase( op==TK_GE );
3489: testcase( op==TK_EQ );
3490: testcase( op==TK_NE );
3491: testcase( jumpIfNull==0 );
3492: r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
3493: r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2);
3494: codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
3495: r1, r2, dest, jumpIfNull);
3496: testcase( regFree1==0 );
3497: testcase( regFree2==0 );
3498: break;
3499: }
3500: case TK_IS:
3501: case TK_ISNOT: {
3502: testcase( op==TK_IS );
3503: testcase( op==TK_ISNOT );
3504: r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
3505: r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2);
3506: op = (op==TK_IS) ? TK_EQ : TK_NE;
3507: codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
3508: r1, r2, dest, SQLITE_NULLEQ);
3509: testcase( regFree1==0 );
3510: testcase( regFree2==0 );
3511: break;
3512: }
3513: case TK_ISNULL:
3514: case TK_NOTNULL: {
3515: assert( TK_ISNULL==OP_IsNull );
3516: assert( TK_NOTNULL==OP_NotNull );
3517: testcase( op==TK_ISNULL );
3518: testcase( op==TK_NOTNULL );
3519: r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
3520: sqlite3VdbeAddOp2(v, op, r1, dest);
3521: testcase( regFree1==0 );
3522: break;
3523: }
3524: case TK_BETWEEN: {
3525: testcase( jumpIfNull==0 );
3526: exprCodeBetween(pParse, pExpr, dest, 1, jumpIfNull);
3527: break;
3528: }
3529: #ifndef SQLITE_OMIT_SUBQUERY
3530: case TK_IN: {
3531: int destIfFalse = sqlite3VdbeMakeLabel(v);
3532: int destIfNull = jumpIfNull ? dest : destIfFalse;
3533: sqlite3ExprCodeIN(pParse, pExpr, destIfFalse, destIfNull);
3534: sqlite3VdbeAddOp2(v, OP_Goto, 0, dest);
3535: sqlite3VdbeResolveLabel(v, destIfFalse);
3536: break;
3537: }
3538: #endif
3539: default: {
3540: r1 = sqlite3ExprCodeTemp(pParse, pExpr, ®Free1);
3541: sqlite3VdbeAddOp3(v, OP_If, r1, dest, jumpIfNull!=0);
3542: testcase( regFree1==0 );
3543: testcase( jumpIfNull==0 );
3544: break;
3545: }
3546: }
3547: sqlite3ReleaseTempReg(pParse, regFree1);
3548: sqlite3ReleaseTempReg(pParse, regFree2);
3549: }
3550:
3551: /*
3552: ** Generate code for a boolean expression such that a jump is made
3553: ** to the label "dest" if the expression is false but execution
3554: ** continues straight thru if the expression is true.
3555: **
3556: ** If the expression evaluates to NULL (neither true nor false) then
3557: ** jump if jumpIfNull is SQLITE_JUMPIFNULL or fall through if jumpIfNull
3558: ** is 0.
3559: */
3560: void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
3561: Vdbe *v = pParse->pVdbe;
3562: int op = 0;
3563: int regFree1 = 0;
3564: int regFree2 = 0;
3565: int r1, r2;
3566:
3567: assert( jumpIfNull==SQLITE_JUMPIFNULL || jumpIfNull==0 );
3568: if( NEVER(v==0) ) return; /* Existance of VDBE checked by caller */
3569: if( pExpr==0 ) return;
3570:
3571: /* The value of pExpr->op and op are related as follows:
3572: **
3573: ** pExpr->op op
3574: ** --------- ----------
3575: ** TK_ISNULL OP_NotNull
3576: ** TK_NOTNULL OP_IsNull
3577: ** TK_NE OP_Eq
3578: ** TK_EQ OP_Ne
3579: ** TK_GT OP_Le
3580: ** TK_LE OP_Gt
3581: ** TK_GE OP_Lt
3582: ** TK_LT OP_Ge
3583: **
3584: ** For other values of pExpr->op, op is undefined and unused.
3585: ** The value of TK_ and OP_ constants are arranged such that we
3586: ** can compute the mapping above using the following expression.
3587: ** Assert()s verify that the computation is correct.
3588: */
3589: op = ((pExpr->op+(TK_ISNULL&1))^1)-(TK_ISNULL&1);
3590:
3591: /* Verify correct alignment of TK_ and OP_ constants
3592: */
3593: assert( pExpr->op!=TK_ISNULL || op==OP_NotNull );
3594: assert( pExpr->op!=TK_NOTNULL || op==OP_IsNull );
3595: assert( pExpr->op!=TK_NE || op==OP_Eq );
3596: assert( pExpr->op!=TK_EQ || op==OP_Ne );
3597: assert( pExpr->op!=TK_LT || op==OP_Ge );
3598: assert( pExpr->op!=TK_LE || op==OP_Gt );
3599: assert( pExpr->op!=TK_GT || op==OP_Le );
3600: assert( pExpr->op!=TK_GE || op==OP_Lt );
3601:
3602: switch( pExpr->op ){
3603: case TK_AND: {
3604: testcase( jumpIfNull==0 );
3605: sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);
3606: sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
3607: break;
3608: }
3609: case TK_OR: {
3610: int d2 = sqlite3VdbeMakeLabel(v);
3611: testcase( jumpIfNull==0 );
3612: sqlite3ExprCachePush(pParse);
3613: sqlite3ExprIfTrue(pParse, pExpr->pLeft, d2, jumpIfNull^SQLITE_JUMPIFNULL);
3614: sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
3615: sqlite3VdbeResolveLabel(v, d2);
3616: sqlite3ExprCachePop(pParse, 1);
3617: break;
3618: }
3619: case TK_NOT: {
3620: testcase( jumpIfNull==0 );
3621: sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);
3622: break;
3623: }
3624: case TK_LT:
3625: case TK_LE:
3626: case TK_GT:
3627: case TK_GE:
3628: case TK_NE:
3629: case TK_EQ: {
3630: testcase( op==TK_LT );
3631: testcase( op==TK_LE );
3632: testcase( op==TK_GT );
3633: testcase( op==TK_GE );
3634: testcase( op==TK_EQ );
3635: testcase( op==TK_NE );
3636: testcase( jumpIfNull==0 );
3637: r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
3638: r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2);
3639: codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
3640: r1, r2, dest, jumpIfNull);
3641: testcase( regFree1==0 );
3642: testcase( regFree2==0 );
3643: break;
3644: }
3645: case TK_IS:
3646: case TK_ISNOT: {
3647: testcase( pExpr->op==TK_IS );
3648: testcase( pExpr->op==TK_ISNOT );
3649: r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
3650: r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2);
3651: op = (pExpr->op==TK_IS) ? TK_NE : TK_EQ;
3652: codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
3653: r1, r2, dest, SQLITE_NULLEQ);
3654: testcase( regFree1==0 );
3655: testcase( regFree2==0 );
3656: break;
3657: }
3658: case TK_ISNULL:
3659: case TK_NOTNULL: {
3660: testcase( op==TK_ISNULL );
3661: testcase( op==TK_NOTNULL );
3662: r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
3663: sqlite3VdbeAddOp2(v, op, r1, dest);
3664: testcase( regFree1==0 );
3665: break;
3666: }
3667: case TK_BETWEEN: {
3668: testcase( jumpIfNull==0 );
3669: exprCodeBetween(pParse, pExpr, dest, 0, jumpIfNull);
3670: break;
3671: }
3672: #ifndef SQLITE_OMIT_SUBQUERY
3673: case TK_IN: {
3674: if( jumpIfNull ){
3675: sqlite3ExprCodeIN(pParse, pExpr, dest, dest);
3676: }else{
3677: int destIfNull = sqlite3VdbeMakeLabel(v);
3678: sqlite3ExprCodeIN(pParse, pExpr, dest, destIfNull);
3679: sqlite3VdbeResolveLabel(v, destIfNull);
3680: }
3681: break;
3682: }
3683: #endif
3684: default: {
3685: r1 = sqlite3ExprCodeTemp(pParse, pExpr, ®Free1);
3686: sqlite3VdbeAddOp3(v, OP_IfNot, r1, dest, jumpIfNull!=0);
3687: testcase( regFree1==0 );
3688: testcase( jumpIfNull==0 );
3689: break;
3690: }
3691: }
3692: sqlite3ReleaseTempReg(pParse, regFree1);
3693: sqlite3ReleaseTempReg(pParse, regFree2);
3694: }
3695:
3696: /*
3697: ** Do a deep comparison of two expression trees. Return 0 if the two
3698: ** expressions are completely identical. Return 1 if they differ only
3699: ** by a COLLATE operator at the top level. Return 2 if there are differences
3700: ** other than the top-level COLLATE operator.
3701: **
3702: ** Sometimes this routine will return 2 even if the two expressions
3703: ** really are equivalent. If we cannot prove that the expressions are
3704: ** identical, we return 2 just to be safe. So if this routine
3705: ** returns 2, then you do not really know for certain if the two
3706: ** expressions are the same. But if you get a 0 or 1 return, then you
3707: ** can be sure the expressions are the same. In the places where
3708: ** this routine is used, it does not hurt to get an extra 2 - that
3709: ** just might result in some slightly slower code. But returning
3710: ** an incorrect 0 or 1 could lead to a malfunction.
3711: */
3712: int sqlite3ExprCompare(Expr *pA, Expr *pB){
3713: if( pA==0||pB==0 ){
3714: return pB==pA ? 0 : 2;
3715: }
3716: assert( !ExprHasAnyProperty(pA, EP_TokenOnly|EP_Reduced) );
3717: assert( !ExprHasAnyProperty(pB, EP_TokenOnly|EP_Reduced) );
3718: if( ExprHasProperty(pA, EP_xIsSelect) || ExprHasProperty(pB, EP_xIsSelect) ){
3719: return 2;
3720: }
3721: if( (pA->flags & EP_Distinct)!=(pB->flags & EP_Distinct) ) return 2;
3722: if( pA->op!=pB->op ) return 2;
3723: if( sqlite3ExprCompare(pA->pLeft, pB->pLeft) ) return 2;
3724: if( sqlite3ExprCompare(pA->pRight, pB->pRight) ) return 2;
3725: if( sqlite3ExprListCompare(pA->x.pList, pB->x.pList) ) return 2;
3726: if( pA->iTable!=pB->iTable || pA->iColumn!=pB->iColumn ) return 2;
3727: if( ExprHasProperty(pA, EP_IntValue) ){
3728: if( !ExprHasProperty(pB, EP_IntValue) || pA->u.iValue!=pB->u.iValue ){
3729: return 2;
3730: }
3731: }else if( pA->op!=TK_COLUMN && pA->u.zToken ){
3732: if( ExprHasProperty(pB, EP_IntValue) || NEVER(pB->u.zToken==0) ) return 2;
3733: if( strcmp(pA->u.zToken,pB->u.zToken)!=0 ){
3734: return 2;
3735: }
3736: }
3737: if( (pA->flags & EP_ExpCollate)!=(pB->flags & EP_ExpCollate) ) return 1;
3738: if( (pA->flags & EP_ExpCollate)!=0 && pA->pColl!=pB->pColl ) return 2;
3739: return 0;
3740: }
3741:
3742: /*
3743: ** Compare two ExprList objects. Return 0 if they are identical and
3744: ** non-zero if they differ in any way.
3745: **
3746: ** This routine might return non-zero for equivalent ExprLists. The
3747: ** only consequence will be disabled optimizations. But this routine
3748: ** must never return 0 if the two ExprList objects are different, or
3749: ** a malfunction will result.
3750: **
3751: ** Two NULL pointers are considered to be the same. But a NULL pointer
3752: ** always differs from a non-NULL pointer.
3753: */
3754: int sqlite3ExprListCompare(ExprList *pA, ExprList *pB){
3755: int i;
3756: if( pA==0 && pB==0 ) return 0;
3757: if( pA==0 || pB==0 ) return 1;
3758: if( pA->nExpr!=pB->nExpr ) return 1;
3759: for(i=0; i<pA->nExpr; i++){
3760: Expr *pExprA = pA->a[i].pExpr;
3761: Expr *pExprB = pB->a[i].pExpr;
3762: if( pA->a[i].sortOrder!=pB->a[i].sortOrder ) return 1;
3763: if( sqlite3ExprCompare(pExprA, pExprB) ) return 1;
3764: }
3765: return 0;
3766: }
3767:
3768: /*
3769: ** Add a new element to the pAggInfo->aCol[] array. Return the index of
3770: ** the new element. Return a negative number if malloc fails.
3771: */
3772: static int addAggInfoColumn(sqlite3 *db, AggInfo *pInfo){
3773: int i;
3774: pInfo->aCol = sqlite3ArrayAllocate(
3775: db,
3776: pInfo->aCol,
3777: sizeof(pInfo->aCol[0]),
3778: 3,
3779: &pInfo->nColumn,
3780: &pInfo->nColumnAlloc,
3781: &i
3782: );
3783: return i;
3784: }
3785:
3786: /*
3787: ** Add a new element to the pAggInfo->aFunc[] array. Return the index of
3788: ** the new element. Return a negative number if malloc fails.
3789: */
3790: static int addAggInfoFunc(sqlite3 *db, AggInfo *pInfo){
3791: int i;
3792: pInfo->aFunc = sqlite3ArrayAllocate(
3793: db,
3794: pInfo->aFunc,
3795: sizeof(pInfo->aFunc[0]),
3796: 3,
3797: &pInfo->nFunc,
3798: &pInfo->nFuncAlloc,
3799: &i
3800: );
3801: return i;
3802: }
3803:
3804: /*
3805: ** This is the xExprCallback for a tree walker. It is used to
3806: ** implement sqlite3ExprAnalyzeAggregates(). See sqlite3ExprAnalyzeAggregates
3807: ** for additional information.
3808: */
3809: static int analyzeAggregate(Walker *pWalker, Expr *pExpr){
3810: int i;
3811: NameContext *pNC = pWalker->u.pNC;
3812: Parse *pParse = pNC->pParse;
3813: SrcList *pSrcList = pNC->pSrcList;
3814: AggInfo *pAggInfo = pNC->pAggInfo;
3815:
3816: switch( pExpr->op ){
3817: case TK_AGG_COLUMN:
3818: case TK_COLUMN: {
3819: testcase( pExpr->op==TK_AGG_COLUMN );
3820: testcase( pExpr->op==TK_COLUMN );
3821: /* Check to see if the column is in one of the tables in the FROM
3822: ** clause of the aggregate query */
3823: if( ALWAYS(pSrcList!=0) ){
3824: struct SrcList_item *pItem = pSrcList->a;
3825: for(i=0; i<pSrcList->nSrc; i++, pItem++){
3826: struct AggInfo_col *pCol;
3827: assert( !ExprHasAnyProperty(pExpr, EP_TokenOnly|EP_Reduced) );
3828: if( pExpr->iTable==pItem->iCursor ){
3829: /* If we reach this point, it means that pExpr refers to a table
3830: ** that is in the FROM clause of the aggregate query.
3831: **
3832: ** Make an entry for the column in pAggInfo->aCol[] if there
3833: ** is not an entry there already.
3834: */
3835: int k;
3836: pCol = pAggInfo->aCol;
3837: for(k=0; k<pAggInfo->nColumn; k++, pCol++){
3838: if( pCol->iTable==pExpr->iTable &&
3839: pCol->iColumn==pExpr->iColumn ){
3840: break;
3841: }
3842: }
3843: if( (k>=pAggInfo->nColumn)
3844: && (k = addAggInfoColumn(pParse->db, pAggInfo))>=0
3845: ){
3846: pCol = &pAggInfo->aCol[k];
3847: pCol->pTab = pExpr->pTab;
3848: pCol->iTable = pExpr->iTable;
3849: pCol->iColumn = pExpr->iColumn;
3850: pCol->iMem = ++pParse->nMem;
3851: pCol->iSorterColumn = -1;
3852: pCol->pExpr = pExpr;
3853: if( pAggInfo->pGroupBy ){
3854: int j, n;
3855: ExprList *pGB = pAggInfo->pGroupBy;
3856: struct ExprList_item *pTerm = pGB->a;
3857: n = pGB->nExpr;
3858: for(j=0; j<n; j++, pTerm++){
3859: Expr *pE = pTerm->pExpr;
3860: if( pE->op==TK_COLUMN && pE->iTable==pExpr->iTable &&
3861: pE->iColumn==pExpr->iColumn ){
3862: pCol->iSorterColumn = j;
3863: break;
3864: }
3865: }
3866: }
3867: if( pCol->iSorterColumn<0 ){
3868: pCol->iSorterColumn = pAggInfo->nSortingColumn++;
3869: }
3870: }
3871: /* There is now an entry for pExpr in pAggInfo->aCol[] (either
3872: ** because it was there before or because we just created it).
3873: ** Convert the pExpr to be a TK_AGG_COLUMN referring to that
3874: ** pAggInfo->aCol[] entry.
3875: */
3876: ExprSetIrreducible(pExpr);
3877: pExpr->pAggInfo = pAggInfo;
3878: pExpr->op = TK_AGG_COLUMN;
3879: pExpr->iAgg = (i16)k;
3880: break;
3881: } /* endif pExpr->iTable==pItem->iCursor */
3882: } /* end loop over pSrcList */
3883: }
3884: return WRC_Prune;
3885: }
3886: case TK_AGG_FUNCTION: {
3887: /* The pNC->nDepth==0 test causes aggregate functions in subqueries
3888: ** to be ignored */
3889: if( pNC->nDepth==0 ){
3890: /* Check to see if pExpr is a duplicate of another aggregate
3891: ** function that is already in the pAggInfo structure
3892: */
3893: struct AggInfo_func *pItem = pAggInfo->aFunc;
3894: for(i=0; i<pAggInfo->nFunc; i++, pItem++){
3895: if( sqlite3ExprCompare(pItem->pExpr, pExpr)==0 ){
3896: break;
3897: }
3898: }
3899: if( i>=pAggInfo->nFunc ){
3900: /* pExpr is original. Make a new entry in pAggInfo->aFunc[]
3901: */
3902: u8 enc = ENC(pParse->db);
3903: i = addAggInfoFunc(pParse->db, pAggInfo);
3904: if( i>=0 ){
3905: assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
3906: pItem = &pAggInfo->aFunc[i];
3907: pItem->pExpr = pExpr;
3908: pItem->iMem = ++pParse->nMem;
3909: assert( !ExprHasProperty(pExpr, EP_IntValue) );
3910: pItem->pFunc = sqlite3FindFunction(pParse->db,
3911: pExpr->u.zToken, sqlite3Strlen30(pExpr->u.zToken),
3912: pExpr->x.pList ? pExpr->x.pList->nExpr : 0, enc, 0);
3913: if( pExpr->flags & EP_Distinct ){
3914: pItem->iDistinct = pParse->nTab++;
3915: }else{
3916: pItem->iDistinct = -1;
3917: }
3918: }
3919: }
3920: /* Make pExpr point to the appropriate pAggInfo->aFunc[] entry
3921: */
3922: assert( !ExprHasAnyProperty(pExpr, EP_TokenOnly|EP_Reduced) );
3923: ExprSetIrreducible(pExpr);
3924: pExpr->iAgg = (i16)i;
3925: pExpr->pAggInfo = pAggInfo;
3926: return WRC_Prune;
3927: }
3928: }
3929: }
3930: return WRC_Continue;
3931: }
3932: static int analyzeAggregatesInSelect(Walker *pWalker, Select *pSelect){
3933: NameContext *pNC = pWalker->u.pNC;
3934: if( pNC->nDepth==0 ){
3935: pNC->nDepth++;
3936: sqlite3WalkSelect(pWalker, pSelect);
3937: pNC->nDepth--;
3938: return WRC_Prune;
3939: }else{
3940: return WRC_Continue;
3941: }
3942: }
3943:
3944: /*
3945: ** Analyze the given expression looking for aggregate functions and
3946: ** for variables that need to be added to the pParse->aAgg[] array.
3947: ** Make additional entries to the pParse->aAgg[] array as necessary.
3948: **
3949: ** This routine should only be called after the expression has been
3950: ** analyzed by sqlite3ResolveExprNames().
3951: */
3952: void sqlite3ExprAnalyzeAggregates(NameContext *pNC, Expr *pExpr){
3953: Walker w;
3954: w.xExprCallback = analyzeAggregate;
3955: w.xSelectCallback = analyzeAggregatesInSelect;
3956: w.u.pNC = pNC;
3957: assert( pNC->pSrcList!=0 );
3958: sqlite3WalkExpr(&w, pExpr);
3959: }
3960:
3961: /*
3962: ** Call sqlite3ExprAnalyzeAggregates() for every expression in an
3963: ** expression list. Return the number of errors.
3964: **
3965: ** If an error is found, the analysis is cut short.
3966: */
3967: void sqlite3ExprAnalyzeAggList(NameContext *pNC, ExprList *pList){
3968: struct ExprList_item *pItem;
3969: int i;
3970: if( pList ){
3971: for(pItem=pList->a, i=0; i<pList->nExpr; i++, pItem++){
3972: sqlite3ExprAnalyzeAggregates(pNC, pItem->pExpr);
3973: }
3974: }
3975: }
3976:
3977: /*
3978: ** Allocate a single new register for use to hold some intermediate result.
3979: */
3980: int sqlite3GetTempReg(Parse *pParse){
3981: if( pParse->nTempReg==0 ){
3982: return ++pParse->nMem;
3983: }
3984: return pParse->aTempReg[--pParse->nTempReg];
3985: }
3986:
3987: /*
3988: ** Deallocate a register, making available for reuse for some other
3989: ** purpose.
3990: **
3991: ** If a register is currently being used by the column cache, then
3992: ** the dallocation is deferred until the column cache line that uses
3993: ** the register becomes stale.
3994: */
3995: void sqlite3ReleaseTempReg(Parse *pParse, int iReg){
3996: if( iReg && pParse->nTempReg<ArraySize(pParse->aTempReg) ){
3997: int i;
3998: struct yColCache *p;
3999: for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
4000: if( p->iReg==iReg ){
4001: p->tempReg = 1;
4002: return;
4003: }
4004: }
4005: pParse->aTempReg[pParse->nTempReg++] = iReg;
4006: }
4007: }
4008:
4009: /*
4010: ** Allocate or deallocate a block of nReg consecutive registers
4011: */
4012: int sqlite3GetTempRange(Parse *pParse, int nReg){
4013: int i, n;
4014: i = pParse->iRangeReg;
4015: n = pParse->nRangeReg;
4016: if( nReg<=n ){
4017: assert( !usedAsColumnCache(pParse, i, i+n-1) );
4018: pParse->iRangeReg += nReg;
4019: pParse->nRangeReg -= nReg;
4020: }else{
4021: i = pParse->nMem+1;
4022: pParse->nMem += nReg;
4023: }
4024: return i;
4025: }
4026: void sqlite3ReleaseTempRange(Parse *pParse, int iReg, int nReg){
4027: sqlite3ExprCacheRemove(pParse, iReg, nReg);
4028: if( nReg>pParse->nRangeReg ){
4029: pParse->nRangeReg = nReg;
4030: pParse->iRangeReg = iReg;
4031: }
4032: }
4033:
4034: /*
4035: ** Mark all temporary registers as being unavailable for reuse.
4036: */
4037: void sqlite3ClearTempRegCache(Parse *pParse){
4038: pParse->nTempReg = 0;
4039: pParse->nRangeReg = 0;
4040: }
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