1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/os/persistentdata/persistentstorage/sqlite3api/SQLite/expr.c Fri Jun 15 03:10:57 2012 +0200
1.3 @@ -0,0 +1,3076 @@
1.4 +/*
1.5 +** 2001 September 15
1.6 +**
1.7 +** The author disclaims copyright to this source code. In place of
1.8 +** a legal notice, here is a blessing:
1.9 +**
1.10 +** May you do good and not evil.
1.11 +** May you find forgiveness for yourself and forgive others.
1.12 +** May you share freely, never taking more than you give.
1.13 +**
1.14 +*************************************************************************
1.15 +** This file contains routines used for analyzing expressions and
1.16 +** for generating VDBE code that evaluates expressions in SQLite.
1.17 +**
1.18 +** $Id: expr.c,v 1.395 2008/10/02 13:50:56 danielk1977 Exp $
1.19 +*/
1.20 +#include "sqliteInt.h"
1.21 +#include <ctype.h>
1.22 +
1.23 +/*
1.24 +** Return the 'affinity' of the expression pExpr if any.
1.25 +**
1.26 +** If pExpr is a column, a reference to a column via an 'AS' alias,
1.27 +** or a sub-select with a column as the return value, then the
1.28 +** affinity of that column is returned. Otherwise, 0x00 is returned,
1.29 +** indicating no affinity for the expression.
1.30 +**
1.31 +** i.e. the WHERE clause expresssions in the following statements all
1.32 +** have an affinity:
1.33 +**
1.34 +** CREATE TABLE t1(a);
1.35 +** SELECT * FROM t1 WHERE a;
1.36 +** SELECT a AS b FROM t1 WHERE b;
1.37 +** SELECT * FROM t1 WHERE (select a from t1);
1.38 +*/
1.39 +char sqlite3ExprAffinity(Expr *pExpr){
1.40 + int op = pExpr->op;
1.41 + if( op==TK_SELECT ){
1.42 + return sqlite3ExprAffinity(pExpr->pSelect->pEList->a[0].pExpr);
1.43 + }
1.44 +#ifndef SQLITE_OMIT_CAST
1.45 + if( op==TK_CAST ){
1.46 + return sqlite3AffinityType(&pExpr->token);
1.47 + }
1.48 +#endif
1.49 + if( (op==TK_COLUMN || op==TK_REGISTER) && pExpr->pTab!=0 ){
1.50 + /* op==TK_REGISTER && pExpr->pTab!=0 happens when pExpr was originally
1.51 + ** a TK_COLUMN but was previously evaluated and cached in a register */
1.52 + int j = pExpr->iColumn;
1.53 + if( j<0 ) return SQLITE_AFF_INTEGER;
1.54 + assert( pExpr->pTab && j<pExpr->pTab->nCol );
1.55 + return pExpr->pTab->aCol[j].affinity;
1.56 + }
1.57 + return pExpr->affinity;
1.58 +}
1.59 +
1.60 +/*
1.61 +** Set the collating sequence for expression pExpr to be the collating
1.62 +** sequence named by pToken. Return a pointer to the revised expression.
1.63 +** The collating sequence is marked as "explicit" using the EP_ExpCollate
1.64 +** flag. An explicit collating sequence will override implicit
1.65 +** collating sequences.
1.66 +*/
1.67 +Expr *sqlite3ExprSetColl(Parse *pParse, Expr *pExpr, Token *pCollName){
1.68 + char *zColl = 0; /* Dequoted name of collation sequence */
1.69 + CollSeq *pColl;
1.70 + sqlite3 *db = pParse->db;
1.71 + zColl = sqlite3NameFromToken(db, pCollName);
1.72 + if( pExpr && zColl ){
1.73 + pColl = sqlite3LocateCollSeq(pParse, zColl, -1);
1.74 + if( pColl ){
1.75 + pExpr->pColl = pColl;
1.76 + pExpr->flags |= EP_ExpCollate;
1.77 + }
1.78 + }
1.79 + sqlite3DbFree(db, zColl);
1.80 + return pExpr;
1.81 +}
1.82 +
1.83 +/*
1.84 +** Return the default collation sequence for the expression pExpr. If
1.85 +** there is no default collation type, return 0.
1.86 +*/
1.87 +CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr){
1.88 + CollSeq *pColl = 0;
1.89 + Expr *p = pExpr;
1.90 + while( p ){
1.91 + int op;
1.92 + pColl = p->pColl;
1.93 + if( pColl ) break;
1.94 + op = p->op;
1.95 + if( (op==TK_COLUMN || op==TK_REGISTER) && p->pTab!=0 ){
1.96 + /* op==TK_REGISTER && p->pTab!=0 happens when pExpr was originally
1.97 + ** a TK_COLUMN but was previously evaluated and cached in a register */
1.98 + const char *zColl;
1.99 + int j = p->iColumn;
1.100 + if( j>=0 ){
1.101 + sqlite3 *db = pParse->db;
1.102 + zColl = p->pTab->aCol[j].zColl;
1.103 + pColl = sqlite3FindCollSeq(db, ENC(db), zColl, -1, 0);
1.104 + pExpr->pColl = pColl;
1.105 + }
1.106 + break;
1.107 + }
1.108 + if( op!=TK_CAST && op!=TK_UPLUS ){
1.109 + break;
1.110 + }
1.111 + p = p->pLeft;
1.112 + }
1.113 + if( sqlite3CheckCollSeq(pParse, pColl) ){
1.114 + pColl = 0;
1.115 + }
1.116 + return pColl;
1.117 +}
1.118 +
1.119 +/*
1.120 +** pExpr is an operand of a comparison operator. aff2 is the
1.121 +** type affinity of the other operand. This routine returns the
1.122 +** type affinity that should be used for the comparison operator.
1.123 +*/
1.124 +char sqlite3CompareAffinity(Expr *pExpr, char aff2){
1.125 + char aff1 = sqlite3ExprAffinity(pExpr);
1.126 + if( aff1 && aff2 ){
1.127 + /* Both sides of the comparison are columns. If one has numeric
1.128 + ** affinity, use that. Otherwise use no affinity.
1.129 + */
1.130 + if( sqlite3IsNumericAffinity(aff1) || sqlite3IsNumericAffinity(aff2) ){
1.131 + return SQLITE_AFF_NUMERIC;
1.132 + }else{
1.133 + return SQLITE_AFF_NONE;
1.134 + }
1.135 + }else if( !aff1 && !aff2 ){
1.136 + /* Neither side of the comparison is a column. Compare the
1.137 + ** results directly.
1.138 + */
1.139 + return SQLITE_AFF_NONE;
1.140 + }else{
1.141 + /* One side is a column, the other is not. Use the columns affinity. */
1.142 + assert( aff1==0 || aff2==0 );
1.143 + return (aff1 + aff2);
1.144 + }
1.145 +}
1.146 +
1.147 +/*
1.148 +** pExpr is a comparison operator. Return the type affinity that should
1.149 +** be applied to both operands prior to doing the comparison.
1.150 +*/
1.151 +static char comparisonAffinity(Expr *pExpr){
1.152 + char aff;
1.153 + assert( pExpr->op==TK_EQ || pExpr->op==TK_IN || pExpr->op==TK_LT ||
1.154 + pExpr->op==TK_GT || pExpr->op==TK_GE || pExpr->op==TK_LE ||
1.155 + pExpr->op==TK_NE );
1.156 + assert( pExpr->pLeft );
1.157 + aff = sqlite3ExprAffinity(pExpr->pLeft);
1.158 + if( pExpr->pRight ){
1.159 + aff = sqlite3CompareAffinity(pExpr->pRight, aff);
1.160 + }
1.161 + else if( pExpr->pSelect ){
1.162 + aff = sqlite3CompareAffinity(pExpr->pSelect->pEList->a[0].pExpr, aff);
1.163 + }
1.164 + else if( !aff ){
1.165 + aff = SQLITE_AFF_NONE;
1.166 + }
1.167 + return aff;
1.168 +}
1.169 +
1.170 +/*
1.171 +** pExpr is a comparison expression, eg. '=', '<', IN(...) etc.
1.172 +** idx_affinity is the affinity of an indexed column. Return true
1.173 +** if the index with affinity idx_affinity may be used to implement
1.174 +** the comparison in pExpr.
1.175 +*/
1.176 +int sqlite3IndexAffinityOk(Expr *pExpr, char idx_affinity){
1.177 + char aff = comparisonAffinity(pExpr);
1.178 + switch( aff ){
1.179 + case SQLITE_AFF_NONE:
1.180 + return 1;
1.181 + case SQLITE_AFF_TEXT:
1.182 + return idx_affinity==SQLITE_AFF_TEXT;
1.183 + default:
1.184 + return sqlite3IsNumericAffinity(idx_affinity);
1.185 + }
1.186 +}
1.187 +
1.188 +/*
1.189 +** Return the P5 value that should be used for a binary comparison
1.190 +** opcode (OP_Eq, OP_Ge etc.) used to compare pExpr1 and pExpr2.
1.191 +*/
1.192 +static u8 binaryCompareP5(Expr *pExpr1, Expr *pExpr2, int jumpIfNull){
1.193 + u8 aff = (char)sqlite3ExprAffinity(pExpr2);
1.194 + aff = sqlite3CompareAffinity(pExpr1, aff) | jumpIfNull;
1.195 + return aff;
1.196 +}
1.197 +
1.198 +/*
1.199 +** Return a pointer to the collation sequence that should be used by
1.200 +** a binary comparison operator comparing pLeft and pRight.
1.201 +**
1.202 +** If the left hand expression has a collating sequence type, then it is
1.203 +** used. Otherwise the collation sequence for the right hand expression
1.204 +** is used, or the default (BINARY) if neither expression has a collating
1.205 +** type.
1.206 +**
1.207 +** Argument pRight (but not pLeft) may be a null pointer. In this case,
1.208 +** it is not considered.
1.209 +*/
1.210 +CollSeq *sqlite3BinaryCompareCollSeq(
1.211 + Parse *pParse,
1.212 + Expr *pLeft,
1.213 + Expr *pRight
1.214 +){
1.215 + CollSeq *pColl;
1.216 + assert( pLeft );
1.217 + if( pLeft->flags & EP_ExpCollate ){
1.218 + assert( pLeft->pColl );
1.219 + pColl = pLeft->pColl;
1.220 + }else if( pRight && pRight->flags & EP_ExpCollate ){
1.221 + assert( pRight->pColl );
1.222 + pColl = pRight->pColl;
1.223 + }else{
1.224 + pColl = sqlite3ExprCollSeq(pParse, pLeft);
1.225 + if( !pColl ){
1.226 + pColl = sqlite3ExprCollSeq(pParse, pRight);
1.227 + }
1.228 + }
1.229 + return pColl;
1.230 +}
1.231 +
1.232 +/*
1.233 +** Generate the operands for a comparison operation. Before
1.234 +** generating the code for each operand, set the EP_AnyAff
1.235 +** flag on the expression so that it will be able to used a
1.236 +** cached column value that has previously undergone an
1.237 +** affinity change.
1.238 +*/
1.239 +static void codeCompareOperands(
1.240 + Parse *pParse, /* Parsing and code generating context */
1.241 + Expr *pLeft, /* The left operand */
1.242 + int *pRegLeft, /* Register where left operand is stored */
1.243 + int *pFreeLeft, /* Free this register when done */
1.244 + Expr *pRight, /* The right operand */
1.245 + int *pRegRight, /* Register where right operand is stored */
1.246 + int *pFreeRight /* Write temp register for right operand there */
1.247 +){
1.248 + while( pLeft->op==TK_UPLUS ) pLeft = pLeft->pLeft;
1.249 + pLeft->flags |= EP_AnyAff;
1.250 + *pRegLeft = sqlite3ExprCodeTemp(pParse, pLeft, pFreeLeft);
1.251 + while( pRight->op==TK_UPLUS ) pRight = pRight->pLeft;
1.252 + pRight->flags |= EP_AnyAff;
1.253 + *pRegRight = sqlite3ExprCodeTemp(pParse, pRight, pFreeRight);
1.254 +}
1.255 +
1.256 +/*
1.257 +** Generate code for a comparison operator.
1.258 +*/
1.259 +static int codeCompare(
1.260 + Parse *pParse, /* The parsing (and code generating) context */
1.261 + Expr *pLeft, /* The left operand */
1.262 + Expr *pRight, /* The right operand */
1.263 + int opcode, /* The comparison opcode */
1.264 + int in1, int in2, /* Register holding operands */
1.265 + int dest, /* Jump here if true. */
1.266 + int jumpIfNull /* If true, jump if either operand is NULL */
1.267 +){
1.268 + int p5;
1.269 + int addr;
1.270 + CollSeq *p4;
1.271 +
1.272 + p4 = sqlite3BinaryCompareCollSeq(pParse, pLeft, pRight);
1.273 + p5 = binaryCompareP5(pLeft, pRight, jumpIfNull);
1.274 + addr = sqlite3VdbeAddOp4(pParse->pVdbe, opcode, in2, dest, in1,
1.275 + (void*)p4, P4_COLLSEQ);
1.276 + sqlite3VdbeChangeP5(pParse->pVdbe, p5);
1.277 + if( (p5 & SQLITE_AFF_MASK)!=SQLITE_AFF_NONE ){
1.278 + sqlite3ExprCacheAffinityChange(pParse, in1, 1);
1.279 + sqlite3ExprCacheAffinityChange(pParse, in2, 1);
1.280 + }
1.281 + return addr;
1.282 +}
1.283 +
1.284 +#if SQLITE_MAX_EXPR_DEPTH>0
1.285 +/*
1.286 +** Check that argument nHeight is less than or equal to the maximum
1.287 +** expression depth allowed. If it is not, leave an error message in
1.288 +** pParse.
1.289 +*/
1.290 +int sqlite3ExprCheckHeight(Parse *pParse, int nHeight){
1.291 + int rc = SQLITE_OK;
1.292 + int mxHeight = pParse->db->aLimit[SQLITE_LIMIT_EXPR_DEPTH];
1.293 + if( nHeight>mxHeight ){
1.294 + sqlite3ErrorMsg(pParse,
1.295 + "Expression tree is too large (maximum depth %d)", mxHeight
1.296 + );
1.297 + rc = SQLITE_ERROR;
1.298 + }
1.299 + return rc;
1.300 +}
1.301 +
1.302 +/* The following three functions, heightOfExpr(), heightOfExprList()
1.303 +** and heightOfSelect(), are used to determine the maximum height
1.304 +** of any expression tree referenced by the structure passed as the
1.305 +** first argument.
1.306 +**
1.307 +** If this maximum height is greater than the current value pointed
1.308 +** to by pnHeight, the second parameter, then set *pnHeight to that
1.309 +** value.
1.310 +*/
1.311 +static void heightOfExpr(Expr *p, int *pnHeight){
1.312 + if( p ){
1.313 + if( p->nHeight>*pnHeight ){
1.314 + *pnHeight = p->nHeight;
1.315 + }
1.316 + }
1.317 +}
1.318 +static void heightOfExprList(ExprList *p, int *pnHeight){
1.319 + if( p ){
1.320 + int i;
1.321 + for(i=0; i<p->nExpr; i++){
1.322 + heightOfExpr(p->a[i].pExpr, pnHeight);
1.323 + }
1.324 + }
1.325 +}
1.326 +static void heightOfSelect(Select *p, int *pnHeight){
1.327 + if( p ){
1.328 + heightOfExpr(p->pWhere, pnHeight);
1.329 + heightOfExpr(p->pHaving, pnHeight);
1.330 + heightOfExpr(p->pLimit, pnHeight);
1.331 + heightOfExpr(p->pOffset, pnHeight);
1.332 + heightOfExprList(p->pEList, pnHeight);
1.333 + heightOfExprList(p->pGroupBy, pnHeight);
1.334 + heightOfExprList(p->pOrderBy, pnHeight);
1.335 + heightOfSelect(p->pPrior, pnHeight);
1.336 + }
1.337 +}
1.338 +
1.339 +/*
1.340 +** Set the Expr.nHeight variable in the structure passed as an
1.341 +** argument. An expression with no children, Expr.pList or
1.342 +** Expr.pSelect member has a height of 1. Any other expression
1.343 +** has a height equal to the maximum height of any other
1.344 +** referenced Expr plus one.
1.345 +*/
1.346 +static void exprSetHeight(Expr *p){
1.347 + int nHeight = 0;
1.348 + heightOfExpr(p->pLeft, &nHeight);
1.349 + heightOfExpr(p->pRight, &nHeight);
1.350 + heightOfExprList(p->pList, &nHeight);
1.351 + heightOfSelect(p->pSelect, &nHeight);
1.352 + p->nHeight = nHeight + 1;
1.353 +}
1.354 +
1.355 +/*
1.356 +** Set the Expr.nHeight variable using the exprSetHeight() function. If
1.357 +** the height is greater than the maximum allowed expression depth,
1.358 +** leave an error in pParse.
1.359 +*/
1.360 +void sqlite3ExprSetHeight(Parse *pParse, Expr *p){
1.361 + exprSetHeight(p);
1.362 + sqlite3ExprCheckHeight(pParse, p->nHeight);
1.363 +}
1.364 +
1.365 +/*
1.366 +** Return the maximum height of any expression tree referenced
1.367 +** by the select statement passed as an argument.
1.368 +*/
1.369 +int sqlite3SelectExprHeight(Select *p){
1.370 + int nHeight = 0;
1.371 + heightOfSelect(p, &nHeight);
1.372 + return nHeight;
1.373 +}
1.374 +#else
1.375 + #define exprSetHeight(y)
1.376 +#endif /* SQLITE_MAX_EXPR_DEPTH>0 */
1.377 +
1.378 +/*
1.379 +** Construct a new expression node and return a pointer to it. Memory
1.380 +** for this node is obtained from sqlite3_malloc(). The calling function
1.381 +** is responsible for making sure the node eventually gets freed.
1.382 +*/
1.383 +Expr *sqlite3Expr(
1.384 + sqlite3 *db, /* Handle for sqlite3DbMallocZero() (may be null) */
1.385 + int op, /* Expression opcode */
1.386 + Expr *pLeft, /* Left operand */
1.387 + Expr *pRight, /* Right operand */
1.388 + const Token *pToken /* Argument token */
1.389 +){
1.390 + Expr *pNew;
1.391 + pNew = sqlite3DbMallocZero(db, sizeof(Expr));
1.392 + if( pNew==0 ){
1.393 + /* When malloc fails, delete pLeft and pRight. Expressions passed to
1.394 + ** this function must always be allocated with sqlite3Expr() for this
1.395 + ** reason.
1.396 + */
1.397 + sqlite3ExprDelete(db, pLeft);
1.398 + sqlite3ExprDelete(db, pRight);
1.399 + return 0;
1.400 + }
1.401 + pNew->op = op;
1.402 + pNew->pLeft = pLeft;
1.403 + pNew->pRight = pRight;
1.404 + pNew->iAgg = -1;
1.405 + pNew->span.z = (u8*)"";
1.406 + if( pToken ){
1.407 + assert( pToken->dyn==0 );
1.408 + pNew->span = pNew->token = *pToken;
1.409 + }else if( pLeft ){
1.410 + if( pRight ){
1.411 + if( pRight->span.dyn==0 && pLeft->span.dyn==0 ){
1.412 + sqlite3ExprSpan(pNew, &pLeft->span, &pRight->span);
1.413 + }
1.414 + if( pRight->flags & EP_ExpCollate ){
1.415 + pNew->flags |= EP_ExpCollate;
1.416 + pNew->pColl = pRight->pColl;
1.417 + }
1.418 + }
1.419 + if( pLeft->flags & EP_ExpCollate ){
1.420 + pNew->flags |= EP_ExpCollate;
1.421 + pNew->pColl = pLeft->pColl;
1.422 + }
1.423 + }
1.424 +
1.425 + exprSetHeight(pNew);
1.426 + return pNew;
1.427 +}
1.428 +
1.429 +/*
1.430 +** Works like sqlite3Expr() except that it takes an extra Parse*
1.431 +** argument and notifies the associated connection object if malloc fails.
1.432 +*/
1.433 +Expr *sqlite3PExpr(
1.434 + Parse *pParse, /* Parsing context */
1.435 + int op, /* Expression opcode */
1.436 + Expr *pLeft, /* Left operand */
1.437 + Expr *pRight, /* Right operand */
1.438 + const Token *pToken /* Argument token */
1.439 +){
1.440 + Expr *p = sqlite3Expr(pParse->db, op, pLeft, pRight, pToken);
1.441 + if( p ){
1.442 + sqlite3ExprCheckHeight(pParse, p->nHeight);
1.443 + }
1.444 + return p;
1.445 +}
1.446 +
1.447 +/*
1.448 +** When doing a nested parse, you can include terms in an expression
1.449 +** that look like this: #1 #2 ... These terms refer to registers
1.450 +** in the virtual machine. #N is the N-th register.
1.451 +**
1.452 +** This routine is called by the parser to deal with on of those terms.
1.453 +** It immediately generates code to store the value in a memory location.
1.454 +** The returns an expression that will code to extract the value from
1.455 +** that memory location as needed.
1.456 +*/
1.457 +Expr *sqlite3RegisterExpr(Parse *pParse, Token *pToken){
1.458 + Vdbe *v = pParse->pVdbe;
1.459 + Expr *p;
1.460 + if( pParse->nested==0 ){
1.461 + sqlite3ErrorMsg(pParse, "near \"%T\": syntax error", pToken);
1.462 + return sqlite3PExpr(pParse, TK_NULL, 0, 0, 0);
1.463 + }
1.464 + if( v==0 ) return 0;
1.465 + p = sqlite3PExpr(pParse, TK_REGISTER, 0, 0, pToken);
1.466 + if( p==0 ){
1.467 + return 0; /* Malloc failed */
1.468 + }
1.469 + p->iTable = atoi((char*)&pToken->z[1]);
1.470 + return p;
1.471 +}
1.472 +
1.473 +/*
1.474 +** Join two expressions using an AND operator. If either expression is
1.475 +** NULL, then just return the other expression.
1.476 +*/
1.477 +Expr *sqlite3ExprAnd(sqlite3 *db, Expr *pLeft, Expr *pRight){
1.478 + if( pLeft==0 ){
1.479 + return pRight;
1.480 + }else if( pRight==0 ){
1.481 + return pLeft;
1.482 + }else{
1.483 + return sqlite3Expr(db, TK_AND, pLeft, pRight, 0);
1.484 + }
1.485 +}
1.486 +
1.487 +/*
1.488 +** Set the Expr.span field of the given expression to span all
1.489 +** text between the two given tokens. Both tokens must be pointing
1.490 +** at the same string.
1.491 +*/
1.492 +void sqlite3ExprSpan(Expr *pExpr, Token *pLeft, Token *pRight){
1.493 + assert( pRight!=0 );
1.494 + assert( pLeft!=0 );
1.495 + if( pExpr ){
1.496 + pExpr->span.z = pLeft->z;
1.497 + pExpr->span.n = pRight->n + (pRight->z - pLeft->z);
1.498 + }
1.499 +}
1.500 +
1.501 +/*
1.502 +** Construct a new expression node for a function with multiple
1.503 +** arguments.
1.504 +*/
1.505 +Expr *sqlite3ExprFunction(Parse *pParse, ExprList *pList, Token *pToken){
1.506 + Expr *pNew;
1.507 + sqlite3 *db = pParse->db;
1.508 + assert( pToken );
1.509 + pNew = sqlite3DbMallocZero(db, sizeof(Expr) );
1.510 + if( pNew==0 ){
1.511 + sqlite3ExprListDelete(db, pList); /* Avoid leaking memory when malloc fails */
1.512 + return 0;
1.513 + }
1.514 + pNew->op = TK_FUNCTION;
1.515 + pNew->pList = pList;
1.516 + assert( pToken->dyn==0 );
1.517 + pNew->token = *pToken;
1.518 + pNew->span = pNew->token;
1.519 +
1.520 + sqlite3ExprSetHeight(pParse, pNew);
1.521 + return pNew;
1.522 +}
1.523 +
1.524 +/*
1.525 +** Assign a variable number to an expression that encodes a wildcard
1.526 +** in the original SQL statement.
1.527 +**
1.528 +** Wildcards consisting of a single "?" are assigned the next sequential
1.529 +** variable number.
1.530 +**
1.531 +** Wildcards of the form "?nnn" are assigned the number "nnn". We make
1.532 +** sure "nnn" is not too be to avoid a denial of service attack when
1.533 +** the SQL statement comes from an external source.
1.534 +**
1.535 +** Wildcards of the form ":aaa" or "$aaa" are assigned the same number
1.536 +** as the previous instance of the same wildcard. Or if this is the first
1.537 +** instance of the wildcard, the next sequenial variable number is
1.538 +** assigned.
1.539 +*/
1.540 +void sqlite3ExprAssignVarNumber(Parse *pParse, Expr *pExpr){
1.541 + Token *pToken;
1.542 + sqlite3 *db = pParse->db;
1.543 +
1.544 + if( pExpr==0 ) return;
1.545 + pToken = &pExpr->token;
1.546 + assert( pToken->n>=1 );
1.547 + assert( pToken->z!=0 );
1.548 + assert( pToken->z[0]!=0 );
1.549 + if( pToken->n==1 ){
1.550 + /* Wildcard of the form "?". Assign the next variable number */
1.551 + pExpr->iTable = ++pParse->nVar;
1.552 + }else if( pToken->z[0]=='?' ){
1.553 + /* Wildcard of the form "?nnn". Convert "nnn" to an integer and
1.554 + ** use it as the variable number */
1.555 + int i;
1.556 + pExpr->iTable = i = atoi((char*)&pToken->z[1]);
1.557 + testcase( i==0 );
1.558 + testcase( i==1 );
1.559 + testcase( i==db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]-1 );
1.560 + testcase( i==db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] );
1.561 + if( i<1 || i>db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ){
1.562 + sqlite3ErrorMsg(pParse, "variable number must be between ?1 and ?%d",
1.563 + db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]);
1.564 + }
1.565 + if( i>pParse->nVar ){
1.566 + pParse->nVar = i;
1.567 + }
1.568 + }else{
1.569 + /* Wildcards of the form ":aaa" or "$aaa". Reuse the same variable
1.570 + ** number as the prior appearance of the same name, or if the name
1.571 + ** has never appeared before, reuse the same variable number
1.572 + */
1.573 + int i, n;
1.574 + n = pToken->n;
1.575 + for(i=0; i<pParse->nVarExpr; i++){
1.576 + Expr *pE;
1.577 + if( (pE = pParse->apVarExpr[i])!=0
1.578 + && pE->token.n==n
1.579 + && memcmp(pE->token.z, pToken->z, n)==0 ){
1.580 + pExpr->iTable = pE->iTable;
1.581 + break;
1.582 + }
1.583 + }
1.584 + if( i>=pParse->nVarExpr ){
1.585 + pExpr->iTable = ++pParse->nVar;
1.586 + if( pParse->nVarExpr>=pParse->nVarExprAlloc-1 ){
1.587 + pParse->nVarExprAlloc += pParse->nVarExprAlloc + 10;
1.588 + pParse->apVarExpr =
1.589 + sqlite3DbReallocOrFree(
1.590 + db,
1.591 + pParse->apVarExpr,
1.592 + pParse->nVarExprAlloc*sizeof(pParse->apVarExpr[0])
1.593 + );
1.594 + }
1.595 + if( !db->mallocFailed ){
1.596 + assert( pParse->apVarExpr!=0 );
1.597 + pParse->apVarExpr[pParse->nVarExpr++] = pExpr;
1.598 + }
1.599 + }
1.600 + }
1.601 + if( !pParse->nErr && pParse->nVar>db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ){
1.602 + sqlite3ErrorMsg(pParse, "too many SQL variables");
1.603 + }
1.604 +}
1.605 +
1.606 +/*
1.607 +** Recursively delete an expression tree.
1.608 +*/
1.609 +void sqlite3ExprDelete(sqlite3 *db, Expr *p){
1.610 + if( p==0 ) return;
1.611 + if( p->span.dyn ) sqlite3DbFree(db, (char*)p->span.z);
1.612 + if( p->token.dyn ) sqlite3DbFree(db, (char*)p->token.z);
1.613 + sqlite3ExprDelete(db, p->pLeft);
1.614 + sqlite3ExprDelete(db, p->pRight);
1.615 + sqlite3ExprListDelete(db, p->pList);
1.616 + sqlite3SelectDelete(db, p->pSelect);
1.617 + sqlite3DbFree(db, p);
1.618 +}
1.619 +
1.620 +/*
1.621 +** The Expr.token field might be a string literal that is quoted.
1.622 +** If so, remove the quotation marks.
1.623 +*/
1.624 +void sqlite3DequoteExpr(sqlite3 *db, Expr *p){
1.625 + if( ExprHasAnyProperty(p, EP_Dequoted) ){
1.626 + return;
1.627 + }
1.628 + ExprSetProperty(p, EP_Dequoted);
1.629 + if( p->token.dyn==0 ){
1.630 + sqlite3TokenCopy(db, &p->token, &p->token);
1.631 + }
1.632 + sqlite3Dequote((char*)p->token.z);
1.633 +}
1.634 +
1.635 +/*
1.636 +** The following group of routines make deep copies of expressions,
1.637 +** expression lists, ID lists, and select statements. The copies can
1.638 +** be deleted (by being passed to their respective ...Delete() routines)
1.639 +** without effecting the originals.
1.640 +**
1.641 +** The expression list, ID, and source lists return by sqlite3ExprListDup(),
1.642 +** sqlite3IdListDup(), and sqlite3SrcListDup() can not be further expanded
1.643 +** by subsequent calls to sqlite*ListAppend() routines.
1.644 +**
1.645 +** Any tables that the SrcList might point to are not duplicated.
1.646 +*/
1.647 +Expr *sqlite3ExprDup(sqlite3 *db, Expr *p){
1.648 + Expr *pNew;
1.649 + if( p==0 ) return 0;
1.650 + pNew = sqlite3DbMallocRaw(db, sizeof(*p) );
1.651 + if( pNew==0 ) return 0;
1.652 + memcpy(pNew, p, sizeof(*pNew));
1.653 + if( p->token.z!=0 ){
1.654 + pNew->token.z = (u8*)sqlite3DbStrNDup(db, (char*)p->token.z, p->token.n);
1.655 + pNew->token.dyn = 1;
1.656 + }else{
1.657 + assert( pNew->token.z==0 );
1.658 + }
1.659 + pNew->span.z = 0;
1.660 + pNew->pLeft = sqlite3ExprDup(db, p->pLeft);
1.661 + pNew->pRight = sqlite3ExprDup(db, p->pRight);
1.662 + pNew->pList = sqlite3ExprListDup(db, p->pList);
1.663 + pNew->pSelect = sqlite3SelectDup(db, p->pSelect);
1.664 + return pNew;
1.665 +}
1.666 +void sqlite3TokenCopy(sqlite3 *db, Token *pTo, Token *pFrom){
1.667 + if( pTo->dyn ) sqlite3DbFree(db, (char*)pTo->z);
1.668 + if( pFrom->z ){
1.669 + pTo->n = pFrom->n;
1.670 + pTo->z = (u8*)sqlite3DbStrNDup(db, (char*)pFrom->z, pFrom->n);
1.671 + pTo->dyn = 1;
1.672 + }else{
1.673 + pTo->z = 0;
1.674 + }
1.675 +}
1.676 +ExprList *sqlite3ExprListDup(sqlite3 *db, ExprList *p){
1.677 + ExprList *pNew;
1.678 + struct ExprList_item *pItem, *pOldItem;
1.679 + int i;
1.680 + if( p==0 ) return 0;
1.681 + pNew = sqlite3DbMallocRaw(db, sizeof(*pNew) );
1.682 + if( pNew==0 ) return 0;
1.683 + pNew->iECursor = 0;
1.684 + pNew->nExpr = pNew->nAlloc = p->nExpr;
1.685 + pNew->a = pItem = sqlite3DbMallocRaw(db, p->nExpr*sizeof(p->a[0]) );
1.686 + if( pItem==0 ){
1.687 + sqlite3DbFree(db, pNew);
1.688 + return 0;
1.689 + }
1.690 + pOldItem = p->a;
1.691 + for(i=0; i<p->nExpr; i++, pItem++, pOldItem++){
1.692 + Expr *pNewExpr, *pOldExpr;
1.693 + pItem->pExpr = pNewExpr = sqlite3ExprDup(db, pOldExpr = pOldItem->pExpr);
1.694 + if( pOldExpr->span.z!=0 && pNewExpr ){
1.695 + /* Always make a copy of the span for top-level expressions in the
1.696 + ** expression list. The logic in SELECT processing that determines
1.697 + ** the names of columns in the result set needs this information */
1.698 + sqlite3TokenCopy(db, &pNewExpr->span, &pOldExpr->span);
1.699 + }
1.700 + assert( pNewExpr==0 || pNewExpr->span.z!=0
1.701 + || pOldExpr->span.z==0
1.702 + || db->mallocFailed );
1.703 + pItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
1.704 + pItem->sortOrder = pOldItem->sortOrder;
1.705 + pItem->done = 0;
1.706 + pItem->iCol = pOldItem->iCol;
1.707 + pItem->iAlias = pOldItem->iAlias;
1.708 + }
1.709 + return pNew;
1.710 +}
1.711 +
1.712 +/*
1.713 +** If cursors, triggers, views and subqueries are all omitted from
1.714 +** the build, then none of the following routines, except for
1.715 +** sqlite3SelectDup(), can be called. sqlite3SelectDup() is sometimes
1.716 +** called with a NULL argument.
1.717 +*/
1.718 +#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_TRIGGER) \
1.719 + || !defined(SQLITE_OMIT_SUBQUERY)
1.720 +SrcList *sqlite3SrcListDup(sqlite3 *db, SrcList *p){
1.721 + SrcList *pNew;
1.722 + int i;
1.723 + int nByte;
1.724 + if( p==0 ) return 0;
1.725 + nByte = sizeof(*p) + (p->nSrc>0 ? sizeof(p->a[0]) * (p->nSrc-1) : 0);
1.726 + pNew = sqlite3DbMallocRaw(db, nByte );
1.727 + if( pNew==0 ) return 0;
1.728 + pNew->nSrc = pNew->nAlloc = p->nSrc;
1.729 + for(i=0; i<p->nSrc; i++){
1.730 + struct SrcList_item *pNewItem = &pNew->a[i];
1.731 + struct SrcList_item *pOldItem = &p->a[i];
1.732 + Table *pTab;
1.733 + pNewItem->zDatabase = sqlite3DbStrDup(db, pOldItem->zDatabase);
1.734 + pNewItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
1.735 + pNewItem->zAlias = sqlite3DbStrDup(db, pOldItem->zAlias);
1.736 + pNewItem->jointype = pOldItem->jointype;
1.737 + pNewItem->iCursor = pOldItem->iCursor;
1.738 + pNewItem->isPopulated = pOldItem->isPopulated;
1.739 + pTab = pNewItem->pTab = pOldItem->pTab;
1.740 + if( pTab ){
1.741 + pTab->nRef++;
1.742 + }
1.743 + pNewItem->pSelect = sqlite3SelectDup(db, pOldItem->pSelect);
1.744 + pNewItem->pOn = sqlite3ExprDup(db, pOldItem->pOn);
1.745 + pNewItem->pUsing = sqlite3IdListDup(db, pOldItem->pUsing);
1.746 + pNewItem->colUsed = pOldItem->colUsed;
1.747 + }
1.748 + return pNew;
1.749 +}
1.750 +IdList *sqlite3IdListDup(sqlite3 *db, IdList *p){
1.751 + IdList *pNew;
1.752 + int i;
1.753 + if( p==0 ) return 0;
1.754 + pNew = sqlite3DbMallocRaw(db, sizeof(*pNew) );
1.755 + if( pNew==0 ) return 0;
1.756 + pNew->nId = pNew->nAlloc = p->nId;
1.757 + pNew->a = sqlite3DbMallocRaw(db, p->nId*sizeof(p->a[0]) );
1.758 + if( pNew->a==0 ){
1.759 + sqlite3DbFree(db, pNew);
1.760 + return 0;
1.761 + }
1.762 + for(i=0; i<p->nId; i++){
1.763 + struct IdList_item *pNewItem = &pNew->a[i];
1.764 + struct IdList_item *pOldItem = &p->a[i];
1.765 + pNewItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
1.766 + pNewItem->idx = pOldItem->idx;
1.767 + }
1.768 + return pNew;
1.769 +}
1.770 +Select *sqlite3SelectDup(sqlite3 *db, Select *p){
1.771 + Select *pNew;
1.772 + if( p==0 ) return 0;
1.773 + pNew = sqlite3DbMallocRaw(db, sizeof(*p) );
1.774 + if( pNew==0 ) return 0;
1.775 + pNew->pEList = sqlite3ExprListDup(db, p->pEList);
1.776 + pNew->pSrc = sqlite3SrcListDup(db, p->pSrc);
1.777 + pNew->pWhere = sqlite3ExprDup(db, p->pWhere);
1.778 + pNew->pGroupBy = sqlite3ExprListDup(db, p->pGroupBy);
1.779 + pNew->pHaving = sqlite3ExprDup(db, p->pHaving);
1.780 + pNew->pOrderBy = sqlite3ExprListDup(db, p->pOrderBy);
1.781 + pNew->op = p->op;
1.782 + pNew->pPrior = sqlite3SelectDup(db, p->pPrior);
1.783 + pNew->pLimit = sqlite3ExprDup(db, p->pLimit);
1.784 + pNew->pOffset = sqlite3ExprDup(db, p->pOffset);
1.785 + pNew->iLimit = 0;
1.786 + pNew->iOffset = 0;
1.787 + pNew->selFlags = p->selFlags & ~SF_UsesEphemeral;
1.788 + pNew->pRightmost = 0;
1.789 + pNew->addrOpenEphm[0] = -1;
1.790 + pNew->addrOpenEphm[1] = -1;
1.791 + pNew->addrOpenEphm[2] = -1;
1.792 + return pNew;
1.793 +}
1.794 +#else
1.795 +Select *sqlite3SelectDup(sqlite3 *db, Select *p){
1.796 + assert( p==0 );
1.797 + return 0;
1.798 +}
1.799 +#endif
1.800 +
1.801 +
1.802 +/*
1.803 +** Add a new element to the end of an expression list. If pList is
1.804 +** initially NULL, then create a new expression list.
1.805 +*/
1.806 +ExprList *sqlite3ExprListAppend(
1.807 + Parse *pParse, /* Parsing context */
1.808 + ExprList *pList, /* List to which to append. Might be NULL */
1.809 + Expr *pExpr, /* Expression to be appended */
1.810 + Token *pName /* AS keyword for the expression */
1.811 +){
1.812 + sqlite3 *db = pParse->db;
1.813 + if( pList==0 ){
1.814 + pList = sqlite3DbMallocZero(db, sizeof(ExprList) );
1.815 + if( pList==0 ){
1.816 + goto no_mem;
1.817 + }
1.818 + assert( pList->nAlloc==0 );
1.819 + }
1.820 + if( pList->nAlloc<=pList->nExpr ){
1.821 + struct ExprList_item *a;
1.822 + int n = pList->nAlloc*2 + 4;
1.823 + a = sqlite3DbRealloc(db, pList->a, n*sizeof(pList->a[0]));
1.824 + if( a==0 ){
1.825 + goto no_mem;
1.826 + }
1.827 + pList->a = a;
1.828 + pList->nAlloc = n;
1.829 + }
1.830 + assert( pList->a!=0 );
1.831 + if( pExpr || pName ){
1.832 + struct ExprList_item *pItem = &pList->a[pList->nExpr++];
1.833 + memset(pItem, 0, sizeof(*pItem));
1.834 + pItem->zName = sqlite3NameFromToken(db, pName);
1.835 + pItem->pExpr = pExpr;
1.836 + pItem->iAlias = 0;
1.837 + }
1.838 + return pList;
1.839 +
1.840 +no_mem:
1.841 + /* Avoid leaking memory if malloc has failed. */
1.842 + sqlite3ExprDelete(db, pExpr);
1.843 + sqlite3ExprListDelete(db, pList);
1.844 + return 0;
1.845 +}
1.846 +
1.847 +/*
1.848 +** If the expression list pEList contains more than iLimit elements,
1.849 +** leave an error message in pParse.
1.850 +*/
1.851 +void sqlite3ExprListCheckLength(
1.852 + Parse *pParse,
1.853 + ExprList *pEList,
1.854 + const char *zObject
1.855 +){
1.856 + int mx = pParse->db->aLimit[SQLITE_LIMIT_COLUMN];
1.857 + testcase( pEList && pEList->nExpr==mx );
1.858 + testcase( pEList && pEList->nExpr==mx+1 );
1.859 + if( pEList && pEList->nExpr>mx ){
1.860 + sqlite3ErrorMsg(pParse, "too many columns in %s", zObject);
1.861 + }
1.862 +}
1.863 +
1.864 +/*
1.865 +** Delete an entire expression list.
1.866 +*/
1.867 +void sqlite3ExprListDelete(sqlite3 *db, ExprList *pList){
1.868 + int i;
1.869 + struct ExprList_item *pItem;
1.870 + if( pList==0 ) return;
1.871 + assert( pList->a!=0 || (pList->nExpr==0 && pList->nAlloc==0) );
1.872 + assert( pList->nExpr<=pList->nAlloc );
1.873 + for(pItem=pList->a, i=0; i<pList->nExpr; i++, pItem++){
1.874 + sqlite3ExprDelete(db, pItem->pExpr);
1.875 + sqlite3DbFree(db, pItem->zName);
1.876 + }
1.877 + sqlite3DbFree(db, pList->a);
1.878 + sqlite3DbFree(db, pList);
1.879 +}
1.880 +
1.881 +/*
1.882 +** These routines are Walker callbacks. Walker.u.pi is a pointer
1.883 +** to an integer. These routines are checking an expression to see
1.884 +** if it is a constant. Set *Walker.u.pi to 0 if the expression is
1.885 +** not constant.
1.886 +**
1.887 +** These callback routines are used to implement the following:
1.888 +**
1.889 +** sqlite3ExprIsConstant()
1.890 +** sqlite3ExprIsConstantNotJoin()
1.891 +** sqlite3ExprIsConstantOrFunction()
1.892 +**
1.893 +*/
1.894 +static int exprNodeIsConstant(Walker *pWalker, Expr *pExpr){
1.895 +
1.896 + /* If pWalker->u.i is 3 then any term of the expression that comes from
1.897 + ** the ON or USING clauses of a join disqualifies the expression
1.898 + ** from being considered constant. */
1.899 + if( pWalker->u.i==3 && ExprHasAnyProperty(pExpr, EP_FromJoin) ){
1.900 + pWalker->u.i = 0;
1.901 + return WRC_Abort;
1.902 + }
1.903 +
1.904 + switch( pExpr->op ){
1.905 + /* Consider functions to be constant if all their arguments are constant
1.906 + ** and pWalker->u.i==2 */
1.907 + case TK_FUNCTION:
1.908 + if( pWalker->u.i==2 ) return 0;
1.909 + /* Fall through */
1.910 + case TK_ID:
1.911 + case TK_COLUMN:
1.912 + case TK_DOT:
1.913 + case TK_AGG_FUNCTION:
1.914 + case TK_AGG_COLUMN:
1.915 +#ifndef SQLITE_OMIT_SUBQUERY
1.916 + case TK_SELECT:
1.917 + case TK_EXISTS:
1.918 + testcase( pExpr->op==TK_SELECT );
1.919 + testcase( pExpr->op==TK_EXISTS );
1.920 +#endif
1.921 + testcase( pExpr->op==TK_ID );
1.922 + testcase( pExpr->op==TK_COLUMN );
1.923 + testcase( pExpr->op==TK_DOT );
1.924 + testcase( pExpr->op==TK_AGG_FUNCTION );
1.925 + testcase( pExpr->op==TK_AGG_COLUMN );
1.926 + pWalker->u.i = 0;
1.927 + return WRC_Abort;
1.928 + default:
1.929 + return WRC_Continue;
1.930 + }
1.931 +}
1.932 +static int selectNodeIsConstant(Walker *pWalker, Select *pSelect){
1.933 + pWalker->u.i = 0;
1.934 + return WRC_Abort;
1.935 +}
1.936 +static int exprIsConst(Expr *p, int initFlag){
1.937 + Walker w;
1.938 + w.u.i = initFlag;
1.939 + w.xExprCallback = exprNodeIsConstant;
1.940 + w.xSelectCallback = selectNodeIsConstant;
1.941 + sqlite3WalkExpr(&w, p);
1.942 + return w.u.i;
1.943 +}
1.944 +
1.945 +/*
1.946 +** Walk an expression tree. Return 1 if the expression is constant
1.947 +** and 0 if it involves variables or function calls.
1.948 +**
1.949 +** For the purposes of this function, a double-quoted string (ex: "abc")
1.950 +** is considered a variable but a single-quoted string (ex: 'abc') is
1.951 +** a constant.
1.952 +*/
1.953 +int sqlite3ExprIsConstant(Expr *p){
1.954 + return exprIsConst(p, 1);
1.955 +}
1.956 +
1.957 +/*
1.958 +** Walk an expression tree. Return 1 if the expression is constant
1.959 +** that does no originate from the ON or USING clauses of a join.
1.960 +** Return 0 if it involves variables or function calls or terms from
1.961 +** an ON or USING clause.
1.962 +*/
1.963 +int sqlite3ExprIsConstantNotJoin(Expr *p){
1.964 + return exprIsConst(p, 3);
1.965 +}
1.966 +
1.967 +/*
1.968 +** Walk an expression tree. Return 1 if the expression is constant
1.969 +** or a function call with constant arguments. Return and 0 if there
1.970 +** are any variables.
1.971 +**
1.972 +** For the purposes of this function, a double-quoted string (ex: "abc")
1.973 +** is considered a variable but a single-quoted string (ex: 'abc') is
1.974 +** a constant.
1.975 +*/
1.976 +int sqlite3ExprIsConstantOrFunction(Expr *p){
1.977 + return exprIsConst(p, 2);
1.978 +}
1.979 +
1.980 +/*
1.981 +** If the expression p codes a constant integer that is small enough
1.982 +** to fit in a 32-bit integer, return 1 and put the value of the integer
1.983 +** in *pValue. If the expression is not an integer or if it is too big
1.984 +** to fit in a signed 32-bit integer, return 0 and leave *pValue unchanged.
1.985 +*/
1.986 +int sqlite3ExprIsInteger(Expr *p, int *pValue){
1.987 + int rc = 0;
1.988 + if( p->flags & EP_IntValue ){
1.989 + *pValue = p->iTable;
1.990 + return 1;
1.991 + }
1.992 + switch( p->op ){
1.993 + case TK_INTEGER: {
1.994 + rc = sqlite3GetInt32((char*)p->token.z, pValue);
1.995 + break;
1.996 + }
1.997 + case TK_UPLUS: {
1.998 + rc = sqlite3ExprIsInteger(p->pLeft, pValue);
1.999 + break;
1.1000 + }
1.1001 + case TK_UMINUS: {
1.1002 + int v;
1.1003 + if( sqlite3ExprIsInteger(p->pLeft, &v) ){
1.1004 + *pValue = -v;
1.1005 + rc = 1;
1.1006 + }
1.1007 + break;
1.1008 + }
1.1009 + default: break;
1.1010 + }
1.1011 + if( rc ){
1.1012 + p->op = TK_INTEGER;
1.1013 + p->flags |= EP_IntValue;
1.1014 + p->iTable = *pValue;
1.1015 + }
1.1016 + return rc;
1.1017 +}
1.1018 +
1.1019 +/*
1.1020 +** Return TRUE if the given string is a row-id column name.
1.1021 +*/
1.1022 +int sqlite3IsRowid(const char *z){
1.1023 + if( sqlite3StrICmp(z, "_ROWID_")==0 ) return 1;
1.1024 + if( sqlite3StrICmp(z, "ROWID")==0 ) return 1;
1.1025 + if( sqlite3StrICmp(z, "OID")==0 ) return 1;
1.1026 + return 0;
1.1027 +}
1.1028 +
1.1029 +#ifdef SQLITE_TEST
1.1030 + int sqlite3_enable_in_opt = 1;
1.1031 +#else
1.1032 + #define sqlite3_enable_in_opt 1
1.1033 +#endif
1.1034 +
1.1035 +/*
1.1036 +** Return true if the IN operator optimization is enabled and
1.1037 +** the SELECT statement p exists and is of the
1.1038 +** simple form:
1.1039 +**
1.1040 +** SELECT <column> FROM <table>
1.1041 +**
1.1042 +** If this is the case, it may be possible to use an existing table
1.1043 +** or index instead of generating an epheremal table.
1.1044 +*/
1.1045 +#ifndef SQLITE_OMIT_SUBQUERY
1.1046 +static int isCandidateForInOpt(Select *p){
1.1047 + SrcList *pSrc;
1.1048 + ExprList *pEList;
1.1049 + Table *pTab;
1.1050 + if( !sqlite3_enable_in_opt ) return 0; /* IN optimization must be enabled */
1.1051 + if( p==0 ) return 0; /* right-hand side of IN is SELECT */
1.1052 + if( p->pPrior ) return 0; /* Not a compound SELECT */
1.1053 + if( p->selFlags & (SF_Distinct|SF_Aggregate) ){
1.1054 + return 0; /* No DISTINCT keyword and no aggregate functions */
1.1055 + }
1.1056 + if( p->pGroupBy ) return 0; /* Has no GROUP BY clause */
1.1057 + if( p->pLimit ) return 0; /* Has no LIMIT clause */
1.1058 + if( p->pOffset ) return 0;
1.1059 + if( p->pWhere ) return 0; /* Has no WHERE clause */
1.1060 + pSrc = p->pSrc;
1.1061 + if( pSrc==0 ) return 0; /* A single table in the FROM clause */
1.1062 + if( pSrc->nSrc!=1 ) return 0;
1.1063 + if( pSrc->a[0].pSelect ) return 0; /* FROM clause is not a subquery */
1.1064 + pTab = pSrc->a[0].pTab;
1.1065 + if( pTab==0 ) return 0;
1.1066 + if( pTab->pSelect ) return 0; /* FROM clause is not a view */
1.1067 + if( IsVirtual(pTab) ) return 0; /* FROM clause not a virtual table */
1.1068 + pEList = p->pEList;
1.1069 + if( pEList->nExpr!=1 ) return 0; /* One column in the result set */
1.1070 + if( pEList->a[0].pExpr->op!=TK_COLUMN ) return 0; /* Result is a column */
1.1071 + return 1;
1.1072 +}
1.1073 +#endif /* SQLITE_OMIT_SUBQUERY */
1.1074 +
1.1075 +/*
1.1076 +** This function is used by the implementation of the IN (...) operator.
1.1077 +** It's job is to find or create a b-tree structure that may be used
1.1078 +** either to test for membership of the (...) set or to iterate through
1.1079 +** its members, skipping duplicates.
1.1080 +**
1.1081 +** The cursor opened on the structure (database table, database index
1.1082 +** or ephermal table) is stored in pX->iTable before this function returns.
1.1083 +** The returned value indicates the structure type, as follows:
1.1084 +**
1.1085 +** IN_INDEX_ROWID - The cursor was opened on a database table.
1.1086 +** IN_INDEX_INDEX - The cursor was opened on a database index.
1.1087 +** IN_INDEX_EPH - The cursor was opened on a specially created and
1.1088 +** populated epheremal table.
1.1089 +**
1.1090 +** An existing structure may only be used if the SELECT is of the simple
1.1091 +** form:
1.1092 +**
1.1093 +** SELECT <column> FROM <table>
1.1094 +**
1.1095 +** If prNotFound parameter is 0, then the structure will be used to iterate
1.1096 +** through the set members, skipping any duplicates. In this case an
1.1097 +** epheremal table must be used unless the selected <column> is guaranteed
1.1098 +** to be unique - either because it is an INTEGER PRIMARY KEY or it
1.1099 +** is unique by virtue of a constraint or implicit index.
1.1100 +**
1.1101 +** If the prNotFound parameter is not 0, then the structure will be used
1.1102 +** for fast set membership tests. In this case an epheremal table must
1.1103 +** be used unless <column> is an INTEGER PRIMARY KEY or an index can
1.1104 +** be found with <column> as its left-most column.
1.1105 +**
1.1106 +** When the structure is being used for set membership tests, the user
1.1107 +** needs to know whether or not the structure contains an SQL NULL
1.1108 +** value in order to correctly evaluate expressions like "X IN (Y, Z)".
1.1109 +** If there is a chance that the structure may contain a NULL value at
1.1110 +** runtime, then a register is allocated and the register number written
1.1111 +** to *prNotFound. If there is no chance that the structure contains a
1.1112 +** NULL value, then *prNotFound is left unchanged.
1.1113 +**
1.1114 +** If a register is allocated and its location stored in *prNotFound, then
1.1115 +** its initial value is NULL. If the structure does not remain constant
1.1116 +** for the duration of the query (i.e. the set is a correlated sub-select),
1.1117 +** the value of the allocated register is reset to NULL each time the
1.1118 +** structure is repopulated. This allows the caller to use vdbe code
1.1119 +** equivalent to the following:
1.1120 +**
1.1121 +** if( register==NULL ){
1.1122 +** has_null = <test if data structure contains null>
1.1123 +** register = 1
1.1124 +** }
1.1125 +**
1.1126 +** in order to avoid running the <test if data structure contains null>
1.1127 +** test more often than is necessary.
1.1128 +*/
1.1129 +#ifndef SQLITE_OMIT_SUBQUERY
1.1130 +int sqlite3FindInIndex(Parse *pParse, Expr *pX, int *prNotFound){
1.1131 + Select *p;
1.1132 + int eType = 0;
1.1133 + int iTab = pParse->nTab++;
1.1134 + int mustBeUnique = !prNotFound;
1.1135 +
1.1136 + /* The follwing if(...) expression is true if the SELECT is of the
1.1137 + ** simple form:
1.1138 + **
1.1139 + ** SELECT <column> FROM <table>
1.1140 + **
1.1141 + ** If this is the case, it may be possible to use an existing table
1.1142 + ** or index instead of generating an epheremal table.
1.1143 + */
1.1144 + p = pX->pSelect;
1.1145 + if( isCandidateForInOpt(p) ){
1.1146 + sqlite3 *db = pParse->db;
1.1147 + Index *pIdx;
1.1148 + Expr *pExpr = p->pEList->a[0].pExpr;
1.1149 + int iCol = pExpr->iColumn;
1.1150 + Vdbe *v = sqlite3GetVdbe(pParse);
1.1151 +
1.1152 + /* This function is only called from two places. In both cases the vdbe
1.1153 + ** has already been allocated. So assume sqlite3GetVdbe() is always
1.1154 + ** successful here.
1.1155 + */
1.1156 + assert(v);
1.1157 + if( iCol<0 ){
1.1158 + int iMem = ++pParse->nMem;
1.1159 + int iAddr;
1.1160 + Table *pTab = p->pSrc->a[0].pTab;
1.1161 + int iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
1.1162 + sqlite3VdbeUsesBtree(v, iDb);
1.1163 +
1.1164 + iAddr = sqlite3VdbeAddOp1(v, OP_If, iMem);
1.1165 + sqlite3VdbeAddOp2(v, OP_Integer, 1, iMem);
1.1166 +
1.1167 + sqlite3OpenTable(pParse, iTab, iDb, pTab, OP_OpenRead);
1.1168 + eType = IN_INDEX_ROWID;
1.1169 +
1.1170 + sqlite3VdbeJumpHere(v, iAddr);
1.1171 + }else{
1.1172 + /* The collation sequence used by the comparison. If an index is to
1.1173 + ** be used in place of a temp-table, it must be ordered according
1.1174 + ** to this collation sequence.
1.1175 + */
1.1176 + CollSeq *pReq = sqlite3BinaryCompareCollSeq(pParse, pX->pLeft, pExpr);
1.1177 +
1.1178 + /* Check that the affinity that will be used to perform the
1.1179 + ** comparison is the same as the affinity of the column. If
1.1180 + ** it is not, it is not possible to use any index.
1.1181 + */
1.1182 + Table *pTab = p->pSrc->a[0].pTab;
1.1183 + char aff = comparisonAffinity(pX);
1.1184 + int affinity_ok = (pTab->aCol[iCol].affinity==aff||aff==SQLITE_AFF_NONE);
1.1185 +
1.1186 + for(pIdx=pTab->pIndex; pIdx && eType==0 && affinity_ok; pIdx=pIdx->pNext){
1.1187 + if( (pIdx->aiColumn[0]==iCol)
1.1188 + && (pReq==sqlite3FindCollSeq(db, ENC(db), pIdx->azColl[0], -1, 0))
1.1189 + && (!mustBeUnique || (pIdx->nColumn==1 && pIdx->onError!=OE_None))
1.1190 + ){
1.1191 + int iDb;
1.1192 + int iMem = ++pParse->nMem;
1.1193 + int iAddr;
1.1194 + char *pKey;
1.1195 +
1.1196 + pKey = (char *)sqlite3IndexKeyinfo(pParse, pIdx);
1.1197 + iDb = sqlite3SchemaToIndex(db, pIdx->pSchema);
1.1198 + sqlite3VdbeUsesBtree(v, iDb);
1.1199 +
1.1200 + iAddr = sqlite3VdbeAddOp1(v, OP_If, iMem);
1.1201 + sqlite3VdbeAddOp2(v, OP_Integer, 1, iMem);
1.1202 +
1.1203 + sqlite3VdbeAddOp2(v, OP_SetNumColumns, 0, pIdx->nColumn);
1.1204 + sqlite3VdbeAddOp4(v, OP_OpenRead, iTab, pIdx->tnum, iDb,
1.1205 + pKey,P4_KEYINFO_HANDOFF);
1.1206 + VdbeComment((v, "%s", pIdx->zName));
1.1207 + eType = IN_INDEX_INDEX;
1.1208 +
1.1209 + sqlite3VdbeJumpHere(v, iAddr);
1.1210 + if( prNotFound && !pTab->aCol[iCol].notNull ){
1.1211 + *prNotFound = ++pParse->nMem;
1.1212 + }
1.1213 + }
1.1214 + }
1.1215 + }
1.1216 + }
1.1217 +
1.1218 + if( eType==0 ){
1.1219 + int rMayHaveNull = 0;
1.1220 + eType = IN_INDEX_EPH;
1.1221 + if( prNotFound ){
1.1222 + *prNotFound = rMayHaveNull = ++pParse->nMem;
1.1223 + }else if( pX->pLeft->iColumn<0 && pX->pSelect==0 ){
1.1224 + eType = IN_INDEX_ROWID;
1.1225 + }
1.1226 + sqlite3CodeSubselect(pParse, pX, rMayHaveNull, eType==IN_INDEX_ROWID);
1.1227 + }else{
1.1228 + pX->iTable = iTab;
1.1229 + }
1.1230 + return eType;
1.1231 +}
1.1232 +#endif
1.1233 +
1.1234 +/*
1.1235 +** Generate code for scalar subqueries used as an expression
1.1236 +** and IN operators. Examples:
1.1237 +**
1.1238 +** (SELECT a FROM b) -- subquery
1.1239 +** EXISTS (SELECT a FROM b) -- EXISTS subquery
1.1240 +** x IN (4,5,11) -- IN operator with list on right-hand side
1.1241 +** x IN (SELECT a FROM b) -- IN operator with subquery on the right
1.1242 +**
1.1243 +** The pExpr parameter describes the expression that contains the IN
1.1244 +** operator or subquery.
1.1245 +**
1.1246 +** If parameter isRowid is non-zero, then expression pExpr is guaranteed
1.1247 +** to be of the form "<rowid> IN (?, ?, ?)", where <rowid> is a reference
1.1248 +** to some integer key column of a table B-Tree. In this case, use an
1.1249 +** intkey B-Tree to store the set of IN(...) values instead of the usual
1.1250 +** (slower) variable length keys B-Tree.
1.1251 +*/
1.1252 +#ifndef SQLITE_OMIT_SUBQUERY
1.1253 +void sqlite3CodeSubselect(
1.1254 + Parse *pParse,
1.1255 + Expr *pExpr,
1.1256 + int rMayHaveNull,
1.1257 + int isRowid
1.1258 +){
1.1259 + int testAddr = 0; /* One-time test address */
1.1260 + Vdbe *v = sqlite3GetVdbe(pParse);
1.1261 + if( v==0 ) return;
1.1262 +
1.1263 +
1.1264 + /* This code must be run in its entirety every time it is encountered
1.1265 + ** if any of the following is true:
1.1266 + **
1.1267 + ** * The right-hand side is a correlated subquery
1.1268 + ** * The right-hand side is an expression list containing variables
1.1269 + ** * We are inside a trigger
1.1270 + **
1.1271 + ** If all of the above are false, then we can run this code just once
1.1272 + ** save the results, and reuse the same result on subsequent invocations.
1.1273 + */
1.1274 + if( !ExprHasAnyProperty(pExpr, EP_VarSelect) && !pParse->trigStack ){
1.1275 + int mem = ++pParse->nMem;
1.1276 + sqlite3VdbeAddOp1(v, OP_If, mem);
1.1277 + testAddr = sqlite3VdbeAddOp2(v, OP_Integer, 1, mem);
1.1278 + assert( testAddr>0 || pParse->db->mallocFailed );
1.1279 + }
1.1280 +
1.1281 + switch( pExpr->op ){
1.1282 + case TK_IN: {
1.1283 + char affinity;
1.1284 + KeyInfo keyInfo;
1.1285 + int addr; /* Address of OP_OpenEphemeral instruction */
1.1286 + Expr *pLeft = pExpr->pLeft;
1.1287 +
1.1288 + if( rMayHaveNull ){
1.1289 + sqlite3VdbeAddOp2(v, OP_Null, 0, rMayHaveNull);
1.1290 + }
1.1291 +
1.1292 + affinity = sqlite3ExprAffinity(pLeft);
1.1293 +
1.1294 + /* Whether this is an 'x IN(SELECT...)' or an 'x IN(<exprlist>)'
1.1295 + ** expression it is handled the same way. A virtual table is
1.1296 + ** filled with single-field index keys representing the results
1.1297 + ** from the SELECT or the <exprlist>.
1.1298 + **
1.1299 + ** If the 'x' expression is a column value, or the SELECT...
1.1300 + ** statement returns a column value, then the affinity of that
1.1301 + ** column is used to build the index keys. If both 'x' and the
1.1302 + ** SELECT... statement are columns, then numeric affinity is used
1.1303 + ** if either column has NUMERIC or INTEGER affinity. If neither
1.1304 + ** 'x' nor the SELECT... statement are columns, then numeric affinity
1.1305 + ** is used.
1.1306 + */
1.1307 + pExpr->iTable = pParse->nTab++;
1.1308 + addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pExpr->iTable, !isRowid);
1.1309 + memset(&keyInfo, 0, sizeof(keyInfo));
1.1310 + keyInfo.nField = 1;
1.1311 +
1.1312 + if( pExpr->pSelect ){
1.1313 + /* Case 1: expr IN (SELECT ...)
1.1314 + **
1.1315 + ** Generate code to write the results of the select into the temporary
1.1316 + ** table allocated and opened above.
1.1317 + */
1.1318 + SelectDest dest;
1.1319 + ExprList *pEList;
1.1320 +
1.1321 + assert( !isRowid );
1.1322 + sqlite3SelectDestInit(&dest, SRT_Set, pExpr->iTable);
1.1323 + dest.affinity = (int)affinity;
1.1324 + assert( (pExpr->iTable&0x0000FFFF)==pExpr->iTable );
1.1325 + if( sqlite3Select(pParse, pExpr->pSelect, &dest) ){
1.1326 + return;
1.1327 + }
1.1328 + pEList = pExpr->pSelect->pEList;
1.1329 + if( pEList && pEList->nExpr>0 ){
1.1330 + keyInfo.aColl[0] = sqlite3BinaryCompareCollSeq(pParse, pExpr->pLeft,
1.1331 + pEList->a[0].pExpr);
1.1332 + }
1.1333 + }else if( pExpr->pList ){
1.1334 + /* Case 2: expr IN (exprlist)
1.1335 + **
1.1336 + ** For each expression, build an index key from the evaluation and
1.1337 + ** store it in the temporary table. If <expr> is a column, then use
1.1338 + ** that columns affinity when building index keys. If <expr> is not
1.1339 + ** a column, use numeric affinity.
1.1340 + */
1.1341 + int i;
1.1342 + ExprList *pList = pExpr->pList;
1.1343 + struct ExprList_item *pItem;
1.1344 + int r1, r2, r3;
1.1345 +
1.1346 + if( !affinity ){
1.1347 + affinity = SQLITE_AFF_NONE;
1.1348 + }
1.1349 + keyInfo.aColl[0] = sqlite3ExprCollSeq(pParse, pExpr->pLeft);
1.1350 +
1.1351 + /* Loop through each expression in <exprlist>. */
1.1352 + r1 = sqlite3GetTempReg(pParse);
1.1353 + r2 = sqlite3GetTempReg(pParse);
1.1354 + for(i=pList->nExpr, pItem=pList->a; i>0; i--, pItem++){
1.1355 + Expr *pE2 = pItem->pExpr;
1.1356 +
1.1357 + /* If the expression is not constant then we will need to
1.1358 + ** disable the test that was generated above that makes sure
1.1359 + ** this code only executes once. Because for a non-constant
1.1360 + ** expression we need to rerun this code each time.
1.1361 + */
1.1362 + if( testAddr && !sqlite3ExprIsConstant(pE2) ){
1.1363 + sqlite3VdbeChangeToNoop(v, testAddr-1, 2);
1.1364 + testAddr = 0;
1.1365 + }
1.1366 +
1.1367 + /* Evaluate the expression and insert it into the temp table */
1.1368 + pParse->disableColCache++;
1.1369 + r3 = sqlite3ExprCodeTarget(pParse, pE2, r1);
1.1370 + assert( pParse->disableColCache>0 );
1.1371 + pParse->disableColCache--;
1.1372 +
1.1373 + if( isRowid ){
1.1374 + sqlite3VdbeAddOp2(v, OP_Null, 0, r2);
1.1375 + sqlite3VdbeAddOp2(v, OP_MustBeInt, r3, sqlite3VdbeCurrentAddr(v)+2);
1.1376 + sqlite3VdbeAddOp3(v, OP_Insert, pExpr->iTable, r2, r3);
1.1377 + }else{
1.1378 + sqlite3VdbeAddOp4(v, OP_MakeRecord, r3, 1, r2, &affinity, 1);
1.1379 + sqlite3ExprCacheAffinityChange(pParse, r3, 1);
1.1380 + sqlite3VdbeAddOp2(v, OP_IdxInsert, pExpr->iTable, r2);
1.1381 + }
1.1382 + }
1.1383 + sqlite3ReleaseTempReg(pParse, r1);
1.1384 + sqlite3ReleaseTempReg(pParse, r2);
1.1385 + }
1.1386 + if( !isRowid ){
1.1387 + sqlite3VdbeChangeP4(v, addr, (void *)&keyInfo, P4_KEYINFO);
1.1388 + }
1.1389 + break;
1.1390 + }
1.1391 +
1.1392 + case TK_EXISTS:
1.1393 + case TK_SELECT: {
1.1394 + /* This has to be a scalar SELECT. Generate code to put the
1.1395 + ** value of this select in a memory cell and record the number
1.1396 + ** of the memory cell in iColumn.
1.1397 + */
1.1398 + static const Token one = { (u8*)"1", 0, 1 };
1.1399 + Select *pSel;
1.1400 + SelectDest dest;
1.1401 +
1.1402 + pSel = pExpr->pSelect;
1.1403 + sqlite3SelectDestInit(&dest, 0, ++pParse->nMem);
1.1404 + if( pExpr->op==TK_SELECT ){
1.1405 + dest.eDest = SRT_Mem;
1.1406 + sqlite3VdbeAddOp2(v, OP_Null, 0, dest.iParm);
1.1407 + VdbeComment((v, "Init subquery result"));
1.1408 + }else{
1.1409 + dest.eDest = SRT_Exists;
1.1410 + sqlite3VdbeAddOp2(v, OP_Integer, 0, dest.iParm);
1.1411 + VdbeComment((v, "Init EXISTS result"));
1.1412 + }
1.1413 + sqlite3ExprDelete(pParse->db, pSel->pLimit);
1.1414 + pSel->pLimit = sqlite3PExpr(pParse, TK_INTEGER, 0, 0, &one);
1.1415 + if( sqlite3Select(pParse, pSel, &dest) ){
1.1416 + return;
1.1417 + }
1.1418 + pExpr->iColumn = dest.iParm;
1.1419 + break;
1.1420 + }
1.1421 + }
1.1422 +
1.1423 + if( testAddr ){
1.1424 + sqlite3VdbeJumpHere(v, testAddr-1);
1.1425 + }
1.1426 +
1.1427 + return;
1.1428 +}
1.1429 +#endif /* SQLITE_OMIT_SUBQUERY */
1.1430 +
1.1431 +/*
1.1432 +** Duplicate an 8-byte value
1.1433 +*/
1.1434 +static char *dup8bytes(Vdbe *v, const char *in){
1.1435 + char *out = sqlite3DbMallocRaw(sqlite3VdbeDb(v), 8);
1.1436 + if( out ){
1.1437 + memcpy(out, in, 8);
1.1438 + }
1.1439 + return out;
1.1440 +}
1.1441 +
1.1442 +/*
1.1443 +** Generate an instruction that will put the floating point
1.1444 +** value described by z[0..n-1] into register iMem.
1.1445 +**
1.1446 +** The z[] string will probably not be zero-terminated. But the
1.1447 +** z[n] character is guaranteed to be something that does not look
1.1448 +** like the continuation of the number.
1.1449 +*/
1.1450 +static void codeReal(Vdbe *v, const char *z, int n, int negateFlag, int iMem){
1.1451 + assert( z || v==0 || sqlite3VdbeDb(v)->mallocFailed );
1.1452 + if( z ){
1.1453 + double value;
1.1454 + char *zV;
1.1455 + assert( !isdigit(z[n]) );
1.1456 + sqlite3AtoF(z, &value);
1.1457 + if( sqlite3IsNaN(value) ){
1.1458 + sqlite3VdbeAddOp2(v, OP_Null, 0, iMem);
1.1459 + }else{
1.1460 + if( negateFlag ) value = -value;
1.1461 + zV = dup8bytes(v, (char*)&value);
1.1462 + sqlite3VdbeAddOp4(v, OP_Real, 0, iMem, 0, zV, P4_REAL);
1.1463 + }
1.1464 + }
1.1465 +}
1.1466 +
1.1467 +
1.1468 +/*
1.1469 +** Generate an instruction that will put the integer describe by
1.1470 +** text z[0..n-1] into register iMem.
1.1471 +**
1.1472 +** The z[] string will probably not be zero-terminated. But the
1.1473 +** z[n] character is guaranteed to be something that does not look
1.1474 +** like the continuation of the number.
1.1475 +*/
1.1476 +static void codeInteger(Vdbe *v, Expr *pExpr, int negFlag, int iMem){
1.1477 + const char *z;
1.1478 + if( pExpr->flags & EP_IntValue ){
1.1479 + int i = pExpr->iTable;
1.1480 + if( negFlag ) i = -i;
1.1481 + sqlite3VdbeAddOp2(v, OP_Integer, i, iMem);
1.1482 + }else if( (z = (char*)pExpr->token.z)!=0 ){
1.1483 + int i;
1.1484 + int n = pExpr->token.n;
1.1485 + assert( !isdigit(z[n]) );
1.1486 + if( sqlite3GetInt32(z, &i) ){
1.1487 + if( negFlag ) i = -i;
1.1488 + sqlite3VdbeAddOp2(v, OP_Integer, i, iMem);
1.1489 + }else if( sqlite3FitsIn64Bits(z, negFlag) ){
1.1490 + i64 value;
1.1491 + char *zV;
1.1492 + sqlite3Atoi64(z, &value);
1.1493 + if( negFlag ) value = -value;
1.1494 + zV = dup8bytes(v, (char*)&value);
1.1495 + sqlite3VdbeAddOp4(v, OP_Int64, 0, iMem, 0, zV, P4_INT64);
1.1496 + }else{
1.1497 + codeReal(v, z, n, negFlag, iMem);
1.1498 + }
1.1499 + }
1.1500 +}
1.1501 +
1.1502 +
1.1503 +/*
1.1504 +** Generate code that will extract the iColumn-th column from
1.1505 +** table pTab and store the column value in a register. An effort
1.1506 +** is made to store the column value in register iReg, but this is
1.1507 +** not guaranteed. The location of the column value is returned.
1.1508 +**
1.1509 +** There must be an open cursor to pTab in iTable when this routine
1.1510 +** is called. If iColumn<0 then code is generated that extracts the rowid.
1.1511 +**
1.1512 +** This routine might attempt to reuse the value of the column that
1.1513 +** has already been loaded into a register. The value will always
1.1514 +** be used if it has not undergone any affinity changes. But if
1.1515 +** an affinity change has occurred, then the cached value will only be
1.1516 +** used if allowAffChng is true.
1.1517 +*/
1.1518 +int sqlite3ExprCodeGetColumn(
1.1519 + Parse *pParse, /* Parsing and code generating context */
1.1520 + Table *pTab, /* Description of the table we are reading from */
1.1521 + int iColumn, /* Index of the table column */
1.1522 + int iTable, /* The cursor pointing to the table */
1.1523 + int iReg, /* Store results here */
1.1524 + int allowAffChng /* True if prior affinity changes are OK */
1.1525 +){
1.1526 + Vdbe *v = pParse->pVdbe;
1.1527 + int i;
1.1528 + struct yColCache *p;
1.1529 +
1.1530 + for(i=0, p=pParse->aColCache; i<pParse->nColCache; i++, p++){
1.1531 + if( p->iTable==iTable && p->iColumn==iColumn
1.1532 + && (!p->affChange || allowAffChng) ){
1.1533 +#if 0
1.1534 + sqlite3VdbeAddOp0(v, OP_Noop);
1.1535 + VdbeComment((v, "OPT: tab%d.col%d -> r%d", iTable, iColumn, p->iReg));
1.1536 +#endif
1.1537 + return p->iReg;
1.1538 + }
1.1539 + }
1.1540 + assert( v!=0 );
1.1541 + if( iColumn<0 ){
1.1542 + int op = (pTab && IsVirtual(pTab)) ? OP_VRowid : OP_Rowid;
1.1543 + sqlite3VdbeAddOp2(v, op, iTable, iReg);
1.1544 + }else if( pTab==0 ){
1.1545 + sqlite3VdbeAddOp3(v, OP_Column, iTable, iColumn, iReg);
1.1546 + }else{
1.1547 + int op = IsVirtual(pTab) ? OP_VColumn : OP_Column;
1.1548 + sqlite3VdbeAddOp3(v, op, iTable, iColumn, iReg);
1.1549 + sqlite3ColumnDefault(v, pTab, iColumn);
1.1550 +#ifndef SQLITE_OMIT_FLOATING_POINT
1.1551 + if( pTab->aCol[iColumn].affinity==SQLITE_AFF_REAL ){
1.1552 + sqlite3VdbeAddOp1(v, OP_RealAffinity, iReg);
1.1553 + }
1.1554 +#endif
1.1555 + }
1.1556 + if( pParse->disableColCache==0 ){
1.1557 + i = pParse->iColCache;
1.1558 + p = &pParse->aColCache[i];
1.1559 + p->iTable = iTable;
1.1560 + p->iColumn = iColumn;
1.1561 + p->iReg = iReg;
1.1562 + p->affChange = 0;
1.1563 + i++;
1.1564 + if( i>=ArraySize(pParse->aColCache) ) i = 0;
1.1565 + if( i>pParse->nColCache ) pParse->nColCache = i;
1.1566 + pParse->iColCache = i;
1.1567 + }
1.1568 + return iReg;
1.1569 +}
1.1570 +
1.1571 +/*
1.1572 +** Clear all column cache entries associated with the vdbe
1.1573 +** cursor with cursor number iTable.
1.1574 +*/
1.1575 +void sqlite3ExprClearColumnCache(Parse *pParse, int iTable){
1.1576 + if( iTable<0 ){
1.1577 + pParse->nColCache = 0;
1.1578 + pParse->iColCache = 0;
1.1579 + }else{
1.1580 + int i;
1.1581 + for(i=0; i<pParse->nColCache; i++){
1.1582 + if( pParse->aColCache[i].iTable==iTable ){
1.1583 + testcase( i==pParse->nColCache-1 );
1.1584 + pParse->aColCache[i] = pParse->aColCache[--pParse->nColCache];
1.1585 + pParse->iColCache = pParse->nColCache;
1.1586 + }
1.1587 + }
1.1588 + }
1.1589 +}
1.1590 +
1.1591 +/*
1.1592 +** Record the fact that an affinity change has occurred on iCount
1.1593 +** registers starting with iStart.
1.1594 +*/
1.1595 +void sqlite3ExprCacheAffinityChange(Parse *pParse, int iStart, int iCount){
1.1596 + int iEnd = iStart + iCount - 1;
1.1597 + int i;
1.1598 + for(i=0; i<pParse->nColCache; i++){
1.1599 + int r = pParse->aColCache[i].iReg;
1.1600 + if( r>=iStart && r<=iEnd ){
1.1601 + pParse->aColCache[i].affChange = 1;
1.1602 + }
1.1603 + }
1.1604 +}
1.1605 +
1.1606 +/*
1.1607 +** Generate code to move content from registers iFrom...iFrom+nReg-1
1.1608 +** over to iTo..iTo+nReg-1. Keep the column cache up-to-date.
1.1609 +*/
1.1610 +void sqlite3ExprCodeMove(Parse *pParse, int iFrom, int iTo, int nReg){
1.1611 + int i;
1.1612 + if( iFrom==iTo ) return;
1.1613 + sqlite3VdbeAddOp3(pParse->pVdbe, OP_Move, iFrom, iTo, nReg);
1.1614 + for(i=0; i<pParse->nColCache; i++){
1.1615 + int x = pParse->aColCache[i].iReg;
1.1616 + if( x>=iFrom && x<iFrom+nReg ){
1.1617 + pParse->aColCache[i].iReg += iTo-iFrom;
1.1618 + }
1.1619 + }
1.1620 +}
1.1621 +
1.1622 +/*
1.1623 +** Generate code to copy content from registers iFrom...iFrom+nReg-1
1.1624 +** over to iTo..iTo+nReg-1.
1.1625 +*/
1.1626 +void sqlite3ExprCodeCopy(Parse *pParse, int iFrom, int iTo, int nReg){
1.1627 + int i;
1.1628 + if( iFrom==iTo ) return;
1.1629 + for(i=0; i<nReg; i++){
1.1630 + sqlite3VdbeAddOp2(pParse->pVdbe, OP_Copy, iFrom+i, iTo+i);
1.1631 + }
1.1632 +}
1.1633 +
1.1634 +/*
1.1635 +** Return true if any register in the range iFrom..iTo (inclusive)
1.1636 +** is used as part of the column cache.
1.1637 +*/
1.1638 +static int usedAsColumnCache(Parse *pParse, int iFrom, int iTo){
1.1639 + int i;
1.1640 + for(i=0; i<pParse->nColCache; i++){
1.1641 + int r = pParse->aColCache[i].iReg;
1.1642 + if( r>=iFrom && r<=iTo ) return 1;
1.1643 + }
1.1644 + return 0;
1.1645 +}
1.1646 +
1.1647 +/*
1.1648 +** Theres is a value in register iCurrent. We ultimately want
1.1649 +** the value to be in register iTarget. It might be that
1.1650 +** iCurrent and iTarget are the same register.
1.1651 +**
1.1652 +** We are going to modify the value, so we need to make sure it
1.1653 +** is not a cached register. If iCurrent is a cached register,
1.1654 +** then try to move the value over to iTarget. If iTarget is a
1.1655 +** cached register, then clear the corresponding cache line.
1.1656 +**
1.1657 +** Return the register that the value ends up in.
1.1658 +*/
1.1659 +int sqlite3ExprWritableRegister(Parse *pParse, int iCurrent, int iTarget){
1.1660 + int i;
1.1661 + assert( pParse->pVdbe!=0 );
1.1662 + if( !usedAsColumnCache(pParse, iCurrent, iCurrent) ){
1.1663 + return iCurrent;
1.1664 + }
1.1665 + if( iCurrent!=iTarget ){
1.1666 + sqlite3VdbeAddOp2(pParse->pVdbe, OP_SCopy, iCurrent, iTarget);
1.1667 + }
1.1668 + for(i=0; i<pParse->nColCache; i++){
1.1669 + if( pParse->aColCache[i].iReg==iTarget ){
1.1670 + pParse->aColCache[i] = pParse->aColCache[--pParse->nColCache];
1.1671 + pParse->iColCache = pParse->nColCache;
1.1672 + }
1.1673 + }
1.1674 + return iTarget;
1.1675 +}
1.1676 +
1.1677 +/*
1.1678 +** If the last instruction coded is an ephemeral copy of any of
1.1679 +** the registers in the nReg registers beginning with iReg, then
1.1680 +** convert the last instruction from OP_SCopy to OP_Copy.
1.1681 +*/
1.1682 +void sqlite3ExprHardCopy(Parse *pParse, int iReg, int nReg){
1.1683 + int addr;
1.1684 + VdbeOp *pOp;
1.1685 + Vdbe *v;
1.1686 +
1.1687 + v = pParse->pVdbe;
1.1688 + addr = sqlite3VdbeCurrentAddr(v);
1.1689 + pOp = sqlite3VdbeGetOp(v, addr-1);
1.1690 + assert( pOp || pParse->db->mallocFailed );
1.1691 + if( pOp && pOp->opcode==OP_SCopy && pOp->p1>=iReg && pOp->p1<iReg+nReg ){
1.1692 + pOp->opcode = OP_Copy;
1.1693 + }
1.1694 +}
1.1695 +
1.1696 +/*
1.1697 +** Generate code to store the value of the iAlias-th alias in register
1.1698 +** target. The first time this is called, pExpr is evaluated to compute
1.1699 +** the value of the alias. The value is stored in an auxiliary register
1.1700 +** and the number of that register is returned. On subsequent calls,
1.1701 +** the register number is returned without generating any code.
1.1702 +**
1.1703 +** Note that in order for this to work, code must be generated in the
1.1704 +** same order that it is executed.
1.1705 +**
1.1706 +** Aliases are numbered starting with 1. So iAlias is in the range
1.1707 +** of 1 to pParse->nAlias inclusive.
1.1708 +**
1.1709 +** pParse->aAlias[iAlias-1] records the register number where the value
1.1710 +** of the iAlias-th alias is stored. If zero, that means that the
1.1711 +** alias has not yet been computed.
1.1712 +*/
1.1713 +static int codeAlias(Parse *pParse, int iAlias, Expr *pExpr){
1.1714 + sqlite3 *db = pParse->db;
1.1715 + int iReg;
1.1716 + if( pParse->aAlias==0 ){
1.1717 + pParse->aAlias = sqlite3DbMallocZero(db,
1.1718 + sizeof(pParse->aAlias[0])*pParse->nAlias );
1.1719 + if( db->mallocFailed ) return 0;
1.1720 + }
1.1721 + assert( iAlias>0 && iAlias<=pParse->nAlias );
1.1722 + iReg = pParse->aAlias[iAlias-1];
1.1723 + if( iReg==0 ){
1.1724 + iReg = ++pParse->nMem;
1.1725 + sqlite3ExprCode(pParse, pExpr, iReg);
1.1726 + pParse->aAlias[iAlias-1] = iReg;
1.1727 + }
1.1728 + return iReg;
1.1729 +}
1.1730 +
1.1731 +/*
1.1732 +** Generate code into the current Vdbe to evaluate the given
1.1733 +** expression. Attempt to store the results in register "target".
1.1734 +** Return the register where results are stored.
1.1735 +**
1.1736 +** With this routine, there is no guarantee that results will
1.1737 +** be stored in target. The result might be stored in some other
1.1738 +** register if it is convenient to do so. The calling function
1.1739 +** must check the return code and move the results to the desired
1.1740 +** register.
1.1741 +*/
1.1742 +int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){
1.1743 + Vdbe *v = pParse->pVdbe; /* The VM under construction */
1.1744 + int op; /* The opcode being coded */
1.1745 + int inReg = target; /* Results stored in register inReg */
1.1746 + int regFree1 = 0; /* If non-zero free this temporary register */
1.1747 + int regFree2 = 0; /* If non-zero free this temporary register */
1.1748 + int r1, r2, r3, r4; /* Various register numbers */
1.1749 + sqlite3 *db;
1.1750 +
1.1751 + db = pParse->db;
1.1752 + assert( v!=0 || db->mallocFailed );
1.1753 + assert( target>0 && target<=pParse->nMem );
1.1754 + if( v==0 ) return 0;
1.1755 +
1.1756 + if( pExpr==0 ){
1.1757 + op = TK_NULL;
1.1758 + }else{
1.1759 + op = pExpr->op;
1.1760 + }
1.1761 + switch( op ){
1.1762 + case TK_AGG_COLUMN: {
1.1763 + AggInfo *pAggInfo = pExpr->pAggInfo;
1.1764 + struct AggInfo_col *pCol = &pAggInfo->aCol[pExpr->iAgg];
1.1765 + if( !pAggInfo->directMode ){
1.1766 + assert( pCol->iMem>0 );
1.1767 + inReg = pCol->iMem;
1.1768 + break;
1.1769 + }else if( pAggInfo->useSortingIdx ){
1.1770 + sqlite3VdbeAddOp3(v, OP_Column, pAggInfo->sortingIdx,
1.1771 + pCol->iSorterColumn, target);
1.1772 + break;
1.1773 + }
1.1774 + /* Otherwise, fall thru into the TK_COLUMN case */
1.1775 + }
1.1776 + case TK_COLUMN: {
1.1777 + if( pExpr->iTable<0 ){
1.1778 + /* This only happens when coding check constraints */
1.1779 + assert( pParse->ckBase>0 );
1.1780 + inReg = pExpr->iColumn + pParse->ckBase;
1.1781 + }else{
1.1782 + testcase( (pExpr->flags & EP_AnyAff)!=0 );
1.1783 + inReg = sqlite3ExprCodeGetColumn(pParse, pExpr->pTab,
1.1784 + pExpr->iColumn, pExpr->iTable, target,
1.1785 + pExpr->flags & EP_AnyAff);
1.1786 + }
1.1787 + break;
1.1788 + }
1.1789 + case TK_INTEGER: {
1.1790 + codeInteger(v, pExpr, 0, target);
1.1791 + break;
1.1792 + }
1.1793 + case TK_FLOAT: {
1.1794 + codeReal(v, (char*)pExpr->token.z, pExpr->token.n, 0, target);
1.1795 + break;
1.1796 + }
1.1797 + case TK_STRING: {
1.1798 + sqlite3DequoteExpr(db, pExpr);
1.1799 + sqlite3VdbeAddOp4(v,OP_String8, 0, target, 0,
1.1800 + (char*)pExpr->token.z, pExpr->token.n);
1.1801 + break;
1.1802 + }
1.1803 + case TK_NULL: {
1.1804 + sqlite3VdbeAddOp2(v, OP_Null, 0, target);
1.1805 + break;
1.1806 + }
1.1807 +#ifndef SQLITE_OMIT_BLOB_LITERAL
1.1808 + case TK_BLOB: {
1.1809 + int n;
1.1810 + const char *z;
1.1811 + char *zBlob;
1.1812 + assert( pExpr->token.n>=3 );
1.1813 + assert( pExpr->token.z[0]=='x' || pExpr->token.z[0]=='X' );
1.1814 + assert( pExpr->token.z[1]=='\'' );
1.1815 + assert( pExpr->token.z[pExpr->token.n-1]=='\'' );
1.1816 + n = pExpr->token.n - 3;
1.1817 + z = (char*)pExpr->token.z + 2;
1.1818 + zBlob = sqlite3HexToBlob(sqlite3VdbeDb(v), z, n);
1.1819 + sqlite3VdbeAddOp4(v, OP_Blob, n/2, target, 0, zBlob, P4_DYNAMIC);
1.1820 + break;
1.1821 + }
1.1822 +#endif
1.1823 + case TK_VARIABLE: {
1.1824 + sqlite3VdbeAddOp2(v, OP_Variable, pExpr->iTable, target);
1.1825 + if( pExpr->token.n>1 ){
1.1826 + sqlite3VdbeChangeP4(v, -1, (char*)pExpr->token.z, pExpr->token.n);
1.1827 + }
1.1828 + break;
1.1829 + }
1.1830 + case TK_REGISTER: {
1.1831 + inReg = pExpr->iTable;
1.1832 + break;
1.1833 + }
1.1834 + case TK_AS: {
1.1835 + inReg = codeAlias(pParse, pExpr->iTable, pExpr->pLeft);
1.1836 + break;
1.1837 + }
1.1838 +#ifndef SQLITE_OMIT_CAST
1.1839 + case TK_CAST: {
1.1840 + /* Expressions of the form: CAST(pLeft AS token) */
1.1841 + int aff, to_op;
1.1842 + inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
1.1843 + aff = sqlite3AffinityType(&pExpr->token);
1.1844 + to_op = aff - SQLITE_AFF_TEXT + OP_ToText;
1.1845 + assert( to_op==OP_ToText || aff!=SQLITE_AFF_TEXT );
1.1846 + assert( to_op==OP_ToBlob || aff!=SQLITE_AFF_NONE );
1.1847 + assert( to_op==OP_ToNumeric || aff!=SQLITE_AFF_NUMERIC );
1.1848 + assert( to_op==OP_ToInt || aff!=SQLITE_AFF_INTEGER );
1.1849 + assert( to_op==OP_ToReal || aff!=SQLITE_AFF_REAL );
1.1850 + testcase( to_op==OP_ToText );
1.1851 + testcase( to_op==OP_ToBlob );
1.1852 + testcase( to_op==OP_ToNumeric );
1.1853 + testcase( to_op==OP_ToInt );
1.1854 + testcase( to_op==OP_ToReal );
1.1855 + sqlite3VdbeAddOp1(v, to_op, inReg);
1.1856 + testcase( usedAsColumnCache(pParse, inReg, inReg) );
1.1857 + sqlite3ExprCacheAffinityChange(pParse, inReg, 1);
1.1858 + break;
1.1859 + }
1.1860 +#endif /* SQLITE_OMIT_CAST */
1.1861 + case TK_LT:
1.1862 + case TK_LE:
1.1863 + case TK_GT:
1.1864 + case TK_GE:
1.1865 + case TK_NE:
1.1866 + case TK_EQ: {
1.1867 + assert( TK_LT==OP_Lt );
1.1868 + assert( TK_LE==OP_Le );
1.1869 + assert( TK_GT==OP_Gt );
1.1870 + assert( TK_GE==OP_Ge );
1.1871 + assert( TK_EQ==OP_Eq );
1.1872 + assert( TK_NE==OP_Ne );
1.1873 + testcase( op==TK_LT );
1.1874 + testcase( op==TK_LE );
1.1875 + testcase( op==TK_GT );
1.1876 + testcase( op==TK_GE );
1.1877 + testcase( op==TK_EQ );
1.1878 + testcase( op==TK_NE );
1.1879 + codeCompareOperands(pParse, pExpr->pLeft, &r1, ®Free1,
1.1880 + pExpr->pRight, &r2, ®Free2);
1.1881 + codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
1.1882 + r1, r2, inReg, SQLITE_STOREP2);
1.1883 + testcase( regFree1==0 );
1.1884 + testcase( regFree2==0 );
1.1885 + break;
1.1886 + }
1.1887 + case TK_AND:
1.1888 + case TK_OR:
1.1889 + case TK_PLUS:
1.1890 + case TK_STAR:
1.1891 + case TK_MINUS:
1.1892 + case TK_REM:
1.1893 + case TK_BITAND:
1.1894 + case TK_BITOR:
1.1895 + case TK_SLASH:
1.1896 + case TK_LSHIFT:
1.1897 + case TK_RSHIFT:
1.1898 + case TK_CONCAT: {
1.1899 + assert( TK_AND==OP_And );
1.1900 + assert( TK_OR==OP_Or );
1.1901 + assert( TK_PLUS==OP_Add );
1.1902 + assert( TK_MINUS==OP_Subtract );
1.1903 + assert( TK_REM==OP_Remainder );
1.1904 + assert( TK_BITAND==OP_BitAnd );
1.1905 + assert( TK_BITOR==OP_BitOr );
1.1906 + assert( TK_SLASH==OP_Divide );
1.1907 + assert( TK_LSHIFT==OP_ShiftLeft );
1.1908 + assert( TK_RSHIFT==OP_ShiftRight );
1.1909 + assert( TK_CONCAT==OP_Concat );
1.1910 + testcase( op==TK_AND );
1.1911 + testcase( op==TK_OR );
1.1912 + testcase( op==TK_PLUS );
1.1913 + testcase( op==TK_MINUS );
1.1914 + testcase( op==TK_REM );
1.1915 + testcase( op==TK_BITAND );
1.1916 + testcase( op==TK_BITOR );
1.1917 + testcase( op==TK_SLASH );
1.1918 + testcase( op==TK_LSHIFT );
1.1919 + testcase( op==TK_RSHIFT );
1.1920 + testcase( op==TK_CONCAT );
1.1921 + r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
1.1922 + r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, ®Free2);
1.1923 + sqlite3VdbeAddOp3(v, op, r2, r1, target);
1.1924 + testcase( regFree1==0 );
1.1925 + testcase( regFree2==0 );
1.1926 + break;
1.1927 + }
1.1928 + case TK_UMINUS: {
1.1929 + Expr *pLeft = pExpr->pLeft;
1.1930 + assert( pLeft );
1.1931 + if( pLeft->op==TK_FLOAT || pLeft->op==TK_INTEGER ){
1.1932 + if( pLeft->op==TK_FLOAT ){
1.1933 + codeReal(v, (char*)pLeft->token.z, pLeft->token.n, 1, target);
1.1934 + }else{
1.1935 + codeInteger(v, pLeft, 1, target);
1.1936 + }
1.1937 + }else{
1.1938 + regFree1 = r1 = sqlite3GetTempReg(pParse);
1.1939 + sqlite3VdbeAddOp2(v, OP_Integer, 0, r1);
1.1940 + r2 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free2);
1.1941 + sqlite3VdbeAddOp3(v, OP_Subtract, r2, r1, target);
1.1942 + testcase( regFree2==0 );
1.1943 + }
1.1944 + inReg = target;
1.1945 + break;
1.1946 + }
1.1947 + case TK_BITNOT:
1.1948 + case TK_NOT: {
1.1949 + assert( TK_BITNOT==OP_BitNot );
1.1950 + assert( TK_NOT==OP_Not );
1.1951 + testcase( op==TK_BITNOT );
1.1952 + testcase( op==TK_NOT );
1.1953 + inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
1.1954 + testcase( inReg==target );
1.1955 + testcase( usedAsColumnCache(pParse, inReg, inReg) );
1.1956 + inReg = sqlite3ExprWritableRegister(pParse, inReg, target);
1.1957 + sqlite3VdbeAddOp1(v, op, inReg);
1.1958 + break;
1.1959 + }
1.1960 + case TK_ISNULL:
1.1961 + case TK_NOTNULL: {
1.1962 + int addr;
1.1963 + assert( TK_ISNULL==OP_IsNull );
1.1964 + assert( TK_NOTNULL==OP_NotNull );
1.1965 + testcase( op==TK_ISNULL );
1.1966 + testcase( op==TK_NOTNULL );
1.1967 + sqlite3VdbeAddOp2(v, OP_Integer, 1, target);
1.1968 + r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
1.1969 + testcase( regFree1==0 );
1.1970 + addr = sqlite3VdbeAddOp1(v, op, r1);
1.1971 + sqlite3VdbeAddOp2(v, OP_AddImm, target, -1);
1.1972 + sqlite3VdbeJumpHere(v, addr);
1.1973 + break;
1.1974 + }
1.1975 + case TK_AGG_FUNCTION: {
1.1976 + AggInfo *pInfo = pExpr->pAggInfo;
1.1977 + if( pInfo==0 ){
1.1978 + sqlite3ErrorMsg(pParse, "misuse of aggregate: %T",
1.1979 + &pExpr->span);
1.1980 + }else{
1.1981 + inReg = pInfo->aFunc[pExpr->iAgg].iMem;
1.1982 + }
1.1983 + break;
1.1984 + }
1.1985 + case TK_CONST_FUNC:
1.1986 + case TK_FUNCTION: {
1.1987 + ExprList *pList = pExpr->pList;
1.1988 + int nExpr = pList ? pList->nExpr : 0;
1.1989 + FuncDef *pDef;
1.1990 + int nId;
1.1991 + const char *zId;
1.1992 + int constMask = 0;
1.1993 + int i;
1.1994 + u8 enc = ENC(db);
1.1995 + CollSeq *pColl = 0;
1.1996 +
1.1997 + testcase( op==TK_CONST_FUNC );
1.1998 + testcase( op==TK_FUNCTION );
1.1999 + zId = (char*)pExpr->token.z;
1.2000 + nId = pExpr->token.n;
1.2001 + pDef = sqlite3FindFunction(db, zId, nId, nExpr, enc, 0);
1.2002 + assert( pDef!=0 );
1.2003 + if( pList ){
1.2004 + nExpr = pList->nExpr;
1.2005 + r1 = sqlite3GetTempRange(pParse, nExpr);
1.2006 + sqlite3ExprCodeExprList(pParse, pList, r1, 1);
1.2007 + }else{
1.2008 + nExpr = r1 = 0;
1.2009 + }
1.2010 +#ifndef SQLITE_OMIT_VIRTUALTABLE
1.2011 + /* Possibly overload the function if the first argument is
1.2012 + ** a virtual table column.
1.2013 + **
1.2014 + ** For infix functions (LIKE, GLOB, REGEXP, and MATCH) use the
1.2015 + ** second argument, not the first, as the argument to test to
1.2016 + ** see if it is a column in a virtual table. This is done because
1.2017 + ** the left operand of infix functions (the operand we want to
1.2018 + ** control overloading) ends up as the second argument to the
1.2019 + ** function. The expression "A glob B" is equivalent to
1.2020 + ** "glob(B,A). We want to use the A in "A glob B" to test
1.2021 + ** for function overloading. But we use the B term in "glob(B,A)".
1.2022 + */
1.2023 + if( nExpr>=2 && (pExpr->flags & EP_InfixFunc) ){
1.2024 + pDef = sqlite3VtabOverloadFunction(db, pDef, nExpr, pList->a[1].pExpr);
1.2025 + }else if( nExpr>0 ){
1.2026 + pDef = sqlite3VtabOverloadFunction(db, pDef, nExpr, pList->a[0].pExpr);
1.2027 + }
1.2028 +#endif
1.2029 + for(i=0; i<nExpr && i<32; i++){
1.2030 + if( sqlite3ExprIsConstant(pList->a[i].pExpr) ){
1.2031 + constMask |= (1<<i);
1.2032 + }
1.2033 + if( pDef->needCollSeq && !pColl ){
1.2034 + pColl = sqlite3ExprCollSeq(pParse, pList->a[i].pExpr);
1.2035 + }
1.2036 + }
1.2037 + if( pDef->needCollSeq ){
1.2038 + if( !pColl ) pColl = db->pDfltColl;
1.2039 + sqlite3VdbeAddOp4(v, OP_CollSeq, 0, 0, 0, (char *)pColl, P4_COLLSEQ);
1.2040 + }
1.2041 + sqlite3VdbeAddOp4(v, OP_Function, constMask, r1, target,
1.2042 + (char*)pDef, P4_FUNCDEF);
1.2043 + sqlite3VdbeChangeP5(v, nExpr);
1.2044 + if( nExpr ){
1.2045 + sqlite3ReleaseTempRange(pParse, r1, nExpr);
1.2046 + }
1.2047 + sqlite3ExprCacheAffinityChange(pParse, r1, nExpr);
1.2048 + break;
1.2049 + }
1.2050 +#ifndef SQLITE_OMIT_SUBQUERY
1.2051 + case TK_EXISTS:
1.2052 + case TK_SELECT: {
1.2053 + testcase( op==TK_EXISTS );
1.2054 + testcase( op==TK_SELECT );
1.2055 + if( pExpr->iColumn==0 ){
1.2056 + sqlite3CodeSubselect(pParse, pExpr, 0, 0);
1.2057 + }
1.2058 + inReg = pExpr->iColumn;
1.2059 + break;
1.2060 + }
1.2061 + case TK_IN: {
1.2062 + int rNotFound = 0;
1.2063 + int rMayHaveNull = 0;
1.2064 + int j2, j3, j4, j5;
1.2065 + char affinity;
1.2066 + int eType;
1.2067 +
1.2068 + VdbeNoopComment((v, "begin IN expr r%d", target));
1.2069 + eType = sqlite3FindInIndex(pParse, pExpr, &rMayHaveNull);
1.2070 + if( rMayHaveNull ){
1.2071 + rNotFound = ++pParse->nMem;
1.2072 + }
1.2073 +
1.2074 + /* Figure out the affinity to use to create a key from the results
1.2075 + ** of the expression. affinityStr stores a static string suitable for
1.2076 + ** P4 of OP_MakeRecord.
1.2077 + */
1.2078 + affinity = comparisonAffinity(pExpr);
1.2079 +
1.2080 +
1.2081 + /* Code the <expr> from "<expr> IN (...)". The temporary table
1.2082 + ** pExpr->iTable contains the values that make up the (...) set.
1.2083 + */
1.2084 + pParse->disableColCache++;
1.2085 + sqlite3ExprCode(pParse, pExpr->pLeft, target);
1.2086 + pParse->disableColCache--;
1.2087 + j2 = sqlite3VdbeAddOp1(v, OP_IsNull, target);
1.2088 + if( eType==IN_INDEX_ROWID ){
1.2089 + j3 = sqlite3VdbeAddOp1(v, OP_MustBeInt, target);
1.2090 + j4 = sqlite3VdbeAddOp3(v, OP_NotExists, pExpr->iTable, 0, target);
1.2091 + sqlite3VdbeAddOp2(v, OP_Integer, 1, target);
1.2092 + j5 = sqlite3VdbeAddOp0(v, OP_Goto);
1.2093 + sqlite3VdbeJumpHere(v, j3);
1.2094 + sqlite3VdbeJumpHere(v, j4);
1.2095 + sqlite3VdbeAddOp2(v, OP_Integer, 0, target);
1.2096 + }else{
1.2097 + r2 = regFree2 = sqlite3GetTempReg(pParse);
1.2098 +
1.2099 + /* Create a record and test for set membership. If the set contains
1.2100 + ** the value, then jump to the end of the test code. The target
1.2101 + ** register still contains the true (1) value written to it earlier.
1.2102 + */
1.2103 + sqlite3VdbeAddOp4(v, OP_MakeRecord, target, 1, r2, &affinity, 1);
1.2104 + sqlite3VdbeAddOp2(v, OP_Integer, 1, target);
1.2105 + j5 = sqlite3VdbeAddOp3(v, OP_Found, pExpr->iTable, 0, r2);
1.2106 +
1.2107 + /* If the set membership test fails, then the result of the
1.2108 + ** "x IN (...)" expression must be either 0 or NULL. If the set
1.2109 + ** contains no NULL values, then the result is 0. If the set
1.2110 + ** contains one or more NULL values, then the result of the
1.2111 + ** expression is also NULL.
1.2112 + */
1.2113 + if( rNotFound==0 ){
1.2114 + /* This branch runs if it is known at compile time (now) that
1.2115 + ** the set contains no NULL values. This happens as the result
1.2116 + ** of a "NOT NULL" constraint in the database schema. No need
1.2117 + ** to test the data structure at runtime in this case.
1.2118 + */
1.2119 + sqlite3VdbeAddOp2(v, OP_Integer, 0, target);
1.2120 + }else{
1.2121 + /* This block populates the rNotFound register with either NULL
1.2122 + ** or 0 (an integer value). If the data structure contains one
1.2123 + ** or more NULLs, then set rNotFound to NULL. Otherwise, set it
1.2124 + ** to 0. If register rMayHaveNull is already set to some value
1.2125 + ** other than NULL, then the test has already been run and
1.2126 + ** rNotFound is already populated.
1.2127 + */
1.2128 + static const char nullRecord[] = { 0x02, 0x00 };
1.2129 + j3 = sqlite3VdbeAddOp1(v, OP_NotNull, rMayHaveNull);
1.2130 + sqlite3VdbeAddOp2(v, OP_Null, 0, rNotFound);
1.2131 + sqlite3VdbeAddOp4(v, OP_Blob, 2, rMayHaveNull, 0,
1.2132 + nullRecord, P4_STATIC);
1.2133 + j4 = sqlite3VdbeAddOp3(v, OP_Found, pExpr->iTable, 0, rMayHaveNull);
1.2134 + sqlite3VdbeAddOp2(v, OP_Integer, 0, rNotFound);
1.2135 + sqlite3VdbeJumpHere(v, j4);
1.2136 + sqlite3VdbeJumpHere(v, j3);
1.2137 +
1.2138 + /* Copy the value of register rNotFound (which is either NULL or 0)
1.2139 + ** into the target register. This will be the result of the
1.2140 + ** expression.
1.2141 + */
1.2142 + sqlite3VdbeAddOp2(v, OP_Copy, rNotFound, target);
1.2143 + }
1.2144 + }
1.2145 + sqlite3VdbeJumpHere(v, j2);
1.2146 + sqlite3VdbeJumpHere(v, j5);
1.2147 + VdbeComment((v, "end IN expr r%d", target));
1.2148 + break;
1.2149 + }
1.2150 +#endif
1.2151 + /*
1.2152 + ** x BETWEEN y AND z
1.2153 + **
1.2154 + ** This is equivalent to
1.2155 + **
1.2156 + ** x>=y AND x<=z
1.2157 + **
1.2158 + ** X is stored in pExpr->pLeft.
1.2159 + ** Y is stored in pExpr->pList->a[0].pExpr.
1.2160 + ** Z is stored in pExpr->pList->a[1].pExpr.
1.2161 + */
1.2162 + case TK_BETWEEN: {
1.2163 + Expr *pLeft = pExpr->pLeft;
1.2164 + struct ExprList_item *pLItem = pExpr->pList->a;
1.2165 + Expr *pRight = pLItem->pExpr;
1.2166 +
1.2167 + codeCompareOperands(pParse, pLeft, &r1, ®Free1,
1.2168 + pRight, &r2, ®Free2);
1.2169 + testcase( regFree1==0 );
1.2170 + testcase( regFree2==0 );
1.2171 + r3 = sqlite3GetTempReg(pParse);
1.2172 + r4 = sqlite3GetTempReg(pParse);
1.2173 + codeCompare(pParse, pLeft, pRight, OP_Ge,
1.2174 + r1, r2, r3, SQLITE_STOREP2);
1.2175 + pLItem++;
1.2176 + pRight = pLItem->pExpr;
1.2177 + sqlite3ReleaseTempReg(pParse, regFree2);
1.2178 + r2 = sqlite3ExprCodeTemp(pParse, pRight, ®Free2);
1.2179 + testcase( regFree2==0 );
1.2180 + codeCompare(pParse, pLeft, pRight, OP_Le, r1, r2, r4, SQLITE_STOREP2);
1.2181 + sqlite3VdbeAddOp3(v, OP_And, r3, r4, target);
1.2182 + sqlite3ReleaseTempReg(pParse, r3);
1.2183 + sqlite3ReleaseTempReg(pParse, r4);
1.2184 + break;
1.2185 + }
1.2186 + case TK_UPLUS: {
1.2187 + inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target);
1.2188 + break;
1.2189 + }
1.2190 +
1.2191 + /*
1.2192 + ** Form A:
1.2193 + ** CASE x WHEN e1 THEN r1 WHEN e2 THEN r2 ... WHEN eN THEN rN ELSE y END
1.2194 + **
1.2195 + ** Form B:
1.2196 + ** CASE WHEN e1 THEN r1 WHEN e2 THEN r2 ... WHEN eN THEN rN ELSE y END
1.2197 + **
1.2198 + ** Form A is can be transformed into the equivalent form B as follows:
1.2199 + ** CASE WHEN x=e1 THEN r1 WHEN x=e2 THEN r2 ...
1.2200 + ** WHEN x=eN THEN rN ELSE y END
1.2201 + **
1.2202 + ** X (if it exists) is in pExpr->pLeft.
1.2203 + ** Y is in pExpr->pRight. The Y is also optional. If there is no
1.2204 + ** ELSE clause and no other term matches, then the result of the
1.2205 + ** exprssion is NULL.
1.2206 + ** Ei is in pExpr->pList->a[i*2] and Ri is pExpr->pList->a[i*2+1].
1.2207 + **
1.2208 + ** The result of the expression is the Ri for the first matching Ei,
1.2209 + ** or if there is no matching Ei, the ELSE term Y, or if there is
1.2210 + ** no ELSE term, NULL.
1.2211 + */
1.2212 + case TK_CASE: {
1.2213 + int endLabel; /* GOTO label for end of CASE stmt */
1.2214 + int nextCase; /* GOTO label for next WHEN clause */
1.2215 + int nExpr; /* 2x number of WHEN terms */
1.2216 + int i; /* Loop counter */
1.2217 + ExprList *pEList; /* List of WHEN terms */
1.2218 + struct ExprList_item *aListelem; /* Array of WHEN terms */
1.2219 + Expr opCompare; /* The X==Ei expression */
1.2220 + Expr cacheX; /* Cached expression X */
1.2221 + Expr *pX; /* The X expression */
1.2222 + Expr *pTest; /* X==Ei (form A) or just Ei (form B) */
1.2223 +
1.2224 + assert(pExpr->pList);
1.2225 + assert((pExpr->pList->nExpr % 2) == 0);
1.2226 + assert(pExpr->pList->nExpr > 0);
1.2227 + pEList = pExpr->pList;
1.2228 + aListelem = pEList->a;
1.2229 + nExpr = pEList->nExpr;
1.2230 + endLabel = sqlite3VdbeMakeLabel(v);
1.2231 + if( (pX = pExpr->pLeft)!=0 ){
1.2232 + cacheX = *pX;
1.2233 + testcase( pX->op==TK_COLUMN || pX->op==TK_REGISTER );
1.2234 + cacheX.iTable = sqlite3ExprCodeTemp(pParse, pX, ®Free1);
1.2235 + testcase( regFree1==0 );
1.2236 + cacheX.op = TK_REGISTER;
1.2237 + opCompare.op = TK_EQ;
1.2238 + opCompare.pLeft = &cacheX;
1.2239 + pTest = &opCompare;
1.2240 + }
1.2241 + pParse->disableColCache++;
1.2242 + for(i=0; i<nExpr; i=i+2){
1.2243 + if( pX ){
1.2244 + opCompare.pRight = aListelem[i].pExpr;
1.2245 + }else{
1.2246 + pTest = aListelem[i].pExpr;
1.2247 + }
1.2248 + nextCase = sqlite3VdbeMakeLabel(v);
1.2249 + testcase( pTest->op==TK_COLUMN || pTest->op==TK_REGISTER );
1.2250 + sqlite3ExprIfFalse(pParse, pTest, nextCase, SQLITE_JUMPIFNULL);
1.2251 + testcase( aListelem[i+1].pExpr->op==TK_COLUMN );
1.2252 + testcase( aListelem[i+1].pExpr->op==TK_REGISTER );
1.2253 + sqlite3ExprCode(pParse, aListelem[i+1].pExpr, target);
1.2254 + sqlite3VdbeAddOp2(v, OP_Goto, 0, endLabel);
1.2255 + sqlite3VdbeResolveLabel(v, nextCase);
1.2256 + }
1.2257 + if( pExpr->pRight ){
1.2258 + sqlite3ExprCode(pParse, pExpr->pRight, target);
1.2259 + }else{
1.2260 + sqlite3VdbeAddOp2(v, OP_Null, 0, target);
1.2261 + }
1.2262 + sqlite3VdbeResolveLabel(v, endLabel);
1.2263 + assert( pParse->disableColCache>0 );
1.2264 + pParse->disableColCache--;
1.2265 + break;
1.2266 + }
1.2267 +#ifndef SQLITE_OMIT_TRIGGER
1.2268 + case TK_RAISE: {
1.2269 + if( !pParse->trigStack ){
1.2270 + sqlite3ErrorMsg(pParse,
1.2271 + "RAISE() may only be used within a trigger-program");
1.2272 + return 0;
1.2273 + }
1.2274 + if( pExpr->iColumn!=OE_Ignore ){
1.2275 + assert( pExpr->iColumn==OE_Rollback ||
1.2276 + pExpr->iColumn == OE_Abort ||
1.2277 + pExpr->iColumn == OE_Fail );
1.2278 + sqlite3DequoteExpr(db, pExpr);
1.2279 + sqlite3VdbeAddOp4(v, OP_Halt, SQLITE_CONSTRAINT, pExpr->iColumn, 0,
1.2280 + (char*)pExpr->token.z, pExpr->token.n);
1.2281 + } else {
1.2282 + assert( pExpr->iColumn == OE_Ignore );
1.2283 + sqlite3VdbeAddOp2(v, OP_ContextPop, 0, 0);
1.2284 + sqlite3VdbeAddOp2(v, OP_Goto, 0, pParse->trigStack->ignoreJump);
1.2285 + VdbeComment((v, "raise(IGNORE)"));
1.2286 + }
1.2287 + break;
1.2288 + }
1.2289 +#endif
1.2290 + }
1.2291 + sqlite3ReleaseTempReg(pParse, regFree1);
1.2292 + sqlite3ReleaseTempReg(pParse, regFree2);
1.2293 + return inReg;
1.2294 +}
1.2295 +
1.2296 +/*
1.2297 +** Generate code to evaluate an expression and store the results
1.2298 +** into a register. Return the register number where the results
1.2299 +** are stored.
1.2300 +**
1.2301 +** If the register is a temporary register that can be deallocated,
1.2302 +** then write its number into *pReg. If the result register is not
1.2303 +** a temporary, then set *pReg to zero.
1.2304 +*/
1.2305 +int sqlite3ExprCodeTemp(Parse *pParse, Expr *pExpr, int *pReg){
1.2306 + int r1 = sqlite3GetTempReg(pParse);
1.2307 + int r2 = sqlite3ExprCodeTarget(pParse, pExpr, r1);
1.2308 + if( r2==r1 ){
1.2309 + *pReg = r1;
1.2310 + }else{
1.2311 + sqlite3ReleaseTempReg(pParse, r1);
1.2312 + *pReg = 0;
1.2313 + }
1.2314 + return r2;
1.2315 +}
1.2316 +
1.2317 +/*
1.2318 +** Generate code that will evaluate expression pExpr and store the
1.2319 +** results in register target. The results are guaranteed to appear
1.2320 +** in register target.
1.2321 +*/
1.2322 +int sqlite3ExprCode(Parse *pParse, Expr *pExpr, int target){
1.2323 + int inReg;
1.2324 +
1.2325 + assert( target>0 && target<=pParse->nMem );
1.2326 + inReg = sqlite3ExprCodeTarget(pParse, pExpr, target);
1.2327 + assert( pParse->pVdbe || pParse->db->mallocFailed );
1.2328 + if( inReg!=target && pParse->pVdbe ){
1.2329 + sqlite3VdbeAddOp2(pParse->pVdbe, OP_SCopy, inReg, target);
1.2330 + }
1.2331 + return target;
1.2332 +}
1.2333 +
1.2334 +/*
1.2335 +** Generate code that evalutes the given expression and puts the result
1.2336 +** in register target.
1.2337 +**
1.2338 +** Also make a copy of the expression results into another "cache" register
1.2339 +** and modify the expression so that the next time it is evaluated,
1.2340 +** the result is a copy of the cache register.
1.2341 +**
1.2342 +** This routine is used for expressions that are used multiple
1.2343 +** times. They are evaluated once and the results of the expression
1.2344 +** are reused.
1.2345 +*/
1.2346 +int sqlite3ExprCodeAndCache(Parse *pParse, Expr *pExpr, int target){
1.2347 + Vdbe *v = pParse->pVdbe;
1.2348 + int inReg;
1.2349 + inReg = sqlite3ExprCode(pParse, pExpr, target);
1.2350 + assert( target>0 );
1.2351 + if( pExpr->op!=TK_REGISTER ){
1.2352 + int iMem;
1.2353 + iMem = ++pParse->nMem;
1.2354 + sqlite3VdbeAddOp2(v, OP_Copy, inReg, iMem);
1.2355 + pExpr->iTable = iMem;
1.2356 + pExpr->op = TK_REGISTER;
1.2357 + }
1.2358 + return inReg;
1.2359 +}
1.2360 +
1.2361 +/*
1.2362 +** Return TRUE if pExpr is an constant expression that is appropriate
1.2363 +** for factoring out of a loop. Appropriate expressions are:
1.2364 +**
1.2365 +** * Any expression that evaluates to two or more opcodes.
1.2366 +**
1.2367 +** * Any OP_Integer, OP_Real, OP_String, OP_Blob, OP_Null,
1.2368 +** or OP_Variable that does not need to be placed in a
1.2369 +** specific register.
1.2370 +**
1.2371 +** There is no point in factoring out single-instruction constant
1.2372 +** expressions that need to be placed in a particular register.
1.2373 +** We could factor them out, but then we would end up adding an
1.2374 +** OP_SCopy instruction to move the value into the correct register
1.2375 +** later. We might as well just use the original instruction and
1.2376 +** avoid the OP_SCopy.
1.2377 +*/
1.2378 +static int isAppropriateForFactoring(Expr *p){
1.2379 + if( !sqlite3ExprIsConstantNotJoin(p) ){
1.2380 + return 0; /* Only constant expressions are appropriate for factoring */
1.2381 + }
1.2382 + if( (p->flags & EP_FixedDest)==0 ){
1.2383 + return 1; /* Any constant without a fixed destination is appropriate */
1.2384 + }
1.2385 + while( p->op==TK_UPLUS ) p = p->pLeft;
1.2386 + switch( p->op ){
1.2387 +#ifndef SQLITE_OMIT_BLOB_LITERAL
1.2388 + case TK_BLOB:
1.2389 +#endif
1.2390 + case TK_VARIABLE:
1.2391 + case TK_INTEGER:
1.2392 + case TK_FLOAT:
1.2393 + case TK_NULL:
1.2394 + case TK_STRING: {
1.2395 + testcase( p->op==TK_BLOB );
1.2396 + testcase( p->op==TK_VARIABLE );
1.2397 + testcase( p->op==TK_INTEGER );
1.2398 + testcase( p->op==TK_FLOAT );
1.2399 + testcase( p->op==TK_NULL );
1.2400 + testcase( p->op==TK_STRING );
1.2401 + /* Single-instruction constants with a fixed destination are
1.2402 + ** better done in-line. If we factor them, they will just end
1.2403 + ** up generating an OP_SCopy to move the value to the destination
1.2404 + ** register. */
1.2405 + return 0;
1.2406 + }
1.2407 + case TK_UMINUS: {
1.2408 + if( p->pLeft->op==TK_FLOAT || p->pLeft->op==TK_INTEGER ){
1.2409 + return 0;
1.2410 + }
1.2411 + break;
1.2412 + }
1.2413 + default: {
1.2414 + break;
1.2415 + }
1.2416 + }
1.2417 + return 1;
1.2418 +}
1.2419 +
1.2420 +/*
1.2421 +** If pExpr is a constant expression that is appropriate for
1.2422 +** factoring out of a loop, then evaluate the expression
1.2423 +** into a register and convert the expression into a TK_REGISTER
1.2424 +** expression.
1.2425 +*/
1.2426 +static int evalConstExpr(Walker *pWalker, Expr *pExpr){
1.2427 + Parse *pParse = pWalker->pParse;
1.2428 + switch( pExpr->op ){
1.2429 + case TK_REGISTER: {
1.2430 + return 1;
1.2431 + }
1.2432 + case TK_FUNCTION:
1.2433 + case TK_AGG_FUNCTION:
1.2434 + case TK_CONST_FUNC: {
1.2435 + /* The arguments to a function have a fixed destination.
1.2436 + ** Mark them this way to avoid generated unneeded OP_SCopy
1.2437 + ** instructions.
1.2438 + */
1.2439 + ExprList *pList = pExpr->pList;
1.2440 + if( pList ){
1.2441 + int i = pList->nExpr;
1.2442 + struct ExprList_item *pItem = pList->a;
1.2443 + for(; i>0; i--, pItem++){
1.2444 + if( pItem->pExpr ) pItem->pExpr->flags |= EP_FixedDest;
1.2445 + }
1.2446 + }
1.2447 + break;
1.2448 + }
1.2449 + }
1.2450 + if( isAppropriateForFactoring(pExpr) ){
1.2451 + int r1 = ++pParse->nMem;
1.2452 + int r2;
1.2453 + r2 = sqlite3ExprCodeTarget(pParse, pExpr, r1);
1.2454 + if( r1!=r2 ) sqlite3ReleaseTempReg(pParse, r1);
1.2455 + pExpr->op = TK_REGISTER;
1.2456 + pExpr->iTable = r2;
1.2457 + return WRC_Prune;
1.2458 + }
1.2459 + return WRC_Continue;
1.2460 +}
1.2461 +
1.2462 +/*
1.2463 +** Preevaluate constant subexpressions within pExpr and store the
1.2464 +** results in registers. Modify pExpr so that the constant subexpresions
1.2465 +** are TK_REGISTER opcodes that refer to the precomputed values.
1.2466 +*/
1.2467 +void sqlite3ExprCodeConstants(Parse *pParse, Expr *pExpr){
1.2468 + Walker w;
1.2469 + w.xExprCallback = evalConstExpr;
1.2470 + w.xSelectCallback = 0;
1.2471 + w.pParse = pParse;
1.2472 + sqlite3WalkExpr(&w, pExpr);
1.2473 +}
1.2474 +
1.2475 +
1.2476 +/*
1.2477 +** Generate code that pushes the value of every element of the given
1.2478 +** expression list into a sequence of registers beginning at target.
1.2479 +**
1.2480 +** Return the number of elements evaluated.
1.2481 +*/
1.2482 +int sqlite3ExprCodeExprList(
1.2483 + Parse *pParse, /* Parsing context */
1.2484 + ExprList *pList, /* The expression list to be coded */
1.2485 + int target, /* Where to write results */
1.2486 + int doHardCopy /* Make a hard copy of every element */
1.2487 +){
1.2488 + struct ExprList_item *pItem;
1.2489 + int i, n;
1.2490 + assert( pList!=0 );
1.2491 + assert( target>0 );
1.2492 + n = pList->nExpr;
1.2493 + for(pItem=pList->a, i=0; i<n; i++, pItem++){
1.2494 + if( pItem->iAlias ){
1.2495 + int iReg = codeAlias(pParse, pItem->iAlias, pItem->pExpr);
1.2496 + Vdbe *v = sqlite3GetVdbe(pParse);
1.2497 + sqlite3VdbeAddOp2(v, OP_SCopy, iReg, target+i);
1.2498 + }else{
1.2499 + sqlite3ExprCode(pParse, pItem->pExpr, target+i);
1.2500 + }
1.2501 + if( doHardCopy ){
1.2502 + sqlite3ExprHardCopy(pParse, target, n);
1.2503 + }
1.2504 + }
1.2505 + return n;
1.2506 +}
1.2507 +
1.2508 +/*
1.2509 +** Generate code for a boolean expression such that a jump is made
1.2510 +** to the label "dest" if the expression is true but execution
1.2511 +** continues straight thru if the expression is false.
1.2512 +**
1.2513 +** If the expression evaluates to NULL (neither true nor false), then
1.2514 +** take the jump if the jumpIfNull flag is SQLITE_JUMPIFNULL.
1.2515 +**
1.2516 +** This code depends on the fact that certain token values (ex: TK_EQ)
1.2517 +** are the same as opcode values (ex: OP_Eq) that implement the corresponding
1.2518 +** operation. Special comments in vdbe.c and the mkopcodeh.awk script in
1.2519 +** the make process cause these values to align. Assert()s in the code
1.2520 +** below verify that the numbers are aligned correctly.
1.2521 +*/
1.2522 +void sqlite3ExprIfTrue(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
1.2523 + Vdbe *v = pParse->pVdbe;
1.2524 + int op = 0;
1.2525 + int regFree1 = 0;
1.2526 + int regFree2 = 0;
1.2527 + int r1, r2;
1.2528 +
1.2529 + assert( jumpIfNull==SQLITE_JUMPIFNULL || jumpIfNull==0 );
1.2530 + if( v==0 || pExpr==0 ) return;
1.2531 + op = pExpr->op;
1.2532 + switch( op ){
1.2533 + case TK_AND: {
1.2534 + int d2 = sqlite3VdbeMakeLabel(v);
1.2535 + testcase( jumpIfNull==0 );
1.2536 + testcase( pParse->disableColCache==0 );
1.2537 + sqlite3ExprIfFalse(pParse, pExpr->pLeft, d2,jumpIfNull^SQLITE_JUMPIFNULL);
1.2538 + pParse->disableColCache++;
1.2539 + sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);
1.2540 + assert( pParse->disableColCache>0 );
1.2541 + pParse->disableColCache--;
1.2542 + sqlite3VdbeResolveLabel(v, d2);
1.2543 + break;
1.2544 + }
1.2545 + case TK_OR: {
1.2546 + testcase( jumpIfNull==0 );
1.2547 + testcase( pParse->disableColCache==0 );
1.2548 + sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);
1.2549 + pParse->disableColCache++;
1.2550 + sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);
1.2551 + assert( pParse->disableColCache>0 );
1.2552 + pParse->disableColCache--;
1.2553 + break;
1.2554 + }
1.2555 + case TK_NOT: {
1.2556 + testcase( jumpIfNull==0 );
1.2557 + sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);
1.2558 + break;
1.2559 + }
1.2560 + case TK_LT:
1.2561 + case TK_LE:
1.2562 + case TK_GT:
1.2563 + case TK_GE:
1.2564 + case TK_NE:
1.2565 + case TK_EQ: {
1.2566 + assert( TK_LT==OP_Lt );
1.2567 + assert( TK_LE==OP_Le );
1.2568 + assert( TK_GT==OP_Gt );
1.2569 + assert( TK_GE==OP_Ge );
1.2570 + assert( TK_EQ==OP_Eq );
1.2571 + assert( TK_NE==OP_Ne );
1.2572 + testcase( op==TK_LT );
1.2573 + testcase( op==TK_LE );
1.2574 + testcase( op==TK_GT );
1.2575 + testcase( op==TK_GE );
1.2576 + testcase( op==TK_EQ );
1.2577 + testcase( op==TK_NE );
1.2578 + testcase( jumpIfNull==0 );
1.2579 + codeCompareOperands(pParse, pExpr->pLeft, &r1, ®Free1,
1.2580 + pExpr->pRight, &r2, ®Free2);
1.2581 + codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
1.2582 + r1, r2, dest, jumpIfNull);
1.2583 + testcase( regFree1==0 );
1.2584 + testcase( regFree2==0 );
1.2585 + break;
1.2586 + }
1.2587 + case TK_ISNULL:
1.2588 + case TK_NOTNULL: {
1.2589 + assert( TK_ISNULL==OP_IsNull );
1.2590 + assert( TK_NOTNULL==OP_NotNull );
1.2591 + testcase( op==TK_ISNULL );
1.2592 + testcase( op==TK_NOTNULL );
1.2593 + r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
1.2594 + sqlite3VdbeAddOp2(v, op, r1, dest);
1.2595 + testcase( regFree1==0 );
1.2596 + break;
1.2597 + }
1.2598 + case TK_BETWEEN: {
1.2599 + /* x BETWEEN y AND z
1.2600 + **
1.2601 + ** Is equivalent to
1.2602 + **
1.2603 + ** x>=y AND x<=z
1.2604 + **
1.2605 + ** Code it as such, taking care to do the common subexpression
1.2606 + ** elementation of x.
1.2607 + */
1.2608 + Expr exprAnd;
1.2609 + Expr compLeft;
1.2610 + Expr compRight;
1.2611 + Expr exprX;
1.2612 +
1.2613 + exprX = *pExpr->pLeft;
1.2614 + exprAnd.op = TK_AND;
1.2615 + exprAnd.pLeft = &compLeft;
1.2616 + exprAnd.pRight = &compRight;
1.2617 + compLeft.op = TK_GE;
1.2618 + compLeft.pLeft = &exprX;
1.2619 + compLeft.pRight = pExpr->pList->a[0].pExpr;
1.2620 + compRight.op = TK_LE;
1.2621 + compRight.pLeft = &exprX;
1.2622 + compRight.pRight = pExpr->pList->a[1].pExpr;
1.2623 + exprX.iTable = sqlite3ExprCodeTemp(pParse, &exprX, ®Free1);
1.2624 + testcase( regFree1==0 );
1.2625 + exprX.op = TK_REGISTER;
1.2626 + testcase( jumpIfNull==0 );
1.2627 + sqlite3ExprIfTrue(pParse, &exprAnd, dest, jumpIfNull);
1.2628 + break;
1.2629 + }
1.2630 + default: {
1.2631 + r1 = sqlite3ExprCodeTemp(pParse, pExpr, ®Free1);
1.2632 + sqlite3VdbeAddOp3(v, OP_If, r1, dest, jumpIfNull!=0);
1.2633 + testcase( regFree1==0 );
1.2634 + testcase( jumpIfNull==0 );
1.2635 + break;
1.2636 + }
1.2637 + }
1.2638 + sqlite3ReleaseTempReg(pParse, regFree1);
1.2639 + sqlite3ReleaseTempReg(pParse, regFree2);
1.2640 +}
1.2641 +
1.2642 +/*
1.2643 +** Generate code for a boolean expression such that a jump is made
1.2644 +** to the label "dest" if the expression is false but execution
1.2645 +** continues straight thru if the expression is true.
1.2646 +**
1.2647 +** If the expression evaluates to NULL (neither true nor false) then
1.2648 +** jump if jumpIfNull is SQLITE_JUMPIFNULL or fall through if jumpIfNull
1.2649 +** is 0.
1.2650 +*/
1.2651 +void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
1.2652 + Vdbe *v = pParse->pVdbe;
1.2653 + int op = 0;
1.2654 + int regFree1 = 0;
1.2655 + int regFree2 = 0;
1.2656 + int r1, r2;
1.2657 +
1.2658 + assert( jumpIfNull==SQLITE_JUMPIFNULL || jumpIfNull==0 );
1.2659 + if( v==0 || pExpr==0 ) return;
1.2660 +
1.2661 + /* The value of pExpr->op and op are related as follows:
1.2662 + **
1.2663 + ** pExpr->op op
1.2664 + ** --------- ----------
1.2665 + ** TK_ISNULL OP_NotNull
1.2666 + ** TK_NOTNULL OP_IsNull
1.2667 + ** TK_NE OP_Eq
1.2668 + ** TK_EQ OP_Ne
1.2669 + ** TK_GT OP_Le
1.2670 + ** TK_LE OP_Gt
1.2671 + ** TK_GE OP_Lt
1.2672 + ** TK_LT OP_Ge
1.2673 + **
1.2674 + ** For other values of pExpr->op, op is undefined and unused.
1.2675 + ** The value of TK_ and OP_ constants are arranged such that we
1.2676 + ** can compute the mapping above using the following expression.
1.2677 + ** Assert()s verify that the computation is correct.
1.2678 + */
1.2679 + op = ((pExpr->op+(TK_ISNULL&1))^1)-(TK_ISNULL&1);
1.2680 +
1.2681 + /* Verify correct alignment of TK_ and OP_ constants
1.2682 + */
1.2683 + assert( pExpr->op!=TK_ISNULL || op==OP_NotNull );
1.2684 + assert( pExpr->op!=TK_NOTNULL || op==OP_IsNull );
1.2685 + assert( pExpr->op!=TK_NE || op==OP_Eq );
1.2686 + assert( pExpr->op!=TK_EQ || op==OP_Ne );
1.2687 + assert( pExpr->op!=TK_LT || op==OP_Ge );
1.2688 + assert( pExpr->op!=TK_LE || op==OP_Gt );
1.2689 + assert( pExpr->op!=TK_GT || op==OP_Le );
1.2690 + assert( pExpr->op!=TK_GE || op==OP_Lt );
1.2691 +
1.2692 + switch( pExpr->op ){
1.2693 + case TK_AND: {
1.2694 + testcase( jumpIfNull==0 );
1.2695 + testcase( pParse->disableColCache==0 );
1.2696 + sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);
1.2697 + pParse->disableColCache++;
1.2698 + sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
1.2699 + assert( pParse->disableColCache>0 );
1.2700 + pParse->disableColCache--;
1.2701 + break;
1.2702 + }
1.2703 + case TK_OR: {
1.2704 + int d2 = sqlite3VdbeMakeLabel(v);
1.2705 + testcase( jumpIfNull==0 );
1.2706 + testcase( pParse->disableColCache==0 );
1.2707 + sqlite3ExprIfTrue(pParse, pExpr->pLeft, d2, jumpIfNull^SQLITE_JUMPIFNULL);
1.2708 + pParse->disableColCache++;
1.2709 + sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
1.2710 + assert( pParse->disableColCache>0 );
1.2711 + pParse->disableColCache--;
1.2712 + sqlite3VdbeResolveLabel(v, d2);
1.2713 + break;
1.2714 + }
1.2715 + case TK_NOT: {
1.2716 + sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);
1.2717 + break;
1.2718 + }
1.2719 + case TK_LT:
1.2720 + case TK_LE:
1.2721 + case TK_GT:
1.2722 + case TK_GE:
1.2723 + case TK_NE:
1.2724 + case TK_EQ: {
1.2725 + testcase( op==TK_LT );
1.2726 + testcase( op==TK_LE );
1.2727 + testcase( op==TK_GT );
1.2728 + testcase( op==TK_GE );
1.2729 + testcase( op==TK_EQ );
1.2730 + testcase( op==TK_NE );
1.2731 + testcase( jumpIfNull==0 );
1.2732 + codeCompareOperands(pParse, pExpr->pLeft, &r1, ®Free1,
1.2733 + pExpr->pRight, &r2, ®Free2);
1.2734 + codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
1.2735 + r1, r2, dest, jumpIfNull);
1.2736 + testcase( regFree1==0 );
1.2737 + testcase( regFree2==0 );
1.2738 + break;
1.2739 + }
1.2740 + case TK_ISNULL:
1.2741 + case TK_NOTNULL: {
1.2742 + testcase( op==TK_ISNULL );
1.2743 + testcase( op==TK_NOTNULL );
1.2744 + r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, ®Free1);
1.2745 + sqlite3VdbeAddOp2(v, op, r1, dest);
1.2746 + testcase( regFree1==0 );
1.2747 + break;
1.2748 + }
1.2749 + case TK_BETWEEN: {
1.2750 + /* x BETWEEN y AND z
1.2751 + **
1.2752 + ** Is equivalent to
1.2753 + **
1.2754 + ** x>=y AND x<=z
1.2755 + **
1.2756 + ** Code it as such, taking care to do the common subexpression
1.2757 + ** elementation of x.
1.2758 + */
1.2759 + Expr exprAnd;
1.2760 + Expr compLeft;
1.2761 + Expr compRight;
1.2762 + Expr exprX;
1.2763 +
1.2764 + exprX = *pExpr->pLeft;
1.2765 + exprAnd.op = TK_AND;
1.2766 + exprAnd.pLeft = &compLeft;
1.2767 + exprAnd.pRight = &compRight;
1.2768 + compLeft.op = TK_GE;
1.2769 + compLeft.pLeft = &exprX;
1.2770 + compLeft.pRight = pExpr->pList->a[0].pExpr;
1.2771 + compRight.op = TK_LE;
1.2772 + compRight.pLeft = &exprX;
1.2773 + compRight.pRight = pExpr->pList->a[1].pExpr;
1.2774 + exprX.iTable = sqlite3ExprCodeTemp(pParse, &exprX, ®Free1);
1.2775 + testcase( regFree1==0 );
1.2776 + exprX.op = TK_REGISTER;
1.2777 + testcase( jumpIfNull==0 );
1.2778 + sqlite3ExprIfFalse(pParse, &exprAnd, dest, jumpIfNull);
1.2779 + break;
1.2780 + }
1.2781 + default: {
1.2782 + r1 = sqlite3ExprCodeTemp(pParse, pExpr, ®Free1);
1.2783 + sqlite3VdbeAddOp3(v, OP_IfNot, r1, dest, jumpIfNull!=0);
1.2784 + testcase( regFree1==0 );
1.2785 + testcase( jumpIfNull==0 );
1.2786 + break;
1.2787 + }
1.2788 + }
1.2789 + sqlite3ReleaseTempReg(pParse, regFree1);
1.2790 + sqlite3ReleaseTempReg(pParse, regFree2);
1.2791 +}
1.2792 +
1.2793 +/*
1.2794 +** Do a deep comparison of two expression trees. Return TRUE (non-zero)
1.2795 +** if they are identical and return FALSE if they differ in any way.
1.2796 +**
1.2797 +** Sometimes this routine will return FALSE even if the two expressions
1.2798 +** really are equivalent. If we cannot prove that the expressions are
1.2799 +** identical, we return FALSE just to be safe. So if this routine
1.2800 +** returns false, then you do not really know for certain if the two
1.2801 +** expressions are the same. But if you get a TRUE return, then you
1.2802 +** can be sure the expressions are the same. In the places where
1.2803 +** this routine is used, it does not hurt to get an extra FALSE - that
1.2804 +** just might result in some slightly slower code. But returning
1.2805 +** an incorrect TRUE could lead to a malfunction.
1.2806 +*/
1.2807 +int sqlite3ExprCompare(Expr *pA, Expr *pB){
1.2808 + int i;
1.2809 + if( pA==0||pB==0 ){
1.2810 + return pB==pA;
1.2811 + }
1.2812 + if( pA->op!=pB->op ) return 0;
1.2813 + if( (pA->flags & EP_Distinct)!=(pB->flags & EP_Distinct) ) return 0;
1.2814 + if( !sqlite3ExprCompare(pA->pLeft, pB->pLeft) ) return 0;
1.2815 + if( !sqlite3ExprCompare(pA->pRight, pB->pRight) ) return 0;
1.2816 + if( pA->pList ){
1.2817 + if( pB->pList==0 ) return 0;
1.2818 + if( pA->pList->nExpr!=pB->pList->nExpr ) return 0;
1.2819 + for(i=0; i<pA->pList->nExpr; i++){
1.2820 + if( !sqlite3ExprCompare(pA->pList->a[i].pExpr, pB->pList->a[i].pExpr) ){
1.2821 + return 0;
1.2822 + }
1.2823 + }
1.2824 + }else if( pB->pList ){
1.2825 + return 0;
1.2826 + }
1.2827 + if( pA->pSelect || pB->pSelect ) return 0;
1.2828 + if( pA->iTable!=pB->iTable || pA->iColumn!=pB->iColumn ) return 0;
1.2829 + if( pA->op!=TK_COLUMN && pA->token.z ){
1.2830 + if( pB->token.z==0 ) return 0;
1.2831 + if( pB->token.n!=pA->token.n ) return 0;
1.2832 + if( sqlite3StrNICmp((char*)pA->token.z,(char*)pB->token.z,pB->token.n)!=0 ){
1.2833 + return 0;
1.2834 + }
1.2835 + }
1.2836 + return 1;
1.2837 +}
1.2838 +
1.2839 +
1.2840 +/*
1.2841 +** Add a new element to the pAggInfo->aCol[] array. Return the index of
1.2842 +** the new element. Return a negative number if malloc fails.
1.2843 +*/
1.2844 +static int addAggInfoColumn(sqlite3 *db, AggInfo *pInfo){
1.2845 + int i;
1.2846 + pInfo->aCol = sqlite3ArrayAllocate(
1.2847 + db,
1.2848 + pInfo->aCol,
1.2849 + sizeof(pInfo->aCol[0]),
1.2850 + 3,
1.2851 + &pInfo->nColumn,
1.2852 + &pInfo->nColumnAlloc,
1.2853 + &i
1.2854 + );
1.2855 + return i;
1.2856 +}
1.2857 +
1.2858 +/*
1.2859 +** Add a new element to the pAggInfo->aFunc[] array. Return the index of
1.2860 +** the new element. Return a negative number if malloc fails.
1.2861 +*/
1.2862 +static int addAggInfoFunc(sqlite3 *db, AggInfo *pInfo){
1.2863 + int i;
1.2864 + pInfo->aFunc = sqlite3ArrayAllocate(
1.2865 + db,
1.2866 + pInfo->aFunc,
1.2867 + sizeof(pInfo->aFunc[0]),
1.2868 + 3,
1.2869 + &pInfo->nFunc,
1.2870 + &pInfo->nFuncAlloc,
1.2871 + &i
1.2872 + );
1.2873 + return i;
1.2874 +}
1.2875 +
1.2876 +/*
1.2877 +** This is the xExprCallback for a tree walker. It is used to
1.2878 +** implement sqlite3ExprAnalyzeAggregates(). See sqlite3ExprAnalyzeAggregates
1.2879 +** for additional information.
1.2880 +*/
1.2881 +static int analyzeAggregate(Walker *pWalker, Expr *pExpr){
1.2882 + int i;
1.2883 + NameContext *pNC = pWalker->u.pNC;
1.2884 + Parse *pParse = pNC->pParse;
1.2885 + SrcList *pSrcList = pNC->pSrcList;
1.2886 + AggInfo *pAggInfo = pNC->pAggInfo;
1.2887 +
1.2888 + switch( pExpr->op ){
1.2889 + case TK_AGG_COLUMN:
1.2890 + case TK_COLUMN: {
1.2891 + testcase( pExpr->op==TK_AGG_COLUMN );
1.2892 + testcase( pExpr->op==TK_COLUMN );
1.2893 + /* Check to see if the column is in one of the tables in the FROM
1.2894 + ** clause of the aggregate query */
1.2895 + if( pSrcList ){
1.2896 + struct SrcList_item *pItem = pSrcList->a;
1.2897 + for(i=0; i<pSrcList->nSrc; i++, pItem++){
1.2898 + struct AggInfo_col *pCol;
1.2899 + if( pExpr->iTable==pItem->iCursor ){
1.2900 + /* If we reach this point, it means that pExpr refers to a table
1.2901 + ** that is in the FROM clause of the aggregate query.
1.2902 + **
1.2903 + ** Make an entry for the column in pAggInfo->aCol[] if there
1.2904 + ** is not an entry there already.
1.2905 + */
1.2906 + int k;
1.2907 + pCol = pAggInfo->aCol;
1.2908 + for(k=0; k<pAggInfo->nColumn; k++, pCol++){
1.2909 + if( pCol->iTable==pExpr->iTable &&
1.2910 + pCol->iColumn==pExpr->iColumn ){
1.2911 + break;
1.2912 + }
1.2913 + }
1.2914 + if( (k>=pAggInfo->nColumn)
1.2915 + && (k = addAggInfoColumn(pParse->db, pAggInfo))>=0
1.2916 + ){
1.2917 + pCol = &pAggInfo->aCol[k];
1.2918 + pCol->pTab = pExpr->pTab;
1.2919 + pCol->iTable = pExpr->iTable;
1.2920 + pCol->iColumn = pExpr->iColumn;
1.2921 + pCol->iMem = ++pParse->nMem;
1.2922 + pCol->iSorterColumn = -1;
1.2923 + pCol->pExpr = pExpr;
1.2924 + if( pAggInfo->pGroupBy ){
1.2925 + int j, n;
1.2926 + ExprList *pGB = pAggInfo->pGroupBy;
1.2927 + struct ExprList_item *pTerm = pGB->a;
1.2928 + n = pGB->nExpr;
1.2929 + for(j=0; j<n; j++, pTerm++){
1.2930 + Expr *pE = pTerm->pExpr;
1.2931 + if( pE->op==TK_COLUMN && pE->iTable==pExpr->iTable &&
1.2932 + pE->iColumn==pExpr->iColumn ){
1.2933 + pCol->iSorterColumn = j;
1.2934 + break;
1.2935 + }
1.2936 + }
1.2937 + }
1.2938 + if( pCol->iSorterColumn<0 ){
1.2939 + pCol->iSorterColumn = pAggInfo->nSortingColumn++;
1.2940 + }
1.2941 + }
1.2942 + /* There is now an entry for pExpr in pAggInfo->aCol[] (either
1.2943 + ** because it was there before or because we just created it).
1.2944 + ** Convert the pExpr to be a TK_AGG_COLUMN referring to that
1.2945 + ** pAggInfo->aCol[] entry.
1.2946 + */
1.2947 + pExpr->pAggInfo = pAggInfo;
1.2948 + pExpr->op = TK_AGG_COLUMN;
1.2949 + pExpr->iAgg = k;
1.2950 + break;
1.2951 + } /* endif pExpr->iTable==pItem->iCursor */
1.2952 + } /* end loop over pSrcList */
1.2953 + }
1.2954 + return WRC_Prune;
1.2955 + }
1.2956 + case TK_AGG_FUNCTION: {
1.2957 + /* The pNC->nDepth==0 test causes aggregate functions in subqueries
1.2958 + ** to be ignored */
1.2959 + if( pNC->nDepth==0 ){
1.2960 + /* Check to see if pExpr is a duplicate of another aggregate
1.2961 + ** function that is already in the pAggInfo structure
1.2962 + */
1.2963 + struct AggInfo_func *pItem = pAggInfo->aFunc;
1.2964 + for(i=0; i<pAggInfo->nFunc; i++, pItem++){
1.2965 + if( sqlite3ExprCompare(pItem->pExpr, pExpr) ){
1.2966 + break;
1.2967 + }
1.2968 + }
1.2969 + if( i>=pAggInfo->nFunc ){
1.2970 + /* pExpr is original. Make a new entry in pAggInfo->aFunc[]
1.2971 + */
1.2972 + u8 enc = ENC(pParse->db);
1.2973 + i = addAggInfoFunc(pParse->db, pAggInfo);
1.2974 + if( i>=0 ){
1.2975 + pItem = &pAggInfo->aFunc[i];
1.2976 + pItem->pExpr = pExpr;
1.2977 + pItem->iMem = ++pParse->nMem;
1.2978 + pItem->pFunc = sqlite3FindFunction(pParse->db,
1.2979 + (char*)pExpr->token.z, pExpr->token.n,
1.2980 + pExpr->pList ? pExpr->pList->nExpr : 0, enc, 0);
1.2981 + if( pExpr->flags & EP_Distinct ){
1.2982 + pItem->iDistinct = pParse->nTab++;
1.2983 + }else{
1.2984 + pItem->iDistinct = -1;
1.2985 + }
1.2986 + }
1.2987 + }
1.2988 + /* Make pExpr point to the appropriate pAggInfo->aFunc[] entry
1.2989 + */
1.2990 + pExpr->iAgg = i;
1.2991 + pExpr->pAggInfo = pAggInfo;
1.2992 + return WRC_Prune;
1.2993 + }
1.2994 + }
1.2995 + }
1.2996 + return WRC_Continue;
1.2997 +}
1.2998 +static int analyzeAggregatesInSelect(Walker *pWalker, Select *pSelect){
1.2999 + NameContext *pNC = pWalker->u.pNC;
1.3000 + if( pNC->nDepth==0 ){
1.3001 + pNC->nDepth++;
1.3002 + sqlite3WalkSelect(pWalker, pSelect);
1.3003 + pNC->nDepth--;
1.3004 + return WRC_Prune;
1.3005 + }else{
1.3006 + return WRC_Continue;
1.3007 + }
1.3008 +}
1.3009 +
1.3010 +/*
1.3011 +** Analyze the given expression looking for aggregate functions and
1.3012 +** for variables that need to be added to the pParse->aAgg[] array.
1.3013 +** Make additional entries to the pParse->aAgg[] array as necessary.
1.3014 +**
1.3015 +** This routine should only be called after the expression has been
1.3016 +** analyzed by sqlite3ResolveExprNames().
1.3017 +*/
1.3018 +void sqlite3ExprAnalyzeAggregates(NameContext *pNC, Expr *pExpr){
1.3019 + Walker w;
1.3020 + w.xExprCallback = analyzeAggregate;
1.3021 + w.xSelectCallback = analyzeAggregatesInSelect;
1.3022 + w.u.pNC = pNC;
1.3023 + sqlite3WalkExpr(&w, pExpr);
1.3024 +}
1.3025 +
1.3026 +/*
1.3027 +** Call sqlite3ExprAnalyzeAggregates() for every expression in an
1.3028 +** expression list. Return the number of errors.
1.3029 +**
1.3030 +** If an error is found, the analysis is cut short.
1.3031 +*/
1.3032 +void sqlite3ExprAnalyzeAggList(NameContext *pNC, ExprList *pList){
1.3033 + struct ExprList_item *pItem;
1.3034 + int i;
1.3035 + if( pList ){
1.3036 + for(pItem=pList->a, i=0; i<pList->nExpr; i++, pItem++){
1.3037 + sqlite3ExprAnalyzeAggregates(pNC, pItem->pExpr);
1.3038 + }
1.3039 + }
1.3040 +}
1.3041 +
1.3042 +/*
1.3043 +** Allocate or deallocate temporary use registers during code generation.
1.3044 +*/
1.3045 +int sqlite3GetTempReg(Parse *pParse){
1.3046 + if( pParse->nTempReg==0 ){
1.3047 + return ++pParse->nMem;
1.3048 + }
1.3049 + return pParse->aTempReg[--pParse->nTempReg];
1.3050 +}
1.3051 +void sqlite3ReleaseTempReg(Parse *pParse, int iReg){
1.3052 + if( iReg && pParse->nTempReg<ArraySize(pParse->aTempReg) ){
1.3053 + sqlite3ExprWritableRegister(pParse, iReg, iReg);
1.3054 + pParse->aTempReg[pParse->nTempReg++] = iReg;
1.3055 + }
1.3056 +}
1.3057 +
1.3058 +/*
1.3059 +** Allocate or deallocate a block of nReg consecutive registers
1.3060 +*/
1.3061 +int sqlite3GetTempRange(Parse *pParse, int nReg){
1.3062 + int i, n;
1.3063 + i = pParse->iRangeReg;
1.3064 + n = pParse->nRangeReg;
1.3065 + if( nReg<=n && !usedAsColumnCache(pParse, i, i+n-1) ){
1.3066 + pParse->iRangeReg += nReg;
1.3067 + pParse->nRangeReg -= nReg;
1.3068 + }else{
1.3069 + i = pParse->nMem+1;
1.3070 + pParse->nMem += nReg;
1.3071 + }
1.3072 + return i;
1.3073 +}
1.3074 +void sqlite3ReleaseTempRange(Parse *pParse, int iReg, int nReg){
1.3075 + if( nReg>pParse->nRangeReg ){
1.3076 + pParse->nRangeReg = nReg;
1.3077 + pParse->iRangeReg = iReg;
1.3078 + }
1.3079 +}