GeezerVisonThe World Wide Web, restored to 800 pixels of glory. |
| Home|About|Gaming cabinet|Archives|How it works|Starter sites |
GeezerVison is showing github.com — sqlcipher/src/expr.c at master · securitykernel/sqlcipher Expand file tree/ Copy pathexpr.cMore file actions 5946 lines (5684 loc) · 204 KB / Copy pathexpr.cFile metadata and controls5946 lines (5684 loc) · 204 KB 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 /* ** 2001 September 15 ** ** The author disclaims copyright to this source code. In place of ** a legal notice, here is a blessing: ** ** May you do good and not evil. ** May you find forgiveness for yourself and forgive others. ** May you share freely, never taking more than you give. ** ************************************************************************* ** This file contains routines used for analyzing expressions and ** for generating VDBE code that evaluates expressions in SQLite. */ #include "sqliteInt.h" /* Forward declarations */ static void exprCodeBetween(Parse*,Expr*,int,void(*)(Parse*,Expr*,int,int),int); static int exprCodeVector(Parse *pParse, Expr *p, int *piToFree); /* ** Return the affinity character for a single column of a table. */ char sqlite3TableColumnAffinity(Table *pTab, int iCol){ assert( iCol<pTab->nCol ); return iCol>=0 ? pTab->aCol[iCol].affinity : SQLITE_AFF_INTEGER; } /* ** Return the 'affinity' of the expression pExpr if any. ** ** If pExpr is a column, a reference to a column via an 'AS' alias, ** or a sub-select with a column as the return value, then the ** affinity of that column is returned. Otherwise, 0x00 is returned, ** indicating no affinity for the expression. ** ** i.e. the WHERE clause expressions in the following statements all ** have an affinity: ** ** CREATE TABLE t1(a); ** SELECT * FROM t1 WHERE a; ** SELECT a AS b FROM t1 WHERE b; ** SELECT * FROM t1 WHERE (select a from t1); */ char sqlite3ExprAffinity(Expr *pExpr){ int op; while( ExprHasProperty(pExpr, EP_Skip) ){ assert( pExpr->op==TK_COLLATE ); pExpr = pExpr->pLeft; assert( pExpr!=0 ); } op = pExpr->op; if( op==TK_SELECT ){ assert( pExpr->flags&EP_xIsSelect ); return sqlite3ExprAffinity(pExpr->x.pSelect->pEList->a[0].pExpr); } if( op==TK_REGISTER ) op = pExpr->op2; #ifndef SQLITE_OMIT_CAST if( op==TK_CAST ){ assert( !ExprHasProperty(pExpr, EP_IntValue) ); return sqlite3AffinityType(pExpr->u.zToken, 0); } #endif if( (op==TK_AGG_COLUMN || op==TK_COLUMN) && pExpr->y.pTab ){ return sqlite3TableColumnAffinity(pExpr->y.pTab, pExpr->iColumn); } if( op==TK_SELECT_COLUMN ){ assert( pExpr->pLeft->flags&EP_xIsSelect ); return sqlite3ExprAffinity( pExpr->pLeft->x.pSelect->pEList->a[pExpr->iColumn].pExpr ); } if( op==TK_VECTOR ){ return sqlite3ExprAffinity(pExpr->x.pList->a[0].pExpr); } return pExpr->affExpr; } /* ** Set the collating sequence for expression pExpr to be the collating ** sequence named by pToken. Return a pointer to a new Expr node that ** implements the COLLATE operator. ** ** If a memory allocation error occurs, that fact is recorded in pParse->db ** and the pExpr parameter is returned unchanged. */ Expr *sqlite3ExprAddCollateToken( Parse *pParse, /* Parsing context */ Expr *pExpr, /* Add the "COLLATE" clause to this expression */ const Token *pCollName, /* Name of collating sequence */ int dequote /* True to dequote pCollName */ ){ if( pCollName->n>0 ){ Expr *pNew = sqlite3ExprAlloc(pParse->db, TK_COLLATE, pCollName, dequote); if( pNew ){ pNew->pLeft = pExpr; pNew->flags |= EP_Collate|EP_Skip; pExpr = pNew; } } return pExpr; } Expr *sqlite3ExprAddCollateString(Parse *pParse, Expr *pExpr, const char *zC){ Token s; assert( zC!=0 ); sqlite3TokenInit(&s, (char*)zC); return sqlite3ExprAddCollateToken(pParse, pExpr, &s, 0); } /* ** Skip over any TK_COLLATE operators. */ Expr *sqlite3ExprSkipCollate(Expr *pExpr){ while( pExpr && ExprHasProperty(pExpr, EP_Skip) ){ assert( pExpr->op==TK_COLLATE ); pExpr = pExpr->pLeft; } return pExpr; } /* ** Skip over any TK_COLLATE operators and/or any unlikely() ** or likelihood() or likely() functions at the root of an ** expression. */ Expr *sqlite3ExprSkipCollateAndLikely(Expr *pExpr){ while( pExpr && ExprHasProperty(pExpr, EP_Skip|EP_Unlikely) ){ if( ExprHasProperty(pExpr, EP_Unlikely) ){ assert( !ExprHasProperty(pExpr, EP_xIsSelect) ); assert( pExpr->x.pList->nExpr>0 ); assert( pExpr->op==TK_FUNCTION ); pExpr = pExpr->x.pList->a[0].pExpr; }else{ assert( pExpr->op==TK_COLLATE ); pExpr = pExpr->pLeft; } } return pExpr; } /* ** Return the collation sequence for the expression pExpr. If ** there is no defined collating sequence, return NULL. ** ** See also: sqlite3ExprNNCollSeq() ** ** The sqlite3ExprNNCollSeq() works the same exact that it returns the ** default collation if pExpr has no defined collation. ** ** The collating sequence might be determined by a COLLATE operator ** or by the presence of a column with a defined collating sequence. ** COLLATE operators take first precedence. Left operands take ** precedence over right operands. */ CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr){ sqlite3 *db = pParse->db; CollSeq *pColl = 0; Expr *p = pExpr; while( p ){ int op = p->op; if( op==TK_REGISTER ) op = p->op2; if( (op==TK_AGG_COLUMN || op==TK_COLUMN || op==TK_TRIGGER) && p->y.pTab!=0 ){ /* op==TK_REGISTER && p->y.pTab!=0 happens when pExpr was originally ** a TK_COLUMN but was previously evaluated and cached in a register */ int j = p->iColumn; if( j>=0 ){ const char *zColl = p->y.pTab->aCol[j].zColl; pColl = sqlite3FindCollSeq(db, ENC(db), zColl, 0); } break; } if( op==TK_CAST || op==TK_UPLUS ){ p = p->pLeft; continue; } if( op==TK_VECTOR ){ p = p->x.pList->a[0].pExpr; continue; } if( op==TK_COLLATE ){ pColl = sqlite3GetCollSeq(pParse, ENC(db), 0, p->u.zToken); break; } if( p->flags & EP_Collate ){ if( p->pLeft && (p->pLeft->flags & EP_Collate)!=0 ){ p = p->pLeft; }else{ Expr *pNext = p->pRight; /* The Expr.x union is never used at the same time as Expr.pRight */ assert( p->x.pList==0 || p->pRight==0 ); if( p->x.pList!=0 && !db->mallocFailed && ALWAYS(!ExprHasProperty(p, EP_xIsSelect)) ){ int i; for(i=0; i<p->x.pList->nExpr; i++){ if( ExprHasProperty(p->x.pList->a[i].pExpr, EP_Collate) ){ pNext = p->x.pList->a[i].pExpr; break; } } } p = pNext; } }else{ break; } } if( sqlite3CheckCollSeq(pParse, pColl) ){ pColl = 0; } return pColl; } /* ** Return the collation sequence for the expression pExpr. If ** there is no defined collating sequence, return a pointer to the ** defautl collation sequence. ** ** See also: sqlite3ExprCollSeq() ** ** The sqlite3ExprCollSeq() routine works the same except that it ** returns NULL if there is no defined collation. */ CollSeq *sqlite3ExprNNCollSeq(Parse *pParse, Expr *pExpr){ CollSeq *p = sqlite3ExprCollSeq(pParse, pExpr); if( p==0 ) p = pParse->db->pDfltColl; assert( p!=0 ); return p; } /* ** Return TRUE if the two expressions have equivalent collating sequences. */ int sqlite3ExprCollSeqMatch(Parse *pParse, Expr *pE1, Expr *pE2){ CollSeq *pColl1 = sqlite3ExprNNCollSeq(pParse, pE1); CollSeq *pColl2 = sqlite3ExprNNCollSeq(pParse, pE2); return sqlite3StrICmp(pColl1->zName, pColl2->zName)==0; } /* ** pExpr is an operand of a comparison operator. aff2 is the ** type affinity of the other operand. This routine returns the ** type affinity that should be used for the comparison operator. */ char sqlite3CompareAffinity(Expr *pExpr, char aff2){ char aff1 = sqlite3ExprAffinity(pExpr); if( aff1>SQLITE_AFF_NONE && aff2>SQLITE_AFF_NONE ){ /* Both sides of the comparison are columns. If one has numeric ** affinity, use that. Otherwise use no affinity. */ if( sqlite3IsNumericAffinity(aff1) || sqlite3IsNumericAffinity(aff2) ){ return SQLITE_AFF_NUMERIC; }else{ return SQLITE_AFF_BLOB; } }else{ /* One side is a column, the other is not. Use the columns affinity. */ assert( aff1<=SQLITE_AFF_NONE || aff2<=SQLITE_AFF_NONE ); return (aff1<=SQLITE_AFF_NONE ? aff2 : aff1) | SQLITE_AFF_NONE; } } /* ** pExpr is a comparison operator. Return the type affinity that should ** be applied to both operands prior to doing the comparison. */ static char comparisonAffinity(Expr *pExpr){ char aff; assert( pExpr->op==TK_EQ || pExpr->op==TK_IN || pExpr->op==TK_LT || pExpr->op==TK_GT || pExpr->op==TK_GE || pExpr->op==TK_LE || pExpr->op==TK_NE || pExpr->op==TK_IS || pExpr->op==TK_ISNOT ); assert( pExpr->pLeft ); aff = sqlite3ExprAffinity(pExpr->pLeft); if( pExpr->pRight ){ aff = sqlite3CompareAffinity(pExpr->pRight, aff); }else if( ExprHasProperty(pExpr, EP_xIsSelect) ){ aff = sqlite3CompareAffinity(pExpr->x.pSelect->pEList->a[0].pExpr, aff); }else if( aff==0 ){ aff = SQLITE_AFF_BLOB; } return aff; } /* ** pExpr is a comparison expression, eg. '=', '<', IN(...) etc. ** idx_affinity is the affinity of an indexed column. Return true ** if the index with affinity idx_affinity may be used to implement ** the comparison in pExpr. */ int sqlite3IndexAffinityOk(Expr *pExpr, char idx_affinity){ char aff = comparisonAffinity(pExpr); if( aff<SQLITE_AFF_TEXT ){ return 1; } if( aff==SQLITE_AFF_TEXT ){ return idx_affinity==SQLITE_AFF_TEXT; } return sqlite3IsNumericAffinity(idx_affinity); } /* ** Return the P5 value that should be used for a binary comparison ** opcode (OP_Eq, OP_Ge etc.) used to compare pExpr1 and pExpr2. */ static u8 binaryCompareP5(Expr *pExpr1, Expr *pExpr2, int jumpIfNull){ u8 aff = (char)sqlite3ExprAffinity(pExpr2); aff = (u8)sqlite3CompareAffinity(pExpr1, aff) | (u8)jumpIfNull; return aff; } /* ** Return a pointer to the collation sequence that should be used by ** a binary comparison operator comparing pLeft and pRight. ** ** If the left hand expression has a collating sequence type, then it is ** used. Otherwise the collation sequence for the right hand expression ** is used, or the default (BINARY) if neither expression has a collating ** type. ** ** Argument pRight (but not pLeft) may be a null pointer. In this case, ** it is not considered. */ CollSeq *sqlite3BinaryCompareCollSeq( Parse *pParse, Expr *pLeft, Expr *pRight ){ CollSeq *pColl; assert( pLeft ); if( pLeft->flags & EP_Collate ){ pColl = sqlite3ExprCollSeq(pParse, pLeft); }else if( pRight && (pRight->flags & EP_Collate)!=0 ){ pColl = sqlite3ExprCollSeq(pParse, pRight); }else{ pColl = sqlite3ExprCollSeq(pParse, pLeft); if( !pColl ){ pColl = sqlite3ExprCollSeq(pParse, pRight); } } return pColl; } /* Expresssion p is a comparison operator. Return a collation sequence ** appropriate for the comparison operator. ** ** This is normally just a wrapper around sqlite3BinaryCompareCollSeq(). ** However, if the OP_Commuted flag is set, then the order of the operands ** is reversed in the sqlite3BinaryCompareCollSeq() call so that the ** correct collating sequence is found. */ CollSeq *sqlite3ExprCompareCollSeq(Parse *pParse, Expr *p){ if( ExprHasProperty(p, EP_Commuted) ){ return sqlite3BinaryCompareCollSeq(pParse, p->pRight, p->pLeft); }else{ return sqlite3BinaryCompareCollSeq(pParse, p->pLeft, p->pRight); } } /* ** Generate code for a comparison operator. */ static int codeCompare( Parse *pParse, /* The parsing (and code generating) context */ Expr *pLeft, /* The left operand */ Expr *pRight, /* The right operand */ int opcode, /* The comparison opcode */ int in1, int in2, /* Register holding operands */ int dest, /* Jump here if true. */ int jumpIfNull, /* If true, jump if either operand is NULL */ int isCommuted /* The comparison has been commuted */ ){ int p5; int addr; CollSeq *p4; if( pParse->nErr ) return 0; if( isCommuted ){ p4 = sqlite3BinaryCompareCollSeq(pParse, pRight, pLeft); }else{ p4 = sqlite3BinaryCompareCollSeq(pParse, pLeft, pRight); } p5 = binaryCompareP5(pLeft, pRight, jumpIfNull); addr = sqlite3VdbeAddOp4(pParse->pVdbe, opcode, in2, dest, in1, (void*)p4, P4_COLLSEQ); sqlite3VdbeChangeP5(pParse->pVdbe, (u8)p5); return addr; } /* ** Return true if expression pExpr is a vector, or false otherwise. ** ** A vector is defined as any expression that results in two or more ** columns of result. Every TK_VECTOR node is an vector because the ** parser will not generate a TK_VECTOR with fewer than two entries. ** But a TK_SELECT might be either a vector or a scalar. It is only ** considered a vector if it has two or more result columns. */ int sqlite3ExprIsVector(Expr *pExpr){ return sqlite3ExprVectorSize(pExpr)>1; } /* ** If the expression passed as the only argument is of type TK_VECTOR ** return the number of expressions in the vector. Or, if the expression ** is a sub-select, return the number of columns in the sub-select. For ** any other type of expression, return 1. */ int sqlite3ExprVectorSize(Expr *pExpr){ u8 op = pExpr->op; if( op==TK_REGISTER ) op = pExpr->op2; if( op==TK_VECTOR ){ return pExpr->x.pList->nExpr; }else if( op==TK_SELECT ){ return pExpr->x.pSelect->pEList->nExpr; }else{ return 1; } } /* ** Return a pointer to a subexpression of pVector that is the i-th ** column of the vector (numbered starting with 0). The caller must ** ensure that i is within range. ** ** If pVector is really a scalar (and "scalar" here includes subqueries ** that return a single column!) then return pVector unmodified. ** ** pVector retains ownership of the returned subexpression. ** ** If the vector is a (SELECT ...) then the expression returned is ** just the expression for the i-th term of the result set, and may ** not be ready for evaluation because the table cursor has not yet ** been positioned. */ Expr *sqlite3VectorFieldSubexpr(Expr *pVector, int i){ assert( i<sqlite3ExprVectorSize(pVector) ); if( sqlite3ExprIsVector(pVector) ){ assert( pVector->op2==0 || pVector->op==TK_REGISTER ); if( pVector->op==TK_SELECT || pVector->op2==TK_SELECT ){ return pVector->x.pSelect->pEList->a[i].pExpr; }else{ return pVector->x.pList->a[i].pExpr; } } return pVector; } /* ** Compute and return a new Expr object which when passed to ** sqlite3ExprCode() will generate all necessary code to compute ** the iField-th column of the vector expression pVector. ** ** It is ok for pVector to be a scalar (as long as iField==0). ** In that case, this routine works like sqlite3ExprDup(). ** ** The caller owns the returned Expr object and is responsible for ** ensuring that the returned value eventually gets freed. ** ** The caller retains ownership of pVector. If pVector is a TK_SELECT, ** then the returned object will reference pVector and so pVector must remain ** valid for the life of the returned object. If pVector is a TK_VECTOR ** or a scalar expression, then it can be deleted as soon as this routine ** returns. ** ** A trick to cause a TK_SELECT pVector to be deleted together with ** the returned Expr object is to attach the pVector to the pRight field ** of the returned TK_SELECT_COLUMN Expr object. */ Expr *sqlite3ExprForVectorField( Parse *pParse, /* Parsing context */ Expr *pVector, /* The vector. List of expressions or a sub-SELECT */ int iField /* Which column of the vector to return */ ){ Expr *pRet; if( pVector->op==TK_SELECT ){ assert( pVector->flags & EP_xIsSelect ); /* The TK_SELECT_COLUMN Expr node: ** ** pLeft: pVector containing TK_SELECT. Not deleted. ** pRight: not used. But recursively deleted. ** iColumn: Index of a column in pVector ** iTable: 0 or the number of columns on the LHS of an assignment ** pLeft->iTable: First in an array of register holding result, or 0 ** if the result is not yet computed. ** ** sqlite3ExprDelete() specifically skips the recursive delete of ** pLeft on TK_SELECT_COLUMN nodes. But pRight is followed, so pVector ** can be attached to pRight to cause this node to take ownership of ** pVector. Typically there will be multiple TK_SELECT_COLUMN nodes ** with the same pLeft pointer to the pVector, but only one of them ** will own the pVector. */ pRet = sqlite3PExpr(pParse, TK_SELECT_COLUMN, 0, 0); if( pRet ){ pRet->iColumn = iField; pRet->pLeft = pVector; } assert( pRet==0 || pRet->iTable==0 ); }else{ if( pVector->op==TK_VECTOR ) pVector = pVector->x.pList->a[iField].pExpr; pRet = sqlite3ExprDup(pParse->db, pVector, 0); sqlite3RenameTokenRemap(pParse, pRet, pVector); } return pRet; } /* ** If expression pExpr is of type TK_SELECT, generate code to evaluate ** it. Return the register in which the result is stored (or, if the ** sub-select returns more than one column, the first in an array ** of registers in which the result is stored). ** ** If pExpr is not a TK_SELECT expression, return 0. */ static int exprCodeSubselect(Parse *pParse, Expr *pExpr){ int reg = 0; #ifndef SQLITE_OMIT_SUBQUERY if( pExpr->op==TK_SELECT ){ reg = sqlite3CodeSubselect(pParse, pExpr); } #endif return reg; } /* ** Argument pVector points to a vector expression - either a TK_VECTOR ** or TK_SELECT that returns more than one column. This function returns ** the register number of a register that contains the value of ** element iField of the vector. ** ** If pVector is a TK_SELECT expression, then code for it must have ** already been generated using the exprCodeSubselect() routine. In this ** case parameter regSelect should be the first in an array of registers ** containing the results of the sub-select. ** ** If pVector is of type TK_VECTOR, then code for the requested field ** is generated. In this case (*pRegFree) may be set to the number of ** a temporary register to be freed by the caller before returning. ** ** Before returning, output parameter (*ppExpr) is set to point to the ** Expr object corresponding to element iElem of the vector. */ static int exprVectorRegister( Parse *pParse, /* Parse context */ Expr *pVector, /* Vector to extract element from */ int iField, /* Field to extract from pVector */ int regSelect, /* First in array of registers */ Expr **ppExpr, /* OUT: Expression element */ int *pRegFree /* OUT: Temp register to free */ ){ u8 op = pVector->op; assert( op==TK_VECTOR || op==TK_REGISTER || op==TK_SELECT ); if( op==TK_REGISTER ){ *ppExpr = sqlite3VectorFieldSubexpr(pVector, iField); return pVector->iTable+iField; } if( op==TK_SELECT ){ *ppExpr = pVector->x.pSelect->pEList->a[iField].pExpr; return regSelect+iField; } *ppExpr = pVector->x.pList->a[iField].pExpr; return sqlite3ExprCodeTemp(pParse, *ppExpr, pRegFree); } /* ** Expression pExpr is a comparison between two vector values. Compute ** the result of the comparison (1, 0, or NULL) and write that ** result into register dest. ** ** The caller must satisfy the following preconditions: ** ** if pExpr->op==TK_IS: op==TK_EQ and p5==SQLITE_NULLEQ ** if pExpr->op==TK_ISNOT: op==TK_NE and p5==SQLITE_NULLEQ ** otherwise: op==pExpr->op and p5==0 */ static void codeVectorCompare( Parse *pParse, /* Code generator context */ Expr *pExpr, /* The comparison operation */ int dest, /* Write results into this register */ u8 op, /* Comparison operator */ u8 p5 /* SQLITE_NULLEQ or zero */ ){ Vdbe *v = pParse->pVdbe; Expr *pLeft = pExpr->pLeft; Expr *pRight = pExpr->pRight; int nLeft = sqlite3ExprVectorSize(pLeft); int i; int regLeft = 0; int regRight = 0; u8 opx = op; int addrDone = sqlite3VdbeMakeLabel(pParse); int isCommuted = ExprHasProperty(pExpr,EP_Commuted); if( pParse->nErr ) return; if( nLeft!=sqlite3ExprVectorSize(pRight) ){ sqlite3ErrorMsg(pParse, "row value misused"); return; } assert( pExpr->op==TK_EQ || pExpr->op==TK_NE || pExpr->op==TK_IS || pExpr->op==TK_ISNOT || pExpr->op==TK_LT || pExpr->op==TK_GT || pExpr->op==TK_LE || pExpr->op==TK_GE ); assert( pExpr->op==op || (pExpr->op==TK_IS && op==TK_EQ) || (pExpr->op==TK_ISNOT && op==TK_NE) ); assert( p5==0 || pExpr->op!=op ); assert( p5==SQLITE_NULLEQ || pExpr->op==op ); p5 |= SQLITE_STOREP2; if( opx==TK_LE ) opx = TK_LT; if( opx==TK_GE ) opx = TK_GT; regLeft = exprCodeSubselect(pParse, pLeft); regRight = exprCodeSubselect(pParse, pRight); for(i=0; 1 /*Loop exits by "break"*/; i++){ int regFree1 = 0, regFree2 = 0; Expr *pL, *pR; int r1, r2; assert( i>=0 && i<nLeft ); r1 = exprVectorRegister(pParse, pLeft, i, regLeft, &pL, ®Free1); r2 = exprVectorRegister(pParse, pRight, i, regRight, &pR, ®Free2); codeCompare(pParse, pL, pR, opx, r1, r2, dest, p5, isCommuted); testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt); testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le); testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt); testcase(op==OP_Ge); VdbeCoverageIf(v,op==OP_Ge); testcase(op==OP_Eq); VdbeCoverageIf(v,op==OP_Eq); testcase(op==OP_Ne); VdbeCoverageIf(v,op==OP_Ne); sqlite3ReleaseTempReg(pParse, regFree1); sqlite3ReleaseTempReg(pParse, regFree2); if( i==nLeft-1 ){ break; } if( opx==TK_EQ ){ sqlite3VdbeAddOp2(v, OP_IfNot, dest, addrDone); VdbeCoverage(v); p5 |= SQLITE_KEEPNULL; }else if( opx==TK_NE ){ sqlite3VdbeAddOp2(v, OP_If, dest, addrDone); VdbeCoverage(v); p5 |= SQLITE_KEEPNULL; }else{ assert( op==TK_LT || op==TK_GT || op==TK_LE || op==TK_GE ); sqlite3VdbeAddOp2(v, OP_ElseNotEq, 0, addrDone); VdbeCoverageIf(v, op==TK_LT); VdbeCoverageIf(v, op==TK_GT); VdbeCoverageIf(v, op==TK_LE); VdbeCoverageIf(v, op==TK_GE); if( i==nLeft-2 ) opx = op; } } sqlite3VdbeResolveLabel(v, addrDone); } #if SQLITE_MAX_EXPR_DEPTH>0 /* ** Check that argument nHeight is less than or equal to the maximum ** expression depth allowed. If it is not, leave an error message in ** pParse. */ int sqlite3ExprCheckHeight(Parse *pParse, int nHeight){ int rc = SQLITE_OK; int mxHeight = pParse->db->aLimit[SQLITE_LIMIT_EXPR_DEPTH]; if( nHeight>mxHeight ){ sqlite3ErrorMsg(pParse, "Expression tree is too large (maximum depth %d)", mxHeight ); rc = SQLITE_ERROR; } return rc; } /* The following three functions, heightOfExpr(), heightOfExprList() ** and heightOfSelect(), are used to determine the maximum height ** of any expression tree referenced by the structure passed as the ** first argument. ** ** If this maximum height is greater than the current value pointed ** to by pnHeight, the second parameter, then set *pnHeight to that ** value. */ static void heightOfExpr(Expr *p, int *pnHeight){ if( p ){ if( p->nHeight>*pnHeight ){ *pnHeight = p->nHeight; } } } static void heightOfExprList(ExprList *p, int *pnHeight){ if( p ){ int i; for(i=0; i<p->nExpr; i++){ heightOfExpr(p->a[i].pExpr, pnHeight); } } } static void heightOfSelect(Select *pSelect, int *pnHeight){ Select *p; for(p=pSelect; p; p=p->pPrior){ heightOfExpr(p->pWhere, pnHeight); heightOfExpr(p->pHaving, pnHeight); heightOfExpr(p->pLimit, pnHeight); heightOfExprList(p->pEList, pnHeight); heightOfExprList(p->pGroupBy, pnHeight); heightOfExprList(p->pOrderBy, pnHeight); } } /* ** Set the Expr.nHeight variable in the structure passed as an ** argument. An expression with no children, Expr.pList or ** Expr.pSelect member has a height of 1. Any other expression ** has a height equal to the maximum height of any other ** referenced Expr plus one. ** ** Also propagate EP_Propagate flags up from Expr.x.pList to Expr.flags, ** if appropriate. */ static void exprSetHeight(Expr *p){ int nHeight = 0; heightOfExpr(p->pLeft, &nHeight); heightOfExpr(p->pRight, &nHeight); if( ExprHasProperty(p, EP_xIsSelect) ){ heightOfSelect(p->x.pSelect, &nHeight); }else if( p->x.pList ){ heightOfExprList(p->x.pList, &nHeight); p->flags |= EP_Propagate & sqlite3ExprListFlags(p->x.pList); } p->nHeight = nHeight + 1; } /* ** Set the Expr.nHeight variable using the exprSetHeight() function. If ** the height is greater than the maximum allowed expression depth, ** leave an error in pParse. ** ** Also propagate all EP_Propagate flags from the Expr.x.pList into ** Expr.flags. */ void sqlite3ExprSetHeightAndFlags(Parse *pParse, Expr *p){ if( pParse->nErr ) return; exprSetHeight(p); sqlite3ExprCheckHeight(pParse, p->nHeight); } /* ** Return the maximum height of any expression tree referenced ** by the select statement passed as an argument. */ int sqlite3SelectExprHeight(Select *p){ int nHeight = 0; heightOfSelect(p, &nHeight); return nHeight; } #else /* ABOVE: Height enforcement enabled. BELOW: Height enforcement off */ /* ** Propagate all EP_Propagate flags from the Expr.x.pList into ** Expr.flags. */ void sqlite3ExprSetHeightAndFlags(Parse *pParse, Expr *p){ if( p && p->x.pList && !ExprHasProperty(p, EP_xIsSelect) ){ p->flags |= EP_Propagate & sqlite3ExprListFlags(p->x.pList); } } #define exprSetHeight(y) #endif /* SQLITE_MAX_EXPR_DEPTH>0 */ /* ** This routine is the core allocator for Expr nodes. ** ** Construct a new expression node and return a pointer to it. Memory ** for this node and for the pToken argument is a single allocation ** obtained from sqlite3DbMalloc(). The calling function ** is responsible for making sure the node eventually gets freed. ** ** If dequote is true, then the token (if it exists) is dequoted. ** If dequote is false, no dequoting is performed. The deQuote ** parameter is ignored if pToken is NULL or if the token does not ** appear to be quoted. If the quotes were of the form "..." (double-quotes) ** then the EP_DblQuoted flag is set on the expression node. ** ** Special case: If op==TK_INTEGER and pToken points to a string that ** can be translated into a 32-bit integer, then the token is not ** stored in u.zToken. Instead, the integer values is written ** into u.iValue and the EP_IntValue flag is set. No extra storage ** is allocated to hold the integer text and the dequote flag is ignored. */ Expr *sqlite3ExprAlloc( sqlite3 *db, /* Handle for sqlite3DbMallocRawNN() */ int op, /* Expression opcode */ const Token *pToken, /* Token argument. Might be NULL */ int dequote /* True to dequote */ ){ Expr *pNew; int nExtra = 0; int iValue = 0; assert( db!=0 ); if( pToken ){ if( op!=TK_INTEGER || pToken->z==0 || sqlite3GetInt32(pToken->z, &iValue)==0 ){ nExtra = pToken->n+1; assert( iValue>=0 ); } } pNew = sqlite3DbMallocRawNN(db, sizeof(Expr)+nExtra); if( pNew ){ memset(pNew, 0, sizeof(Expr)); pNew->op = (u8)op; pNew->iAgg = -1; if( pToken ){ if( nExtra==0 ){ pNew->flags |= EP_IntValue|EP_Leaf|(iValue?EP_IsTrue:EP_IsFalse); pNew->u.iValue = iValue; }else{ pNew->u.zToken = (char*)&pNew[1]; assert( pToken->z!=0 || pToken->n==0 ); if( pToken->n ) memcpy(pNew->u.zToken, pToken->z, pToken->n); pNew->u.zToken[pToken->n] = 0; if( dequote && sqlite3Isquote(pNew->u.zToken[0]) ){ sqlite3DequoteExpr(pNew); } } } #if SQLITE_MAX_EXPR_DEPTH>0 pNew->nHeight = 1; #endif } return pNew; } /* ** Allocate a new expression node from a zero-terminated token that has ** already been dequoted. */ Expr *sqlite3Expr( sqlite3 *db, /* Handle for sqlite3DbMallocZero() (may be null) */ int op, /* Expression opcode */ const char *zToken /* Token argument. Might be NULL */ ){ Token x; x.z = zToken; x.n = sqlite3Strlen30(zToken); return sqlite3ExprAlloc(db, op, &x, 0); } /* ** Attach subtrees pLeft and pRight to the Expr node pRoot. ** ** If pRoot==NULL that means that a memory allocation error has occurred. ** In that case, delete the subtrees pLeft and pRight. */ void sqlite3ExprAttachSubtrees( sqlite3 *db, Expr *pRoot, Expr *pLeft, Expr *pRight ){ if( pRoot==0 ){ assert( db->mallocFailed ); sqlite3ExprDelete(db, pLeft); sqlite3ExprDelete(db, pRight); }else{ if( pRight ){ pRoot->pRight = pRight; pRoot->flags |= EP_Propagate & pRight->flags; } if( pLeft ){ pRoot->pLeft = pLeft; pRoot->flags |= EP_Propagate & pLeft->flags; } exprSetHeight(pRoot); } } /* ** Allocate an Expr node which joins as many as two subtrees. ** ** One or both of the subtrees can be NULL. Return a pointer to the new ** Expr node. Or, if an OOM error occurs, set pParse->db->mallocFailed, ** free the subtrees and return NULL. */ Expr *sqlite3PExpr( Parse *pParse, /* Parsing context */ int op, /* Expression opcode */ Expr *pLeft, /* Left operand */ Expr *pRight /* Right operand */ ){ Expr *p; p = sqlite3DbMallocRawNN(pParse->db, sizeof(Expr)); if( p ){ memset(p, 0, sizeof(Expr)); p->op = op & 0xff; p->iAgg = -1; sqlite3ExprAttachSubtrees(pParse->db, p, pLeft, pRight); sqlite3ExprCheckHeight(pParse, p->nHeight); }else{ sqlite3ExprDelete(pParse->db, pLeft); sqlite3ExprDelete(pParse->db, pRight); } return p; } /* ** Add pSelect to the Expr.x.pSelect field. Or, if pExpr is NULL (due ** do a memory allocation failure) then delete the pSelect object. */ void sqlite3PExprAddSelect(Parse *pParse, Expr *pExpr, Select *pSelect){ if( pExpr ){ pExpr->x.pSelect = pSelect; ExprSetProperty(pExpr, EP_xIsSelect|EP_Subquery); sqlite3ExprSetHeightAndFlags(pParse, pExpr); }else{ assert( pParse->db->mallocFailed ); sqlite3SelectDelete(pParse->db, pSelect); } } /* ** Join two expressions using an AND operator. If either expression is ** NULL, then just return the other expression. ** ** If one side or the other of the AND is known to be false, then instead ** of returning an AND expression, just return a constant expression with ** a value of false. */ Expr *sqlite3ExprAnd(Parse *pParse, Expr *pLeft, Expr *pRight){ sqlite3 *db = pParse->db; if( pLeft==0 ){ return pRight; }else if( pRight==0 ){ return pLeft; }else if( (ExprAlwaysFalse(pLeft) || ExprAlwaysFalse(pRight)) && !IN_RENAME_OBJECT ){ sqlite3ExprDelete(db, pLeft); sqlite3ExprDelete(db, pRight); return sqlite3Expr(db, TK_INTEGER, "0"); }else{ return sqlite3PExpr(pParse, TK_AND, pLeft, pRight); } } /* ** Construct a new expression node for a function with multiple ** arguments. */ Expr *sqlite3ExprFunction( Parse *pParse, /* Parsing context */ ExprList *pList, /* Argument list */ Token *pToken, /* Name of the function */ int eDistinct /* SF_Distinct or SF_ALL or 0 */ ){ Expr *pNew; sqlite3 *db = pParse->db; assert( pToken ); pNew = sqlite3ExprAlloc(db, TK_FUNCTION, pToken, 1); if( pNew==0 ){ sqlite3ExprListDelete(db, pList); /* Avoid memory leak when malloc fails */ return 0; } if( pList && pList->nExpr > pParse->db->aLimit[SQLITE_LIMIT_FUNCTION_ARG] ){ sqlite3ErrorMsg(pParse, "too many arguments on function %T", pToken); } pNew->x.pList = pList; ExprSetProperty(pNew, EP_HasFunc); assert( !ExprHasProperty(pNew, EP_xIsSelect) ); sqlite3ExprSetHeightAndFlags(pParse, pNew); if( eDistinct==SF_Distinct ) ExprSetProperty(pNew, EP_Distinct); return pNew; } /* ** Check to see if a function is usable according to current access ** rules: ** ** SQLITE_FUNC_DIRECT - Only usable from top-level SQL ** ** SQLITE_FUNC_UNSAFE - Usable if TRUSTED_SCHEMA or from ** top-level SQL ** ** If the function is not usable, create an error. */ void sqlite3ExprFunctionUsable( Parse *pParse, /* Parsing and code generating context */ Expr *pExpr, /* The function invocation */ FuncDef *pDef /* The function being invoked */ ){ assert( !IN_RENAME_OBJECT ); assert( (pDef->funcFlags & (SQLITE_FUNC_DIRECT|SQLITE_FUNC_UNSAFE))!=0 ); if( ExprHasProperty(pExpr, EP_FromDDL) ){ if( (pDef->funcFlags & SQLITE_FUNC_DIRECT)!=0 || (pParse->db->flags & SQLITE_TrustedSchema)==0 ){ /* Functions prohibited in triggers and views if: ** (1) tagged with SQLITE_DIRECTONLY ** (2) not tagged with SQLITE_INNOCUOUS (which means it |
| You are visitor 01402520 — GeezerVison does not store the pages you look up. Best viewed with Netscape Navigator 4.7 or Internet Explorer 6 at 800×600. No cookies required. |