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Overview
Comment: | Split the code generation for the RHS of IN operators and for SELECT and EXISTS expressions into two separate subroutines, because there is now little commonality between those to functions. This is intended to help make the code easier to read and maintain. |
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SHA3-256: |
2b6494b1509f0d0189f98aa34c990eee |
User & Date: | drh 2018-12-23 21:27:29.955 |
Context
2018-12-24
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13:34 | Change the way a comparison used to detect corrupt databases in fts3 is done to avoid potential pointer overflow in 32-bit builds. (check-in: 95a9a39ff7 user: dan tags: trunk) | |
02:34 | Experimental code that tries to put the computation of subqueries inside a subroutine, and reuse that subroutine if the same subquery is evaluated more than once. Current code does not work for CHECK constraints. (check-in: 6c44838adb user: drh tags: reuse-subqueries) | |
2018-12-23
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21:27 | Split the code generation for the RHS of IN operators and for SELECT and EXISTS expressions into two separate subroutines, because there is now little commonality between those to functions. This is intended to help make the code easier to read and maintain. (check-in: 2b6494b150 user: drh tags: trunk) | |
2018-12-22
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20:32 | Improve the coverage of wal.c provided by the "coverage-wal" test permutation. (check-in: 6231485114 user: dan tags: trunk) | |
Changes
Changes to src/expr.c.
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477 478 479 480 481 482 483 | ** ** 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 ){ | | | 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 | ** ** 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 |
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2538 2539 2540 2541 2542 2543 2544 | pParse->nQueryLoop = 0; if( pX->pLeft->iColumn<0 && !ExprHasProperty(pX, EP_xIsSelect) ){ eType = IN_INDEX_ROWID; } }else if( prRhsHasNull ){ *prRhsHasNull = rMayHaveNull = ++pParse->nMem; } | > | > > > | 2538 2539 2540 2541 2542 2543 2544 2545 2546 2547 2548 2549 2550 2551 2552 2553 2554 2555 2556 | pParse->nQueryLoop = 0; if( pX->pLeft->iColumn<0 && !ExprHasProperty(pX, EP_xIsSelect) ){ eType = IN_INDEX_ROWID; } }else if( prRhsHasNull ){ *prRhsHasNull = rMayHaveNull = ++pParse->nMem; } assert( pX->op==TK_IN ); sqlite3CodeRhsOfIN(pParse, pX, eType==IN_INDEX_ROWID); if( rMayHaveNull ){ sqlite3SetHasNullFlag(v, pX->iTable, rMayHaveNull); } pParse->nQueryLoop = savedNQueryLoop; }else{ pX->iTable = iTab; } if( aiMap && eType!=IN_INDEX_INDEX_ASC && eType!=IN_INDEX_INDEX_DESC ){ int i, n; |
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2622 2623 2624 2625 2626 2627 2628 2629 | }else #endif { sqlite3ErrorMsg(pParse, "row value misused"); } } /* | > | | > < < | < | > > > > > > > > > > > > > > > > > > > > > > > > | > > | > > > > > > > > > > > > > | > > > > | > > > > > > > > > > | > > > > > > > > > > > > > > > > > > > > > > > > > > > > | > > > > > > > > > > > > > > > > > > > > > > > > > > > > > | > > > > > > > | > > > > > > > > > | > > > > > > > > > > > > > > > > > > > > > > > > > > > | > > > > > > > > | | | | | < < < < < | | > > > > | | | < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < | | | | | | | | | | < < < < < | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | < < < < < < < | 2626 2627 2628 2629 2630 2631 2632 2633 2634 2635 2636 2637 2638 2639 2640 2641 2642 2643 2644 2645 2646 2647 2648 2649 2650 2651 2652 2653 2654 2655 2656 2657 2658 2659 2660 2661 2662 2663 2664 2665 2666 2667 2668 2669 2670 2671 2672 2673 2674 2675 2676 2677 2678 2679 2680 2681 2682 2683 2684 2685 2686 2687 2688 2689 2690 2691 2692 2693 2694 2695 2696 2697 2698 2699 2700 2701 2702 2703 2704 2705 2706 2707 2708 2709 2710 2711 2712 2713 2714 2715 2716 2717 2718 2719 2720 2721 2722 2723 2724 2725 2726 2727 2728 2729 2730 2731 2732 2733 2734 2735 2736 2737 2738 2739 2740 2741 2742 2743 2744 2745 2746 2747 2748 2749 2750 2751 2752 2753 2754 2755 2756 2757 2758 2759 2760 2761 2762 2763 2764 2765 2766 2767 2768 2769 2770 2771 2772 2773 2774 2775 2776 2777 2778 2779 2780 2781 2782 2783 2784 2785 2786 2787 2788 2789 2790 2791 2792 2793 2794 2795 2796 2797 2798 2799 2800 2801 2802 2803 2804 2805 2806 2807 2808 2809 2810 2811 2812 2813 2814 2815 2816 2817 2818 2819 2820 2821 2822 2823 2824 2825 2826 2827 2828 2829 2830 2831 2832 2833 2834 2835 2836 2837 2838 2839 2840 2841 2842 2843 2844 2845 2846 2847 2848 2849 2850 2851 2852 2853 2854 2855 2856 2857 2858 2859 2860 2861 2862 2863 2864 2865 2866 2867 2868 2869 2870 2871 2872 2873 2874 2875 2876 2877 2878 2879 2880 2881 2882 2883 2884 2885 2886 2887 2888 2889 2890 2891 2892 2893 2894 2895 2896 2897 2898 | }else #endif { sqlite3ErrorMsg(pParse, "row value misused"); } } #ifndef SQLITE_OMIT_SUBQUERY /* ** Generate code that will construct an ephemeral table containing all terms ** in the RHS of an IN operator. The IN operator can be in either of two ** forms: ** ** x IN (4,5,11) -- IN operator with list on right-hand side ** x IN (SELECT a FROM b) -- IN operator with subquery on the right ** ** The pExpr parameter is the IN operator. ** ** If parameter isRowid is non-zero, then LHS of the IN operator is guaranteed ** to be a non-null integer. In this case, the ephemeral table can be an ** table B-Tree that keyed by only integers. The more general cases uses ** an index B-Tree which can have arbitrary keys, but is slower to both ** read and write. ** ** If the LHS expression ("x" in the examples) is a column value, or ** the SELECT statement returns a column value, then the affinity of that ** column is used to build the index keys. If both 'x' and the ** SELECT... statement are columns, then numeric affinity is used ** if either column has NUMERIC or INTEGER affinity. If neither ** 'x' nor the SELECT... statement are columns, then numeric affinity ** is used. */ void sqlite3CodeRhsOfIN( Parse *pParse, /* Parsing context */ Expr *pExpr, /* The IN operator */ int isRowid /* If true, LHS is a rowid */ ){ int jmpIfDynamic = -1; /* One-time test address */ int addr; /* Address of OP_OpenEphemeral instruction */ Expr *pLeft; /* the LHS of the IN operator */ KeyInfo *pKeyInfo = 0; /* Key information */ int nVal; /* Size of vector pLeft */ Vdbe *v; /* The prepared statement under construction */ v = sqlite3GetVdbe(pParse); assert( v!=0 ); /* The evaluation of the RHS of IN operator must be repeated every time it ** is encountered if any of the following is true: ** ** * The right-hand side is a correlated subquery ** * The right-hand side is an expression list containing variables ** * We are inside a trigger ** ** If all of the above are false, then we can run this code just once ** save the results, and reuse the same result on subsequent invocations. */ if( !ExprHasProperty(pExpr, EP_VarSelect) ){ jmpIfDynamic = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v); } /* Check to see if this is a vector IN operator */ pLeft = pExpr->pLeft; nVal = sqlite3ExprVectorSize(pLeft); assert( !isRowid || nVal==1 ); /* Construct the ephemeral table that will contain the content of ** RHS of the IN operator. */ pExpr->iTable = pParse->nTab++; addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pExpr->iTable, (isRowid?0:nVal)); pKeyInfo = isRowid ? 0 : sqlite3KeyInfoAlloc(pParse->db, nVal, 1); if( ExprHasProperty(pExpr, EP_xIsSelect) ){ /* Case 1: expr IN (SELECT ...) ** ** Generate code to write the results of the select into the temporary ** table allocated and opened above. */ Select *pSelect = pExpr->x.pSelect; ExprList *pEList = pSelect->pEList; ExplainQueryPlan((pParse, 1, "%sLIST SUBQUERY", jmpIfDynamic>=0?"":"CORRELATED " )); assert( !isRowid ); /* If the LHS and RHS of the IN operator do not match, that ** error will have been caught long before we reach this point. */ if( ALWAYS(pEList->nExpr==nVal) ){ SelectDest dest; int i; sqlite3SelectDestInit(&dest, SRT_Set, pExpr->iTable); dest.zAffSdst = exprINAffinity(pParse, pExpr); pSelect->iLimit = 0; testcase( pSelect->selFlags & SF_Distinct ); testcase( pKeyInfo==0 ); /* Caused by OOM in sqlite3KeyInfoAlloc() */ if( sqlite3Select(pParse, pSelect, &dest) ){ sqlite3DbFree(pParse->db, dest.zAffSdst); sqlite3KeyInfoUnref(pKeyInfo); return; } sqlite3DbFree(pParse->db, dest.zAffSdst); assert( pKeyInfo!=0 ); /* OOM will cause exit after sqlite3Select() */ assert( pEList!=0 ); assert( pEList->nExpr>0 ); assert( sqlite3KeyInfoIsWriteable(pKeyInfo) ); for(i=0; i<nVal; i++){ Expr *p = sqlite3VectorFieldSubexpr(pLeft, i); pKeyInfo->aColl[i] = sqlite3BinaryCompareCollSeq( pParse, p, pEList->a[i].pExpr ); } } }else if( ALWAYS(pExpr->x.pList!=0) ){ /* Case 2: expr IN (exprlist) ** ** For each expression, build an index key from the evaluation and ** store it in the temporary table. If <expr> is a column, then use ** that columns affinity when building index keys. If <expr> is not ** a column, use numeric affinity. */ char affinity; /* Affinity of the LHS of the IN */ int i; ExprList *pList = pExpr->x.pList; struct ExprList_item *pItem; int r1, r2, r3; affinity = sqlite3ExprAffinity(pLeft); if( !affinity ){ affinity = SQLITE_AFF_BLOB; } if( pKeyInfo ){ assert( sqlite3KeyInfoIsWriteable(pKeyInfo) ); pKeyInfo->aColl[0] = sqlite3ExprCollSeq(pParse, pExpr->pLeft); } /* Loop through each expression in <exprlist>. */ r1 = sqlite3GetTempReg(pParse); r2 = sqlite3GetTempReg(pParse); if( isRowid ) sqlite3VdbeAddOp4(v, OP_Blob, 0, r2, 0, "", P4_STATIC); for(i=pList->nExpr, pItem=pList->a; i>0; i--, pItem++){ Expr *pE2 = pItem->pExpr; int iValToIns; /* If the expression is not constant then we will need to ** disable the test that was generated above that makes sure ** this code only executes once. Because for a non-constant ** expression we need to rerun this code each time. */ if( jmpIfDynamic>=0 && !sqlite3ExprIsConstant(pE2) ){ sqlite3VdbeChangeToNoop(v, jmpIfDynamic); jmpIfDynamic = -1; } /* Evaluate the expression and insert it into the temp table */ if( isRowid && sqlite3ExprIsInteger(pE2, &iValToIns) ){ sqlite3VdbeAddOp3(v, OP_InsertInt, pExpr->iTable, r2, iValToIns); }else{ r3 = sqlite3ExprCodeTarget(pParse, pE2, r1); if( isRowid ){ sqlite3VdbeAddOp2(v, OP_MustBeInt, r3, sqlite3VdbeCurrentAddr(v)+2); VdbeCoverage(v); sqlite3VdbeAddOp3(v, OP_Insert, pExpr->iTable, r2, r3); }else{ sqlite3VdbeAddOp4(v, OP_MakeRecord, r3, 1, r2, &affinity, 1); sqlite3VdbeAddOp4Int(v, OP_IdxInsert, pExpr->iTable, r2, r3, 1); } } } sqlite3ReleaseTempReg(pParse, r1); sqlite3ReleaseTempReg(pParse, r2); } if( pKeyInfo ){ sqlite3VdbeChangeP4(v, addr, (void *)pKeyInfo, P4_KEYINFO); } if( jmpIfDynamic>=0 ){ sqlite3VdbeJumpHere(v, jmpIfDynamic); } } #endif /* SQLITE_OMIT_SUBQUERY */ /* ** Generate code for scalar subqueries used as a subquery expression ** or EXISTS operator: ** ** (SELECT a FROM b) -- subquery ** EXISTS (SELECT a FROM b) -- EXISTS subquery ** ** The pExpr parameter is the SELECT or EXISTS operator to be coded. ** ** The register that holds the result. For a multi-column SELECT, ** the result is stored in a contiguous array of registers and the ** return value is the register of the left-most result column. ** Return 0 if an error occurs. */ #ifndef SQLITE_OMIT_SUBQUERY int sqlite3CodeSubselect(Parse *pParse, Expr *pExpr){ int jmpIfDynamic = -1; /* One-time test address */ int rReg = 0; /* Register storing resulting */ Select *pSel; /* SELECT statement to encode */ SelectDest dest; /* How to deal with SELECT result */ int nReg; /* Registers to allocate */ Expr *pLimit; /* New limit expression */ Vdbe *v = sqlite3GetVdbe(pParse); assert( v!=0 ); /* The evaluation of the EXISTS/SELECT must be repeated every time it ** is encountered if any of the following is true: ** ** * The right-hand side is a correlated subquery ** * The right-hand side is an expression list containing variables ** * We are inside a trigger ** ** If all of the above are false, then we can run this code just once ** save the results, and reuse the same result on subsequent invocations. */ if( !ExprHasProperty(pExpr, EP_VarSelect) ){ jmpIfDynamic = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v); } /* For a SELECT, generate code to put the values for all columns of ** the first row into an array of registers and return the index of ** the first register. ** ** If this is an EXISTS, write an integer 0 (not exists) or 1 (exists) ** into a register and return that register number. ** ** In both cases, the query is augmented with "LIMIT 1". Any ** preexisting limit is discarded in place of the new LIMIT 1. */ testcase( pExpr->op==TK_EXISTS ); testcase( pExpr->op==TK_SELECT ); assert( pExpr->op==TK_EXISTS || pExpr->op==TK_SELECT ); assert( ExprHasProperty(pExpr, EP_xIsSelect) ); pSel = pExpr->x.pSelect; ExplainQueryPlan((pParse, 1, "%sSCALAR SUBQUERY", jmpIfDynamic>=0?"":"CORRELATED ")); nReg = pExpr->op==TK_SELECT ? pSel->pEList->nExpr : 1; sqlite3SelectDestInit(&dest, 0, pParse->nMem+1); pParse->nMem += nReg; if( pExpr->op==TK_SELECT ){ dest.eDest = SRT_Mem; dest.iSdst = dest.iSDParm; dest.nSdst = nReg; sqlite3VdbeAddOp3(v, OP_Null, 0, dest.iSDParm, dest.iSDParm+nReg-1); VdbeComment((v, "Init subquery result")); }else{ dest.eDest = SRT_Exists; sqlite3VdbeAddOp2(v, OP_Integer, 0, dest.iSDParm); VdbeComment((v, "Init EXISTS result")); } pLimit = sqlite3ExprAlloc(pParse->db, TK_INTEGER,&sqlite3IntTokens[1], 0); if( pSel->pLimit ){ sqlite3ExprDelete(pParse->db, pSel->pLimit->pLeft); pSel->pLimit->pLeft = pLimit; }else{ pSel->pLimit = sqlite3PExpr(pParse, TK_LIMIT, pLimit, 0); } pSel->iLimit = 0; if( sqlite3Select(pParse, pSel, &dest) ){ return 0; } rReg = dest.iSDParm; ExprSetVVAProperty(pExpr, EP_NoReduce); if( jmpIfDynamic>=0 ){ sqlite3VdbeJumpHere(v, jmpIfDynamic); } return rReg; } |
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3339 3340 3341 3342 3343 3344 3345 | iResult = sqlite3ExprCodeTemp(pParse, p, piFreeable); }else{ *piFreeable = 0; if( p->op==TK_SELECT ){ #if SQLITE_OMIT_SUBQUERY iResult = 0; #else | | | 3351 3352 3353 3354 3355 3356 3357 3358 3359 3360 3361 3362 3363 3364 3365 | iResult = sqlite3ExprCodeTemp(pParse, p, piFreeable); }else{ *piFreeable = 0; if( p->op==TK_SELECT ){ #if SQLITE_OMIT_SUBQUERY iResult = 0; #else iResult = sqlite3CodeSubselect(pParse, p); #endif }else{ int i; iResult = pParse->nMem+1; pParse->nMem += nResult; for(i=0; i<nResult; i++){ sqlite3ExprCodeFactorable(pParse, p->x.pList->a[i].pExpr, i+iResult); |
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3813 3814 3815 3816 3817 3818 3819 | case TK_SELECT: { int nCol; testcase( op==TK_EXISTS ); testcase( op==TK_SELECT ); if( op==TK_SELECT && (nCol = pExpr->x.pSelect->pEList->nExpr)!=1 ){ sqlite3SubselectError(pParse, nCol, 1); }else{ | | | | 3825 3826 3827 3828 3829 3830 3831 3832 3833 3834 3835 3836 3837 3838 3839 3840 3841 3842 3843 3844 3845 3846 | case TK_SELECT: { int nCol; testcase( op==TK_EXISTS ); testcase( op==TK_SELECT ); if( op==TK_SELECT && (nCol = pExpr->x.pSelect->pEList->nExpr)!=1 ){ sqlite3SubselectError(pParse, nCol, 1); }else{ return sqlite3CodeSubselect(pParse, pExpr); } break; } case TK_SELECT_COLUMN: { int n; if( pExpr->pLeft->iTable==0 ){ pExpr->pLeft->iTable = sqlite3CodeSubselect(pParse, pExpr->pLeft); } assert( pExpr->iTable==0 || pExpr->pLeft->op==TK_SELECT ); if( pExpr->iTable && pExpr->iTable!=(n = sqlite3ExprVectorSize(pExpr->pLeft)) ){ sqlite3ErrorMsg(pParse, "%d columns assigned %d values", pExpr->iTable, n); |
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Changes to src/sqliteInt.h.
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4254 4255 4256 4257 4258 4259 4260 | void sqlite3Reindex(Parse*, Token*, Token*); void sqlite3AlterFunctions(void); void sqlite3AlterRenameTable(Parse*, SrcList*, Token*); void sqlite3AlterRenameColumn(Parse*, SrcList*, Token*, Token*); int sqlite3GetToken(const unsigned char *, int *); void sqlite3NestedParse(Parse*, const char*, ...); void sqlite3ExpirePreparedStatements(sqlite3*, int); | > | | 4254 4255 4256 4257 4258 4259 4260 4261 4262 4263 4264 4265 4266 4267 4268 4269 | void sqlite3Reindex(Parse*, Token*, Token*); void sqlite3AlterFunctions(void); void sqlite3AlterRenameTable(Parse*, SrcList*, Token*); void sqlite3AlterRenameColumn(Parse*, SrcList*, Token*, Token*); int sqlite3GetToken(const unsigned char *, int *); void sqlite3NestedParse(Parse*, const char*, ...); void sqlite3ExpirePreparedStatements(sqlite3*, int); void sqlite3CodeRhsOfIN(Parse*, Expr*, int); int sqlite3CodeSubselect(Parse*, Expr*); void sqlite3SelectPrep(Parse*, Select*, NameContext*); void sqlite3SelectWrongNumTermsError(Parse *pParse, Select *p); int sqlite3MatchSpanName(const char*, const char*, const char*, const char*); int sqlite3ResolveExprNames(NameContext*, Expr*); int sqlite3ResolveExprListNames(NameContext*, ExprList*); void sqlite3ResolveSelectNames(Parse*, Select*, NameContext*); void sqlite3ResolveSelfReference(Parse*,Table*,int,Expr*,ExprList*); |
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Changes to src/wherecode.c.
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1072 1073 1074 1075 1076 1077 1078 | */ static void codeExprOrVector(Parse *pParse, Expr *p, int iReg, int nReg){ assert( nReg>0 ); if( p && sqlite3ExprIsVector(p) ){ #ifndef SQLITE_OMIT_SUBQUERY if( (p->flags & EP_xIsSelect) ){ Vdbe *v = pParse->pVdbe; | > > | | 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 | */ static void codeExprOrVector(Parse *pParse, Expr *p, int iReg, int nReg){ assert( nReg>0 ); if( p && sqlite3ExprIsVector(p) ){ #ifndef SQLITE_OMIT_SUBQUERY if( (p->flags & EP_xIsSelect) ){ Vdbe *v = pParse->pVdbe; int iSelect; assert( p->op==TK_SELECT ); iSelect = sqlite3CodeSubselect(pParse, p); sqlite3VdbeAddOp3(v, OP_Copy, iSelect, iReg, nReg-1); }else #endif { int i; ExprList *pList = p->x.pList; assert( nReg<=pList->nExpr ); |
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