Factor out the IN operator code generation into a subroutine. Use this
subroutine to implement both logic and branching versions of the IN operator.
FossilOrigin-Name: fcff5b7e2d059ffb8d21df57d0c9648bd876e813
diff --git a/src/expr.c b/src/expr.c
index b16657c..8ff4338 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -1345,16 +1345,16 @@
** When the b-tree is being used for membership tests, the calling function
** needs to know whether or not the structure contains an SQL NULL
** value in order to correctly evaluate expressions like "X IN (Y, Z)".
-** If there is a chance that the b-tree might contain a NULL value at
+** If there is any chance that the (...) might contain a NULL value at
** runtime, then a register is allocated and the register number written
-** to *prNotFound. If there is no chance that the b-tree contains a
+** to *prNotFound. If there is no chance that the (...) contains a
** NULL value, then *prNotFound is left unchanged.
**
** If a register is allocated and its location stored in *prNotFound, then
-** its initial value is NULL. If the b-tree does not remain constant
-** for the duration of the query (i.e. the SELECT that generates the b-tree
+** its initial value is NULL. If the (...) does not remain constant
+** for the duration of the query (i.e. the SELECT within the (...)
** is a correlated subquery) then the value of the allocated register is
-** reset to NULL each time the b-tree is repopulated. This allows the
+** reset to NULL each time the subquery is rerun. This allows the
** caller to use vdbe code equivalent to the following:
**
** if( register==NULL ){
@@ -1694,6 +1694,136 @@
}
#endif /* SQLITE_OMIT_SUBQUERY */
+#ifndef SQLITE_OMIT_SUBQUERY
+/*
+** Generate code for an IN expression.
+**
+** x IN (SELECT ...)
+** x IN (value, value, ...)
+**
+** The left-hand side (LHS) is a scalar expression. The right-hand side (RHS)
+** is an array of zero or more values. The expression is true if the LHS is
+** contained within the RHS. The value of the expression is unknown (NULL)
+** if the LHS is NULL or if the LHS is not contained within the RHS and the
+** RHS contains one or more NULL values.
+**
+** This routine generates code will jump to destIfFalse if the LHS is not
+** contained within the RHS. If due to NULLs we cannot determine if the LHS
+** is contained in the RHS then jump to destIfNull. If the LHS is contained
+** within the RHS then fall through.
+*/
+static void sqlite3ExprCodeIN(
+ Parse *pParse, /* Parsing and code generating context */
+ Expr *pExpr, /* The IN expression */
+ int destIfFalse, /* Jump here if LHS is not contained in the RHS */
+ int destIfNull /* Jump here if the results are unknown due to NULLs */
+){
+ int rRhsHasNull = 0; /* Register that is true if RHS contains NULL values */
+ char affinity; /* Comparison affinity to use */
+ int eType; /* Type of the RHS */
+ int r1; /* Temporary use register */
+ Vdbe *v; /* Statement under construction */
+
+ /* Compute the RHS. After this step, the table with cursor
+ ** pExpr->iTable will contains the values that make up the RHS.
+ */
+ v = pParse->pVdbe;
+ assert( v!=0 ); /* OOM detected prior to this routine */
+ VdbeNoopComment((v, "begin IN expr"));
+ eType = sqlite3FindInIndex(pParse, pExpr, &rRhsHasNull);
+
+ /* Figure out the affinity to use to create a key from the results
+ ** of the expression. affinityStr stores a static string suitable for
+ ** P4 of OP_MakeRecord.
+ */
+ affinity = comparisonAffinity(pExpr);
+
+ /* Code the LHS, the <expr> from "<expr> IN (...)".
+ */
+ sqlite3ExprCachePush(pParse);
+ r1 = sqlite3GetTempReg(pParse);
+ sqlite3ExprCode(pParse, pExpr->pLeft, r1);
+ sqlite3VdbeAddOp2(v, OP_IsNull, r1, destIfNull);
+
+
+ if( eType==IN_INDEX_ROWID ){
+ /* In this case, the RHS is the ROWID of table b-tree
+ */
+ sqlite3VdbeAddOp2(v, OP_MustBeInt, r1, destIfFalse);
+ sqlite3VdbeAddOp3(v, OP_NotExists, pExpr->iTable, destIfFalse, r1);
+ }else{
+ /* In this case, the RHS is an index b-tree.
+ */
+ int r2; /* Register holding LHS value as a Record */
+
+ /* Create a record that can be used for membership testing.
+ */
+ r2 = sqlite3GetTempReg(pParse);
+ sqlite3VdbeAddOp4(v, OP_MakeRecord, r1, 1, r2, &affinity, 1);
+
+ /* If the set membership test fails, then the result of the
+ ** "x IN (...)" expression must be either 0 or NULL. If the set
+ ** contains no NULL values, then the result is 0. If the set
+ ** contains one or more NULL values, then the result of the
+ ** expression is also NULL.
+ */
+ if( rRhsHasNull==0 || destIfFalse==destIfNull ){
+ /* This branch runs if it is known at compile time that the RHS
+ ** cannot contain NULL values. This happens as the result
+ ** of a "NOT NULL" constraint in the database schema.
+ **
+ ** Also run this branch if NULL is equivalent to FALSE
+ ** for this particular IN operator.
+ */
+ sqlite3VdbeAddOp3(v, OP_NotFound, pExpr->iTable, destIfFalse, r2);
+
+ }else{
+ /* In this branch, the RHS of the IN might contain a NULL and
+ ** the presence of a NULL on the RHS makes a difference in the
+ ** outcome.
+ */
+ static const char nullRecord[] = { 0x02, 0x00 };
+ int j1, j2, j3;
+
+ /* First check to see if the LHS is contained in the RHS. If so,
+ ** then the presence of NULLs in the RHS does not matter, so jump
+ ** over all of the code that follows.
+ */
+ j1 = sqlite3VdbeAddOp3(v, OP_Found, pExpr->iTable, 0, r2);
+
+ /* Here we begin generating code that runs if the LHS is not
+ ** contained within the RHS. Generate additional code that
+ ** tests the RHS for NULLs. If the RHS contains a NULL then
+ ** jump to destIfNull. If there are no NULLs in the RHS then
+ ** jump to destIfFalse.
+ */
+ j2 = sqlite3VdbeAddOp1(v, OP_NotNull, rRhsHasNull);
+ sqlite3VdbeAddOp4(v, OP_Blob, 2, r2, 0, nullRecord, P4_STATIC);
+ j3 = sqlite3VdbeAddOp3(v, OP_Found, pExpr->iTable, 0, r2);
+ sqlite3VdbeAddOp2(v, OP_Integer, -1, rRhsHasNull);
+ sqlite3VdbeJumpHere(v, j3);
+ sqlite3VdbeAddOp2(v, OP_AddImm, rRhsHasNull, 1);
+ sqlite3VdbeJumpHere(v, j2);
+
+ /* Jump to the appropriate target depending on whether or not
+ ** the RHS contains a NULL
+ */
+ sqlite3VdbeAddOp2(v, OP_If, rRhsHasNull, destIfNull);
+ sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfFalse);
+
+ /* The OP_Found at the top of this branch jumps here when true,
+ ** causing the overall IN expression evaluation to fall through.
+ */
+ sqlite3VdbeJumpHere(v, j1);
+ }
+ sqlite3ReleaseTempReg(pParse, r2);
+ }
+ sqlite3ReleaseTempReg(pParse, r1);
+ sqlite3ExprCachePop(pParse, 1);
+ VdbeComment((v, "end IN expr"));
+}
+#endif /* SQLITE_OMIT_SUBQUERY */
+
/*
** Duplicate an 8-byte value
*/
@@ -2472,95 +2602,19 @@
break;
}
case TK_IN: {
- int rNotFound = 0;
- int rMayHaveNull = 0;
- int j2, j3, j4, j5;
- char affinity;
- int eType;
-
- VdbeNoopComment((v, "begin IN expr r%d", target));
- eType = sqlite3FindInIndex(pParse, pExpr, &rMayHaveNull);
- if( rMayHaveNull ){
- rNotFound = ++pParse->nMem;
- }
-
- /* Figure out the affinity to use to create a key from the results
- ** of the expression. affinityStr stores a static string suitable for
- ** P4 of OP_MakeRecord.
- */
- affinity = comparisonAffinity(pExpr);
-
-
- /* Code the <expr> from "<expr> IN (...)". The temporary table
- ** pExpr->iTable contains the values that make up the (...) set.
- */
- sqlite3ExprCachePush(pParse);
- sqlite3ExprCode(pParse, pExpr->pLeft, target);
- j2 = sqlite3VdbeAddOp1(v, OP_IsNull, target);
- if( eType==IN_INDEX_ROWID ){
- j3 = sqlite3VdbeAddOp1(v, OP_MustBeInt, target);
- j4 = sqlite3VdbeAddOp3(v, OP_NotExists, pExpr->iTable, 0, target);
- sqlite3VdbeAddOp2(v, OP_Integer, 1, target);
- j5 = sqlite3VdbeAddOp0(v, OP_Goto);
- sqlite3VdbeJumpHere(v, j3);
- sqlite3VdbeJumpHere(v, j4);
- sqlite3VdbeAddOp2(v, OP_Integer, 0, target);
- }else{
- r2 = regFree2 = sqlite3GetTempReg(pParse);
-
- /* Create a record and test for set membership. If the set contains
- ** the value, then jump to the end of the test code. The target
- ** register still contains the true (1) value written to it earlier.
- */
- sqlite3VdbeAddOp4(v, OP_MakeRecord, target, 1, r2, &affinity, 1);
- sqlite3VdbeAddOp2(v, OP_Integer, 1, target);
- j5 = sqlite3VdbeAddOp3(v, OP_Found, pExpr->iTable, 0, r2);
-
- /* If the set membership test fails, then the result of the
- ** "x IN (...)" expression must be either 0 or NULL. If the set
- ** contains no NULL values, then the result is 0. If the set
- ** contains one or more NULL values, then the result of the
- ** expression is also NULL.
- */
- if( rNotFound==0 ){
- /* This branch runs if it is known at compile time (now) that
- ** the set contains no NULL values. This happens as the result
- ** of a "NOT NULL" constraint in the database schema. No need
- ** to test the data structure at runtime in this case.
- */
- sqlite3VdbeAddOp2(v, OP_Integer, 0, target);
- }else{
- /* This block populates the rNotFound register with either NULL
- ** or 0 (an integer value). If the data structure contains one
- ** or more NULLs, then set rNotFound to NULL. Otherwise, set it
- ** to 0. If register rMayHaveNull is already set to some value
- ** other than NULL, then the test has already been run and
- ** rNotFound is already populated.
- */
- static const char nullRecord[] = { 0x02, 0x00 };
- j3 = sqlite3VdbeAddOp1(v, OP_NotNull, rMayHaveNull);
- sqlite3VdbeAddOp2(v, OP_Null, 0, rNotFound);
- sqlite3VdbeAddOp4(v, OP_Blob, 2, rMayHaveNull, 0,
- nullRecord, P4_STATIC);
- j4 = sqlite3VdbeAddOp3(v, OP_Found, pExpr->iTable, 0, rMayHaveNull);
- sqlite3VdbeAddOp2(v, OP_Integer, 0, rNotFound);
- sqlite3VdbeJumpHere(v, j4);
- sqlite3VdbeJumpHere(v, j3);
-
- /* Copy the value of register rNotFound (which is either NULL or 0)
- ** into the target register. This will be the result of the
- ** expression.
- */
- sqlite3VdbeAddOp2(v, OP_Copy, rNotFound, target);
- }
- }
- sqlite3VdbeJumpHere(v, j2);
- sqlite3VdbeJumpHere(v, j5);
- sqlite3ExprCachePop(pParse, 1);
- VdbeComment((v, "end IN expr r%d", target));
+ int destIfFalse = sqlite3VdbeMakeLabel(v);
+ int destIfNull = sqlite3VdbeMakeLabel(v);
+ sqlite3VdbeAddOp2(v, OP_Null, 0, target);
+ sqlite3ExprCodeIN(pParse, pExpr, destIfFalse, destIfNull);
+ sqlite3VdbeAddOp2(v, OP_Integer, 1, target);
+ sqlite3VdbeResolveLabel(v, destIfFalse);
+ sqlite3VdbeAddOp2(v, OP_AddImm, target, 0);
+ sqlite3VdbeResolveLabel(v, destIfNull);
break;
}
-#endif
+#endif /* SQLITE_OMIT_SUBQUERY */
+
+
/*
** x BETWEEN y AND z
**
@@ -3149,6 +3203,14 @@
exprCodeBetween(pParse, pExpr, dest, 1, jumpIfNull);
break;
}
+ case TK_IN: {
+ int destIfFalse = sqlite3VdbeMakeLabel(v);
+ int destIfNull = jumpIfNull ? dest : destIfFalse;
+ sqlite3ExprCodeIN(pParse, pExpr, destIfFalse, destIfNull);
+ sqlite3VdbeAddOp2(v, OP_Goto, 0, dest);
+ sqlite3VdbeResolveLabel(v, destIfFalse);
+ break;
+ }
default: {
r1 = sqlite3ExprCodeTemp(pParse, pExpr, ®Free1);
sqlite3VdbeAddOp3(v, OP_If, r1, dest, jumpIfNull!=0);
@@ -3280,6 +3342,16 @@
exprCodeBetween(pParse, pExpr, dest, 0, jumpIfNull);
break;
}
+ case TK_IN: {
+ if( jumpIfNull ){
+ sqlite3ExprCodeIN(pParse, pExpr, dest, dest);
+ }else{
+ int destIfNull = sqlite3VdbeMakeLabel(v);
+ sqlite3ExprCodeIN(pParse, pExpr, dest, destIfNull);
+ sqlite3VdbeResolveLabel(v, destIfNull);
+ }
+ break;
+ }
default: {
r1 = sqlite3ExprCodeTemp(pParse, pExpr, ®Free1);
sqlite3VdbeAddOp3(v, OP_IfNot, r1, dest, jumpIfNull!=0);