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-rw-r--r--src/expr.c137
1 files changed, 82 insertions, 55 deletions
diff --git a/src/expr.c b/src/expr.c
index a07fdcd00..75167579b 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -12,7 +12,7 @@
** This file contains routines used for analyzing expressions and
** for generating VDBE code that evaluates expressions in SQLite.
**
-** $Id: expr.c,v 1.165 2004/09/25 13:12:15 drh Exp $
+** $Id: expr.c,v 1.166 2004/10/04 13:19:24 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
@@ -1180,41 +1180,19 @@ static void codeInteger(Vdbe *v, const char *z, int n){
/*
** Generate code into the current Vdbe to evaluate the given
** expression and leave the result on the top of stack.
+**
+** This code depends on the fact that certain token values (ex: TK_EQ)
+** are the same as opcode values (ex: OP_Eq) that implement the corresponding
+** operation. Special comments in vdbe.c and the mkopcodeh.awk script in
+** the make process cause these values to align. Assert()s in the code
+** below verify that the numbers are aligned correctly.
*/
void sqlite3ExprCode(Parse *pParse, Expr *pExpr){
Vdbe *v = pParse->pVdbe;
int op;
if( v==0 || pExpr==0 ) return;
- switch( pExpr->op ){
- case TK_PLUS: op = OP_Add; break;
- case TK_MINUS: op = OP_Subtract; break;
- case TK_STAR: op = OP_Multiply; break;
- case TK_SLASH: op = OP_Divide; break;
- case TK_AND: op = OP_And; break;
- case TK_OR: op = OP_Or; break;
- case TK_LT: op = OP_Lt; break;
- case TK_LE: op = OP_Le; break;
- case TK_GT: op = OP_Gt; break;
- case TK_GE: op = OP_Ge; break;
- case TK_NE: op = OP_Ne; break;
- case TK_EQ: op = OP_Eq; break;
- case TK_ISNULL: op = OP_IsNull; break;
- case TK_NOTNULL: op = OP_NotNull; break;
- case TK_NOT: op = OP_Not; break;
- case TK_UMINUS: op = OP_Negative; break;
- case TK_BITAND: op = OP_BitAnd; break;
- case TK_BITOR: op = OP_BitOr; break;
- case TK_BITNOT: op = OP_BitNot; break;
- case TK_LSHIFT: op = OP_ShiftLeft; break;
- case TK_RSHIFT: op = OP_ShiftRight; break;
- case TK_REM: op = OP_Remainder; break;
- case TK_FLOAT: op = OP_Real; break;
- case TK_STRING: op = OP_String8; break;
- case TK_BLOB: op = OP_HexBlob; break;
- case TK_CONCAT: op = OP_Concat; break;
- default: op = 0; break;
- }
- switch( pExpr->op ){
+ op = pExpr->op;
+ switch( op ){
case TK_COLUMN: {
if( pParse->useAgg ){
sqlite3VdbeAddOp(v, OP_AggGet, 0, pExpr->iAgg);
@@ -1236,11 +1214,14 @@ void sqlite3ExprCode(Parse *pParse, Expr *pExpr){
}
case TK_FLOAT:
case TK_STRING: {
+ assert( TK_FLOAT==OP_Real );
+ assert( TK_STRING==OP_String8 );
sqlite3VdbeOp3(v, op, 0, 0, pExpr->token.z, pExpr->token.n);
sqlite3VdbeDequoteP3(v, -1);
break;
}
case TK_BLOB: {
+ assert( TK_BLOB==OP_HexBlob );
sqlite3VdbeOp3(v, op, 0, 0, pExpr->token.z+1, pExpr->token.n-1);
sqlite3VdbeDequoteP3(v, -1);
break;
@@ -1262,6 +1243,12 @@ void sqlite3ExprCode(Parse *pParse, Expr *pExpr){
case TK_GE:
case TK_NE:
case TK_EQ: {
+ assert( TK_LT==OP_Lt );
+ assert( TK_LE==OP_Le );
+ assert( TK_GT==OP_Gt );
+ assert( TK_GE==OP_Ge );
+ assert( TK_EQ==OP_Eq );
+ assert( TK_NE==OP_Ne );
sqlite3ExprCode(pParse, pExpr->pLeft);
sqlite3ExprCode(pParse, pExpr->pRight);
codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op, 0, 0);
@@ -1279,6 +1266,17 @@ void sqlite3ExprCode(Parse *pParse, Expr *pExpr){
case TK_LSHIFT:
case TK_RSHIFT:
case TK_CONCAT: {
+ assert( TK_AND==OP_And );
+ assert( TK_OR==OP_Or );
+ assert( TK_PLUS==OP_Add );
+ assert( TK_MINUS==OP_Subtract );
+ assert( TK_REM==OP_Remainder );
+ assert( TK_BITAND==OP_BitAnd );
+ assert( TK_BITOR==OP_BitOr );
+ assert( TK_SLASH==OP_Divide );
+ assert( TK_LSHIFT==OP_ShiftLeft );
+ assert( TK_RSHIFT==OP_ShiftRight );
+ assert( TK_CONCAT==OP_Concat );
sqlite3ExprCode(pParse, pExpr->pLeft);
sqlite3ExprCode(pParse, pExpr->pRight);
sqlite3VdbeAddOp(v, op, 0, 0);
@@ -1303,6 +1301,8 @@ void sqlite3ExprCode(Parse *pParse, Expr *pExpr){
}
case TK_BITNOT:
case TK_NOT: {
+ assert( TK_BITNOT==OP_BitNot );
+ assert( TK_NOT==OP_Not );
sqlite3ExprCode(pParse, pExpr->pLeft);
sqlite3VdbeAddOp(v, op, 0, 0);
break;
@@ -1310,13 +1310,15 @@ void sqlite3ExprCode(Parse *pParse, Expr *pExpr){
case TK_ISNULL:
case TK_NOTNULL: {
int dest;
+ assert( TK_ISNULL==OP_IsNull );
+ assert( TK_NOTNULL==OP_NotNull );
sqlite3VdbeAddOp(v, OP_Integer, 1, 0);
sqlite3ExprCode(pParse, pExpr->pLeft);
dest = sqlite3VdbeCurrentAddr(v) + 2;
sqlite3VdbeAddOp(v, op, 1, dest);
sqlite3VdbeAddOp(v, OP_AddImm, -1, 0);
+ break;
}
- break;
case TK_AGG_FUNCTION: {
sqlite3VdbeAddOp(v, OP_AggGet, 0, pExpr->iAgg);
break;
@@ -1503,23 +1505,19 @@ int sqlite3ExprCodeExprList(
**
** If the expression evaluates to NULL (neither true nor false), then
** take the jump if the jumpIfNull flag is true.
+**
+** This code depends on the fact that certain token values (ex: TK_EQ)
+** are the same as opcode values (ex: OP_Eq) that implement the corresponding
+** operation. Special comments in vdbe.c and the mkopcodeh.awk script in
+** the make process cause these values to align. Assert()s in the code
+** below verify that the numbers are aligned correctly.
*/
void sqlite3ExprIfTrue(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
Vdbe *v = pParse->pVdbe;
int op = 0;
if( v==0 || pExpr==0 ) return;
- switch( pExpr->op ){
- case TK_LT: op = OP_Lt; break;
- case TK_LE: op = OP_Le; break;
- case TK_GT: op = OP_Gt; break;
- case TK_GE: op = OP_Ge; break;
- case TK_NE: op = OP_Ne; break;
- case TK_EQ: op = OP_Eq; break;
- case TK_ISNULL: op = OP_IsNull; break;
- case TK_NOTNULL: op = OP_NotNull; break;
- default: break;
- }
- switch( pExpr->op ){
+ op = pExpr->op;
+ switch( op ){
case TK_AND: {
int d2 = sqlite3VdbeMakeLabel(v);
sqlite3ExprIfFalse(pParse, pExpr->pLeft, d2, !jumpIfNull);
@@ -1542,6 +1540,12 @@ void sqlite3ExprIfTrue(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
case TK_GE:
case TK_NE:
case TK_EQ: {
+ assert( TK_LT==OP_Lt );
+ assert( TK_LE==OP_Le );
+ assert( TK_GT==OP_Gt );
+ assert( TK_GE==OP_Ge );
+ assert( TK_EQ==OP_Eq );
+ assert( TK_NE==OP_Ne );
sqlite3ExprCode(pParse, pExpr->pLeft);
sqlite3ExprCode(pParse, pExpr->pRight);
codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op, dest, jumpIfNull);
@@ -1549,6 +1553,8 @@ void sqlite3ExprIfTrue(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
}
case TK_ISNULL:
case TK_NOTNULL: {
+ assert( TK_ISNULL==OP_IsNull );
+ assert( TK_NOTNULL==OP_NotNull );
sqlite3ExprCode(pParse, pExpr->pLeft);
sqlite3VdbeAddOp(v, op, 1, dest);
break;
@@ -1597,17 +1603,38 @@ void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
Vdbe *v = pParse->pVdbe;
int op = 0;
if( v==0 || pExpr==0 ) return;
- switch( pExpr->op ){
- case TK_LT: op = OP_Ge; break;
- case TK_LE: op = OP_Gt; break;
- case TK_GT: op = OP_Le; break;
- case TK_GE: op = OP_Lt; break;
- case TK_NE: op = OP_Eq; break;
- case TK_EQ: op = OP_Ne; break;
- case TK_ISNULL: op = OP_NotNull; break;
- case TK_NOTNULL: op = OP_IsNull; break;
- default: break;
- }
+
+ /* The value of pExpr->op and op are related as follows:
+ **
+ ** pExpr->op op
+ ** --------- ----------
+ ** TK_ISNULL OP_NotNull
+ ** TK_NOTNULL OP_IsNull
+ ** TK_NE OP_Eq
+ ** TK_EQ OP_Ne
+ ** TK_GT OP_Le
+ ** TK_LE OP_Gt
+ ** TK_GE OP_Lt
+ ** TK_LT OP_Ge
+ **
+ ** For other values of pExpr->op, op is undefined and unused.
+ ** The value of TK_ and OP_ constants are arranged such that we
+ ** can compute the mapping above using the following expression.
+ ** Assert()s verify that the computation is correct.
+ */
+ op = ((pExpr->op+(TK_ISNULL&1))^1)-(TK_ISNULL&1);
+
+ /* Verify correct alignment of TK_ and OP_ constants
+ */
+ assert( pExpr->op!=TK_ISNULL || op==OP_NotNull );
+ assert( pExpr->op!=TK_NOTNULL || op==OP_IsNull );
+ assert( pExpr->op!=TK_NE || op==OP_Eq );
+ assert( pExpr->op!=TK_EQ || op==OP_Ne );
+ assert( pExpr->op!=TK_LT || op==OP_Ge );
+ assert( pExpr->op!=TK_LE || op==OP_Gt );
+ assert( pExpr->op!=TK_GT || op==OP_Le );
+ assert( pExpr->op!=TK_GE || op==OP_Lt );
+
switch( pExpr->op ){
case TK_AND: {
sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);
generated by cgit v1.2.3 (git 2.25.1) at 2025-07-17 19:24:07 +0000