Use macros to determine if an expression is always true or always false.
FossilOrigin-Name: 6de980a09c3a7adf71f2c9a63a242673b5e1f246e8ee071b26844275f0dad0fc
diff --git a/src/expr.c b/src/expr.c
index c9f917c..0484f3b 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -773,7 +773,7 @@
pNew->iAgg = -1;
if( pToken ){
if( nExtra==0 ){
- pNew->flags |= EP_IntValue|EP_Leaf;
+ pNew->flags |= EP_IntValue|EP_Leaf|(iValue?EP_IsTrue:EP_IsFalse);
pNew->u.iValue = iValue;
}else{
pNew->u.zToken = (char*)&pNew[1];
@@ -881,33 +881,6 @@
/*
-** If the expression is always either TRUE or FALSE (respectively),
-** then return 1. If one cannot determine the truth value of the
-** expression at compile-time return 0.
-**
-** This is an optimization. If is OK to return 0 here even if
-** the expression really is always false or false (a false negative).
-** But it is a bug to return 1 if the expression might have different
-** boolean values in different circumstances (a false positive.)
-**
-** Note that if the expression is part of conditional for a
-** LEFT JOIN, then we cannot determine at compile-time whether or not
-** is it true or false, so always return 0.
-*/
-static int exprAlwaysTrue(Expr *p){
- int v = 0;
- if( ExprHasProperty(p, EP_FromJoin) ) return 0;
- if( !sqlite3ExprIsInteger(p, &v) ) return 0;
- return v!=0;
-}
-static int exprAlwaysFalse(Expr *p){
- int v = 0;
- if( ExprHasProperty(p, EP_FromJoin) ) return 0;
- if( !sqlite3ExprIsInteger(p, &v) ) return 0;
- return v==0;
-}
-
-/*
** Join two expressions using an AND operator. If either expression is
** NULL, then just return the other expression.
**
@@ -923,7 +896,7 @@
return pLeft;
}else if( pParse->nErr || IN_RENAME_OBJECT ){
return sqlite3PExpr(pParse, TK_AND, pLeft, pRight);
- }else if( exprAlwaysFalse(pLeft) || exprAlwaysFalse(pRight) ){
+ }else if( ExprAlwaysFalse(pLeft) || ExprAlwaysFalse(pRight) ){
sqlite3ExprDelete(db, pLeft);
sqlite3ExprDelete(db, pRight);
return sqlite3ExprAlloc(db, TK_INTEGER, &sqlite3IntTokens[0], 0);
@@ -1818,6 +1791,7 @@
|| sqlite3StrICmp(pExpr->u.zToken, "false")==0)
){
pExpr->op = TK_TRUEFALSE;
+ ExprSetProperty(pExpr, pExpr->u.zToken[4]==0 ? EP_IsTrue : EP_IsFalse);
return 1;
}
return 0;
@@ -4522,9 +4496,9 @@
#endif
default: {
default_expr:
- if( exprAlwaysTrue(pExpr) ){
+ if( ExprAlwaysTrue(pExpr) ){
sqlite3VdbeGoto(v, dest);
- }else if( exprAlwaysFalse(pExpr) ){
+ }else if( ExprAlwaysFalse(pExpr) ){
/* No-op */
}else{
r1 = sqlite3ExprCodeTemp(pParse, pExpr, ®Free1);
@@ -4692,9 +4666,9 @@
#endif
default: {
default_expr:
- if( exprAlwaysFalse(pExpr) ){
+ if( ExprAlwaysFalse(pExpr) ){
sqlite3VdbeGoto(v, dest);
- }else if( exprAlwaysTrue(pExpr) ){
+ }else if( ExprAlwaysTrue(pExpr) ){
/* no-op */
}else{
r1 = sqlite3ExprCodeTemp(pParse, pExpr, ®Free1);
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 8868fd3..2812433 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -2530,6 +2530,8 @@
#define EP_Subrtn 0x2000000 /* Uses Expr.y.sub. TK_IN, _SELECT, or _EXISTS */
#define EP_Quoted 0x4000000 /* TK_ID was originally quoted */
#define EP_Static 0x8000000 /* Held in memory not obtained from malloc() */
+#define EP_IsTrue 0x10000000 /* Always has boolean value of TRUE */
+#define EP_IsFalse 0x20000000 /* Always has boolean value of FALSE */
/*
** The EP_Propagate mask is a set of properties that automatically propagate
@@ -2545,6 +2547,8 @@
#define ExprHasAllProperty(E,P) (((E)->flags&(P))==(P))
#define ExprSetProperty(E,P) (E)->flags|=(P)
#define ExprClearProperty(E,P) (E)->flags&=~(P)
+#define ExprAlwaysTrue(E) (((E)->flags&(EP_FromJoin|EP_IsTrue))==EP_IsTrue)
+#define ExprAlwaysFalse(E) (((E)->flags&(EP_FromJoin|EP_IsFalse))==EP_IsFalse)
/* The ExprSetVVAProperty() macro is used for Verification, Validation,
** and Accreditation only. It works like ExprSetProperty() during VVA