Additional refinements to Expr handling. Restore compression of trigger

expressions.  Change Expr.zToken to Expr.u.zToken and added Expr.u.iValue.
Remove an unnecessary ExprDup from CHECK constraint processing.  And so forth. (CVS 6682)

FossilOrigin-Name: 4ac2bdfbb4230b6ceaae87e738fa61036bbe03cb

1 files changed, 22 insertions, 7 deletions

diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 3c0a525dd..97de27667 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -11,7 +11,7 @@
 *************************************************************************
 ** Internal interface definitions for SQLite.
 **
-** @(#) $Id: sqliteInt.h,v 1.876 2009/05/27 10:31:29 drh Exp $
+** @(#) $Id: sqliteInt.h,v 1.877 2009/05/28 01:00:55 drh Exp $
 */
 #ifndef _SQLITEINT_H_
 #define _SQLITEINT_H_
@@ -1464,7 +1464,7 @@ struct AggInfo {
 ** help reduce memory requirements, sometimes an Expr object will be
 ** truncated.  And to reduce the number of memory allocations, sometimes
 ** two or more Expr objects will be stored in a single memory allocation,
-** together with Expr.token strings.
+** together with Expr.zToken strings.
 **
 ** If the EP_Reduced and EP_TokenOnly flags are set when
 ** an Expr object is truncated.  When EP_Reduced is set, then all
@@ -1477,7 +1477,10 @@ struct Expr {
   u8 op;                 /* Operation performed by this node */
   char affinity;         /* The affinity of the column or 0 if not a column */
   u16 flags;             /* Various flags.  EP_* See below */
-  char *zToken;          /* Token value. Zero terminated and dequoted */
+  union {
+    char *zToken;          /* Token value. Zero terminated and dequoted */
+    int iValue;            /* Integer value if EP_IntValue */
+  } u;
 
   /* If the EP_TokenOnly flag is set in the Expr.flags mask, then no
   ** space is allocated for the fields below this point. An attempt to
@@ -1498,8 +1501,7 @@ struct Expr {
   *********************************************************************/
 
   int iTable;            /* TK_COLUMN: cursor number of table holding column
-                         ** TK_REGISTER: register number 
-                         ** EP_IntValue: integer value */
+                         ** TK_REGISTER: register number */
   i16 iColumn;           /* TK_COLUMN: column index.  -1 for rowid */
   i16 iAgg;              /* Which entry in pAggInfo->aCol[] or ->aFunc[] */
   i16 iRightJoinTable;   /* If EP_FromJoin, the right table of the join */
@@ -1525,7 +1527,7 @@ struct Expr {
 #define EP_ExpCollate 0x0100  /* Collating sequence specified explicitly */
 #define EP_AnyAff     0x0200  /* Can take a cached column of any affinity */
 #define EP_FixedDest  0x0400  /* Result needed in a specific register */
-#define EP_IntValue   0x0800  /* Integer value contained in iTable */
+#define EP_IntValue   0x0800  /* Integer value contained in u.iValue */
 #define EP_xIsSelect  0x1000  /* x.pSelect is valid (otherwise x.pList is) */
 
 #define EP_Reduced    0x2000  /* Expr struct is EXPR_REDUCEDSIZE bytes only */
@@ -1535,7 +1537,20 @@ struct Expr {
 /*
 ** The following are the meanings of bits in the Expr.flags2 field.
 */
-#define EP2_FreeToken 0x0001  /* Need to call sqlite3DbFree() on Expr.zToken */
+#define EP2_MallocedToken  0x0001  /* Need to sqlite3DbFree() Expr.zToken */
+#define EP2_Irreducible    0x0002  /* Cannot EXPRDUP_REDUCE this Expr */
+
+/*
+** The pseudo-routine sqlite3ExprSetIrreducible sets the EP2_Irreducible
+** flag on an expression structure.  This flag is used for VV&A only.  The
+** routine is implemented as a macro that only works when in debugging mode,
+** so as not to burden production code.
+*/
+#ifdef SQLITE_DEBUG
+# define ExprSetIrreducible(X)  (X)->flags2 |= EP2_Irreducible
+#else
+# define ExprSetIrreducible(X)
+#endif
 
 /*
 ** These macros can be used to test, set, or clear bits in the