An early attempt at refactoring Expr

FossilOrigin-Name: fc90a53de7ebca5d4cd3aac40d6e9d001350a932eb99fdaedb6826597c8a973c

manifest

@@ -1,5 +1,5 @@
-C Improvements\sto\sthe\sparser\sto\sincrease\scoverage.\s\sFix\sthe\sparser\sso\sthat\nat\sleast\sone\sexpresssion\sis\srequired\safter\sPARTITION\sBY\sand\swithin\sthe\nlist\sof\sexpressions\son\sVALUES().
-D 2018-07-27T23:33:16.472
+C An\searly\sattempt\sat\srefactoring\sExpr
+D 2018-07-28T13:37:44.333
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F Makefile.in 0a3a6c81e6fcb969ff9106e882f0a08547014ba463cb6beca4c4efaecc924ee6
@@ -450,7 +450,7 @@ F src/date.c ebe1dc7c8a347117bb02570f1a931c62dd78f4a2b1b516f4837d45b7d6426957
 F src/dbpage.c 4aa7f26198934dbd002e69418220eae3dbc71b010bbac32bd78faf86b52ce6c3
 F src/dbstat.c edabb82611143727511a45ca0859b8cd037851ebe756ae3db289859dd18b6f91
 F src/delete.c 4c8c7604277a2041647f96b78f4b9a47858e9217e4fb333d35e7b5ab32c5b57f
-F src/expr.c 907d7de6cac23e55e32f22133a4fa8ca1558d7fe7c9a37e01feebb1106416fe7
+F src/expr.c dff6636152ebc54e394a2133b2c4cc1c3f7de2130d7933362487be07cf19264b
 F src/fault.c 460f3e55994363812d9d60844b2a6de88826e007
 F src/fkey.c f59253c0be4b1e9dfcb073b6d6d6ab83090ae50c08b5c113b76013c4b157cd6a
 F src/func.c 7c288b4ce309b5a8b8473514b88e1f8e69a80134509a8c0db8e39c858e367e7f
@@ -503,7 +503,7 @@ F src/shell.c.in f6ebd05c461805a7c708333cd645e74e0a93560d2118f5adb73a75d8c9cf6b0
 F src/sqlite.h.in c6451bb876adced3aba5b1682c6317d215c5eceaba21a6ce979e71a0b8d0bf95
 F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
 F src/sqlite3ext.h 9887b27e69c01e79c2cbe74ef73bf01af5b5703d6a7f0a4371e386d7249cb1c7
-F src/sqliteInt.h de37aae03c6a4e4f1e1eff15c04292153dbba015ad8e0dc0dffe82ea0fe76d5e
+F src/sqliteInt.h d9e843d00aee15d12c5d67556b3d61688103c945da5bedd071d2a5966df907dc
 F src/sqliteLimit.h 1513bfb7b20378aa0041e7022d04acb73525de35b80b252f1b83fedb4de6a76b
 F src/status.c 46e7aec11f79dad50965a5ca5fa9de009f7d6bde08be2156f1538a0a296d4d0e
 F src/table.c b46ad567748f24a326d9de40e5b9659f96ffff34
@@ -1753,7 +1753,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 7efdba2bbc8547ee9292a1bbd1e61d38b40d7aabc0860ceba188bdec539f5114
-R 471a9deda4100ce593be82a25e7c7930
+P 81f25d5c84e4d2d0cd3c6a7c105c7c93d310218feeea4e023dbc32e7e96b2a52
+R 2f4d5976ed1b9b3eff7341b424df6edf
 U drh
-Z 49ba2c803564fb9ad5a228c53691471f
+Z 2ce8b95bf3ceede5076a1330ec36f69d

manifest.uuid

@@ -1 +1 @@
-02204f8b246c868846f39bd44f2e3bc0fab0275aa09ef3a0e5a8e3d58f484ca8
+fc90a53de7ebca5d4cd3aac40d6e9d001350a932eb99fdaedb6826597c8a973c

src/expr.c

@@ -1060,6 +1060,17 @@ static SQLITE_NOINLINE void sqlite3ExprDeleteNN(sqlite3 *db, Expr *p){
     assert( p->pRight==0 );
     assert( p->x.pSelect==0 );
   }
+  if( !ExprHasProperty(p, EP_TokenOnly) ){
+    assert( p->op!=TK_FUNCTION || p->pLeft==0 );
+    assert( p->pRight==0 || p->x.pSelect==0 );
+  }
+  if( !ExprHasProperty(p, (EP_TokenOnly|EP_Reduced)) ){
+    assert( p->pWin==0 || p->pLeft==0 );
+    assert( p->pWin==0 || p->pTab==0 );
+    assert( p->pWin==0 || p->op==TK_FUNCTION );
+    assert( p->pWin==0 || !ExprHasProperty(p, EP_xIsSelect) );
+    assert( p->pTab==0 || (p->pRight==0 && p->x.pSelect==0) );
+  }
 #endif
   if( !ExprHasProperty(p, (EP_TokenOnly|EP_Leaf)) ){
     /* The Expr.x union is never used at the same time as Expr.pRight */
@@ -1135,21 +1146,16 @@ static int dupedExprStructSize(Expr *p, int flags){
   assert( flags==EXPRDUP_REDUCE || flags==0 ); /* Only one flag value allowed */
   assert( EXPR_FULLSIZE<=0xfff );
   assert( (0xfff & (EP_Reduced|EP_TokenOnly))==0 );
-  if( 0==flags || p->op==TK_SELECT_COLUMN 
-#ifndef SQLITE_OMIT_WINDOWFUNC
-   || p->pWin 
-#endif
-  ){
+  if( 0==flags || p->op==TK_SELECT_COLUMN ){
     nSize = EXPR_FULLSIZE;
   }else{
     assert( !ExprHasProperty(p, EP_TokenOnly|EP_Reduced) );
     assert( !ExprHasProperty(p, EP_FromJoin) ); 
     assert( !ExprHasProperty(p, EP_MemToken) );
     assert( !ExprHasProperty(p, EP_NoReduce) );
-    if( p->pLeft || p->x.pList ){
+    if( p->eV || p->eX ){
       nSize = EXPR_REDUCEDSIZE | EP_Reduced;
     }else{
-      assert( p->pRight==0 );
       nSize = EXPR_TOKENONLYSIZE | EP_TokenOnly;
     }
   }
@@ -1178,7 +1184,7 @@ static int dupedExprNodeSize(Expr *p, int flags){
 ** itself and the buffer referred to by Expr.u.zToken, if any.
 **
 ** If the EXPRDUP_REDUCE flag is set, then the return value includes 
-** space to duplicate all Expr nodes in the tree formed by Expr.pLeft 
+** space to duplicate all Expr nodes in the tree formed by Expr.v.pLeft 
 ** and Expr.pRight variables (but not for any structures pointed to or 
 ** descended from the Expr.x.pList or Expr.x.pSelect variables).
 */
@@ -1187,7 +1193,8 @@ static int dupedExprSize(Expr *p, int flags){
   if( p ){
     nByte = dupedExprNodeSize(p, flags);
     if( flags&EXPRDUP_REDUCE ){
-      nByte += dupedExprSize(p->pLeft, flags) + dupedExprSize(p->pRight, flags);
+      if( p->eV==EV_Left ) nByte += dupedExprSize(p->v.pLeft, flags);
+      if( p->eV==EX_Right ) nByte += dupedExprSize(p->x.pRight, flags);
     }
   }
   return nByte;
@@ -1197,7 +1204,7 @@ static int dupedExprSize(Expr *p, int flags){
 ** This function is similar to sqlite3ExprDup(), except that if pzBuffer 
 ** is not NULL then *pzBuffer is assumed to point to a buffer large enough 
 ** to store the copy of expression p, the copies of p->u.zToken
-** (if applicable), and the copies of the p->pLeft and p->pRight expressions,
+** (if applicable), and the copies of the p->v.pLeft and p->pRight expressions,
 ** if any. Before returning, *pzBuffer is set to the first byte past the
 ** portion of the buffer copied into by this function.
 */
@@ -1257,6 +1264,7 @@ static Expr *exprDup(sqlite3 *db, Expr *p, int dupFlags, u8 **pzBuffer){
       memcpy(zToken, p->u.zToken, nToken);
     }
 
+#if 0
     if( 0==((p->flags|pNew->flags) & (EP_TokenOnly|EP_Leaf)) ){
       /* Fill in the pNew->x.pSelect or pNew->x.pList member. */
       if( ExprHasProperty(p, EP_xIsSelect) ){
@@ -1265,8 +1273,14 @@ static Expr *exprDup(sqlite3 *db, Expr *p, int dupFlags, u8 **pzBuffer){
         pNew->x.pList = sqlite3ExprListDup(db, p->x.pList, dupFlags);
       }
     }
+#endif
+    if( p->eX==EX_Select ){
+      pNew->x.pSelect = sqlite3SelectDup(db, p->x.pSelect, dupFlags);
+    }else if( p->eX==EX_List ){
+      pNew->x.pList = sqlite3ExprListDup(db, p->x.pList, dupFlags);
+    }
 
-    /* Fill in pNew->pLeft and pNew->pRight. */
+    /* Fill in pNew->v.pLeft and pNew->x.pRight. */
     if( ExprHasProperty(pNew, EP_Reduced|EP_TokenOnly) ){
       zAlloc += dupedExprNodeSize(p, dupFlags);
       if( !ExprHasProperty(pNew, EP_TokenOnly|EP_Leaf) ){

src/sqliteInt.h

@@ -2426,6 +2426,8 @@ typedef int ynVar;
 struct Expr {
   u8 op;                 /* Operation performed by this node */
   char affinity;         /* The affinity of the column or 0 if not a column */
+  u8 eV;                 /* Which element of v-union is used */
+  u8 eX;                 /* Which element of x-union is used */
   u32 flags;             /* Various flags.  EP_* See below */
   union {
     char *zToken;          /* Token value. Zero terminated and dequoted */
@@ -2437,11 +2439,17 @@ struct Expr {
   ** access them will result in a segfault or malfunction.
   *********************************************************************/
 
-  Expr *pLeft;           /* Left subnode */
-  Expr *pRight;          /* Right subnode */
-  union {
-    ExprList *pList;     /* op = IN, EXISTS, SELECT, CASE, FUNCTION, BETWEEN */
-    Select *pSelect;     /* EP_xIsSelect and op = IN, EXISTS, SELECT */
+  union {                /* Usage determined by Expr.eV */
+    Expr *pLeft;           /* Left subnode */
+    Expr *pVector;         /* TK_SELECT_COLUMN: The SELECT */
+    Window *pWin;          /* TK_FUNCTION: Window definition */
+  } v;
+  union {                /* Usage determined by Expr.eX */
+    Expr *pRight;          /* Right subnode */
+    ExprList *pList;       /* IN, EXISTS, SELECT, CASE, FUNCTION, BETWEEN */
+    Select *pSelect;       /* IN, EXISTS, SELECT */
+    Table *pTab;           /* Table for TK_COLUMN expressions. Can be NULL
+                           ** for a column of an index on an expression */
   } x;
 
   /* If the EP_Reduced flag is set in the Expr.flags mask, then no
@@ -2466,13 +2474,22 @@ struct Expr {
                          ** TK_COLUMN: the value of p5 for OP_Column
                          ** TK_AGG_FUNCTION: nesting depth */
   AggInfo *pAggInfo;     /* Used by TK_AGG_COLUMN and TK_AGG_FUNCTION */
-  Table *pTab;           /* Table for TK_COLUMN expressions.  Can be NULL
-                         ** for a column of an index on an expression */
-#ifndef SQLITE_OMIT_WINDOWFUNC
-  Window *pWin;          /* Window definition for window functions */
-#endif
 };
 
+/*
+** Allowed values for the Expr.eV and Expr.eX fields:
+*/
+#define EV_None     0    /* Expr.v is not used */
+#define EV_Left     1    /* Expr.v.pLeft */
+#define EV_Vector   2    /* Expr.v.pVector */
+#dfeine EV_Win      3    /* Expr.v.pWin */
+
+#define EX_None     0    /* Expr.x is not used */
+#define EX_Right    1    /* Expr.x.pRight */
+#define EX_List     2    /* Expr.x.pList */
+#define EX_Select   3    /* Expr.x.pSelect */
+#define EX_Tab      4    /* Expr.x.pTab */
+
 /*
 ** The following are the meanings of bits in the Expr.flags field.
 */