Simplify the interface to the subst() routines that are part of the

query flattener by collecting common parameters into the SubstContext object
and passing around a pointer to that object.

FossilOrigin-Name: e651074be28b2077b8a298f513e2e699ceca99164ace9869ea50873c0637fd2e

diff --git a/manifest b/manifest
index 9ba1b45229a34ffee46f592481d2351a16ccdfa1..dfc566055a9fbfde463887b200961ad8b138623f 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Remove\san\sincorrect\sALWAYS().
-D 2017-04-14T12:27:45.370
+C Simplify\sthe\sinterface\sto\sthe\ssubst()\sroutines\sthat\sare\spart\sof\sthe\nquery\sflattener\sby\scollecting\scommon\sparameters\sinto\sthe\sSubstContext\sobject\nand\spassing\saround\sa\spointer\sto\sthat\sobject.
+D 2017-04-14T12:39:37.290
 F Makefile.in 1cc758ce3374a32425e4d130c2fe7b026b20de5b8843243de75f087c0a2661fb
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 F Makefile.msc a4c0613a18663bda56d8cf76079ab6590a7c3602e54befb4bbdef76bcaa38b6a
@@ -401,7 +401,7 @@ F src/printf.c 8757834f1b54dae512fb25eb1acc8e94a0d15dd2290b58f2563f65973265adb2
 F src/random.c 80f5d666f23feb3e6665a6ce04c7197212a88384
 F src/resolve.c 3e518b962d932a997fae373366880fc028c75706
 F src/rowset.c 7b7e7e479212e65b723bf40128c7b36dc5afdfac
-F src/select.c cc9129bc97d20f3c79b9dfcc555db37eed28a660cc6954bf3b282d8e1e5593a2
+F src/select.c 4588dcfb0fa430012247a209ba08e17904dd32ec7690e9cb6c85e0ef012b0518
 F src/shell.c 70f4957b988572315e97c56941fdc81fd35907fee36b7b2e7be5ec4c7e9d065d
 F src/sqlite.h.in 40233103e3e4e10f8a63523498d0259d232e42aba478e2d3fb914799185aced6
 F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
@@ -1571,7 +1571,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 59c70108fd179932ccdd860f93e1cd68b77476d3b1af1af00cf6e378c9984862
-R c91754472255c67faea0aa47fea74aba
+P f956f6ae6b0863c70c4a2b227338d5c332e87f2ec6f3fcdf2233c14c5b78ca2b
+R 2c7a884b60bf790d155a528d4c22c0f3
 U drh
-Z 5034d642c46b4ea39fd9a8ac97c67432
+Z a742bed33077887f6256b75655f887d2

diff --git a/manifest.uuid b/manifest.uuid
index 924660ea405aeb644eae02bb33a005a0d97878c9..d990b4deec4c251dac572d85aa2bf45b484ef3e8 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-f956f6ae6b0863c70c4a2b227338d5c332e87f2ec6f3fcdf2233c14c5b78ca2b
\ No newline at end of file
+e651074be28b2077b8a298f513e2e699ceca99164ace9869ea50873c0637fd2e
\ No newline at end of file

diff --git a/src/select.c b/src/select.c
index 3c35c750417858cc0617a4b24afb1949ce09b6cb..d7ba1f8068c56d886990ac76682d774f6bd7b427 100644 (file)
--- a/src/select.c
+++ b/src/select.c
@@ -3144,9 +3144,22 @@ static int multiSelectOrderBy(
 #endif
 
 #if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
+
+/* An instance of the SubstContext object describes an substitution edit
+** to be performed on a parse tree.
+**
+** All references to columns in table iTable are to be replaced by corresponding
+** expressions in pEList.
+*/
+typedef struct SubstContext {
+  Parse *pParse;            /* The parsing context */
+  int iTable;               /* Replace references to this table */
+  ExprList *pEList;         /* Replacement expressions */
+} SubstContext;
+
 /* Forward Declarations */
-static void substExprList(Parse*, ExprList*, int, ExprList*);
-static void substSelect(Parse*, Select *, int, ExprList*, int);
+static void substExprList(SubstContext*, ExprList*);
+static void substSelect(SubstContext*, Select*, int);
 
 /*
 ** Scan through the expression pExpr.  Replace every reference to
@@ -3162,24 +3175,22 @@ static void substSelect(Parse*, Select *, int, ExprList*, int);
 ** of the subquery rather the result set of the subquery.
 */
 static Expr *substExpr(
-  Parse *pParse,      /* Report errors here */
-  Expr *pExpr,        /* Expr in which substitution occurs */
-  int iTable,         /* Table to be substituted */
-  ExprList *pEList    /* Substitute expressions */
+  SubstContext *pSubst,  /* Description of the substitution */
+  Expr *pExpr            /* Expr in which substitution occurs */
 ){
-  sqlite3 *db = pParse->db;
   if( pExpr==0 ) return 0;
-  if( pExpr->op==TK_COLUMN && pExpr->iTable==iTable ){
+  if( pExpr->op==TK_COLUMN && pExpr->iTable==pSubst->iTable ){
     if( pExpr->iColumn<0 ){
       pExpr->op = TK_NULL;
     }else{
       Expr *pNew;
-      Expr *pCopy = pEList->a[pExpr->iColumn].pExpr;
-      assert( pEList!=0 && pExpr->iColumn<pEList->nExpr );
+      Expr *pCopy = pSubst->pEList->a[pExpr->iColumn].pExpr;
+      assert( pSubst->pEList!=0 && pExpr->iColumn<pSubst->pEList->nExpr );
       assert( pExpr->pLeft==0 && pExpr->pRight==0 );
       if( sqlite3ExprIsVector(pCopy) ){
-        sqlite3VectorErrorMsg(pParse, pCopy);
+        sqlite3VectorErrorMsg(pSubst->pParse, pCopy);
       }else{
+        sqlite3 *db = pSubst->pParse->db;
         pNew = sqlite3ExprDup(db, pCopy, 0);
         if( pNew && (pExpr->flags & EP_FromJoin) ){
           pNew->iRightJoinTable = pExpr->iRightJoinTable;
@@ -3190,51 +3201,47 @@ static Expr *substExpr(
       }
     }
   }else{
-    pExpr->pLeft = substExpr(pParse, pExpr->pLeft, iTable, pEList);
-    pExpr->pRight = substExpr(pParse, pExpr->pRight, iTable, pEList);
+    pExpr->pLeft = substExpr(pSubst, pExpr->pLeft);
+    pExpr->pRight = substExpr(pSubst, pExpr->pRight);
     if( ExprHasProperty(pExpr, EP_xIsSelect) ){
-      substSelect(pParse, pExpr->x.pSelect, iTable, pEList, 1);
+      substSelect(pSubst, pExpr->x.pSelect, 1);
     }else{
-      substExprList(pParse, pExpr->x.pList, iTable, pEList);
+      substExprList(pSubst, pExpr->x.pList);
     }
   }
   return pExpr;
 }
 static void substExprList(
-  Parse *pParse,       /* Report errors here */
-  ExprList *pList,     /* List to scan and in which to make substitutes */
-  int iTable,          /* Table to be substituted */
-  ExprList *pEList     /* Substitute values */
+  SubstContext *pSubst, /* Description of the substitution */
+  ExprList *pList       /* List to scan and in which to make substitutes */
 ){
   int i;
   if( pList==0 ) return;
   for(i=0; i<pList->nExpr; i++){
-    pList->a[i].pExpr = substExpr(pParse, pList->a[i].pExpr, iTable, pEList);
+    pList->a[i].pExpr = substExpr(pSubst, pList->a[i].pExpr);
   }
 }
 static void substSelect(
-  Parse *pParse,       /* Report errors here */
-  Select *p,           /* SELECT statement in which to make substitutions */
-  int iTable,          /* Table to be replaced */
-  ExprList *pEList,    /* Substitute values */
-  int doPrior          /* Do substitutes on p->pPrior too */
+  SubstContext *pSubst, /* Description of the substitution */
+  Select *p,            /* SELECT statement in which to make substitutions */
+  int doPrior           /* Do substitutes on p->pPrior too */
 ){
   SrcList *pSrc;
   struct SrcList_item *pItem;
   int i;
   if( !p ) return;
   do{
-    substExprList(pParse, p->pEList, iTable, pEList);
-    substExprList(pParse, p->pGroupBy, iTable, pEList);
-    substExprList(pParse, p->pOrderBy, iTable, pEList);
-    p->pHaving = substExpr(pParse, p->pHaving, iTable, pEList);
-    p->pWhere = substExpr(pParse, p->pWhere, iTable, pEList);
+    substExprList(pSubst, p->pEList);
+    substExprList(pSubst, p->pGroupBy);
+    substExprList(pSubst, p->pOrderBy);
+    p->pHaving = substExpr(pSubst, p->pHaving);
+    p->pWhere = substExpr(pSubst, p->pWhere);
     pSrc = p->pSrc;
     assert( pSrc!=0 );
     for(i=pSrc->nSrc, pItem=pSrc->a; i>0; i--, pItem++){
-      substSelect(pParse, pItem->pSelect, iTable, pEList, 1);
+      substSelect(pSubst, pItem->pSelect, 1);
       if( pItem->fg.isTabFunc ){
-        substExprList(pParse, pItem->u1.pFuncArg, iTable, pEList);
+        substExprList(pSubst, pItem->u1.pFuncArg);
       }
     }
   }while( doPrior && (p = p->pPrior)!=0 );
@@ -3760,7 +3767,11 @@ static int flattenSubquery(
       pParent->pWhere = sqlite3ExprAnd(db, pWhere, pParent->pWhere);
     }
     if( db->mallocFailed==0 ){
-      substSelect(pParse, pParent, iParent, pSub->pEList, 0);
+      SubstContext x;
+      x.pParse = pParse;
+      x.iTable = iParent;
+      x.pEList = pSub->pEList;
+      substSelect(&x, pParent, 0);
     }
   
     /* The flattened query is distinct if either the inner or the
@@ -3863,8 +3874,12 @@ static int pushDownWhereTerms(
   if( sqlite3ExprIsTableConstant(pWhere, iCursor) ){
     nChng++;
     while( pSubq ){
+      SubstContext x;
       pNew = sqlite3ExprDup(pParse->db, pWhere, 0);
-      pNew = substExpr(pParse, pNew, iCursor, pSubq->pEList);
+      x.pParse = pParse;
+      x.iTable = iCursor;
+      x.pEList = pSubq->pEList;
+      pNew = substExpr(&x, pNew);
       pSubq->pWhere = sqlite3ExprAnd(pParse->db, pSubq->pWhere, pNew);
       pSubq = pSubq->pPrior;
     }