[sql] Import SQLite 3.17.0.

third_party/sqlite/src/src/walker.c

 /*
 ** 2008 August 16
 **
 ** The author disclaims copyright to this source code.  In place of
 ** a legal notice, here is a blessing:
 **
 **    May you do good and not evil.
 **    May you find forgiveness for yourself and forgive others.
 **    May you share freely, never taking more than you give.
 **
@@ skipping 18 matching lines @@
 **
 **    WRC_Prune         Do not descend into child nodes.  But allow
 **                      the walk to continue with sibling nodes.
 **
 **    WRC_Abort         Do no more callbacks.  Unwind the stack and
 **                      return the top-level walk call.
 **
 ** The return value from this routine is WRC_Abort to abandon the tree walk
 ** and WRC_Continue to continue.
 */
-int sqlite3WalkExpr(Walker *pWalker, Expr *pExpr){
+static SQLITE_NOINLINE int walkExpr(Walker *pWalker, Expr *pExpr){
   int rc;
-  if( pExpr==0 ) return WRC_Continue;
   testcase( ExprHasProperty(pExpr, EP_TokenOnly) );
   testcase( ExprHasProperty(pExpr, EP_Reduced) );
   rc = pWalker->xExprCallback(pWalker, pExpr);
-  if( rc==WRC_Continue
-              && !ExprHasProperty(pExpr,EP_TokenOnly) ){
-    if( sqlite3WalkExpr(pWalker, pExpr->pLeft) ) return WRC_Abort;
-    if( sqlite3WalkExpr(pWalker, pExpr->pRight) ) return WRC_Abort;
-    if( ExprHasProperty(pExpr, EP_xIsSelect) ){
-      if( sqlite3WalkSelect(pWalker, pExpr->x.pSelect) ) return WRC_Abort;
-    }else{
-      if( sqlite3WalkExprList(pWalker, pExpr->x.pList) ) return WRC_Abort;
-    }
+  if( rc || ExprHasProperty(pExpr,(EP_TokenOnly|EP_Leaf)) ){
+    return rc & WRC_Abort;
   }
-  return rc & WRC_Abort;
+  if( pExpr->pLeft && walkExpr(pWalker, pExpr->pLeft) ) return WRC_Abort;
+  if( pExpr->pRight && walkExpr(pWalker, pExpr->pRight) ) return WRC_Abort;
+  if( ExprHasProperty(pExpr, EP_xIsSelect) ){
+    if( sqlite3WalkSelect(pWalker, pExpr->x.pSelect) ) return WRC_Abort;
+  }else if( pExpr->x.pList ){
+    if( sqlite3WalkExprList(pWalker, pExpr->x.pList) ) return WRC_Abort;
+  }
+  return WRC_Continue;
+}
+int sqlite3WalkExpr(Walker *pWalker, Expr *pExpr){
+  return pExpr ? walkExpr(pWalker,pExpr) : WRC_Continue;
 }
 
 /*
 ** Call sqlite3WalkExpr() for every expression in list p or until
 ** an abort request is seen.
 */
 int sqlite3WalkExprList(Walker *pWalker, ExprList *p){
   int i;
   struct ExprList_item *pItem;
   if( p ){
@@ skipping 84 matching lines @@
       return WRC_Abort;
     }
     if( pWalker->xSelectCallback2 ){
       pWalker->xSelectCallback2(pWalker, p);
     }
     p = p->pPrior;
   }
   pWalker->walkerDepth--;
   return rc & WRC_Abort;
 }