On 12/03/2019 17:22, Vlad Khorsun wrote: >> >> Let me demonstrate it. With this (wrong) patch now the code compiles: >> >> -------------- >> diff --git a/src/dsql/ExprNodes.cpp b/src/dsql/ExprNodes.cpp >> index 4ff5253a2b..26f826ae09 100644 >> --- a/src/dsql/ExprNodes.cpp >> +++ b/src/dsql/ExprNodes.cpp >> @@ -10836,6 +10836,7 @@ void SubQueryNode::getChildren(NodeRefsHolder& >> holder, bool dsql) const >> holder.add(value1); >> holder.add(value2); >> + holder.add(test); >> } >> string SubQueryNode::internalPrint(NodePrinter& printer) const >> diff --git a/src/dsql/ExprNodes.h b/src/dsql/ExprNodes.h >> index 3478e4056b..38469e826e 100644 >> --- a/src/dsql/ExprNodes.h >> +++ b/src/dsql/ExprNodes.h >> @@ -1860,6 +1860,7 @@ public: >> NestConst<ValueExprNode> value1; >> NestConst<ValueExprNode> value2; >> NestConst<SubQuery> subQuery; >> + NestConst<CastNode> test; >> }; >> -------------- >> >> While previously it correctly detected the problem, as a specialized >> node cannot become some other node not inherited from it. > > Please, define "specialized node". I assumed it is descendants of the > ExprNode, but it seems it is not enough. What makes node "specialized" ? > > ...
As the code demonstrate, "NestConst<CastNode> test" should always point to a CastNode (or a possible descendant). CastNode::pass1 currently returns this (a CastNode, but doesn't matter), but it declares return type as ValueExprNode so it can return other things that is not a CastNode descendant. Some other nodes does that. And if does that, "NestConst<CastNode> test" will point to a wrong thing without the compiler detect when doPass1 (or pass2, remap, etc) is called. NodeRefImpl was there to detect that wrong cases. >> If the change really increases performance, then I suppose it should be >> conditionally defined based on DEBUG build, so debug could use NodeRef >> with virtual method and NodeRefImpl, and release something like >> currently (non-virtual method and no NodeRefImpl usage). > > According to profiler, new\delete of NodeRefImpl takes near 28% of > request compilation time. > It's should be possible to rewrite the code to have the checks and avoid the performance problem. Adriano Firebird-Devel mailing list, web interface at https://lists.sourceforge.net/lists/listinfo/firebird-devel
