Function dsqlPassHiddenVariable

src/dsql/StmtNodes.cpp:10269–10299

Create (if necessary) a hidden variable to store a temporary value.

// Create (if necessary) a hidden variable to store a temporary value.
static VariableNode* dsqlPassHiddenVariable(DsqlCompilerScratch* dsqlScratch, ValueExprNode* expr)
{
	thread_db* tdbb = JRD_get_thread_data();

	// For some node types, it's better to not create temporary value.
	switch (expr->getType())
	{
		case ExprNode::TYPE_CURRENT_DATE:
		case ExprNode::TYPE_CURRENT_TIME:
		case ExprNode::TYPE_CURRENT_TIMESTAMP:
		case ExprNode::TYPE_CURRENT_ROLE:
		case ExprNode::TYPE_CURRENT_USER:
		case ExprNode::TYPE_FIELD:
		case ExprNode::TYPE_INTERNAL_INFO:
		case ExprNode::TYPE_LITERAL:
		case ExprNode::TYPE_NULL:
		case ExprNode::TYPE_PARAMETER:
		case ExprNode::TYPE_RECORD_KEY:
		case ExprNode::TYPE_VARIABLE:
			return NULL;
	}

	VariableNode* varNode = FB_NEW_POOL(*tdbb->getDefaultPool()) VariableNode(*tdbb->getDefaultPool());
	varNode->dsqlVar = dsqlScratch->makeVariable(NULL, "", dsql_var::TYPE_HIDDEN,
		0, 0, dsqlScratch->hiddenVarsNumber++);

	DsqlDescMaker::fromNode(dsqlScratch, &varNode->dsqlVar->desc, expr);
	varNode->setDsqlDesc(varNode->dsqlVar->desc);

	return varNode;
}

// Process loop interruption.
static USHORT dsqlPassLabel(DsqlCompilerScratch* dsqlScratch, bool breakContinue, MetaName* label)