Example of ambiguous bug

gistfile1.pl

use strict;
use warnings FATAL => 'all';
use MarpaX::Languages::SQL2003::AST;
use Data::Dump qw(pp);

my $input = "";
while (<>) {
	$input = $input . $_;
}

my $obj = MarpaX::Languages::SQL2003::AST->new(host => 'C');
my $ast = $obj->parse($input);
pp($ast);

storedProc

USE [AdventureWorks2014]
GO
/****** Object:  StoredProcedure [dbo].[uspGetManagerEmployees]    Script Date: 1/20/2015 9:50:52 AM ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO

ALTER PROCEDURE [dbo].[uspGetManagerEmployees]
    @BusinessEntityID [int]
AS
BEGIN
    SET NOCOUNT ON;

    -- Use recursive query to list out all Employees required for a particular Manager
    WITH [EMP_cte]([BusinessEntityID], [OrganizationNode], [FirstName], [LastName], [RecursionLevel]) -- CTE name and columns
    AS (
        SELECT e.[BusinessEntityID], e.[OrganizationNode], p.[FirstName], p.[LastName], 0 -- Get the initial list of Employees for Manager n
        FROM [HumanResources].[Employee] e
INNER JOIN [Person].[Person] p
ON p.[BusinessEntityID] = e.[BusinessEntityID]
        WHERE e.[BusinessEntityID] = @BusinessEntityID
        UNION ALL
        SELECT e.[BusinessEntityID], e.[OrganizationNode], p.[FirstName], p.[LastName], [RecursionLevel] + 1 -- Join recursive member to anchor
        FROM [HumanResources].[Employee] e
            INNER JOIN [EMP_cte]
            ON e.[OrganizationNode].GetAncestor(1) = [EMP_cte].[OrganizationNode]
INNER JOIN [Person].[Person] p
ON p.[BusinessEntityID] = e.[BusinessEntityID]
        )
    -- Join back to Employee to return the manager name
    SELECT [EMP_cte].[RecursionLevel], [EMP_cte].[OrganizationNode].ToString() as [OrganizationNode], p.[FirstName] AS 'ManagerFirstName', p.[LastName] AS 'ManagerLastName',
        [EMP_cte].[BusinessEntityID], [EMP_cte].[FirstName], [EMP_cte].[LastName] -- Outer select from the CTE
    FROM [EMP_cte]
        INNER JOIN [HumanResources].[Employee] e
        ON [EMP_cte].[OrganizationNode].GetAncestor(1) = e.[OrganizationNode]
INNER JOIN [Person].[Person] p
ON p.[BusinessEntityID] = e.[BusinessEntityID]
    ORDER BY [RecursionLevel], [EMP_cte].[OrganizationNode].ToString()
    OPTION (MAXRECURSION 25)
END;