According to the present invention, a compiler generates, as debugging information on variables appearing in a source program and the allocation of hardware resources, location information made up of elements showing, for each entry of a variable, an address range within which the variable is valid, a condition flag which is made true within the address range when the variable is valid, and a resource allocated to the variable. A debugging device analyzes the debugging information and stores it. When examining the value of a variable, an entry for the valid variable is determined from the address currently being executed and the value held in the condition flag register, and the resource allocated to that variable is obtained. In this way, the contents of the variable can be referenced correctly.