Identifying conflicting declared invalid runtime references of overlaid data structures of a shared memory area as declared in a program listing. The identifying includes identifying a first data structure and a first parameter list in the program listing. A first routine call and a sequential flow of execution of the first routine call through the program listing in order to write data to the shared memory area are identified. A second data structure and a second parameter list in the program listing are identified. A second routine call and a second sequential flow of execution of the second routine call through the program listing in order to write data to the shared memory area are identified. It is determined whether the second routine call is attempting to overwrite data of the first routine call with the data of the second routine call in the shared memory area.