.ERRDEF          Error If Name Is Defined                      MASM Directive
 
  .ERRDEF   name
 
    Forces a fatal error if name is defined.
 
       Notes:     If the name is defined as a forward reference, it is
                  considered undefined on the first pass, but defined on
                  the second.
 
                  The error message that may be generated by this
                  directive is 'Forced error - symbol defined', which is
                  error number 93.
 
                  If an error is generated, the object module is deleted
                  and the assembler exits with an exit code of 7.

Seealso:


 .ERRNDEF 
 IFDEF 
 IFNDEF