Use conditional error control directives to debug programs and check for assembly-time errors. If you insert a conditional assembly directive in your code, you can test assembly-time conditions at that point. You can also test for boundary conditions in macros by using conditional error control directives.
Errors generated by conditional error control directives cause ALP to return a nonzero return code. If a severe error is detected during assembly, ALP does not generate the object module.
This section describes the following conditional error control directives: