The #warning Conditional Directive
The #warning directive takes a string as an argument and produces a warning message at compile-time. Warnings produced by this directive are displayed as normal compiler warnings.
Like the #error directive, this directive is most useful for detecting pre-defined constraints and inconsistencies during preprocessing of a source file.
#warning <message string>
The message string identifier shown above indicates the warning message to be displayed. The following example illustrates use of the #warning directive:
#if !TRACING #warning This interface has not been completely tested yet! #endif
When the warning above is encountered, the following line will be output:
#warning 'This interface has not been completely tested yet!' (J5500)