#error
The #error directive can be used to generate an error message when the preprocessor runs.
Syntax
#error text
Parameter
text
A text value that will be included in the error message. The value does not need to be enclosed in quotation marks.
Example
The following example uses the #error directive to generate an error message if the identifier MyTextFile has not been previously defined in a #define directive:
#if ! defined (MyTextFile)
#error You must include a #define directive for MyTextFile.
#endif
See also