The #error
directive causes a diagnostic message, along with any included token
arguments, to be produced by the compiler.
Examples
#ifndef (HP_C) #error "HP_C not defined!" /* This directive will produce #endif the diagnostic message "HP_C not defined!" */
#if TABLE_SIZE % 256 != 0 #error "TABLE_SIZE must be a multiple of 256!" #endif /* This directive will produce the diagnostic message "TABLE_SIZE must be a multiple of 256! */
NOTE: The #error
directive is only supported in ANSI mode.