1.7.7 Predefined Macros

The following macros are already defined by the compiler and cannot be changed.

__LINE__A decimal constant representing the current line number.
__FILE__A string representing the current name of the source code file.
__DATE__A string representing the current date when compiling began for the current source file. It is in the format “mmm dd yyyy”, the same as what is generated by the asctime function.
__TIME__A string literal representing the current time when cimpiling began for the current source file. It is in the format “hh:mm:ss”, the same as what is generated by the asctime function.
__STDC__The decimal constant 1. Used to indicate if this is a standard C compiler.