The preprocessor supports conditional compilation of parts of source file.

Shows the given error message and renders the program ill-formed, or shows the given warning message without affecting the validity of the program.

Changes the source code's line number and, optionally, the current file name, in the preprocessor.

Implementation defined behavior is controlled by #pragma directive.

The preprocessor is executed at translation phase 4, before the compilation. The result of preprocessing is a single file which is then passed to the actual compiler.

The preprocessor supports text macro replacement. Function-like text macro replacement is also supported.

Includes other source file into current source file at the line immediately after the directive.