C251 User's Guide

Preprocessor

The preprocessor built into the C251 Compiler handles directives found in the source file. The C251 Compiler supports all of the ANSI Standard C directives.

Preprocessing is the first action the compiler performs. The purpose of the preprocessor is to replace or insert additional text into the source file just prior to compilation.

Most preprocessor functions require activation by including Preprocessor Directives in your source code. However, the preprocessor always:

• Replaces each C comment by a single space.
• Removes line continuations (indicated by a backslash ('\') at the end of a line) and joins the lines broken apart for compilation.
• Replaces predefined macro names with their predefined text.

In addition to these operations, the preprocessor in the C251 Compiler supports the more obvious preprocessor operations:

• Header Files,
• Macros,
• Conditional Compilation.

If you encounter preprocessor problems, you may direct the compiler to generate a Preprocessor File that shows the exact output from the preprocessor.