Table of Contents

Preprocessing

Many programming languages feature a preprocessor that processes macros, allows conditional compilation based on certain criteria, etc.

XC=BASIC doesn't have a preprocessor, but you can use a third-party (generic) preprocessor as part of your toolchain.

This guide guide advises using GPP, a general-purpose preprocessor.

Using GPP with XC=BASIC

To run GPP before the input is passed to XC=BASIC, you can use piping: 

gpp -n source.bas | xcbasic3 /dev/stdin result.prg

What it does is call GPP first, then pass its output to XC=BASIC that does the rest.

Examples

The simplest example is defining a macro and creating a conditional block: 

REM #define TARGET c64

REM #ifeq TARGET plus4
CONST BGCOLOR = $FF15
REM #else
CONST BGCOLOR = $D021
REM #endif

POKE BGCOLOR, 0

Note

To make code more readable and not to confuse your syntax highlighter, is it advised that you put preprocessor metacommands in XC=BASIC comments, like in the example above.