Preprocessor
The task of the preprocessor is to work through the files to be compiled before the actual compilation and to implement so-called directives
. These directives are mainly used to include additional files, define macros, control conditional compilation and manipulate compiler errors.
Most Important Directives
Conditional Compilation
#ifConditional compilation
#elseElse part of a conditional compilation
#elifConsecutive condition of a conditional compilation
#endifEnd of a conditional compilation
#ifdefConditional compilation when a macro exists
#ifndefConditional compilation when a macro does not exists
Compiler Control
Other Preprocessor Elements
Rare Directives
#identIdentification directive
#sccsBSD specific directive