Defined()
Preprocessor | Solely a Preprocessor function |
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Checks if a symbol or constant is defined. The Preprocessor functions are for #if..#endif-Structures and allow conditional compiling of program code dependent on the existance of a symbol. Defined() is similar to the #ifdef-Directive in C as a function. Valid are:
- Constants, also controller constants like avr.TIMSK
- Labels from assembler source
- Library names e.g. Graphics.interface
Syntax:
- defined( symbol )
The result is true, if symbol is defined.
See also: Directives, Compile process
Example
Luna
#if defined(avr.TIMSK0) 'more #endif #if defined(Graphics.interface) 'more #endif #if defined(mylabel) 'more #endif
Assembler
.if defined(avr.TIMSK0) 'more .endif .if defined(Graphics.interface) 'more .endif .if defined(mylabel) 'more .endif