Atmel CAVR-4 Manual De Usuario

CAVR-4

Part 2. Compiler reference

This chapter gives a brief overview of the preprocessor, including reference 

information about the different preprocessor directives, symbols, and other 

related information.

The preprocessor of the AVR IAR C/C++ Compiler adheres to the ISO/ANSI standard. 
The compiler also makes the following preprocessor-related features available to you:

●

Predefined preprocessor symbols. These symbols allow you to inspect the 
compile-time environment, for example the time and date of compilation. Some of 
the symbols take arguments and perform more advanced operations than just 
inspecting the compile-time environment. For details, see Predefined symbols, page 
227.

●

User-defined preprocessor symbols. Use the option 

-D

 to define your own 

preprocessor symbols, see -D, page 174.

●

Preprocessor extensions. There are several preprocessor extensions, for example 
many pragma directives; for more information, see the chapter Pragma directives in 
this guide. For information about other extensions, see Preprocessor extensions, 
page 235.

●

Preprocessor output. Use the option 

--preprocess

 to direct preprocessor output 

to a named file, see --preprocess, page 193.

●

Implementation-defined behavior. Some parts listed by the ISO/ANSI standard 
are implementation-defined, for example the character set used in the preprocessor 
directives and inclusion of bracketed and quoted filenames. To read more about this, 
see Preprocessing directives, page 260.

This section first summarizes all predefined symbols and then provides detailed 
information about each symbol.