Atmel CAVR-4 Manual De Usuario

CAVR-4

Part 2. Compiler reference

Note: The predefined symbol 

_ _TID_ _

 is available for backward compatibility. We 

recommend that you use the symbols 

_ _ICCAVR_ _

 and 

_ _MEMORY_MODEL_ _

 instead.

The following section gives reference information about each predefined symbol.

_ _ALIGNOF_ _()

The 

_ _ALIGNOF_ _

 operator is used to access the alignment of an object. It takes one of 

two forms:

●

_ _ALIGNOF_ _

 

(type)

●

_ _ALIGNOF_ _

 

(expression)

In the second form, the expression is not evaluated.

_ _BASE_FILE_ _

Use this symbol to identify which file is currently being compiled. This symbol expands 
to the name of that file, unless the file is a header file. In that case, the name of the file 
that includes the header file is identified.

See also, __FILE__, page 230.

_ _CORE_ _

This symbol identifies the used processor variant.

This symbol expands to a number which corresponds to the processor option 

-vn

 in use.

_ _CPU_ _

Use this symbol to identify the used processor variant.

This symbol expands to a number which corresponds to the processor option 

-vn

 in use.

_ _cplusplus

This predefined symbol expands to the number 

199711L

 when the compiler runs in any 

of the C++ modes. When the compiler runs in ISO/ANSI C mode, the symbol is 
undefined. 

This symbol can be used with 

#ifdef

 to detect whether the compiler accepts C++ code. 

It is particularly useful when creating header files that are to be shared by C and C++ 
code.