10.68 __attribute__((unused)) variable attribute

Normally, the compiler warns if a variable is declared but is never referenced. This attribute informs the compiler that you expect a variable to be unused and tells it not to issue a warning if it is not used.

Note

This variable attribute is a GNU compiler extension that the ARM compiler supports.

Examples

void Variable_Attributes_unused_0()
{
    static int aStatic =0;
    int aUnused __attribute__((unused));
    int bUnused;
    aStatic++;
}

In this example, the compiler warns that bUnused is declared but never referenced, but does not warn about aUnused.

Note

The GNU compiler does not give any warning.

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