This variable attribute enables you to specify multiple aliases for variables.

Where a variable is defined in the current translation unit, the alias reference is replaced by a reference to the variable, and the alias is emitted alongside the original name. Where a variable is not defined in the current translation unit, the alias reference is replaced by a reference to the real variable. Where a variable is defined as static, the variable name is replaced by the alias name and the variable is declared external if the alias is declared external.

type newname __attribute__((alias("oldname")));

#include <stdio.h>
int oldname = 1;
extern int newname __attribute__((alias("oldname"))); // declaration
void foo(void)
{
    printf("newname = %d\n", newname); // prints 1
}