Tutorial of gcc __attribute__ ((alias))

GCC Attribute alias allows you to specify multiple aliases(other names) for a symbol (function/variable).

Example of aliasing a function name:

Code:

	#include <stdio.h>
	static int myfunc(int a, int b)
	{
	printf("%s: Adding %d with %d:\t Result:%d\n",
	__func__, a, b, a+b);
	return a+b;
	}
	static int add(int a, int b) __attribute__((alias("myfunc")));
	int main()
	{
	add(3, 6);
	myfunc(3, 5);
	return 0;
	}

view raw alias_function.c hosted with ❤ by GitHub

Output:

myfunc: Adding 3 with 6: Result:9

myfunc: Adding 3 with 5: Result:8

Notes:

You can see, calling add, the compiler will only call myfunc. Also point to be noted is __func__ returns myfunc on call to add.

Example of aliasing a variable:

Code:

	#include <stdio.h>
	int oldname = 5;
	extern int newname __attribute__((alias("oldname")));
	int main()
	{
	printf("Value of new name is :%d\n", newname);
	return 0;
	}

view raw alias_variable.c hosted with ❤ by GitHub

Output:

Value of new name is :5