9.58 __attribute__((alias)) variable attribute

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

Aliases must be defined in the same translation unit as the original variable.


You cannot specify aliases in block scope. The compiler ignores aliasing attributes attached to local variable definitions and treats the variable definition as a normal local definition.
In the output object file, the compiler replaces alias references with a reference to the original variable name, and emits the alias alongside the original name. For example:
int oldname = 1;
extern int newname __attribute__((alias("oldname")));
This code compiles to:
     LDR      r1,[r0,#0]  ; oldname
     DCD      0x00000001
If the original variable is defined as static but the alias is defined as extern, then the compiler changes the original variable to be external.


Function names might also be aliased using the corresponding function attribute __attribute__((alias)).


type newname __attribute__((alias("oldname")));
is the name of the variable to be aliased
is the new name of the aliased variable.


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