Aliases must be defined in the same translation unit as the original variable.
Note
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
...
oldname
newname
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.
Note
Function names might also be aliased using the corresponding function attribute
__attribute__((alias))
.