Why use the same identifier for a macro AND a function (GNOME source code)?

Question

I just happened to stumble across the following question on stack overflow:

In gatomic.c of glib there are several function declarations that look like this:

gboolean
(g_atomic_int_compare_and_exchange_full) (gint *atomic,
 gint oldval,
 gint newval,
 gint *preval)
{
 return g_atomic_int_compare_and_exchange_full (atomic, oldval, newval, preval);
}

Where the OP of the question asks how this piece of code could work as it looks like a function that calls itself (it doesn't).

Why would anyone write code like this?

That is, defining a function with the exact same name as a macro.

Why not use two separate identifiers (or write the macro in ALL CAPS for that reason).

Possible answer: Why does the C library use macros and functions with same name? although this is about the C standard library, not some user library.

• Bart van Ingen Schenau: Does this answer your question? Why does the C library use macros and functions with same name?
• Marco: Did you even read the question? I linked that answer in my post.
• Bart van Ingen Schenau: Yes, I did read the question in full and the reason for the duplicate vote is because in my opinion that answer applies here as well.
• Philip Kendall: Could you please edit your question to explain why you think there is a fundamental difference between the C stdlib and a user library? I agree with Bart that the reasons given there apply equally to a user library.
• Marco: Possibly one of the fundamental differences is that the C stdlib is not governed by the same restrictions as user code, e.g. identifiers starting with __ are reserved for the implementation, so its invalid to use them in user code. An argument could be made that this type of behaviour is acceptable for the C stdlib, but not user code.

Answer 1

Why not? It works, and it doesn’t affect anyone because it is hidden in a .c file. It’s a proven pattern, no need to change it.