Generate non-stringified text literal macro at build time - c

Question

Background
In a separate question of mine, I created a function-like-macro that allows me to concatenate a user-supplied text literal to create a macro name, i.e.:
/******************************************************************************
* coconut.h
******************************************************************************/
#define COCONUT_FX_REGISTER (100)
#define COCONUT_BASE_REGISTER (101)
/*******************************************************************************
* pineapple.h
******************************************************************************/
#define PINEAPPLE_FX_REGISTER (200)
#define PINEAPPLE_BASE_REGISTER (201)
/*******************************************************************************
* test.c.
******************************************************************************/
#include <stdio.h>
#include "translation.h"
#include "coconut.h"
#include "pineapple.h"
int main(void) {
int i = getTranslation(FX_REGISTER, COCONUT);
printf("Translation:%d.\n", i);
return 0;
}
/*******************************************************************************
* translation.h
******************************************************************************/
#define getTranslation(x, y) y ## _ ## x
Goal
I would like to extend this logic so that I can use a macro for a default value to pass to getTranslation, i.e.:
#define XFRM(x) #x
#define XFRM2(x) XFRM(x)
#define DEFAULT_PRODUCT XFRM2(COCONUT)
int main(void) {
int i = getTranslation(FX_REGISTER, DEFAULT_PRODUCT);
printf("Translation:%d.\n", i);
return 0;
}
Problem
However, I can't seem to get DEFAULT_PRODUCT to be converted to a non-string text literal.
Build Errors
main.c: In function ‘main’:
main.c:14:35: error: ‘DEFAULT_PRODUCT_FX_REGISTER’ undeclared (first use in this function)
printf("%d\n", getTranslation(FX_REGISTER, DEFAULT_PRODUCT));
^
translation.h:33:25: note: in definition of macro ‘getTranslation’
#define getTranslation(x, y) y ## _ ## x
^
main.c:14:35: note: each undeclared identifier is reported only once for each function it appears in
printf("%d\n", getTranslation(FX_REGISTER, DEFAULT_PRODUCT));
^
translation.h:33:25: note: in definition of macro ‘getTranslation’
#define getTranslation(x, y) y ## _ ## x
Question
How can I create a DEFAULT_PRODUCT macro that resolves to a non-string text literal so that I can create a "default" value to use with getTranslation? This is using GCC set to C99 pedantic.

Answer 1

Sounds like an XY problem.
It seems that macro concatenations are processed simultaneous to macro literal expansions, so I'm afraid there's no way to create a DEFAULT_PRODUCT macro that gets expanded before getTranslation.
My proposal: Create another macro function getDefaultTranslation(x) and you'll easily achieve what you want.
// You may want to add appropriate comments
// so code reviewers know what this is doing.
#define getDefaultTranslation(x) COCONUT ## x
Regarding this question, macro expansion is done layer-by-layer, and at the same layer concatenation has a higher precedence , so adding another layer should work. See ringø's answer below.

Answer 2

You need to add an indirection in order to let the preprocessor expand the macros before doing the concatenation
#define CONCAT(a, b) a ## _ ## b
#define getTranslation(x, y) CONCAT(x,y)
#define XFRM(x) x
#define XFRM2(x) XFRM(x)
#define DEFAULT_PRODUCT XFRM2(COCONUT)
Note that XFRM has its # removed (off x), otherwise the " gives an invalid preprocessing token.
This way you get
int i = FX_REGISTER_COCONUT;