Printing enum field symbolically

[pdc]

For debugging purposes, is there any way of programatically retrieving the symbolic name of a field in an enum, rather than just printing its numeric value? I'm pretty sure there's no way in ANSI C, but I'm using GCC... does it have any non-standard hacks that might allow this?

[Codeplug]

Nothing like this exists as a compiler extension to GCC (that I can find). The only thing close is the Function Names as Strings extension.
You're better off doing it in a portable fashion:

#include <stdio.h>

typedef enum 
{
    value_1,
    value_2,
    value_3,
} MyEnum;

/*---------------------------------------------------------------------------*/
#ifndef NDEBUG
/*---------------------------------------------------------------------------*/

typedef struct 
{
    MyEnum val;
    const char *val_name;
} MyEnum_TxtMap;

static const MyEnum_TxtMap g_MyEnum_TxtMap[] =
{
    {value_1, "value_1"},
    {value_2, "value_2"},
    {value_3, "value_3"},
};

const char* MyEnum2Text(MyEnum val)
{
    const size_t map_sz = sizeof(g_MyEnum_TxtMap) / sizeof(*g_MyEnum_TxtMap);
    size_t n = 0;
    
    for (; n < map_sz; ++n)
    {
        if (g_MyEnum_TxtMap[n].val == val)
            return g_MyEnum_TxtMap[n].val_name;
    }//for

    return "!!invalid MyEnum val!!";
}

/*---------------------------------------------------------------------------*/
#else /* NDEBUG */
/*---------------------------------------------------------------------------*/

const char* MyEnum2Text(MyEnum val) 
{
    return "!!non-debug build!!";
}

/*---------------------------------------------------------------------------*/
#endif /* NDEBUG */
/*---------------------------------------------------------------------------*/

int main()
{
    MyEnum val = value_2;

    printf("val = %s\n", MyEnum2Text(val));

    return 0;
}

gg

[pdc]

Thanks, yeah, I just went with something similar myself in the end. It was always going to be an opportunistic hack, nothing Dijkstra would approve of

[Salem]

Well if you're consistent enough about how you declare and name things, you should be able to write say a perl script (or other scripting language of your choice) to parse your source code and generate the lookup tables automatically.