Get the value of a C constant by name

I have a .h file in which hundreds of constants are defined as macros:

#define C_CONST_NAME Value

I need a function that can dynamically get the value of one of these constants.

Needed function header:

int getConstValue(char * constName);

Is that even possible in the C language?

Here you go. You will need to add a line for each new constant, but it should give you an idea about how macros work:

#include <stdio.h>

#define C_TEN 10
#define C_TWENTY 20
#define C_THIRTY 30

#define IFCONST(charstar, define) if(strcmp((charstar), #define) == 0) { \
    return (define); \
}

int getConstValue(const char* constName)
{
    IFCONST(constName, C_TEN);
    IFCONST(constName, C_TWENTY);
    IFCONST(constName, C_THIRTY);

    // No match                                                                                                                                                                                                                              
    return -1;
}

int main(int argc, char **argv)
{
    printf("C_TEN is %d\n", getConstValue("C_TEN"));

    return 0;
}

I suggest you run gcc -E filename.c to see what gcc does with this code.