How to make gcc warn about passing wrong enum to a function

Question

gcc doesn\'t seem to produce a warning with the following code. How can I get it to produce a warning?

typedef enum
{
    REG8_A,
    REG8_B,
    REG8_C
}REG         


        

Answer 1

The only way I can see of generating a warning is if you are prepared to pass pointers rather than bare enums, e.g.

typedef enum
{
    REG8_A,
    REG8_B,
    REG8_C
} REG8;

typedef enum
{
    REG16_A,
    REG16_B,
    REG16_C
} REG16;

void function(REG8 * reg8)
{

}

int main(void)
{
    REG16 r = REG16_A;
    function(&r);
    return 0;
}

Not exactly an elegant solution, but it does give a warning, at least with gcc -Wall:

$ gcc -Wall warn_enum.c -o warn_enum
warn_enum.c: In function ‘main’:
warn_enum.c:23: warning: passing argument 1 of ‘function’ from incompatible pointer type
$