Factor out the code to find gcc, and add a command-line option to override the default executable name. This should help cross-compilation by allowing a cross-gcc to be specified from the configuration file instead of only through the CC environment variable.

module a;

extern(C) int printf(char*, ...);

int i = 42;

void main()
{
    int j;
    j = i;
    int* p;
    p = &j;
    int k = *p;
    assert(k == 42);

    byte b = -1;
    int i = b;
    assert(i == -1);

    int* p2 = p;

    printf("Done\n");
}