Mutable Initializers are not Detected

[ajbeach]

int x = 0;
int y @= x; // invalid C initialization

int main(void) {
    return (x + y);
}

C only allows initialization of a global variable with a constant expression; therefore, the initialization y @= x fails with the gcc error:

error: initializer element is not constant

which is correct.

The enhancement is for Cforall to detect this case and print an appropriate error message instead of passing it off to the underlying C compiler.