[sdk77]

On some microcontrollers I know a pointer to address 0 really is just that. I tested compiling the following

    unsigned short *a = 0;
    ((void (*)(void))a)();

which may cause a jump to address 0 (usually the reset vector).

On R8C with the NC30 compiler there are no warnings and the output is:

    MOV.W:Q #0H, -2H[FB]
    MOV.W:G -2H[FB], R0
    MOV.W:Q #0H, R2
    JSRI.A  R2R0

It jumps to 0. But on PIC 16 with the XC compiler a warning is emitted warning: (1471) indirect function call via a NULL pointer ignored and the statement is not compiled at all.