pointerOverflow

fn pointerOverflow(
    _: *const PointerOverflowData,
    base: usize,
    result: usize,
) callconv(.c) noreturn

File

Code

fn pointerOverflow(
    _: *const PointerOverflowData,
    base: usize,
    result: usize,
) callconv(.c) noreturn {
    if (base == 0) {
        if (result == 0) {
            panic(@returnAddress(), "applying zero offset to null pointer", .{});
        } else {
            panic(@returnAddress(), "applying non-zero offset {d} to null pointer", .{result});
        }
    } else {
        if (result == 0) {
            panic(
                @returnAddress(),
                "applying non-zero offset to non-null pointer 0x{x} produced null pointer",
                .{base},
            );
        } else {
            const signed_base: isize = @bitCast(base);
            const signed_result: isize = @bitCast(result);
            if ((signed_base >= 0) == (signed_result >= 0)) {
                if (base > result) {
                    panic(
                        @returnAddress(),
                        "addition of unsigned offset to 0x{x} overflowed to 0x{x}",
                        .{ base, result },
                    );
                } else {
                    panic(
                        @returnAddress(),
                        "subtraction of unsigned offset to 0x{x} overflowed to 0x{x}",
                        .{ base, result },
                    );
                }
            } else {
                panic(
                    @returnAddress(),
                    "pointer index expression with base 0x{x} overflowed to 0x{x}",
                    .{ base, result },
                );
            }
        }
    }
}