[SeaBIOS] Re: [PATCH 7/9] acpi: add dsdt parser

[Kevin O'Connor]

On Wed, Apr 08, 2020 at 02:39:39PM +0200, Gerd Hoffmann wrote:
> > > +again:
> > > switch (ptr[offset]) {
> > > case 0: /* null name */
> > >    offset++;
> > >    *(dst++) = 0;
> > >    break;
>
> [ ... ]
> > > case '^':
> > >    *(dst++) = '^';
> > >    offset++;
> > >    goto again;
> >
> > I think this code would be more clear if it used "for (;;) {" and
> > "continue" instead of a backwards goto.
>
> Hmm, doesn't help that much due to for + switch nesting.  I would need
> either an additional state variable or use goto to jump from inside
> switch out of the for loop.  Both ways don't make things more clear
> compared to the current state ...

static int parse_namestring(struct parse_state *s,
                            u8 *ptr, const char *item)
{
    char *dst = s->name;
    int offset = 0;
    int i, count;

for (;;) {
        switch (ptr[offset]) {
        case 0: /* null name */
            offset++;
            *(dst++) = 0;
            break;
        case 0x2e:
            offset++;
            offset += parse_nameseg(ptr + offset, &dst);
            *(dst++) = '.';
            offset += parse_nameseg(ptr + offset, &dst);
            break;
        case 0x2f:
            offset++;
            count = ptr[offset];
            offset++;
            for (i = 0; i < count; i++) {
                if (i)
                    *(dst++) = '.';
                offset += parse_nameseg(ptr + offset, &dst);
            }
            break;
        case '\':
            *(dst++) = '\';
            offset++;
            continue;
        case '^':
            *(dst++) = '^';
            offset++;
            continue;
        case 'A' ... 'Z':
        case '_':
            offset += parse_nameseg(ptr, &dst);
            break;
        default:
            hex(ptr, 16, 3, __func__);
            s->error = 1;
            break;
        }
        break;
    }
    dprintf(5, "%s: %d %s '%s'\n", __func__, s->depth,
            item, s->name);
    return offset;
}

-Kevin