在 2022-10-29星期六的 06:28 +1100，Richard Henderson写道：
> On 10/28/22 18:21, Icenowy Zheng wrote:
> > When registering helpers via FFI for TCI, the inner loop that
> > iterates
> > parameters of the helper reuses (and thus pollutes) the same
> > variable
> > used by the outer loop that iterates all helpers, thus made some
> > helpers
> > unregistered.
> >
> > Fix this logic error by using a dedicated temporary variable for
> > the
> > inner loop.
> >
> > Signed-off-by: Icenowy Zheng <u...@icenowy.me>
> > ---
> > tcg/tcg.c | 7 ++++---
> > 1 file changed, 4 insertions(+), 3 deletions(-)
> >
> > diff --git a/tcg/tcg.c b/tcg/tcg.c
> > index 612a12f58f..adfaf61a32 100644
> > --- a/tcg/tcg.c
> > +++ b/tcg/tcg.c
> > @@ -619,6 +619,7 @@ static void tcg_context_init(unsigned max_cpus)
> > gpointer hash = (gpointer)(uintptr_t)typemask;
> > ffi_status status;
> > int nargs;
> > + int j;
> >
> > if (g_hash_table_lookup(ffi_table, hash)) {
> > continue;
> > @@ -634,9 +635,9 @@ static void tcg_context_init(unsigned max_cpus)
> >
> > if (nargs != 0) {
> > ca->cif.arg_types = ca->args;
> > - for (i = 0; i < nargs; ++i) {
> > - int typecode = extract32(typemask, (i + 1) * 3,
> > 3);
> > - ca->args[i] = typecode_to_ffi[typecode];
> > + for (j = 0; j < nargs; ++j) {
> > + int typecode = extract32(typemask, (j + 1) * 3,
> > 3);
> > + ca->args[j] = typecode_to_ffi[typecode];
>
> Oh my. I'm surprised any test cases at all worked.
> Queued to tcg-next, with the declaration of j moved to the loop
> itself:
>
> for (int j = 0; j < nargs; ++j)
Ah I think this is a C99 feature. Is our C standard baseline high
enough to use it?
>
>
> r~
>
