On Tue, Apr 04, 2023 at 08:59:06AM -0700, Tyler Retzlaff wrote:
> On Tue, Apr 04, 2023 at 09:01:50AM +0000, Konstantin Ananyev wrote:
> >
> >
> > > -----Original Message-----
> > > From: Tyler Retzlaff <roret...@linux.microsoft.com>
> > > Sent: Monday, April 3, 2023 7:59 PM
> > > To: dev@dpdk.org
> > > Cc: ciara.po...@intel.com; bruce.richard...@intel.com;
> > > david.march...@redhat.com; tho...@monjalon.net; Tyler Retzlaff
> > > <roret...@linux.microsoft.com>
> > > Subject: [PATCH v3] telemetry: use portable syntax to initialize array
> > >
> > > Use of ranges in designated initialization are a non-standard gcc
> > > extension. Use loops to initialize permitted characters on first use.
> > >
> > > Signed-off-by: Tyler Retzlaff <roret...@linux.microsoft.com>
> > > ---
> > > lib/telemetry/telemetry_data.c | 22 +++++++++++++++-------
> > > 1 file changed, 15 insertions(+), 7 deletions(-)
> > >
> > > diff --git a/lib/telemetry/telemetry_data.c
> > > b/lib/telemetry/telemetry_data.c
> > > index 2bac2de..562b387 100644
> > > --- a/lib/telemetry/telemetry_data.c
> > > +++ b/lib/telemetry/telemetry_data.c
> > > @@ -152,13 +152,21 @@
> > > static bool
> > > valid_name(const char *name)
> > > {
> > > - char allowed[128] = {
> > > - ['0' ... '9'] = 1,
> > > - ['A' ... 'Z'] = 1,
> > > - ['a' ... 'z'] = 1,
> > > - ['_'] = 1,
> > > - ['/'] = 1,
> > > - };
> > > + int index;
> > > + static bool initialized;
> > > + static char allowed[128];
> > > +
> > > + if (!initialized) {
> > > + for (index = '0'; index <= '9'; index++)
> > > + allowed[index] = 1;
> > > + for (index = 'A'; index <= 'Z'; index++)
> > > + allowed[index] = 1;
> > > + for (index = 'a'; index <= 'z'; index++)
> > > + allowed[index] = 1;
> > > + allowed[(int)'_'] = allowed[(int)'/'] = 1;
> > > + initialized = true;
> > > + }
> > > +
> > > while (*name != '\0') {
> > > if ((size_t)*name >= RTE_DIM(allowed) || allowed[(int)*name] ==
> > > 0)
> > > return false;
> >
> > Wonder isn't the same as:
> > while (*name != 0)
> > if (!isascii(name[0] || (!isalnum(name[0]) && name[0] != '_' &&
> > name[0] != '/'))
> > return false;
> >
> > Or MSVC doesn't support these macros?
>
> it's standard C msvc supports it. Bruce acceptable to take Konstantin's
> suggestion here?
>
Yep, I'm ok with it.
If I may confuse things a little, how about combining the two? Use an array
with individual initializers for the "special characters", but using
isalnum() for the rest. That way we get a clear list of allowed chars at
the top of the array, without having a massive list of individual letters
and numbers. For example: [completely untested and not compiled!].
{
/* non-alpha-numeric characters allowed in names */
static const char allowed[128] = { ['_'] = 1, ['/'] = 1 };
for ( ; *name != '\0'; name++) {
if (isalnum(*name))
continue;
if ((size_t)*name >= RTE_DIM(allowed) || allowed[(int)*name] ==
0)
return false;
}
return true;
}
I think something like this achieves a good balance between clarity and
brevity.
1. We don't have a massive array definition
2. We do have a static constant array
3. We don't have the non-alnum character list hidden inside the middle of
an "if" statement.
/Bruce
