Re: [PATCH v3] telemetry: use portable syntax to initialize array

[Tyler Retzlaff <roretzla@linux.microsoft.com>]

On Tue, Apr 04, 2023 at 09:51:04AM +0100, Bruce Richardson wrote:
> On Mon, Apr 03, 2023 at 11:59:25AM -0700, Tyler Retzlaff wrote:
> > 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 <roretzla@linux.microsoft.com>
> 
> Acked-by: Bruce Richardson <bruce.richardson@intel.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;
> 
> My preference would be to limit the scope of index to the if block, but ok
> to keep as here.

yes, mine too.  but i forgot we aren't C99 (yet) so i had to move it for
this patch.

> 
> [In fact, when we switch to C11, I'd love to see the coding standards
> relaxed to allow loop variable definition inside the for statement itself]

i'm for it, in fact for any variable i prefer declaration at or near
first use because it let's me const more. but i know that can be an
unpopular opinion so no need to hit 'r' to tell me off, i will follow
any and all documented convention the community has.

> 
> > +	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;
> > -- 
> > 1.8.3.1
> >