Re: Redacting information from logs

Hi,

On 2019-08-05 14:32:36 -0700, Jeff Davis wrote:
> On Mon, 2019-08-05 at 14:10 -0700, Andres Freund wrote:
> > I was thinking that it'd just store a struct ErrParam, which'd
> > reference
> > the passed value and metadata like the name (for structured log
> > output) and redaction category. The bigger problem I see is handling
> > the different types of arguments - but perhaps the answer there would
> > be
> > to just make the macro typesafe? Or have one for scalar values and
> > one
> > for pointer types?
>
> Losing the compile-time checks for compatibility between format codes
> and arguments would be a shame. Are you saying there's a potential
> solution for that?

Yea, I'd just written that in another reply to yours. I did actually
think about this some recently:
https://www.postgresql.org/message-id/20190730181845.jyyk4selyohagwnf%40alap3.anarazel.de

Not sure if any of that is really applicable. Once more I really am
regretting that PG is C rather than C++.

> > Doing something like this does however require not directly using
> > plain
> > sprintf. I'm personally not bothered by that, but I'd not be
> > surprised
> > if e.g. Tom saw that differently.
>
> It may be possible to still use sprintf if we translate the ErrParams
> into plain values first.

It's pretty hard to call those functions with a runtime variable number
of arguments. va_list as an interface is not great...

Greetings,

Andres Freund