Re: [HACKERS] [PATCH] quiet conversion warning in DatumGetFloat4

Chapman Flack <chap@anastigmatix.net> writes:
> On 05/31/2017 11:36 AM, Tom Lane wrote:
>> However, I grant your point that some extensions may have outside
>> constraints that mandate using -Wconversion, so to the extent that
>> we can keep key headers like postgres.h from triggering those warnings,
>> it's probably worth doing.  I suspect you're still seeing a lot of them
>> though --- experiments with some contrib modules suggest that a lot of
>> our other headers also contain code that would trigger them.  I do not
>> think I'd be on board with trying to silence them generally.

> That was actually the only one PL/Java gets, outside of /sign/
> conversions, a special subset of conversion warnings that can be
> separately turned off with -Wno-sign-conversion.

Just for the archives' sake: I experimented with this, using Fedora 25's
compiler (gcc version 6.3.1) against current HEAD (including your patch).
For the core build only, no contrib, I see:

12169 warnings generated by -Wconversion

4106 warnings generated by -Wconversion -Wno-sign-conversion

It's not just the core code that has issues either: contrib has 2202
warnings for the first case, 683 for the second.

So it's better with -Wno-sign-conversion, but I'd say we're still not
going there anytime soon.
        regards, tom lane