Re: [PATCH] Redudant initilization - Mailing list pgsql-hackers

Em sex., 4 de set. de 2020 às 14:40, Tom Lane <tgl@sss.pgh.pa.us> escreveu:

Bruce Momjian <bruce@momjian.us> writes:
> I have to say, I am kind of stumped why compilers do not warn of such
> cases, and why we haven't gotten reports about these cases before.

I was just experimenting with clang's "scan-build" tool.  It finds
all of the cases you just fixed, and several dozen more beside.
Quite a few are things that, as a matter of style, we should *not*
change, for instance

rewriteHandler.c:2807:5: warning: Value stored to 'outer_reloids' is never read
                                outer_reloids = list_delete_last(outer_reloids);
                                ^               ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

There are some like this, in the analyzes that I did.
Even when it is the last action of the function.

Failing to update the list pointer here would just be asking for bugs.
However, I see some that look like genuine oversights; will go fix.

Thanks for fixing this.

(I'm not sure how much I trust scan-build overall.  It produces a
whole bunch of complaints about null pointer dereferences, for instance.
If those aren't 99% false positives, we'd be crashing constantly.
It's also dog-slow.  But it might be something to try occasionally.)

I believe it would be very beneficial.

 

Attached is a patch I made in March/2020, but due to problems,

it was sent but did not make the list.
Would you mind taking a look?
Certainly, if accepted, rebasing would have to be done.