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

From Tom Lane
Subject Re: [PATCH] Redudant initilization
Date
Msg-id 915973.1599241226@sss.pgh.pa.us
Whole thread Raw
In response to Re: [PATCH] Redudant initilization  (Bruce Momjian <bruce@momjian.us>)
Responses Re: [PATCH] Redudant initilization  (Ranier Vilela <ranier.vf@gmail.com>)
List pgsql-hackers
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);
                                ^               ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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.

(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.)

            regards, tom lane



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