Horton

Re: Detecting pointer misalignment (was Re: pgsql: Implementation of subscripting for jsonb)

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Alexander Korotkov <aekorotkov@gmail.com>
Cc: Thomas Munro <thomas.munro@gmail.com>, Heikki Linnakangas <hlinnaka@iki.fi>, Alexander Korotkov <akorotkov@postgresql.org>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2021-02-12T22:55:00Z
Lists: pgsql-hackers 
Alexander Korotkov <aekorotkov@gmail.com> writes:
> On Fri, Feb 12, 2021 at 8:19 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> So maybe it'd better be __GNUC__ >= 6 not __GNUC__ >= 5.  I think
>> we can wait a little bit for more reports before messing with that,
>> though.

> I've rechecked this in the documentation. no_sanitize attribute seems
> to appear since gcc 8.0.  Much later than alignment sanitizer itself.

Yeah, I'd just come to that conclusion from scraping the buildfarm
logs.  Good to see it confirmed in the manual though.

>> Once this does settle, should we consider back-patching so that it's
>> possible to run alignment checks in the back branches too?

> +1

Let's make sure we have a clean set of builds and then do that.

			regards, tom lane

Commits

  1. pg_attribute_no_sanitize_alignment() macro

  2. Tweak compiler version cutoff for no_sanitize("alignment") support.

  3. Implementation of subscripting for jsonb