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Re: Pre-RFC: Configure option for whether to include taint support

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Leon Timmermans
August 12, 2021 22:28
Re: Pre-RFC: Configure option for whether to include taint support
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On Fri, Aug 13, 2021 at 12:19 AM Neil Bowers <> wrote:

> Back in 2012, Steffen Mueller did some experimenting and found that taint
> adds somewhere between 10% and 20% runtime overhead:
> As you can see, there was some discussion at that time, but it didn’t seem
> to go anywhere. This has come up again as a result of the Quirks document,
> and we discussed it in last week’s PSC meeting.
> Anecdotally, very few people use taint (these days), yet we’re all paying
> the price. Furthermore, taint causes problems on Windows. For example,
> File::Spec is broken on Windows when used with Taint mode on, because Taint
> mode restricts use of environment variables (which doesn't protect
> anything). See also this reddit discussion[1], on the problems with taint.
> We’d like to consider adding a Configure option for disabling taint mode.
> We see this as a potential first step to having this disabled by default,
> and then possibly removing support for taint entirely.
> We’re interested in hearing thoughts on this.
> Neil
> [1]

Using -DNO_TAINT_SUPPORT as Steffen mentioned you can already build such a
perl. All we really need to do is add a Configure option so that it can
easily be disabled and so that code (especially tests) can keep it into

One open question is if SILENT_NO_TAINT_SUPPORT should be enabled along
with it. I would argue it should, without it many tests will refuse to even
start running.


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