Re: [PATCH 00/26] constify local structures

Geert Uytterhoeven
2016-09-12T13:57:40Z

On Mon, Sep 12, 2016 at 3:43 PM, Felipe Balbi
<felipe.balbi@linux.intel.com> wrote:
> Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> writes:
>> On Mon, Sep 12, 2016 at 10:54:07AM +0200, Julia Lawall wrote:
>>> On Sun, 11 Sep 2016, Jarkko Sakkinen wrote:
>>> > On Sun, Sep 11, 2016 at 03:05:42PM +0200, Julia Lawall wrote:
>>> > > Constify local structures.
>>> > >
>>> > > The semantic patch that makes this change is as follows:
>>> > > (http://coccinelle.lip6.fr/)
>>> >
>>> > Just my two cents but:
>>> >
>>> > 1. You *can* use a static analysis too to find bugs or other issues.
>>> > 2. However, you should manually do the commits and proper commit
>>> > messages to subsystems based on your findings. And I generally think
>>> > that if one contributes code one should also at least smoke test changes
>>> > somehow.
>>> >
>>> > I don't know if I'm alone with my opinion. I just think that one should
>>> > also do the analysis part and not blindly create and submit patches.
>>>
>>> All of the patches are compile tested. And the individual patches are
>>
>> Compile-testing is not testing. If you are not able to test a commit,
>> you should explain why.
>
> Dude, Julia has been doing semantic patching for years already and
> nobody has raised any concerns so far. There's already an expectation
> that Coccinelle *works* and Julia's sematic patches are sound.

+1

> Besides, adding 'const' is something that causes virtually no functional
> changes to the point that build-testing is really all you need. Any
> problems caused by adding 'const' to a definition will be seen by build
> errors or warnings.

Unfortunately in this particular case they could lead to failures that can only
be detected at runtime, when failing o write to a read-only piece of memory,
due to the casting away of the constness of the pointers later.
Fortunately this was detected during code review (doh...).

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds