Thread

Re: Mark function arguments of type "T *" as "const T *" where possible

Bertrand Drouvot <bertranddrouvot.pg@gmail.com> — 2025-12-12T14:33:39Z

Hi,

On Thu, Dec 11, 2025 at 09:51:49AM -0800, Jacob Champion wrote:
> On Wed, Dec 10, 2025 at 11:22 PM Bertrand Drouvot
> <bertranddrouvot.pg@gmail.com> wrote:
> > Let me try to focus on functions that really
> > deserve the change. I could look at function names that contain "copy" or "cmp",
> > functions that are used for formatting/printing and size/length calculations as
> > examples.
> 
> Sure, that sounds reasonable, and I would hope that those sorts of
> functions are not very high on the list of backport contention.

So, with a filter like:

"^.*(cmp|copy|Cmp|Copy|Control|control|Check|check|Size|size|Length|length).*$";

(maybe other filters will come to mind)

that gives:

 36 files changed, 92 insertions(+), 78 deletions(-)

I did not check the details, just the repartition and that gives:

cmp: 3 functions
copy: 18
control: 1
check: 35
size: 15
length: 2

The numbers are more manageable. Maybe be could put check, copy and size in their
own patches and put the remaining in a 4th one? (and I'd look closely if the
changes make sense based on the function name and content, means the const
addition has a "real" intent i.e not just a technical one).

> > Any other ideas?
> 
> Just that the most useful const additions (IMHO) are going to be
> places at the top of a big hierarchy, where callers expect something
> not to be modified, but the lowest levels are too far removed from
> that expectation for developers to easily remember.

I think that's a good idea, thanks!

> I imagine those
> cases are not going to be easy to find automatically (but that
> shouldn't discourage incremental improvements that can be found that
> way).

Yeah, will git it a try though.

Regards,

-- 
Bertrand Drouvot
PostgreSQL Contributors Team
RDS Open Source Databases
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