Re: [PATCH][14 backport] c++: Fix instantiation of imported temploid friends [PR114275]

[Jason Merrill <jason@redhat.com>]

On 5/24/24 04:06, Nathaniel Shead wrote:
> On Thu, May 23, 2024 at 06:41:06PM -0400, Jason Merrill wrote:
>> On 5/13/24 07:56, Nathaniel Shead wrote:
>>>>> @@ -11751,9 +11767,16 @@ tsubst_friend_class (tree friend_tmpl, tree args)
>>>>>           if (tmpl != error_mark_node)
>>>>>     	{
>>>>>     	  /* The new TMPL is not an instantiation of anything, so we
>>>>> -	     forget its origins.  We don't reset CLASSTYPE_TI_TEMPLATE
>>>>> +	     forget its origins.  It is also not a specialization of
>>>>> +	     anything.  We don't reset CLASSTYPE_TI_TEMPLATE
>>>>>     	     for the new type because that is supposed to be the
>>>>>     	     corresponding template decl, i.e., TMPL.  */
>>>>> +	  spec_entry elt;
>>>>> +	  elt.tmpl = friend_tmpl;
>>>>> +	  elt.args = CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl));
>>>>> +	  elt.spec = TREE_TYPE (tmpl);
>>>>> +	  type_specializations->remove_elt (&elt);
>>>>
>>>> For GCC 14.2 let's guard this with if (modules_p ()); for GCC 15 it can be
>>>> unconditional.  OK.
>>>
>>> I'm looking to backport this patch to GCC 14 now that it's been on trunk
>>> some time.  Here's the patch I'm aiming to add (squashed with the
>>> changes from r15-220-gec2365e07537e8) after cherrypicking the
>>> prerequisite commit r15-58-g2faf040335f9b4; is this OK?
>>>
>>> Or should I keep it as two separate commits to make the cherrypicking
>>> more obvious? Not entirely sure on the etiquette around this.
>>
>> It's OK to squash them, but it's typical to use -x (directly or via git
>> gcc-backport) to mention where a branch change was cherry-picked from, and
>> in this case it would make sense to edit in the second commit so it's clear
>> the backport includes both.  OK that way.
> 
> Sorry, still a bit confused :)  Do you mean to merge the two commits
> together such that there are two "cherry picked from commit ..."s in the
> commit message?  Or just list second commit, and mention that it
> includes both in the commit message?

I was thinking

(cherry picked from commit aaaaa and bbbbb)

but the exact format doesn't matter, just looking for a mention of both 
commits.

Jason