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

[Jason Merrill <jason@redhat.com>]

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.

Jason