Re: [PATCH] c++: stream PACK_EXPANSION_EXTRA_ARGS [PR106761]

[Nathan Sidwell <nathan@acm.org>]

On 9/19/22 09:52, Patrick Palka wrote:
> It looks like some xtreme-header-* tests are failing after the libstdc++
> change r13-2158-g02f6b405f0e9dc ultimately because we're neglecting
> to stream PACK_EXPANSION_EXTRA_ARGS, which leads to false equivalences
> of different partial instantiations of _TupleConstraints::__constructible.
> 
> Tested on x86_64-pc-linux-gnu, does this look OK for trunk?
> 
> 	PR c++/106761
> 
> gcc/cp/ChangeLog:
> 
> 	* module.cc (trees_out::type_node) <case TYPE_PACK_EXPANSION>:
> 	Stream PACK_EXPANSION_EXTRA_ARGS.
> 	(trees_in::tree_node) <case TYPE_PACK_EXPANSION>: Likewise.


Looks good, I wonder why I missed that.  (I guess extracting a testcase 
out of the headers was too tricky?)

nathan
> ---
>   gcc/cp/module.cc | 3 +++
>   1 file changed, 3 insertions(+)
> 
> diff --git a/gcc/cp/module.cc b/gcc/cp/module.cc
> index 1a1ff5be574..9a9ef4e3332 100644
> --- a/gcc/cp/module.cc
> +++ b/gcc/cp/module.cc
> @@ -8922,6 +8922,7 @@ trees_out::type_node (tree type)
>         if (streaming_p ())
>   	u (PACK_EXPANSION_LOCAL_P (type));
>         tree_node (PACK_EXPANSION_PARAMETER_PACKS (type));
> +      tree_node (PACK_EXPANSION_EXTRA_ARGS (type));
>         break;
>   
>       case TYPENAME_TYPE:
> @@ -9455,12 +9456,14 @@ trees_in::tree_node (bool is_use)
>   	    {
>   	      bool local = u ();
>   	      tree param_packs = tree_node ();
> +	      tree extra_args = tree_node ();
>   	      if (!get_overrun ())
>   		{
>   		  tree expn = cxx_make_type (TYPE_PACK_EXPANSION);
>   		  SET_TYPE_STRUCTURAL_EQUALITY (expn);
>   		  PACK_EXPANSION_PATTERN (expn) = res;
>   		  PACK_EXPANSION_PARAMETER_PACKS (expn) = param_packs;
> +		  PACK_EXPANSION_EXTRA_ARGS (expn) = extra_args;
>   		  PACK_EXPANSION_LOCAL_P (expn) = local;
>   		  res = expn;
>   		}

-- 
Nathan Sidwell