[Bug c++/105322] [modules] ICE with constexpr object of local class type from another function

["guojiufu at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105322

Jiu Fu Guo <guojiufu at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |guojiufu at gcc dot gnu.org

--- Comment #3 from Jiu Fu Guo <guojiufu at gcc dot gnu.org> ---
One finding:
In trees_out::decl_node, there are code lines:

    case FIELD_DECL:
      {
        if (streaming_p ())
          i (tt_data_member);

        tree ctx = DECL_CONTEXT (decl);
        tree_node (ctx); //The context, is the struct "S" inside foo, "S" is
handled in 'tree_node', and "insert" is called for member "d".

        tree name = NULL_TREE;

        if (TREE_CODE (decl) == USING_DECL)
          ;
        else
          {
            name = DECL_NAME (decl);
            if (name && IDENTIFIER_ANON_P (name))
              name = NULL_TREE;
          }

        tree_node (name);
        if (!name && streaming_p ())
          {
            unsigned ix = get_field_ident (ctx, decl);
            u (ix);
          }

        int tag = insert (decl); //HERE, "insert" is called again member "d". 

It may be a direct cause that "insert" is called twice for "d", and then a
crash occurs.

While I do not know much about the code and do not found a fix.