Re: C++ PATCH to deal with trivial but non-callable [cd]tors

[Eric Botcazou <ebotcazou at adacore dot com>]

> > +/* Return whether DECL, a method of a C++ TYPE, is trivial, that is to
> > say +   doesn't do anything for the objects of TYPE.  */
> > +
> > +static bool
> > +is_trivial_method (const_tree decl, const_tree type)
> > +{
> > +  if (cpp_check (decl, IS_CONSTRUCTOR) && !TYPE_NEEDS_CONSTRUCTING
> > (type)) +    return true;
> 
> This will tell you whether decl is a constructor for a type with some
> non-trivial constructor, but not whether decl itself is non-trivial.

I think that's good enough though, in practice we only need to eliminate 
constructors/destructors for POD types.  As soon as there is one non-trivial 
method, the game is essentially over.

> I think a good way to check for any non-trivial methods would be to
> check trivial_type_p in the front end and then see if there are any
> !DECL_ARTIFICIAL decls in TYPE_METHODS.

That sounds interesting indeed, thanks for the tip.  I was initially reluctant 
to call into the front-end because of side-effects, but the various predicates 
in tree.c seem fine in this respect.

-- 
Eric Botcazou