On 2/14/13, Richard Biener <richard.guent...@gmail.com> wrote:
> On Tue, Feb 12, 2013 at 8:47 PM, Lawrence Crowl <cr...@google.com> wrote:
> > Add class record_builder to ease construction of records and unions. Use
> > it
> > in some appropriate places.
....
> > tree
> > -default_emutls_var_fields (tree type, tree *name ATTRIBUTE_UNUSED)
> > +default_emutls_object_type (void)
> > {
> > - tree word_type_node, field, next_field;
> > -
> > - field = build_decl (UNKNOWN_LOCATION,
> > - FIELD_DECL, get_identifier ("__templ"),
> > ptr_type_node);
> > - DECL_CONTEXT (field) = type;
> > - next_field = field;
> > -
> > - field = build_decl (UNKNOWN_LOCATION,
> > - FIELD_DECL, get_identifier ("__offset"),
> > - ptr_type_node);
> > - DECL_CONTEXT (field) = type;
> > - DECL_CHAIN (field) = next_field;
> > - next_field = field;
> > -
> > - word_type_node = lang_hooks.types.type_for_mode (word_mode, 1);
> > - field = build_decl (UNKNOWN_LOCATION,
> > - FIELD_DECL, get_identifier ("__align"),
> > - word_type_node);
> > - DECL_CONTEXT (field) = type;
> > - DECL_CHAIN (field) = next_field;
> > - next_field = field;
> > -
> > - field = build_decl (UNKNOWN_LOCATION,
> > - FIELD_DECL, get_identifier ("__size"),
> > word_type_node);
> > - DECL_CONTEXT (field) = type;
> > - DECL_CHAIN (field) = next_field;
> > -
> > - return field;
> > + tree word_type_node = lang_hooks.types.type_for_mode (word_mode, 1);
> > + record_builder rec;
> > + rec.add_field ("__size", word_type_node);
> > + rec.add_field ("__align", word_type_node);
> > + rec.add_field ("__offset", ptr_type_node);
> > + rec.add_field ("__templ", ptr_type_node);
> > + rec.layout ();
>
> That's awkward - you want to hide the fact that layout has
> to happen and that it has to happen "last". Just make it a
> side-effect of .as_tree ().
Sometimes you want to construct recursive types, and for that you
need .as_tree to execute before layout. This feature is used in
the patch.
> Note that add_field want's to return the FIELD_DECL created,
> people may want to alter it.
Do you have a use case? Until we have one, I'm not convinced that
we should widen the interface.
> Note that tag_name does not allow the way C++ uses this (it can
> be a TYPE_DECL).
That is what the .decl_name member function does.
> Overall I'm not sure this is a good abstraction unless you manage
> to make the frontends use it.
The intent is for use by the middle/back ends constructing code.
As such, it should be using middle/back end types, not front-end
types.
--
Lawrence Crowl
