On Fri, 26 Oct 2018, Jan Hubicka wrote:
> > > OK if it survives more testing on firefox and lto bootstrap?
> >
> > It looks like a hack to do free_lang_data_in_type from
> > free_lang_data_in_decl
> > walk - I remember you wanted to unify find_* and free_*? If not doing that
>
> I did try it :) There is a catch - free lang data calls langhooks to produce
> mangled
> assembler names. For that the trees must be non-freed yet.
> So you can't do freeing as you discover what trees to follow.
>
> We can save one walk by computing assembler names during the discovery, but we
> need to know all trees we want to do langhooks on before we start putting NULL
> pointers around.
>
> > why would first doing the type walk and only then the decl walk not work
> > to avoid this ugliness?
>
> Hmm, currently we first walk decl and then types,so swapping them woudl work.
> But since I want to also simplify types in function types, it would break
> next.
>
> >
> > That we need to have variants of the incomplete types at all for the place
> > you substitute them (FIELD_DECLs) has what reason? See also comments
> > below...
> >
> > We are getting more and more "interesting" in things we free. _Please_
> > work on
> > enabling free-lang-data (portions) for all compilations (with
> > -fchecking?). It's disturbing to see
> > so much differences creep in in the supposedly "shared" part of regular and
> > LTO compilation.
>
> I wonder what is the plan to make late warnings to work reliably in this case?
Well - late warnings are a red herring. And we have caret locations
citing source. And we could look into the DWARF (well, not from lto1,
but there it's "broken" already anyways)
> > > +/* Do same comparsion as check_qualified_type skipping lang part of type
> > > + and be more permissive about type names: we only care that names are
> > > + same (for diagnostics) and that ODR names are the same. */
> > > +
> > > +static bool
> > > +types_equal_p (tree t, tree v)
> >
> > The function name is of course totally misleading. Please use sth like
> > fld_type_variants_equal_p.
> >
> > Note we already split check_qualified_type - can't you somehow re-use
> > check_base_type (only)?
>
> Hmm, you are right. I can re-unify those since this function basically cared
> about ...
> >
> > > +{
> > > + if (t==v)
> > > + return true;
> > > +
> > > + if (TYPE_QUALS (t) != TYPE_QUALS (v))
> > > + return false;
> > > +
> > > + if (TYPE_NAME (t) != TYPE_NAME (v)
> > > + && (!TYPE_NAME (t) || !TYPE_NAME (v)
> > > + || TREE_CODE (TYPE_NAME (t)) != TYPE_DECL
> > > + || TREE_CODE (TYPE_NAME (v)) != TYPE_DECL
> > > + || DECL_ASSEMBLER_NAME_RAW (TYPE_NAME (t))
> > > + != DECL_ASSEMBLER_NAME_RAW (TYPE_NAME (v))
> >
> > I wonder what this is about...
>
> ... unmerged TYPE_NAMEs which happens only on WPA state. It is leftover of
> my merging during streaming experiment.
>
> I will clean this up and send updated patch. I was bit in hurry leaving today
> and wanted to send at least initial patch for discussion.
OK, btw I noticed that we simply do
DECL_ORIGINAL_TYPE (decl) = NULL_TREE;
on TYPE_DECLs. But the bigger benefit would be dropping the typedef
variants completely by doing
if (TREE_CODE (TYPE_NAME (TREE_TYPE (t))) == TYPE_DECL
&& DECL_ORIGINAL_TYPE (TYPE_NAME (TREE_TYPE (t))))
TREE_TYPE (t) = DECL_ORIGINAL_TYPE (TYPE_NAME (TREE_TYPE (t)));
for all type references. That should get rid of most TYPE_DECLs
(the DECL_ORIGINAL_TYPE has no name IIRC).
Simply NULLing DECL_ORIGINAL_TYPE on TYPE_DECLs will make this
impossible.
Richard.
