[C++] make TYPE_DECLs public for builtin type and templates

[C++] make TYPE_DECLs public for builtin type and templates

[Jan Hubicka]

Jason,
I made a verifier that types not considered anonymous are not built
from types that are anonymous and that public types have TREE_PUBLIC
flag on their TYPE_DECLS (as that seem to be what tree.h says).

This catches two cases in C++ FE and several other cases elsewhere.
Does something like this make sense? I think bulitin_types are
generally public, but I am not quite sure about templates.

Honza

	* decl.c (record_builtin_type): Make builting types public.
	* pt.c (reduce_template_parm_level): Make TYPE_DECL public.
Index: decl.c
===================================================================
--- decl.c	(revision 212098)
+++ decl.c	(working copy)
@@ -3591,6 +3591,7 @@ record_builtin_type (enum rid rid_index,
       tdecl = build_decl (BUILTINS_LOCATION, TYPE_DECL, tname, type);
       DECL_ARTIFICIAL (tdecl) = 1;
       SET_IDENTIFIER_GLOBAL_VALUE (tname, tdecl);
+      TREE_PUBLIC (tdecl) = true;
     }
   if (rname)
     {
@@ -3598,6 +3599,7 @@ record_builtin_type (enum rid rid_index,
 	{
 	  tdecl = build_decl (BUILTINS_LOCATION, TYPE_DECL, rname, type);
 	  DECL_ARTIFICIAL (tdecl) = 1;
+	  TREE_PUBLIC (tdecl) = true;
 	}
       SET_IDENTIFIER_GLOBAL_VALUE (rname, tdecl);
     }
Index: pt.c
===================================================================
--- pt.c	(revision 212098)
+++ pt.c	(working copy)
@@ -3623,6 +3623,8 @@ reduce_template_parm_level (tree index,
 			 TREE_CODE (orig_decl), DECL_NAME (orig_decl), type);
       TREE_CONSTANT (decl) = TREE_CONSTANT (orig_decl);
       TREE_READONLY (decl) = TREE_READONLY (orig_decl);
+      if (TREE_CODE (decl) == TYPE_DECL)
+        TREE_PUBLIC (decl) = 1;
       DECL_ARTIFICIAL (decl) = 1;
       SET_DECL_TEMPLATE_PARM_P (decl);
 

Re: [C++] make TYPE_DECLs public for builtin type and templates

[Jason Merrill]

On 06/30/2014 03:27 PM, Jan Hubicka wrote:
> This catches two cases in C++ FE and several other cases elsewhere.
> Does something like this make sense? I think bulitin_types are
> generally public, but I am not quite sure about templates.

Template parms have no linkage, but they certainly don't prevent a 
template from being public.  So I guess setting TREE_PUBLIC makes sense.

> I also wonder if I should copy
> PUBLIC flag from component type in complex numbers - can we produce complex
> number from anonymous type?

Only from built-in types I think, but it wouldn't hurt to copy 
TREE_PUBLIC from component_type.

> Finally type_in_anonymous_namespace_p needs to be extended into two cases where
> the type is considered nonanonymous by lack of DECL_NAME.

I would think the right fix is to avoid calling it for non-class types?

Jason

Re: [C++] make TYPE_DECLs public for builtin type and templates

[Jan Hubicka]

> On 06/30/2014 03:27 PM, Jan Hubicka wrote:
> >This catches two cases in C++ FE and several other cases elsewhere.
> >Does something like this make sense? I think bulitin_types are
> >generally public, but I am not quite sure about templates.
> 
> Template parms have no linkage, but they certainly don't prevent a
> template from being public.  So I guess setting TREE_PUBLIC makes
> sense.
> 
> >I also wonder if I should copy
> >PUBLIC flag from component type in complex numbers - can we produce complex
> >number from anonymous type?
> 
> Only from built-in types I think, but it wouldn't hurt to copy
> TREE_PUBLIC from component_type.

OK, I updated my copy of the patch.
> 
> >Finally type_in_anonymous_namespace_p needs to be extended into two cases where
> >the type is considered nonanonymous by lack of DECL_NAME.
> 
> I would think the right fix is to avoid calling it for non-class types?

I am trying to make LTO tree streaming to not unify types that are known to be local
to a compilation unit.  This allows better TBAA to be preserved, since two anonymous
namespace types from two different unit are not the same.

I want to avoid the overhead of SCC hashing and canonical type computation for these
and here I want the concept of anonymous namespace types to be closed upwards.
That is if I have type that is not considered anonymous it should not be built from
non-anonymous types.

So here I need to test anonymity of non-class types...

Thanks for looking into this!
Honza

Re: [C++] make TYPE_DECLs public for builtin type and templates

[Jason Merrill]

On 07/01/2014 07:40 PM, Jan Hubicka wrote:
> I want to avoid the overhead of SCC hashing and canonical type computation for these
> and here I want the concept of anonymous namespace types to be closed upwards.
> That is if I have type that is not considered anonymous it should not be built from
> non-anonymous types.
>
> So here I need to test anonymity of non-class types...

OK.  If you want to cover all compound types, you have more code to 
write, to cover pointer/reference/offset types and parameter types of 
function/method types.

Jason