[C++ PATCH]: new abi rtti hint flags

[Nathan Sidwell]

Hi,
I've installed the attached which calculates the new abi's
vmi_class_type_info hint flags. No change in old abi behaviour.
The runtime makes some use of these at the moment, but not
complete use (yet).

booted and tested on i686-pc-linux-gnu

nathan
-- 
Dr Nathan Sidwell   ::   http://www.codesourcery.com   ::   CodeSourcery LLC
         'But that's a lie.' - 'Yes it is. What's your point?'
nathan@codesourcery.com : http://www.cs.bris.ac.uk/~nathan/ : nathan@acm.org
2000-04-03  Nathan Sidwell  <nathan@codesourcery.com>

	* rtti.c (dfs_class_hint_mark): New static function.
	(dfs_class_hint_unmark): New static function.
	(class_hint_flags): Use them.

Index: cp/rtti.c
===================================================================
RCS file: /cvs/gcc/egcs/gcc/cp/rtti.c,v
retrieving revision 1.79
diff -c -3 -p -r1.79 rtti.c
*** rtti.c	2000/04/02 22:50:55	1.79
--- rtti.c	2000/04/04 12:31:36
*************** static tree tinfo_base_init PARAMS((tree
*** 66,71 ****
--- 66,73 ----
  static tree generic_initializer PARAMS((tree, tree));
  static tree ptr_initializer PARAMS((tree, tree));
  static tree ptmd_initializer PARAMS((tree, tree));
+ static tree dfs_class_hint_mark PARAMS ((tree, void *));
+ static tree dfs_class_hint_unmark PARAMS ((tree, void *));
  static int class_hint_flags PARAMS((tree));
  static tree class_initializer PARAMS((tree, tree, tree));
  static tree synthesize_tinfo_var PARAMS((tree, tree));
*************** ptmd_initializer (desc, target)
*** 1381,1403 ****
    return init;  
  }
  
! /* Determine the hint flags describing the features of a class's heirarchy.
!    FIXME: better set the hint_flags here!  For now set them
!    to safe 'don't know' values.  The specification is under
!    review.  Don't forget to check the runtime dynamic_cast and
!    catch machinery if these change.  */
  
  static int
  class_hint_flags (type)
       tree type;
  {
    int hint_flags = 0;
    
!   hint_flags |= 0x1;  /* non-diamond shaped repeated base */
!   hint_flags |= 0x2;  /* diamond shaped */
!   hint_flags |= 0x4;  /* non-public base */
!   hint_flags |= 0x8;  /* public base */
!   type = 0; /* FIXME: Use it! */
    return hint_flags;
  }
          
--- 1390,1460 ----
    return init;  
  }
  
! /* Check base BINFO to set hint flags in *DATA, which is really an int.
!    We use CLASSTYPE_MARKED to tag types we've found as non-virtual bases and
!    CLASSTYPE_MARKED2 to tag those which are virtual bases. Remember it is
!    possible for a type to be both a virtual and non-virtual base.  */
! 
! static tree
! dfs_class_hint_mark (binfo, data)
!      tree binfo;
!      void *data;
! {
!   tree basetype = BINFO_TYPE (binfo);
!   int *hint = (int *) data;
!   
!   if (TREE_VIA_VIRTUAL (binfo))
!     {
!       if (CLASSTYPE_MARKED (basetype))
!         *hint |= 1;
!       if (CLASSTYPE_MARKED2 (basetype))
!         *hint |= 2;
!       SET_CLASSTYPE_MARKED2 (basetype);
!     }
!   else
!     {
!       if (CLASSTYPE_MARKED (basetype) || CLASSTYPE_MARKED2 (basetype))
!         *hint |= 1;
!       SET_CLASSTYPE_MARKED (basetype);
!     }
!   if (!TREE_VIA_PUBLIC (binfo) && TYPE_BINFO (basetype) != binfo)
!     *hint |= 4;
!   return NULL_TREE;
! };
  
+ /* Clear the base's dfs marks, after searching for duplicate bases. */
+ 
+ static tree
+ dfs_class_hint_unmark (binfo, data)
+      tree binfo;
+      void *data ATTRIBUTE_UNUSED;
+ {
+   tree basetype = BINFO_TYPE (binfo);
+   
+   CLEAR_CLASSTYPE_MARKED (basetype);
+   CLEAR_CLASSTYPE_MARKED2 (basetype);
+   return NULL_TREE;
+ }
+ 
+ /* Determine the hint flags describing the features of a class's heirarchy.  */
+ 
  static int
  class_hint_flags (type)
       tree type;
  {
    int hint_flags = 0;
+   int i;
+   
+   dfs_walk (TYPE_BINFO (type), dfs_class_hint_mark, NULL, &hint_flags);
+   dfs_walk (TYPE_BINFO (type), dfs_class_hint_unmark, NULL, NULL);
    
!   for (i = 0; i < CLASSTYPE_N_BASECLASSES (type); ++i)
!     {
!       tree base_binfo = BINFO_BASETYPE (TYPE_BINFO (type), i);
!       
!       if (TREE_VIA_PUBLIC (base_binfo))
!         hint_flags |= 0x8;
!     }
    return hint_flags;
  }