[Bug objc/43061] 47 new GCC HEAD@156527 regressions

["developer at sandoe-acoustics dot co dot uk" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #34 from developer at sandoe-acoustics dot co dot uk  2010-02-16 14:58 -------
Created an attachment (id=19889)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=19889&action=view)
patch with CLASS and SELECTOR refs. marked as TREE_ADDRESSABLE &
DECL_PRESERVE_P (for NeXT runtime)

In view of the comments in
http://gcc.gnu.org/ml/gcc-patches/2010-02/msg00597.html and
http://gcc.gnu.org/ml/gcc-patches/2010-02/msg00587.html it's clear that people
feel that the bug is actually in ipa* and cgraphunit.c.  

However, a grep of lookup_attribute ipa* etc. suggests that altering these has
possibly wide-reaching effects, which might not be welcome at this stage.

I've added back in the marking of CLASS_REFERENCES_* and SELECTOR_REFERENCES_*
as TREE_ADDRESSABLE and DECL_PRESERVE_P.  Of course, this doesn't solve the
problem unless the addition of the "used" attribute in finish_var_decl() is
left in place too (although that can be removed once the underlying problem is
resolved).

Would it be best to close this bug with the lookup_attribute fix - and open a
new bug for ipa*.c and cgraphunit.c to support DECL_PRESERVE_P and/or
TREE_USED? 

In fact, I'm a bit confused about what combination of flags is really needed. 
TREE_USED appears to match in intent with "used" attribute - which is placed on
the vars in objc-act.c/finish_var_decl().

DECL_PRESERVE_P presumably should only be used on the
CLASS_REFERENCES/SELECTOR_REFERENCES - and thus I've placed it local to those
two definitions.


-- 

developer at sandoe-acoustics dot co dot uk changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
  Attachment #19884|0                           |1
        is obsolete|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43061