Re: GCC 3.0 Status Report

["John David Anglin" <dave@hiauly1.hia.nrc.ca>]

> I think that probably the other part is correct, but can you explain
> it in more detail?  Not what the problem is (I get that), but why your
> fix is the correct approach?

I am not entirely certain the approach is correct as my knowledge of
C++ and g++ is limited.  Can you see another way to copy the result
without using build_aggr_init?

My approach was based on debugging the existing code.  The call_expr
is converted by ocp_convert to a tree expression containing another
aggr_init_expr in expand_default_init.  Here is the code there:

      if (flags & DIRECT_BIND)
	/* Do nothing.  We hit this in two cases:  Reference initialization,
	   where we aren't initializing a real variable, so we don't want
	   to run a new constructor; and catching an exception, where we
	   have already built up the constructor call so we could wrap it
	   in an exception region.  */;
      else if (TREE_CODE (init) == CONSTRUCTOR)
	/* A brace-enclosed initializer has whatever type is
	   required.  There's no need to convert it.  */
	;
      else
        init = ocp_convert (type, init, CONV_IMPLICIT|CONV_FORCE_TEMP, flags);

It looked to me like the call was already built, so adding DIRECT_BIND
to the flags was the right thing to do to prevent the conversion.  However,
maybe the code here should be checking for a CALL_EXPR.  There is this
comment for build_aggr_init:

   If INIT resolves to a CALL_EXPR which happens to return
   something of the type we are looking for, then we know
   that we can safely use that call to perform the
   initialization.

Dave
-- 
J. David Anglin                                  dave.anglin@nrc.ca
National Research Council of Canada              (613) 990-0752 (FAX: 952-6605)