------- Comment #17 from ebotcazou at gcc dot gnu dot org 2006-01-22 11:43
-------
> No real solution as of this writing, only a poor workaround: not compiling the
> support files with -gnato (overflow checks).
Well, I may have spoken too soon. :-) We are calling Remove_Side_Effects on:
N_Type_Conversion (Node_Id=1679) (analyzed)
Rewritten: original node = N_Op_Add "Oadd" (Node_Id=39499)
Parent = N_Range (Node_Id=1681)
Sloc = 7611 fdd2a00.adb:6:38
Etype = N_Defining_Identifier "Tstream_element_offsetB" (Entity_Id=2017)
Subtype_Mark = N_Identifier "Tstream_element_offsetB" (Node_Id=39497)
Expression = N_Function_Call (Node_Id=39496)
Conversion_OK = True
It turns out that the fix is already present in the front-end, but inhibited:
-- If this is a type conversion, leave the type conversion and remove
-- the side effects in the expression. This is important in several
-- circumstances: for change of representations, and also when this
-- is a view conversion to a smaller object, where gigi can end up
-- creating its own temporary of the wrong size.
-- ??? this transformation is inhibited for elementary types that are
-- not involved in a change of representation because it causes
-- regressions that are not fully understood yet.
elsif Nkind (Exp) = N_Type_Conversion
and then (not Is_Elementary_Type (Underlying_Type (Exp_Type))
or else Nkind (Parent (Exp)) = N_Assignment_Statement)
then
Remove_Side_Effects (Expression (Exp), Name_Req, Variable_Ref);
Scope_Suppress := Svg_Suppress;
return;
However, another possible fix is to make a copy when we know we will not be
able to use a renaming. Tentative patch to be attached.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18819
