http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48835
--- Comment #11 from Eric Botcazou <ebotcazou at gcc dot gnu.org> 2011-06-14 08:44:12 UTC --- > In that case the Ada side of __gnat_malloc has to be changed to use a pointer > type rather than Address. Is Interfaces.C.Strings.chars_ptr acceptible, or is > there a better approximation for void* somewhere? The problem is that pointers drag a heavy machinery in Ada (to make it impossible to introduce the dangling sub-species) so low-level routines don't really want to use pointers, as they (are supposed to) know what they are doing. > The effect is that a pointer-valued callee returns its value in both %a0 and > %d0. A caller that has seen the pointer-valued prototype picks up the value > from %a0, but a caller that hasn't seen that prototype picks it up from %d0. I see, thanks. What about creating a machine-specific attribute, tentatively named "pointer return", that a m68k-specific version of s-memory.ads would put on the problematic functions? GNAT already supports machine-specific attributes. The effect would be the same as the one implemented in m68k_function_value.
