64 bits (irrelevant), union type (irrelevant either) cc -c -64 -g -Demacs -I. -DHAVE_CONFIG_H -I/usr/local/include -xansi /users/model/galibert/org/xemacs/xemacs-20/src/extents.c "/users/model/galibert/org/xemacs/xemacs-20/src/extents.c", line 4435: warning(1110): statement is unreachable RETURN_NOT_REACHED(0) ^ "/users/model/galibert/org/xemacs/xemacs-20/src/extents.c", line 4987: warning(1185): enumerated type mixed with another type return glyph_layout_to_symbol (extent_begin_glyph_layout (e)); ^ "/users/model/galibert/org/xemacs/xemacs-20/src/extents.c", line 4997: warning(1185): enumerated type mixed with another type return glyph_layout_to_symbol (extent_end_glyph_layout (e)); ^ "/users/model/galibert/org/xemacs/xemacs-20/src/extents.c", line 5362: warning(1185): enumerated type mixed with another type if ((layout = extent_begin_glyph_layout (anc)) != GL_TEXT) ^ "/users/model/galibert/org/xemacs/xemacs-20/src/extents.c", line 5369: warning(1185): enumerated type mixed with another type if ((layout = extent_end_glyph_layout (anc)) != GL_TEXT) ^ The first warning I don't really care about. The other ones suck. The root cause is that enum_field (enabling enum bitfields, a non-ISO C extension[1]) is used only on GNU C. It is perfectly supported by the irix compiler I use. So that should be tested in configure. Martin, do you want to do it or should I hack up something? OG. PS: gdb 4.17 has just been released. Happy hacking. [1] At least for the first version of ISO C. I don't know since then.