Christian Convey <christian.convey@xxxxxxxxx> writes: >>>> Are you sure that's a bug in the legalistic sense? IIRC, C and C++ >>>> don't promise any particular memory layout for structs. >>> >>> They don't promise any particular memory layout, but gcc does promise >>> that it will not arbitrarily change the layout in new releases. If it >>> did, it would be impossible for code compiled by one version of gcc to >>> call a function defined by a different version of gcc while passing a >>> struct parameter. >>> >>> Ian >> >> I always thought that structure layout conventions are plarform-wide >> much like calling conventions. Otherwise, how can we link together >> code compiled by different compilers? > > > My impression is that it works more by luck and convention, than by > any particular promise. No, within a single platform, it's a promise. Processors have specific written ABIs which describe, among other things, precisely how struct fields are laid out in memory. Ian
