On Wed, Sep 9, 2020 at 4:59 AM Jan Mercl <0xj...@gmail.com> wrote: > > If the intent is to have Go alignments/offsets of types compatible > with the C ABI then I think it's safe to say this is a bug. > > And the existence of the syscall package, in some cases passing > Go-defined structs to the kernel that must be binary compatible with > their C definitions, IMO suggests that the intent is indeed there.
Exact alignment/offset compatibility with the C ABI is not a goal. Sorry. (It's actually harder than one might think to maintain that kind of compatibility. For example, on x86, the C ABI uses one alignment for double variables and a different alignment for double variables that appear as a field in a struct. Unless, of course, you use the -malign-double option. And more generally some platforms have multiple C ABIs, including x86 if you count the MCU psABI.) The Go structs in the syscall package that need to match C structs are carefully written to work correctly. You may find the cgo -godefs option to be helpful, as it provides Go structs that exactly match C structs, given a particular set of compiler options. Ian -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/CAOyqgcW%2ByA%2BzE4afZ81GJHCXm%3De9tfz-8gD99EQiEe%2Bk7xOKRw%40mail.gmail.com.
