* H. J. Lu: >> I tested GCC 5.3.1 and Clang 3.5.0. >> >> GCC Clang >> s0 non-empty non-empty >> s1 non-empty empty >> s2 non-empty empty >> s3 empty empty >> s4 empty empty >> s5 non-empty empty >> >> I believe s3, s4, s5 are non-empty according to your rules. Why put >> both compilers in the wrong? That doesn't make sense to me. > > Please try testcases in > > https://llvm.org/bugs/show_bug.cgi?id=26337 > > with clang on both ia32 and x86-64. Clang isn't consistent between > ia32 and x86-64.
Okay, with -m32, I get non-empty passing for s5 from Clang as well. But I still don't think it makes sense to change the ABI for s3 and s4, and even for s5, the Clang/x86_64 behavior is arguably more correct. >> Jason already indicated he intends GCC to move towards more empty >> arguments, not fewer. >> >>>> How do existing C++ compilers implement empty array members (an >>>> extension)? Does the type of such members affect whether a class is a >>>> standard-layout class? >> >>> Are they "POD for the purpose of layout"? If yes, they are covered here. >> >> The C++ standard does not define this. > > GCC has > > * Nonzero means that this class type is not POD for the purpose of layout > (as defined in the ABI). This is different from the language's POD. */ > #define CLASSTYPE_NON_LAYOUT_POD_P(NODE) \ > > We can use this definition for ia32, x86-64 and IA MCU psABIs. It still has to be spelled out in non-GCC terms, IMHO. _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
