Werner LEMBERG wrote: > > Could you try incorporating the std-gnu11 module into your package, > > and see whether that fixes things? If so, perhaps we could fix this > > problem for everybody by having stddef depend on std-gnu11. > > This approach worked
Nevertheless, I don't agree that this is the solution. What you are trying to do is to run the configure tests with a C compiler and then use the resulting config.h with C code [1] and C++ code [2]. [1] http://repo.or.cz/ttfautohint.git/tree/HEAD:/lib [2] http://repo.or.cz/ttfautohint.git/tree/HEAD:/frontend This is not supported by Autoconf, and this is not supported by Gnulib - simply because _any_ test result (not just the one for max_align_t) may be different in C++ than it is in C. There is one real fix for this problem: You create separate configure.ac files for the lib/ and for the frontend directory, and each of them uses a separate gnulib-tool invocation. (So, you must use the options --lib and --source-base of gnulib-tool, to make sure the two gnulib-tool results don't interfere.) The configure.ac for frontend/ must use AC_LANG_PUSH([C++]) before gl_INIT. This fix is future-proof: It will work even after - you request additional gnulib modules, - the C standard features change, - the C++ standard features change. The other approaches are brittle: If we/you change something regarding the max_align_t problem, you will continue to see issues - on other platforms, - when you request additional gnulib modules, - when the C standard features change, - when the C++ standard features change. Among these other approaches are the following: * You could add gnulib module 'std-gnu11' to the list of gnulib modules you request. This has the chance of fixing other problems than the max_align_t one, because C++ is closer to C11 than it is to C99. But still, newer C or C++ standard can bring new problems. * Gnulib could add a dependency from 'stddef' to 'std-gnu11'. I reject this idea because this is a big change that affects all users, for a situation that is not supported. * Gnulib could test something like HAVE_MAX_ALIGN_T || (defined(__APPLE__) && defined(__MACH__) && defined(__cplusplus)) instead of HAVE_MAX_ALIGN_T This is not such a big change, but it is brittle code, may only fix the max_align_t problem, and is for a situation that is not supported. In summary, I don't think Gnulib should change here, and you still the choice among a real fix and a quick-fix. Bruno
