On Sun, Oct 28, 2012 at 5:25 PM, Florian Weimer <fw@xxxxxxxxxxxxx> wrote: > * Roger Leigh: > >> I would propose to add: >> >> AC_PROG_CXX_STDCXX >> AC_PROG_CXX_CXX98 >> AC_PROG_CXX_CXXTR1 [CXX98 with additional checks for TR1 headers] >> AC_PROG_CXX_CXX11 >> >> With behaviour the same as the existing C macros. > > This would be unwise because picking the most recent > compiler-supported standard will likely break programs on GNU/Linux. > Switching from C++98 to C++11 changes the ABI of standard library > templates, so it's basically an all-or-nothing choice for the entire > system. (Other language changes can break compilation, but these are > less obnoxious and easier to work around.) ABI break by gcc-4.7.0 and 4.7.1 in c++11 mode was a bug (or misfeature, call it as you want). Fixed in gcc-4.7.2. >From http://gcc.gnu.org/gcc-4.7/changes.html : o GCC versions 4.7.0 and 4.7.1 had changes to the C++ standard library which affected the ABI in C++11 mode: a data member was added to std::list changing its size and altering the definitions of some member functions, and std::pair's move constructor was non-trivial which altered the calling convention for functions with std::pair arguments or return types. The ABI incompatibilities have been fixed for GCC version 4.7.2 but as a result C++11 code compiled with GCC 4.7.0 or 4.7.1 may be incompatible with C++11 code compiled with different GCC versions and with C++98/C++03 code compiled with any version. -- Andrew W. Nosenko <andrew.w.nosenko@xxxxxxxxx> _______________________________________________ Autoconf mailing list Autoconf@xxxxxxx https://lists.gnu.org/mailman/listinfo/autoconf
