Hi, As a user of C++11 and C++14, I use the ax_cxx_compile_stdcxx variants, these have seemed to work on the various combinations of platforms/compilers I've used.
https://github.com/jamal-fuma/fuma_m4/blob/master/ax_cxx_compile_stdcxx.m4 https://github.com/jamal-fuma/fuma_m4/blob/master/ax_cxx_compile_stdcxx_14.m4 Perhaps these will offer a workaround until such time as you can solve the issue. HTH Jamal On 15:56 Wed 02 May 2018 , Mike Miller wrote: > Hi, > > In GNU Octave, we are embracing a lot of C++11, and so we are using the > gnulib std-gnu11.m4 drop-in to ensure that the compiler conforms to the > latest standards. I think several other GNU projects also use this file. > > The std-gnu11.m4 file defines AC_PROG_CC and AC_PROG_CXX replacements, > which I think are backported from Autoconf git. > > In a trivial project, for example > > AC_INIT([test], [0]) > AM_INIT_AUTOMAKE([1.14 foreign]) > AC_PROG_CC > AC_CONFIG_FILES([Makefile]) > AC_OUTPUT > > the AM_PROG_CC_C_O feature test is automatically called, as expected and > described in the Automake 1.14 NEWS. > > With std-gnu11.m4 added to this project, however, the AM_PROG_CC_C_O > macro is no longer called, either automatically or manually. The > intention of Automake to ensure that this test is always done is > defeated simply by including this file. > > If a call to the real macro > > _AM_PROG_CC_C_O > > is added after AC_PROG_CC, then the feature test is restored. > > I know enough m4 to get by, but I suspect this has to do with the order > of inclusion, and that Automake redefines AC_PROG_CC to call its own > _AM_PROG_CC_C_O, which is later clobbered by the inclusion of > std-gnu11.m4. > > Is there anything Automake can do to ensure that AM_PROG_CC_C_O is > called even if AC_PROG_CC is redefined locally? > > Even if you judge this not to be an Automake bug, I wanted to bring this > to your attention, since the std-gnu11.m4 file is the recommended way to > rely on modern language standards support at the moment. > > Thanks, > > -- > mike -- Fuma Software Ltd. Kemp House, 152-160 City Road, London, EC1V 2NX mob : +44(0)7830 164 097 tel : +44(0)2070 961 904 mail: jamal.nat...@fumasoftware.com Registered in England and Wales 6870430
