build: Make sure $CXX supports C++11.

* m4/guix.m4 (GUIX_CHECK_CXX11, GUIX_ASSERT_CXX11): New macros.
* config-daemon.ac: Use 'AC_LANG([C++])' and 'GUIX_ASSERT_CXX11'.C
* doc/guix.texi (Requirements): Mention C++11 support.
This commit is contained in:
Ludovic Courtès 2015-05-19 09:09:47 +02:00
parent 2bb04905f8
commit 368d08f747
3 changed files with 46 additions and 3 deletions

View file

@ -5,9 +5,12 @@ AC_MSG_RESULT([$guix_build_daemon])
dnl C++ environment. This macro must be used unconditionnaly.
AC_PROG_CXX
AC_LANG([C++])
if test "x$guix_build_daemon" = "xyes"; then
GUIX_ASSERT_CXX11
AC_PROG_RANLIB
AC_CONFIG_HEADER([nix/config.h])

View file

@ -368,9 +368,10 @@ Unless @code{--disable-daemon} was passed to @command{configure}, the
following packages are also needed:
@itemize
@item @url{http://sqlite.org, SQLite 3}
@item @url{http://www.bzip.org, libbz2}
@item @url{http://gcc.gnu.org, GCC's g++}
@item @url{http://sqlite.org, SQLite 3};
@item @url{http://www.bzip.org, libbz2};
@item @url{http://gcc.gnu.org, GCC's g++}, with support for the
C++11 standard.
@end itemize
When a working installation of @url{http://nixos.org/nix/, the Nix package

View file

@ -218,3 +218,42 @@ AC_DEFUN([GUIX_CHECK_FILE_NAME_LIMITS], [
AC_MSG_ERROR([store directory '$storedir' would lead to overly long hash-bang lines])
fi
])
dnl GUIX_CHECK_CXX11
dnl
dnl Check whether the C++ compiler can compile a typical C++11 program.
AC_DEFUN([GUIX_CHECK_CXX11], [
AC_REQUIRE([AC_PROG_CXX])
AC_CACHE_CHECK([whether $CXX supports C++11],
[ac_cv_guix_cxx11_support],
[save_CXXFLAGS="$CXXFLAGS"
CXXFLAGS="-std=c++11 $CXXFLAGS"
AC_COMPILE_IFELSE([
AC_LANG_SOURCE([
#include <functional>
std::function<int(int)>
return_plus_lambda (int x)
{
auto result = [[&]](int y) {
return x + y;
};
return result;
}
])],
[ac_cv_guix_cxx11_support=yes],
[ac_cv_guix_cxx11_support=no])
CXXFLAGS="$save_CXXFLAGS"
])
])
dnl GUIX_ASSERT_CXX11
dnl
dnl Error out if the C++ compiler cannot compile C++11 code.
AC_DEFUN([GUIX_ASSERT_CXX11], [
GUIX_CHECK_CXX11
if test "x$ac_cv_guix_cxx11_support" != "xyes"; then
AC_MSG_ERROR([C++ compiler '$CXX' does not support the C++11 standard])
fi
])