diff options
Diffstat (limited to 'm4/ax_cxx_compile_stdcxx_11.m4')
| -rw-r--r-- | m4/ax_cxx_compile_stdcxx_11.m4 | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/m4/ax_cxx_compile_stdcxx_11.m4 b/m4/ax_cxx_compile_stdcxx_11.m4 new file mode 100644 index 00000000..f6cf4a15 --- /dev/null +++ b/m4/ax_cxx_compile_stdcxx_11.m4 @@ -0,0 +1,140 @@ +# ============================================================================ +# http://www.gnu.org/software/autoconf-archive/ax_cxx_compile_stdcxx_11.html +# ============================================================================ +# +# SYNOPSIS +# +# AX_CXX_COMPILE_STDCXX_11([ext|noext],[mandatory|optional]) +# +# DESCRIPTION +# +# Check for baseline language coverage in the compiler for the C++11 +# standard; if necessary, add switches to CXXFLAGS to enable support. +# +# The first argument, if specified, indicates whether you insist on an +# extended mode (e.g. -std=gnu++11) or a strict conformance mode (e.g. +# -std=c++11). If neither is specified, you get whatever works, with +# preference for an extended mode. +# +# The second argument, if specified 'mandatory' or if left unspecified, +# indicates that baseline C++11 support is required and that the macro +# should error out if no mode with that support is found. If specified +# 'optional', then configuration proceeds regardless, after defining +# HAVE_CXX11 if and only if a supporting mode is found. +# +# LICENSE +# +# Copyright (c) 2008 Benjamin Kosnik <bkoz@redhat.com> +# Copyright (c) 2012 Zack Weinberg <zackw@panix.com> +# Copyright (c) 2013 Roy Stogner <roystgnr@ices.utexas.edu> +# +# Copying and distribution of this file, with or without modification, are +# permitted in any medium without royalty provided the copyright notice +# and this notice are preserved. This file is offered as-is, without any +# warranty. + +#serial 3 + +m4_define([_AX_CXX_COMPILE_STDCXX_11_testbody], [ + template <typename T> + struct check + { + static_assert(sizeof(int) <= sizeof(T), "not big enough"); + }; + + typedef check<check<bool>> right_angle_brackets; + + int a; + decltype(a) b; + + typedef check<int> check_type; + check_type c; + check_type&& cr = static_cast<check_type&&>(c); + + auto d = a; +]) + +AC_DEFUN([AX_CXX_COMPILE_STDCXX_11], [dnl + m4_if([$1], [], [], + [$1], [ext], [], + [$1], [noext], [], + [m4_fatal([invalid argument `$1' to AX_CXX_COMPILE_STDCXX_11])])dnl + m4_if([$2], [], [ax_cxx_compile_cxx11_required=true], + [$2], [mandatory], [ax_cxx_compile_cxx11_required=true], + [$2], [optional], [ax_cxx_compile_cxx11_required=false], + [m4_fatal([invalid second argument `$2' to AX_CXX_COMPILE_STDCXX_11])])dnl + AC_LANG_PUSH([C++])dnl + ac_success=no + AC_CACHE_CHECK(whether $CXX supports C++11 features by default, + ax_cv_cxx_compile_cxx11, + [AC_COMPILE_IFELSE([AC_LANG_SOURCE([_AX_CXX_COMPILE_STDCXX_11_testbody])], + [ax_cv_cxx_compile_cxx11=yes], + [ax_cv_cxx_compile_cxx11=no])]) + if test x$ax_cv_cxx_compile_cxx11 = xyes; then + ac_success=yes + fi + + restore_it="$CXXFLAGS" + m4_if([$1], [noext], [], [dnl + if test x$ac_success = xno; then + for switch in -std=gnu++11 -std=gnu++0x; do + cachevar=AS_TR_SH([ax_cv_cxx_compile_cxx11_$switch]) + AC_CACHE_CHECK(whether $CXX supports C++11 features with $switch, + $cachevar, + [ac_save_CXXFLAGS="$CXXFLAGS" + CXXFLAGS="$CXXFLAGS $switch" + AC_COMPILE_IFELSE([AC_LANG_SOURCE([_AX_CXX_COMPILE_STDCXX_11_testbody])], + [eval $cachevar=yes], + [eval $cachevar=no]) + CXXFLAGS="$ac_save_CXXFLAGS"]) + if eval test x\$$cachevar = xyes; then + CXXFLAGS="$CXXFLAGS" + c11switch="$switch" + ac_success=yes + break + fi + done + fi]) + + m4_if([$1], [ext], [], [dnl + if test x$ac_success = xno; then + for switch in -std=c++11 -std=c++0x; do + cachevar=AS_TR_SH([ax_cv_cxx_compile_cxx11_$switch]) + AC_CACHE_CHECK(whether $CXX supports C++11 features with $switch, + $cachevar, + [ac_save_CXXFLAGS="$CXXFLAGS" + CXXFLAGS="$CXXFLAGS $switch" + AC_COMPILE_IFELSE([AC_LANG_SOURCE([_AX_CXX_COMPILE_STDCXX_11_testbody])], + [eval $cachevar=yes], + [eval $cachevar=no]) + CXXFLAGS="$ac_save_CXXFLAGS"]) + if eval test x\$$cachevar = xyes; then + CXXFLAGS="$CXXFLAGS" + c11switch="$switch" + ac_success=yes + break + fi + done + fi]) + CXXFLAGS="$restore_it" + AC_SUBST([CXX11_SWITCH], ["$c11switch"]) + AC_LANG_POP([C++]) + if test x$ax_cxx_compile_cxx11_required = xtrue; then + if test x$ac_success = xno; then + AC_MSG_ERROR([*** A compiler with support for C++11 language features is required.]) + fi + else + if test x$ac_success = xno; then + HAVE_CXX11=0 + AC_MSG_NOTICE([No compiler with C++11 support was found]) + else + HAVE_CXX11=1 + AC_DEFINE(HAVE_CXX11,1, + [define if the compiler supports basic C++11 syntax]) + fi + AM_CONDITIONAL([HAVE_CXX11],[test "x$HAVE_CXX11" = "x1"]) + + AC_SUBST(HAVE_CXX11) + fi +]) + |