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Diffstat (limited to 'Tools/config/ax_cxx_compile_stdcxx_11.m4')
| -rw-r--r-- | Tools/config/ax_cxx_compile_stdcxx_11.m4 | 121 |
1 files changed, 121 insertions, 0 deletions
diff --git a/Tools/config/ax_cxx_compile_stdcxx_11.m4 b/Tools/config/ax_cxx_compile_stdcxx_11.m4 new file mode 100644 index 000000000..138ca2aca --- /dev/null +++ b/Tools/config/ax_cxx_compile_stdcxx_11.m4 @@ -0,0 +1,121 @@ +# ============================================================================ +# http://www.gnu.org/software/autoconf-archive/ax_cxx_compile_stdcxx_11.html +# ============================================================================ +# +# SYNOPSIS +# +# AX_CXX_COMPILE_STDCXX_11([ext|noext], [nostop]) +# +# DESCRIPTION +# +# Check for baseline language coverage in the compiler for the C++11 +# standard; if necessary, add switches to CXXFLAGS to enable support. +# CXX11FLAGS will also contain any necessary switches to enable support. +# HAVE_CXX11_COMPILER will additionally be set to yes if there is support. +# If the second argument is not specified, errors out if no mode that +# supports C++11 baseline syntax can be found. 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. +# +# LICENSE +# +# Copyright (c) 2008 Benjamin Kosnik <bkoz@redhat.com> +# Copyright (c) 2012 Zack Weinberg <zackw@panix.com> +# Copyright (c) 2012 William Fulton <wsf@fultondesigns.co.uk> +# +# 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 1 + +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); +]) + +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], [], [], + [$2], [nostop], [], + [m4_fatal([invalid argument `$2' to AX_CXX_COMPILE_STDCXX_11])])dnl + AC_LANG_ASSERT([C++])dnl + ac_success=no + CXX11FLAGS= + 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 + + 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 $switch" + CXX11FLAGS=$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 $switch" + CXX11FLAGS=$switch + ac_success=yes + break + fi + done + fi]) + + if test x$ac_success = xno; then + if test x$2 != xnostop; then + AC_MSG_ERROR([*** A compiler with support for C++11 language features is required.]) + fi + else + HAVE_CXX11_COMPILER=yes + fi +]) |