diff options
Diffstat (limited to 'm4')
| -rw-r--r-- | m4/ax_cxx_compile_stdcxx.m4 | 89 |
1 files changed, 78 insertions, 11 deletions
diff --git a/m4/ax_cxx_compile_stdcxx.m4 b/m4/ax_cxx_compile_stdcxx.m4 index 43087b2..8edf515 100644 --- a/m4/ax_cxx_compile_stdcxx.m4 +++ b/m4/ax_cxx_compile_stdcxx.m4 @@ -10,13 +10,13 @@ # # Check for baseline language coverage in the compiler for the specified # version of the C++ standard. If necessary, add switches to CXX and -# CXXCPP to enable support. VERSION may be '11' (for the C++11 standard) -# or '14' (for the C++14 standard). +# CXXCPP to enable support. VERSION may be '11', '14', '17', or '20' for +# the respective C++ standard version. # # The second 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. +# preference for no added switch, and then for an extended mode. # # The third argument, if specified 'mandatory' or if left unspecified, # indicates that baseline support for the specified C++ standard is @@ -35,13 +35,15 @@ # Copyright (c) 2015 Moritz Klammler <moritz@klammler.eu> # Copyright (c) 2016, 2018 Krzesimir Nowak <qdlacz@gmail.com> # Copyright (c) 2019 Enji Cooper <yaneurabeya@gmail.com> +# Copyright (c) 2020 Jason Merrill <jason@redhat.com> +# Copyright (c) 2021 Jörn Heusipp <osmanx@problemloesungsmaschine.de> # # 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 11 +#serial 18 dnl This macro is based on the code from the AX_CXX_COMPILE_STDCXX_11 macro dnl (serial version number 13). @@ -50,6 +52,7 @@ AC_DEFUN([AX_CXX_COMPILE_STDCXX], [dnl m4_if([$1], [11], [ax_cxx_compile_alternatives="11 0x"], [$1], [14], [ax_cxx_compile_alternatives="14 1y"], [$1], [17], [ax_cxx_compile_alternatives="17 1z"], + [$1], [20], [ax_cxx_compile_alternatives="20"], [m4_fatal([invalid first argument `$1' to AX_CXX_COMPILE_STDCXX])])dnl m4_if([$2], [], [], [$2], [ext], [], @@ -62,6 +65,16 @@ AC_DEFUN([AX_CXX_COMPILE_STDCXX], [dnl AC_LANG_PUSH([C++])dnl ac_success=no + m4_if([$2], [], [dnl + AC_CACHE_CHECK(whether $CXX supports C++$1 features by default, + ax_cv_cxx_compile_cxx$1, + [AC_COMPILE_IFELSE([AC_LANG_SOURCE([_AX_CXX_COMPILE_STDCXX_testbody_$1])], + [ax_cv_cxx_compile_cxx$1=yes], + [ax_cv_cxx_compile_cxx$1=no])]) + if test x$ax_cv_cxx_compile_cxx$1 = xyes; then + ac_success=yes + fi]) + m4_if([$2], [noext], [], [dnl if test x$ac_success = xno; then for alternative in ${ax_cxx_compile_alternatives}; do @@ -91,9 +104,18 @@ AC_DEFUN([AX_CXX_COMPILE_STDCXX], [dnl dnl HP's aCC needs +std=c++11 according to: dnl http://h21007.www2.hp.com/portal/download/files/unprot/aCxx/PDF_Release_Notes/769149-001.pdf dnl Cray's crayCC needs "-h std=c++11" + dnl MSVC needs -std:c++NN for C++17 and later (default is C++14) for alternative in ${ax_cxx_compile_alternatives}; do - for switch in -std=c++${alternative} +std=c++${alternative} "-h std=c++${alternative}"; do - cachevar=AS_TR_SH([ax_cv_cxx_compile_cxx$1_$switch]) + for switch in -std=c++${alternative} +std=c++${alternative} "-h std=c++${alternative}" MSVC; do + if test x"$switch" = xMSVC; then + dnl AS_TR_SH maps both `:` and `=` to `_` so -std:c++17 would collide + dnl with -std=c++17. We suffix the cache variable name with _MSVC to + dnl avoid this. + switch=-std:c++${alternative} + cachevar=AS_TR_SH([ax_cv_cxx_compile_cxx$1_${switch}_MSVC]) + else + cachevar=AS_TR_SH([ax_cv_cxx_compile_cxx$1_$switch]) + fi AC_CACHE_CHECK(whether $CXX supports C++$1 features with $switch, $cachevar, [ac_save_CXX="$CXX" @@ -140,7 +162,6 @@ m4_define([_AX_CXX_COMPILE_STDCXX_testbody_11], _AX_CXX_COMPILE_STDCXX_testbody_new_in_11 ) - dnl Test body for checking C++14 support m4_define([_AX_CXX_COMPILE_STDCXX_testbody_14], @@ -148,12 +169,24 @@ m4_define([_AX_CXX_COMPILE_STDCXX_testbody_14], _AX_CXX_COMPILE_STDCXX_testbody_new_in_14 ) +dnl Test body for checking C++17 support + m4_define([_AX_CXX_COMPILE_STDCXX_testbody_17], _AX_CXX_COMPILE_STDCXX_testbody_new_in_11 _AX_CXX_COMPILE_STDCXX_testbody_new_in_14 _AX_CXX_COMPILE_STDCXX_testbody_new_in_17 ) +dnl Test body for checking C++20 support + +m4_define([_AX_CXX_COMPILE_STDCXX_testbody_20], + _AX_CXX_COMPILE_STDCXX_testbody_new_in_11 + _AX_CXX_COMPILE_STDCXX_testbody_new_in_14 + _AX_CXX_COMPILE_STDCXX_testbody_new_in_17 + _AX_CXX_COMPILE_STDCXX_testbody_new_in_20 +) + + dnl Tests for new features in C++11 m4_define([_AX_CXX_COMPILE_STDCXX_testbody_new_in_11], [[ @@ -165,7 +198,11 @@ m4_define([_AX_CXX_COMPILE_STDCXX_testbody_new_in_11], [[ #error "This is not a C++ compiler" -#elif __cplusplus < 201103L +// MSVC always sets __cplusplus to 199711L in older versions; newer versions +// only set it correctly if /Zc:__cplusplus is specified as well as a +// /std:c++NN switch: +// https://devblogs.microsoft.com/cppblog/msvc-now-correctly-reports-__cplusplus/ +#elif __cplusplus < 201103L && !defined _MSC_VER #error "This is not a C++11 compiler" @@ -456,7 +493,7 @@ m4_define([_AX_CXX_COMPILE_STDCXX_testbody_new_in_14], [[ #error "This is not a C++ compiler" -#elif __cplusplus < 201402L +#elif __cplusplus < 201402L && !defined _MSC_VER #error "This is not a C++14 compiler" @@ -580,7 +617,7 @@ m4_define([_AX_CXX_COMPILE_STDCXX_testbody_new_in_17], [[ #error "This is not a C++ compiler" -#elif __cplusplus < 201703L +#elif __cplusplus < 201703L && !defined _MSC_VER #error "This is not a C++17 compiler" @@ -946,6 +983,36 @@ namespace cxx17 } // namespace cxx17 -#endif // __cplusplus < 201703L +#endif // __cplusplus < 201703L && !defined _MSC_VER + +]]) + + +dnl Tests for new features in C++20 + +m4_define([_AX_CXX_COMPILE_STDCXX_testbody_new_in_20], [[ + +#ifndef __cplusplus + +#error "This is not a C++ compiler" + +#elif __cplusplus < 202002L && !defined _MSC_VER + +#error "This is not a C++20 compiler" + +#else + +#include <version> + +namespace cxx20 +{ + +// As C++20 supports feature test macros in the standard, there is no +// immediate need to actually test for feature availability on the +// Autoconf side. + +} // namespace cxx20 + +#endif // __cplusplus < 202002L && !defined _MSC_VER ]]) |