X-Git-Url: https://git.liburcu.org/?p=urcu.git;a=blobdiff_plain;f=m4%2Fax_cxx_compile_stdcxx.m4;fp=m4%2Fax_cxx_compile_stdcxx.m4;h=c081ffacc03ace7b740b4a33a8b68dab4cd8dae7;hp=9413da624d2545123501b7788b7ac6d96fd322e8;hb=d001c88633f6a58e94eb73f4814976d13f61bd77;hpb=65eaf4b646f566324b92c25c8760a204bfbdffa8 diff --git a/m4/ax_cxx_compile_stdcxx.m4 b/m4/ax_cxx_compile_stdcxx.m4 index 9413da6..c081ffa 100644 --- a/m4/ax_cxx_compile_stdcxx.m4 +++ b/m4/ax_cxx_compile_stdcxx.m4 @@ -1,3 +1,4 @@ +# SPDX-License-Identifier: FSFAP # =========================================================================== # https://www.gnu.org/software/autoconf-archive/ax_cxx_compile_stdcxx.html # =========================================================================== @@ -10,8 +11,8 @@ # # 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. @@ -36,13 +37,14 @@ # Copyright (c) 2016, 2018 Krzesimir Nowak # Copyright (c) 2019 Enji Cooper # Copyright (c) 2020 Jason Merrill +# Copyright (c) 2021 Jörn Heusipp # # 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 12 +#serial 18 dnl This macro is based on the code from the AX_CXX_COMPILE_STDCXX_11 macro dnl (serial version number 13). @@ -51,6 +53,7 @@ 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], [], @@ -102,9 +105,18 @@ 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" @@ -151,7 +163,6 @@ 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], @@ -159,12 +170,24 @@ 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], [[ @@ -176,7 +199,11 @@ 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" @@ -467,7 +494,7 @@ 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" @@ -591,7 +618,7 @@ 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" @@ -957,6 +984,36 @@ 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 + +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 ]])