From d996e8074ce122c887617c2c7fb20c4a67530aa3 Mon Sep 17 00:00:00 2001 From: Stephan Bergmann Date: Mon, 20 Apr 2020 11:40:24 +0200 Subject: Add --with-latest-c++ to explicitly opt in for -std=c++20/-std:c++latest cd472d1d8489f30797f47d3f6dafede28c1feb90 "Compile as C++2a, where available" had started to unconditionally check for support of -std=c++2a (and later also -std=c++20) for Clang and GCC, but that can cause occasional issues especially for Linux distros, see e.g. 55c724b93dfd4c9a1afb10d60fbc2d7a9a66cf61 "replace boost::bimap in sdext pdfimport" or "/usr/include/boost/format/alt_sstream_impl.hpp incompatible with -std=c++20 (std::allocator::allocate hint argument)" (where 677c8de4fa79cd9b278b142013ba7f1c9e4e41c3 "external/boost: Adapt to std::allocator parts removed in C++20" is not picked up due to --with-system-boost). So better require an explicit opt-in via a new --with-latest-c++. And while at it, also make that enable -std:c++latest for MSVC. Change-Id: I2d1f03144fad9a7884562e56b1b76cab5eb8f080 Reviewed-on: https://gerrit.libreoffice.org/c/core/+/92555 Tested-by: Jenkins Reviewed-by: Stephan Bergmann Reviewed-on: https://gerrit.libreoffice.org/c/core/+/93204 Tested-by: Jenkins CollaboraOffice Reviewed-by: Tor Lillqvist --- configure.ac | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) (limited to 'configure.ac') diff --git a/configure.ac b/configure.ac index 76cc8f5f3ca8..c64fa51b7dbf 100644 --- a/configure.ac +++ b/configure.ac @@ -2144,6 +2144,12 @@ libo_FUZZ_ARG_WITH(lxml, report widget classes and ids.]), ,) +libo_FUZZ_ARG_WITH(latest-c++, + AS_HELP_STRING([--with-latest-c++], + [Try to enable the latest features of the C++ compiler, even if they are not yet part of a + published standard.]),, + [$with_latest_c__=no]) + dnl =================================================================== dnl Branding dnl =================================================================== @@ -6248,14 +6254,21 @@ libo_FUZZ_ARG_ENABLE(c++17, AC_MSG_CHECKING([whether $CXX supports C++17, C++14, or C++11]) CXXFLAGS_CXX11= if test "$COM" = MSC -a "$COM_IS_CLANG" != TRUE; then - CXXFLAGS_CXX11=-std:c++17 + if test "$with_latest_c__" = yes; then + CXXFLAGS_CXX11=-std:c++latest + else + CXXFLAGS_CXX11=-std:c++17 + fi elif test "$GCC" = "yes" -o "$COM_IS_CLANG" = TRUE; then dnl But only use C++17 if the gperf that is being used knows not to emit dnl "register" in C++ output: printf 'foo\n' | $GPERF -L C++ > conftest.inc my_flags='-std=gnu++14 -std=gnu++1y -std=c++14 -std=c++1y -std=gnu++11 -std=gnu++0x -std=c++11 -std=c++0x' if test "$enable_c__17" != no; then - my_flags="-std=gnu++2a -std=c++2a -std=gnu++17 -std=gnu++1z -std=c++17 -std=c++1z $my_flags" + my_flags="-std=gnu++17 -std=gnu++1z -std=c++17 -std=c++1z $my_flags" + if test "$with_latest_c__" = yes; then + my_flags="-std=gnu++2a -std=c++2a $my_flags" + fi fi for flag in $my_flags; do if test "$COM" = MSC; then -- cgit