From a9f77e87f3e6ca3333bbb16dec5456f3bf2903b8 Mon Sep 17 00:00:00 2001 From: Stephan Bergmann Date: Sun, 20 Oct 2019 14:42:56 +0200 Subject: We do not need a C++ GNU dialect MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 1cf7ab61a71d4b7295942ff5c855896e60c15081 "use -std=gnu++0x rather than -std=c++0x" appears to have started this, but the only rationale it gives is that it keeps things in sync with GCC's default behavior when no -std= is given. But it apparently works fine to build with a -std=c++... standard dialect. This allows to get rid of the check introduced with 50cd28e5728b6a64c1e605567540739ea6ef42ca "Ensure configuration that defines math_errhandling in ". (It kept bothering me to say "I observe this-and-this with -std=c++2a" when what configure.ac made me actually use was -std=gnu++2a. And truthfully saying "-std=gnu++2a" would have been a distraction, as what is relevant for such an observation is most likely the "2a" and not the "gnu" part.) Change-Id: I7c213a702ffb7df6f4c2c4a421008e30e2712a51 Reviewed-on: https://gerrit.libreoffice.org/81176 Tested-by: Jenkins Reviewed-by: Luboš Luňák --- configure.ac | 10 +--------- 1 file changed, 1 insertion(+), 9 deletions(-) (limited to 'configure.ac') diff --git a/configure.ac b/configure.ac index 422efbdc7b46..9c8d512be07b 100644 --- a/configure.ac +++ b/configure.ac @@ -6432,7 +6432,7 @@ CXXFLAGS_CXX11= if test "$COM" = MSC -a "$COM_IS_CLANG" != TRUE; then CXXFLAGS_CXX11='-std:c++17 -Zc:__cplusplus' elif test "$GCC" = "yes" -o "$COM_IS_CLANG" = TRUE; then - my_flags='-std=gnu++2a -std=c++2a -std=gnu++17 -std=gnu++1z -std=c++17 -std=c++1z' + my_flags='-std=c++2a -std=c++17 -std=c++1z' for flag in $my_flags; do if test "$COM" = MSC; then flag="-Xclang $flag" @@ -6475,7 +6475,6 @@ elif test "$GCC" = "yes" -o "$COM_IS_CLANG" = TRUE; then ]) AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[ #include - #include #include #include @@ -6495,13 +6494,6 @@ elif test "$GCC" = "yes" -o "$COM_IS_CLANG" = TRUE; then void f(std::vector & v, std::function fn) { std::sort(v.begin(), v.end(), fn); } - - // At least with glibc-headers-2.28-26.fc29.x86_64, when building for Linux x86 32-bit - // (via -m32) and passed-in CXXFLAGS setting -O1 (or higher; overriding -Os as set in - // solenv/gbuild/platform/LINUX_INTEL_GCC.mk), std=gnu* would cause math_errhandling to - // get undef'ed in /usr/include/bits/mathinline.h, while std=c* keeps it defined (as - // needed by sc/source/core/tool/math.cxx): - int g() { return math_errhandling; } ]])],[CXXFLAGS_CXX11=$flag $my_float128hack]) AC_LANG_POP([C++]) CXXFLAGS=$save_CXXFLAGS -- cgit v1.2.1 From f0b74640137f07ed74027f98fbf6d1c0d98939bf 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 Adaptation of this change to this branch. The point is to avoid compiling as C++2a as the code for externals has not been patched properly for that here. Here is the original commit message even if I assume it is a bit misleading in this branch: 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 Reviewed-on: https://gerrit.libreoffice.org/c/core/+/93692 Tested-by: Tor Lillqvist --- configure.ac | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/configure.ac b/configure.ac index 78080305f3d6..8364138bdc96 100644 --- a/configure.ac +++ b/configure.ac @@ -2143,6 +2143,12 @@ 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 =================================================================== @@ -6456,9 +6462,17 @@ dnl =================================================================== AC_MSG_CHECKING([whether $CXX_BASE supports C++17]) CXXFLAGS_CXX11= if test "$COM" = MSC -a "$COM_IS_CLANG" != TRUE; then - CXXFLAGS_CXX11='-std:c++17 -Zc:__cplusplus' + if test "$with_latest_c__" = yes; then + CXXFLAGS_CXX11=-std:c++latest + else + CXXFLAGS_CXX11=-std:c++17 + fi + CXXFLAGS_CXX11="$CXXFLAGS_CXX11 -Zc:__cplusplus" elif test "$GCC" = "yes" -o "$COM_IS_CLANG" = TRUE; then - my_flags='-std=c++2a -std=c++17 -std=c++1z' + my_flags='-std=c++17 -std=c++1z' + if test "$with_latest_c__" = yes; then + my_flags="-std=gnu++2a -std=c++2a $my_flags" + fi for flag in $my_flags; do if test "$COM" = MSC; then flag="-Xclang $flag" -- cgit v1.2.1