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| author | Stephan Bergmann <stephan.bergmann@allotropia.de> | 2024-02-07 09:39:27 +0100 |
|---|---|---|
| committer | Stephan Bergmann <stephan.bergmann@allotropia.de> | 2024-02-07 21:03:46 +0100 |
| commit | 56e6d683dba66d4f2f80145064d2bda2ea4b27b1 (patch) | |
| tree | a67de3c1f2e841179ad9359740a1db60eda04712 /configure.ac | |
| parent | 43451b31969db882cd6c36054f43915ffbd8f252 (diff) | |
double operator < is not a strict weak ordering due to NaN
...so recent LLVM 19 trunk libc++ in debug mode complained during
CppunitTest_chart2_export2 about
> ~/llvm/inst/bin/../include/c++/v1/__debug_utils/strict_weak_ordering_check.h:59: assertion __comp(*(__first + __a), *(__first + __b)) failed: Your comparator is not a valid strict-weak ordering
at
> 5 libsystem_c.dylib 0x0000000183279a40 abort + 180
> 6 libc++.1.0.dylib 0x00000001030f9d98 _ZNSt3__123__cxx_atomic_notify_oneEPVKv + 0
> 7 libchartcorelo.dylib 0x00000002f817f0ec _ZNSt3__135__check_strict_weak_ordering_sortedB8de190000INS_11__wrap_iterIPNS_6vectorIdNS_9allocatorIdEEEEEEN5chart12_GLOBAL__N_116lcl_LessXOfPointEEEvT_SB_RT0_ + 960
> 8 libchartcorelo.dylib 0x00000002f817e6cc _ZNSt3__118__stable_sort_implB8de190000INS_17_ClassicAlgPolicyENS_11__wrap_iterIPNS_6vectorIdNS_9allocatorIdEEEEEEN5chart12_GLOBAL__N_116lcl_LessXOfPointEEEvT0_SC_RT1_ + 268
> 9 libchartcorelo.dylib 0x00000002f8172a90 _ZNSt3__111stable_sortB8de190000INS_11__wrap_iterIPNS_6vectorIdNS_9allocatorIdEEEEEEN5chart12_GLOBAL__N_116lcl_LessXOfPointEEEvT_SB_T0_ + 68
> 10 libchartcorelo.dylib 0x00000002f8172820 _ZN5chart11VDataSeries15doSortByXValuesEv + 508
> 11 libchartcorelo.dylib 0x00000002f8064c44 _ZN5chart9AreaChart12createShapesEv + 1528
> 12 libchartcorelo.dylib 0x00000002f80f2ae0 _ZN5chart9ChartView28impl_createDiagramAndContentERKNS_18CreateShapeParam2DERKN3com3sun4star3awt4SizeE + 4440
> 13 libchartcorelo.dylib 0x00000002f80f77ac _ZN5chart9ChartView14createShapes2DERKN3com3sun4star3awt4SizeE + 2728
> 14 libchartcorelo.dylib 0x00000002f80f58ec _ZN5chart9ChartView12createShapesEv + 692
> 15 libchartcorelo.dylib 0x00000002f80f4598 _ZN5chart9ChartView15impl_updateViewEb + 288
But the introduced use of `std::strong_order(first[0], second[0]) < 0` then
triggered a false
> lo/core/chart2/source/view/main/VDataSeries.cxx:105:61: error: NullToMemberPointer ValueDependentIsNotNull ZeroLiteral -> nullptr [loplugin:nullptr]
> 105 | return std::strong_order(first[0], second[0]) < 0;
> | ^
so needed some hack in loplugin:nullptr.
And old versions of libc++, still used at least on Android, do not have any
implementations of std::strong_order. So detect those cases in configure.ac
(checking for std::strong_order for double, which is what is actually being used
in the code) and fall back to operator <=> for now, even if that will not
provide a strict weak ordering and will thus continue to violate the
requirements of std::sort.
And then our venerable clang-format 5.0.0 would have broken the token `<=>` into
`<= >`, so exclude include/o3tl/compare.hxx from its mis-treatment.
Change-Id: I7a64a630eb5f560dce59f3ff9d51ca3d1adc70be
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/163075
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <stephan.bergmann@allotropia.de>
Diffstat (limited to 'configure.ac')
| -rw-r--r-- | configure.ac | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/configure.ac b/configure.ac index 5937983f7ac2..721851c52d87 100644 --- a/configure.ac +++ b/configure.ac @@ -14787,6 +14787,29 @@ CXX=$save_CXX CXXFLAGS=$save_CXXFLAGS AC_LANG_POP([C++]) +AC_MSG_CHECKING([whether $CXX_BASE supports a working C++20 std::strong_order]) +dnl ...which is known to not be implemented in libc++ prior to +dnl <https://github.com/llvm/llvm-project/commit/d8380ad977e94498e170b06449c81f1fc27da7b5> "[libc++] +dnl [P1614] Implement [cmp.alg]'s std::{strong,weak,partial}_order" in LLVM 14: +AC_LANG_PUSH([C++]) +save_CXX=$CXX +if test "$COM" = MSC && test "$COM_IS_CLANG" != TRUE; then + CXX="env LIB=$ILIB $CXX" +fi +save_CXXFLAGS=$CXXFLAGS +CXXFLAGS="$CXXFLAGS $CXXFLAGS_CXX11" +AC_LINK_IFELSE([AC_LANG_PROGRAM([ + #include <compare> + ], [ + (void) (std::strong_order(1.0, 2.0) < 0); + ])], [ + AC_DEFINE([HAVE_CPP_STRONG_ORDER],[1]) + AC_MSG_RESULT([yes]) + ], [AC_MSG_RESULT([no])]) +CXX=$save_CXX +CXXFLAGS=$save_CXXFLAGS +AC_LANG_POP([C++]) + # =================================================================== # Creating bigger shared library to link against # =================================================================== |