configure.ac | 36 +++++++++++++++++++++++++++++++++++-
1 file changed, 35 insertions(+), 1 deletion(-)
New commits:
commit ffc1ab15ae358315516aab319778a254688afbd3
Author: Stephan Bergmann <stephan.bergm...@allotropia.de>
AuthorDate: Thu Feb 15 08:44:22 2024 +0100
Commit: Stephan Bergmann <stephan.bergm...@allotropia.de>
CommitDate: Thu Feb 15 14:52:01 2024 +0100
Work around some Clang PCH consteval issue by disabling HAVE_CPP_CONSTEVAL
(see the links in the configure.ac check for details)
Change-Id: I9a98f784f68931cb4482bc02be313d18c5464105
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/163422
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <stephan.bergm...@allotropia.de>
diff --git a/configure.ac b/configure.ac
index 48b325790b80..aca1d243ced5 100644
--- a/configure.ac
+++ b/configure.ac
@@ -14724,6 +14724,7 @@ dnl
`cast<PointerType>(getOperand(1)->getType())->isOpaqueOrPointeeTypeMatches(g
dnl && "Ptr must be a pointer to Val type!"' failed." (which should be fixed
since Clang 17), or
dnl
<https://developercommunity.visualstudio.com/t/Bogus-error-C2440-with-consteval-constru/10579616>
dnl "Bogus error C2440 with consteval constructor (/std:c++20)":
+have_cpp_consteval=
AC_LANG_PUSH([C++])
save_CXX=$CXX
if test "$COM" = MSC && test "$COM_IS_CLANG" != TRUE; then
@@ -14783,12 +14784,45 @@ AC_RUN_IFELSE([AC_LANG_PROGRAM([
], [
return (s.i == 1) ? 0 : 1;
])], [
- AC_DEFINE([HAVE_CPP_CONSTEVAL],[1])
+ have_cpp_consteval=1
AC_MSG_RESULT([yes])
], [AC_MSG_RESULT([no])], [AC_MSG_RESULT([assumed no (cross compiling)])])
CXX=$save_CXX
CXXFLAGS=$save_CXXFLAGS
AC_LANG_POP([C++])
+if test -n "$have_cpp_consteval" && test "$COM_IS_CLANG" = TRUE && test -n
"$BUILDING_PCH_WITH_OBJ"
+then
+ AC_MSG_CHECKING([whether $CXX_BASE has working consteval in combination
with PCH])
+ dnl ...that does not suffer from
<https://github.com/llvm/llvm-project/issues/81745> "undefined
+ dnl reference to consteval constructor exported from module" (which also
affects PCH, see
+ dnl
<https://lists.freedesktop.org/archives/libreoffice/2024-February/091564.html>
"Our Clang
+ dnl --enable-pch setup is known broken"):
+ printf 'export module M;
export struct S1 { consteval S1(int) {} };' >conftest.cppm
+ $CXX $CXXFLAGS $CXXFLAGS_CXX11 --precompile conftest.cppm
+ rm conftest.cppm
+ AC_LANG_PUSH([C++])
+ save_CXXFLAGS=$CXXFLAGS
+ save_LDFLAGS=$LDFLAGS
+ CXXFLAGS="$CXXFLAGS $CXXFLAGS_CXX11"
+ LDFLAGS="$LDFLAGS -fmodule-file=M=conftest.pcm conftest.pcm"
+ AC_LINK_IFELSE([AC_LANG_PROGRAM([
+ import M;
+ ], [
+ struct S2 { S1 s = 0; };
+ S2 s;
+ ])], [
+ AC_MSG_RESULT([yes])
+ ], [
+ have_cpp_consteval=
+ AC_MSG_RESULT([no])])
+ CXXFLAGS=$save_CXXFLAGS
+ LDFLAGS=$save_LDFLAGS
+ AC_LANG_POP([C++])
+ rm confetst.pcm
+fi
+if test -n "$have_cpp_consteval"; then
+ AC_DEFINE([HAVE_CPP_CONSTEVAL],[1])
+fi
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
