silence use-after-free warning in mdds for gcc12 in optimized build

Change-Id: I15385718dd705128e9e02541f33e46069dec5251
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/154890
Tested-by: Jenkins
Reviewed-by: Christian Lohmaier <lohmaier+LibreOffice@googlemail.com>

2 files changed, 43 insertions, 0 deletions

diff --git a/external/mdds/UnpackedTarball_mdds.mk b/external/mdds/UnpackedTarball_mdds.mk
index 271d20b0f4d1..5745da0b11c5 100644
--- a/external/mdds/UnpackedTarball_mdds.mk
+++ b/external/mdds/UnpackedTarball_mdds.mk
@@ -15,6 +15,7 @@ $(eval $(call gb_UnpackedTarball_set_patchlevel,mdds,0))
 
 $(eval $(call gb_UnpackedTarball_add_patches,mdds,\
     external/mdds/use-after-free.patch \
+    external/mdds/gcc-12-silence-use-after-free.patch.1 \
 ))
 
 # vim: set noet sw=4 ts=4:
diff --git a/external/mdds/gcc-12-silence-use-after-free.patch.1 b/external/mdds/gcc-12-silence-use-after-free.patch.1
new file mode 100644
index 000000000000..3f8dd0afe0f3
--- /dev/null
+++ b/external/mdds/gcc-12-silence-use-after-free.patch.1
@@ -0,0 +1,42 @@
+Workaround for gcc-toolset-12 on almalinux8 on a release/optimized build:
+[build CXX] sc/source/core/data/column2.cxx
+In file included from /home/tdf/lode/jenkins/workspace/lo_gerrit/Config/linux_gcc_release_64/workdir/UnpackedTarball/mdds/include/mdds/flat_segment_tree.hpp:37,
+                 from /home/tdf/lode/jenkins/workspace/lo_gerrit/Config/linux_gcc_release_64/sc/inc/columnspanset.hxx:16,
+                 from /home/tdf/lode/jenkins/workspace/lo_gerrit/Config/linux_gcc_release_64/sc/inc/column.hxx:25,
+                 from /home/tdf/lode/jenkins/workspace/lo_gerrit/Config/linux_gcc_release_64/sc/source/core/data/column2.cxx:20:
+In function ‘void mdds::__st::intrusive_ptr_release(node<T>*) [with T = mdds::flat_segment_tree<int, bool>]’,
+    inlined from ‘boost::intrusive_ptr<T>::~intrusive_ptr() [with T = mdds::__st::node<mdds::flat_segment_tree<int, bool> >]’ at /home/tdf/lode/jenkins/workspace/lo_gerrit/Config/linux_gcc_release_64/workdir/UnpackedTarball/boost/boost/smart_ptr/intrusive_ptr.hpp:100:44,
+    inlined from ‘std::pair<mdds::flat_segment_tree<Key, Value>::const_iterator, bool> mdds::flat_segment_tree<Key, Value>::insert_segment_impl(key_type, key_type, value_type, bool) [with Key = int; Value = bool]’ at /home/tdf/lode/jenkins/workspace/lo_gerrit/Config/linux_gcc_release_64/workdir/UnpackedTarball/mdds/include/mdds/flat_segment_tree_def.inl:225:1:
+/home/tdf/lode/jenkins/workspace/lo_gerrit/Config/linux_gcc_release_64/workdir/UnpackedTarball/mdds/include/mdds/node.hpp:247:10: error: pointer used after ‘void operator delete(void*, std::size_t)’ [-Werror=use-after-free]
+  247 |     --p->refcount;
+      |       ~~~^~~~~~~~
+In function ‘void mdds::__st::intrusive_ptr_release(node<T>*) [with T = mdds::flat_segment_tree<int, bool>]’,
+    inlined from ‘void mdds::__st::intrusive_ptr_release(node<T>*) [with T = mdds::flat_segment_tree<int, bool>]’ at /home/tdf/lode/jenkins/workspace/lo_gerrit/Config/linux_gcc_release_64/workdir/UnpackedTarball/mdds/include/mdds/node.hpp:245:13,
+    inlined from ‘boost::intrusive_ptr<T>::~intrusive_ptr() [with T = mdds::__st::node<mdds::flat_segment_tree<int, bool> >]’ at /home/tdf/lode/jenkins/workspace/lo_gerrit/Config/linux_gcc_release_64/workdir/UnpackedTarball/boost/boost/smart_ptr/intrusive_ptr.hpp:100:44,
+    inlined from ‘std::pair<mdds::flat_segment_tree<Key, Value>::const_iterator, bool> mdds::flat_segment_tree<Key, Value>::insert_segment_impl(key_type, key_type, value_type, bool) [with Key = int; Value = bool]’ at /home/tdf/lode/jenkins/workspace/lo_gerrit/Config/linux_gcc_release_64/workdir/UnpackedTarball/mdds/include/mdds/flat_segment_tree_def.inl:224:93:
+/home/tdf/lode/jenkins/workspace/lo_gerrit/Config/linux_gcc_release_64/workdir/UnpackedTarball/mdds/include/mdds/node.hpp:249:9: note: call to ‘void operator delete(void*, std::size_t)’ here
+  249 |         delete p;
+      |         ^~~~~~~~
+cc1plus: all warnings being treated as errors
+
+diff -ur mdds.org/include/mdds/node.hpp mdds/include/mdds/node.hpp
+--- mdds.org/include/mdds/node.hpp	2023-07-24 18:27:14.427139325 +0000
++++ mdds/include/mdds/node.hpp	2023-07-24 18:26:54.554461294 +0000
+@@ -244,9 +244,15 @@
+ template<typename T>
+ inline void intrusive_ptr_release(node<T>* p)
+ {
+-    --p->refcount;
+-    if (!p->refcount)
++#if defined __GNUC__ && __GNUC__ == 12 && __GNUC_MINOR__ < 3 && !defined __clang__
++#pragma GCC diagnostic push
++#pragma GCC diagnostic ignored "-Wuse-after-free"
++#endif
++    if(--p->refcount == 0)
+         delete p;
++#if defined __GNUC__ && __GNUC__ == 12 && __GNUC_MINOR__ < 3 && !defined __clang__
++#pragma GCC diagnostic pop
++#endif
+ }
+ 
+ template<typename T>