libstdc++: [_GLIBCXX_DEBUG] Fix assignment of value-initialized iterator
[PR112477]
Now that _M_Detach do not reset iterator _M_version value we need to
reset it when
the iterator is attached to a new sequence. Even if this sequencer is
null like when
assigning a value-initialized iterator. In this case _M_version shall be
reset to 0.
libstdc++-v3/ChangeLog:
PR libstdc++/112477
* src/c++11/debug.cc
(_Safe_iterator_base::_M_attach): Reset _M_version to 0 if
attaching to null
sequence.
(_Safe_iterator_base::_M_attach_single): Likewise.
(_Safe_local_iterator_base::_M_attach): Likewise.
(_Safe_local_iterator_base::_M_attach_single): Likewise.
* testsuite/23_containers/map/debug/112477.cc: New test case.
Tested under Linux x64 _GLIBCXX_DEBUG mode.
Ok to commit and backport to gcc 13 ?
François
On 09/01/2024 22:47, fdumont at gcc dot gnu.org wrote:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112477
François Dumont <fdumont at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Assignee|unassigned at gcc dot gnu.org |fdumont at gcc dot
gnu.org
--- Comment #8 from François Dumont <fdumont at gcc dot gnu.org> ---
Hi
I'm going to have a look but if you wish to contribute do not hesitate.
Thanks for the report.
diff --git a/libstdc++-v3/src/c++11/debug.cc b/libstdc++-v3/src/c++11/debug.cc
index bb0d0db6679..cb2cbf9d312 100644
--- a/libstdc++-v3/src/c++11/debug.cc
+++ b/libstdc++-v3/src/c++11/debug.cc
@@ -437,6 +437,8 @@ namespace __gnu_debug
_M_version = _M_sequence->_M_version;
_M_sequence->_M_attach(this, __constant);
}
+ else
+ _M_version = 0;
}
void
@@ -452,6 +454,8 @@ namespace __gnu_debug
_M_version = _M_sequence->_M_version;
_M_sequence->_M_attach_single(this, __constant);
}
+ else
+ _M_version = 0;
}
void
@@ -528,6 +532,8 @@ namespace __gnu_debug
_M_version = _M_sequence->_M_version;
_M_get_container()->_M_attach_local(this, __constant);
}
+ else
+ _M_version = 0;
}
void
@@ -543,6 +549,8 @@ namespace __gnu_debug
_M_version = _M_sequence->_M_version;
_M_get_container()->_M_attach_local_single(this, __constant);
}
+ else
+ _M_version = 0;
}
void
diff --git a/libstdc++-v3/testsuite/23_containers/map/debug/112477.cc
b/libstdc++-v3/testsuite/23_containers/map/debug/112477.cc
new file mode 100644
index 00000000000..bde613b8905
--- /dev/null
+++ b/libstdc++-v3/testsuite/23_containers/map/debug/112477.cc
@@ -0,0 +1,20 @@
+// { dg-do run { target c++11 } }
+// { dg-require-debug-mode "" }
+
+// PR libstdc++/112477
+
+#include <map>
+
+int main()
+{
+ using M = std::map<int, int>;
+ using I = M::iterator;
+
+ M map{ {1, 1}, {2, 2} };
+
+ I it1 = map.begin();
+ it1 = I{};
+
+ I it2{};
+ (void)(it1 == it2);
+}
