libstdc++: [_GLIBCXX_DEBUG] Fix std::erase_if for std::vector behavior
When using directly __gnu_debug::vector the std::erase_if is called
with a
reference to the std::vector base class and so is missing the
invalidation
of the iterators that might result from the erase.
To fix this provide a std::erase_if overload dedicated to
__gnu_debug::vector.
Doing so we can cleanup the implementation dedicated to std::vector
from any
_GLIBCXX_DEBUG consideration.
libstdc++-v3/ChangeLog:
* include/debug/vector (std::erase_if, std::erase): New
overloads for
__gnu_debug::vector instances.
* include/std/vector (std::erase_if, std::erase): Make
overloads specific
to normal std::vector implementation.
* testsuite/23_containers/vector/debug/erase.cc: New test case.
*
testsuite/23_containers/vector/debug/invalidation/erase.cc: New test case.
Tested under Linux x86_64,
ok to commit ?
François
diff --git a/libstdc++-v3/include/debug/vector
b/libstdc++-v3/include/debug/vector
index 1b3486b0dc0..d1aea194d3d 100644
--- a/libstdc++-v3/include/debug/vector
+++ b/libstdc++-v3/include/debug/vector
@@ -920,13 +920,23 @@ namespace __debug
#endif
private:
- void
+ _GLIBCXX20_CONSTEXPR void
_M_invalidate_after_nth(difference_type __n) _GLIBCXX_NOEXCEPT
{
- typedef __gnu_debug::_After_nth_from<_Base_const_iterator> _After_nth;
- this->_M_invalidate_if(_After_nth(__n, _Base::begin()));
+ if (!std::__is_constant_evaluated())
+ {
+ typedef
+ __gnu_debug::_After_nth_from<_Base_const_iterator> _After_nth;
+ this->_M_invalidate_if(_After_nth(__n, _Base::begin()));
+ }
}
- };
+
+#ifdef __cpp_lib_erase_if
+ template<typename _Tp2, typename _Alloc2, typename _Pred>
+ friend constexpr typename vector<_Tp2, _Alloc2>::size_type
+ std::erase_if(vector<_Tp2, _Alloc2>&, _Pred);
+#endif
+ };
template<typename _Tp, typename _Alloc>
_GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
@@ -1038,6 +1048,35 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
} // namespace __detail::__variant
#endif // C++17
+#ifdef __cpp_lib_erase_if // C++ >= 20 && HOSTED
+ template<typename _Tp, typename _Alloc, typename _Predicate>
+ constexpr typename __debug::vector<_Tp, _Alloc>::size_type
+ erase_if(__debug::vector<_Tp, _Alloc>& __cont, _Predicate __pred)
+ {
+ auto& __unsafe_cont = __cont._M_base();
+ const auto __osz = __cont.size();
+ const auto __end = __unsafe_cont.end();
+ auto __begin = std::__find_if(__unsafe_cont.begin(), __end, __pred);
+ const auto __offset = __begin - __unsafe_cont.begin();
+ auto __removed =
+ std::__remove_if(__begin, __end, std::move(__pred));
+ if (__removed != __end)
+ {
+ __cont.erase(__niter_wrap(__cont.begin(), __removed),
+ __cont.end());
+ __cont._M_invalidate_after_nth(__offset);
+ return __osz - __cont.size();
+ }
+
+ return 0;
+ }
+
+ template<typename _Tp, typename _Alloc, typename _Up = _Tp>
+ constexpr typename __debug::vector<_Tp, _Alloc>::size_type
+ erase(__debug::vector<_Tp, _Alloc>& __cont, const _Up& __value)
+ { return std::erase_if(__cont, __gnu_cxx::__ops::__equal_to(__value)); }
+#endif // __cpp_lib_erase_if
+
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace std
diff --git a/libstdc++-v3/include/std/vector b/libstdc++-v3/include/std/vector
index 920f852f794..375011fff69 100644
--- a/libstdc++-v3/include/std/vector
+++ b/libstdc++-v3/include/std/vector
@@ -112,19 +112,16 @@ namespace std _GLIBCXX_VISIBILITY(default)
_GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _Tp, typename _Alloc, typename _Predicate>
- constexpr typename vector<_Tp, _Alloc>::size_type
- erase_if(vector<_Tp, _Alloc>& __cont, _Predicate __pred)
+ constexpr typename _GLIBCXX_STD_C::vector<_Tp, _Alloc>::size_type
+ erase_if(_GLIBCXX_STD_C::vector<_Tp, _Alloc>& __cont, _Predicate __pred)
{
- using namespace __gnu_cxx;
- _GLIBCXX_STD_C::vector<_Tp, _Alloc>& __ucont = __cont;
const auto __osz = __cont.size();
- const auto __end = __ucont.end();
- auto __removed = std::__remove_if(__ucont.begin(), __end,
+ const auto __end = __cont.end();
+ auto __removed = std::__remove_if(__cont.begin(), __end,
std::move(__pred));
if (__removed != __end)
{
- __cont.erase(__niter_wrap(__cont.begin(), __removed),
- __cont.end());
+ __cont.erase(__removed, __end);
return __osz - __cont.size();
}
@@ -133,8 +130,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _Tp, typename _Alloc,
typename _Up _GLIBCXX26_DEF_VAL_T(_Tp)>
- constexpr typename vector<_Tp, _Alloc>::size_type
- erase(vector<_Tp, _Alloc>& __cont, const _Up& __value)
+ constexpr typename _GLIBCXX_STD_C::vector<_Tp, _Alloc>::size_type
+ erase(_GLIBCXX_STD_C::vector<_Tp, _Alloc>& __cont, const _Up& __value)
{ return std::erase_if(__cont, __gnu_cxx::__ops::__equal_to(__value)); }
_GLIBCXX_END_NAMESPACE_VERSION
diff --git a/libstdc++-v3/testsuite/23_containers/vector/debug/erase.cc
b/libstdc++-v3/testsuite/23_containers/vector/debug/erase.cc
new file mode 100644
index 00000000000..95bfd9cc130
--- /dev/null
+++ b/libstdc++-v3/testsuite/23_containers/vector/debug/erase.cc
@@ -0,0 +1,27 @@
+// { dg-do run { target c++20 } }
+// { dg-require-debug-mode "" }
+
+#include <vector>
+#include <testsuite_hooks.h>
+
+void test01()
+{
+ std::vector<int> v;
+
+ for (int i = 0; i != 10; ++i)
+ v.push_back(i);
+
+ auto before = v.begin() + 4;
+ auto after = std::next(before, 4);
+
+ VERIFY( std::erase(v, 6) == 1 );
+
+ VERIFY(before._M_dereferenceable());
+ VERIFY(after._M_singular());
+}
+
+int main()
+{
+ test01();
+ return 0;
+}
diff --git
a/libstdc++-v3/testsuite/23_containers/vector/debug/invalidation/erase.cc
b/libstdc++-v3/testsuite/23_containers/vector/debug/invalidation/erase.cc
new file mode 100644
index 00000000000..f28bbadaf54
--- /dev/null
+++ b/libstdc++-v3/testsuite/23_containers/vector/debug/invalidation/erase.cc
@@ -0,0 +1,28 @@
+// { dg-do run { target c++20 } }
+
+#include <debug/vector>
+#include <testsuite_hooks.h>
+
+using __gnu_debug::vector;
+
+void test01()
+{
+ vector<int> v;
+
+ for (int i = 0; i != 10; ++i)
+ v.push_back(i);
+
+ auto before = v.begin() + 4;
+ auto after = std::next(before, 4);
+
+ VERIFY( std::erase(v, 6) == 1 );
+
+ VERIFY(before._M_dereferenceable());
+ VERIFY(after._M_singular());
+}
+
+int main()
+{
+ test01();
+ return 0;
+}
