[committed] libstdc++: Prevent unwanted ADL in std::to_array [PR111512]
This is the fix for the release branches, where std::to_array is
implemented differently.
Tested x86_64-linux. Pushed to gcc-13 and gcc-12. Will push to gcc-11
after testing.
-- >8 --
Qualify the calls to the __to_array helper to prevent ADL, so we don't
try to complete associated classes.
libstdc++-v3/ChangeLog:
PR libstdc++/111511
PR c++/111512
* include/std/array (to_array): Qualify calls to __to_array.
* testsuite/23_containers/array/creation/111512.cc: New test.
(cherry picked from commit 77cf3773021b0a20d89623e09d620747a05588ec)
---
libstdc++-v3/include/std/array| 4 +--
.../23_containers/array/creation/111512.cc| 25 +++
2 files changed, 27 insertions(+), 2 deletions(-)
create mode 100644
libstdc++-v3/testsuite/23_containers/array/creation/111512.cc
diff --git a/libstdc++-v3/include/std/array b/libstdc++-v3/include/std/array
index 70280c1beeb..97cca454ef9 100644
--- a/libstdc++-v3/include/std/array
+++ b/libstdc++-v3/include/std/array
@@ -436,7 +436,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
static_assert(!is_array_v<_Tp>);
static_assert(is_constructible_v<_Tp, _Tp&>);
if constexpr (is_constructible_v<_Tp, _Tp&>)
- return __to_array(__a, make_index_sequence<_Nm>{});
+ return std::__to_array(__a, make_index_sequence<_Nm>{});
__builtin_unreachable(); // FIXME: see PR c++/91388
}
@@ -449,7 +449,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
static_assert(!is_array_v<_Tp>);
static_assert(is_move_constructible_v<_Tp>);
if constexpr (is_move_constructible_v<_Tp>)
- return __to_array<1>(__a, make_index_sequence<_Nm>{});
+ return std::__to_array<1>(__a, make_index_sequence<_Nm>{});
__builtin_unreachable(); // FIXME: see PR c++/91388
}
#endif // C++20
diff --git a/libstdc++-v3/testsuite/23_containers/array/creation/111512.cc
b/libstdc++-v3/testsuite/23_containers/array/creation/111512.cc
new file mode 100644
index 000..f510480ae4b
--- /dev/null
+++ b/libstdc++-v3/testsuite/23_containers/array/creation/111512.cc
@@ -0,0 +1,25 @@
+// { dg-options "-std=gnu++20" }
+// { dg-do compile { target c++20 } }
+
+// Bug libstdc++/111511 - Incorrect ADL in std::to_array in GCC 11/12/13
+// Bug c++/111512 - GCC's __builtin_memcpy can trigger ADL
+
+#include
+#include
+
+struct incomplete;
+
+template
+struct holder {
+T t; // { dg-bogus "'holder::t' has incomplete type" }
+};
+
+// A complete type that cannot be used as an associated type for ADL.
+using adl_bomb = holder*;
+
+int main()
+{
+adl_bomb a[1]{};
+(void) std::to_array(a);
+(void) std::to_array(std::move(a));
+}
--
2.41.0
[committed] libstdc++: Prevent unwanted ADL in std::to_array [PR111512]
Tested x86_64-linux. Pushed to trunk.
-- >8 --
As noted in PR c++/111512, GCC does ADL for __builtin_memcpy if it is
unqualified, which can cause errors for template argument types which
cannot be completed.
Casting the memcpy arguments to void* prevents ADL from considering the
problem type.
libstdc++-v3/ChangeLog:
PR libstdc++/111511
PR c++/111512
* include/std/array (to_array): Cast memcpy arguments to void*.
* testsuite/23_containers/array/creation/111512.cc: New test.
---
libstdc++-v3/include/std/array| 4 ++--
.../23_containers/array/creation/111512.cc| 24 +++
2 files changed, 26 insertions(+), 2 deletions(-)
create mode 100644
libstdc++-v3/testsuite/23_containers/array/creation/111512.cc
diff --git a/libstdc++-v3/include/std/array b/libstdc++-v3/include/std/array
index 0e32d7b52d0..c4d534c3a34 100644
--- a/libstdc++-v3/include/std/array
+++ b/libstdc++-v3/include/std/array
@@ -432,7 +432,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
{
array, _Nm> __arr;
if (!__is_constant_evaluated() && _Nm != 0)
- __builtin_memcpy(__arr.data(), __a, sizeof(__a));
+ __builtin_memcpy((void*)__arr.data(), (void*)__a, sizeof(__a));
else
for (size_t __i = 0; __i < _Nm; ++__i)
__arr._M_elems[__i] = __a[__i];
@@ -461,7 +461,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
{
array, _Nm> __arr;
if (!__is_constant_evaluated() && _Nm != 0)
- __builtin_memcpy(__arr.data(), __a, sizeof(__a));
+ __builtin_memcpy((void*)__arr.data(), (void*)__a, sizeof(__a));
else
for (size_t __i = 0; __i < _Nm; ++__i)
__arr._M_elems[__i] = __a[__i];
diff --git a/libstdc++-v3/testsuite/23_containers/array/creation/111512.cc
b/libstdc++-v3/testsuite/23_containers/array/creation/111512.cc
new file mode 100644
index 000..b0f25a62153
--- /dev/null
+++ b/libstdc++-v3/testsuite/23_containers/array/creation/111512.cc
@@ -0,0 +1,24 @@
+// { dg-do compile { target c++20 } }
+
+// Bug libstdc++/111511 - Incorrect ADL in std::to_array in GCC 11/12/13
+// Bug c++/111512 - GCC's __builtin_memcpy can trigger ADL
+
+#include
+#include
+
+struct incomplete;
+
+template
+struct holder {
+T t; // { dg-bogus "'holder::t' has incomplete type" }
+};
+
+// A complete type that cannot be used as an associated type for ADL.
+using adl_bomb = holder*;
+
+int main()
+{
+adl_bomb a[1]{};
+(void) std::to_array(a);
+(void) std::to_array(std::move(a));
+}
--
2.41.0
