diff options
| author | Jonathan Wakely <jwakely@redhat.com> | 2023-09-21 09:14:57 +0100 |
|---|---|---|
| committer | Jonathan Wakely <jwakely@redhat.com> | 2023-09-25 09:48:44 +0100 |
| commit | 77cf3773021b0a20d89623e09d620747a05588ec (patch) | |
| tree | ad38cad339b9a4898b95106bc5d6d666f1bb8cce | |
| parent | 55cf4f843790faa3335ef3e4baf758860a9a107d (diff) | |
| download | gcc-77cf3773021b0a20d89623e09d620747a05588ec.zip gcc-77cf3773021b0a20d89623e09d620747a05588ec.tar.gz gcc-77cf3773021b0a20d89623e09d620747a05588ec.tar.bz2 | |
libstdc++: Prevent unwanted ADL in std::to_array [PR111512]
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.
| -rw-r--r-- | libstdc++-v3/include/std/array | 4 | ||||
| -rw-r--r-- | libstdc++-v3/testsuite/23_containers/array/creation/111512.cc | 24 |
2 files changed, 26 insertions, 2 deletions
diff --git a/libstdc++-v3/include/std/array b/libstdc++-v3/include/std/array index 0e32d7b..c4d534c 100644 --- a/libstdc++-v3/include/std/array +++ b/libstdc++-v3/include/std/array @@ -432,7 +432,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION { array<remove_cv_t<_Tp>, _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<remove_cv_t<_Tp>, _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 0000000..b0f25a62 --- /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 <array> +#include <utility> + +struct incomplete; + +template<class T> +struct holder { + T t; // { dg-bogus "'holder<T>::t' has incomplete type" } +}; + +// A complete type that cannot be used as an associated type for ADL. +using adl_bomb = holder<incomplete>*; + +int main() +{ + adl_bomb a[1]{}; + (void) std::to_array(a); + (void) std::to_array(std::move(a)); +} |