Refuse to relocate non-copy/move-constructible types
When a type was explicitly made non-copyable and non-movable, refuse attempts to mark it as relocatable. Trivial relocatability is an optimization for move+destroy, so we shouldn't allow working around the class author's wish to have a non-movable type by a user making it Q_RELOCATABLE_TYPE. Therefore, add a static_assert() to Q_DECLARE_TYPEINFO that fires when a non-copy/move-constructible type is made Q_RELOCATABLE_TYPE. Also add a similar static assertion to QTypeInfoMerger: All members of a class T may be Q_RELOCATABLE_TYPE. But that doesn't mean that T itself is: class T { QString m_s; QByteArray m_b; Q_DISABLE_COPY(T) public: ~~~~ }; so check that T is actually copyable (or movable) when QTypeInfoMerger would have have yielded isRelocatable. Since Q_DECLARE_TYPEINFO and QTypeInfoMerger are not the only ways in which a user can mark a type as relocatable (manual QTypeInfo specialization is another option, and required, for certain template classes), also check in q_uninitialized_relocate_n(). [ChangeLog][QtCore][QTypeInfo/QTypeInfoMerger] No longer allows marking as Q_RELOCATABLE_TYPE a type that is neither movable nor copyable. Change-Id: If6b3e5c1bfb6538bd280262eefbb08ba3c810e4c Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
This commit is contained in:
parent
2d052b038d
commit
ff7d69dafd
@ -97,6 +97,11 @@ public:
|
||||
[[deprecated("Use std::is_pointer instead")]] static constexpr bool isPointer = false;
|
||||
[[deprecated("Use std::is_integral instead")]] static constexpr bool isIntegral = false;
|
||||
static constexpr bool isValueInitializationBitwiseZero = false;
|
||||
static_assert(!isRelocatable ||
|
||||
std::is_copy_constructible_v<T> ||
|
||||
std::is_move_constructible_v<T>,
|
||||
"All Ts... are Q_RELOCATABLE_TYPE, but T is neither copy- nor move-constructible, "
|
||||
"so cannot be Q_RELOCATABLE_TYPE. Please mark T as Q_COMPLEX_TYPE manually.");
|
||||
};
|
||||
|
||||
// QTypeInfo for std::pair:
|
||||
@ -158,6 +163,10 @@ public: \
|
||||
isIntegral [[deprecated("Use std::is_integral instead")]] = std::is_integral< TYPE >::value, \
|
||||
isValueInitializationBitwiseZero = QtPrivate::qIsValueInitializationBitwiseZero<TYPE>, \
|
||||
}; \
|
||||
static_assert(!isRelocatable || \
|
||||
std::is_copy_constructible_v<TYPE > || \
|
||||
std::is_move_constructible_v<TYPE >, \
|
||||
#TYPE " is neither copy- nor move-constructible, so cannot be Q_RELOCATABLE_TYPE"); \
|
||||
}
|
||||
|
||||
#define Q_DECLARE_TYPEINFO(TYPE, FLAGS) \
|
||||
|
@ -72,6 +72,8 @@ template <typename T, typename N>
|
||||
void q_uninitialized_relocate_n(T* first, N n, T* out)
|
||||
{
|
||||
if constexpr (QTypeInfo<T>::isRelocatable) {
|
||||
static_assert(std::is_copy_constructible_v<T> || std::is_move_constructible_v<T>,
|
||||
"Refusing to relocate this non-copy/non-move-constructible type.");
|
||||
if (n != N(0)) { // even if N == 0, out == nullptr or first == nullptr are UB for memcpy()
|
||||
std::memcpy(static_cast<void *>(out),
|
||||
static_cast<const void *>(first),
|
||||
|
Loading…
x
Reference in New Issue
Block a user