On Wed, Jun 16, 2021 at 5:18 AM Trevor Saunders <tbsau...@tbsaunde.org> wrote:
>
> - Unfortunately using_auto_storage () needs to handle m_vec being null.
> - Handle self move of an auto_vec to itself.
> - Make sure auto_vec defines the classes move constructor and assignment
> operator, as well as ones taking vec<T>, so the compiler does not generate
> them for us. Per https://en.cppreference.com/w/cpp/language/move_constructor
> the ones taking vec<T> do not count as the classes move constructor or
> assignment operator, but we want them as well to assign a plain vec to a
> auto_vec.
> - Explicitly delete auto_vec's copy constructor and assignment operator. This
> prevents unintentional expenssive coppies of the vector and makes it clear
> when coppies are needed that that is what is intended. When it is necessary
> to
> copy a vector copy () can be used.
>
> Signed-off-by: Trevor Saunders <tbsau...@tbsaunde.org>
>
> This time without the changes to the inline storage version of auto_vec as
> requested. bootstrap andregtest on x86_64-linux-gnu with the other patches in
> the series ongoing, ok if that passes?
OK.
Thanks,
Richard.
> Thanks
>
> Trev
>
> gcc/ChangeLog:
>
> * vec.h (vl_ptr>::using_auto_storage): Handle null m_vec.
> (auto_vec<T, 0>::auto_vec): Define move constructor, and delete copy
> constructor.
> (auto_vec<T, 0>::operator=): Define move assignment and delete copy
> assignment.
> ---
> gcc/vec.h | 31 ++++++++++++++++++++++++++++++-
> 1 file changed, 30 insertions(+), 1 deletion(-)
>
> diff --git a/gcc/vec.h b/gcc/vec.h
> index 193377cb69c..30ef9a69473 100644
> --- a/gcc/vec.h
> +++ b/gcc/vec.h
> @@ -1570,14 +1570,43 @@ public:
> this->m_vec = r.m_vec;
> r.m_vec = NULL;
> }
> +
> + auto_vec (auto_vec<T> &&r)
> + {
> + gcc_assert (!r.using_auto_storage ());
> + this->m_vec = r.m_vec;
> + r.m_vec = NULL;
> + }
> +
> auto_vec& operator= (vec<T, va_heap>&& r)
> {
> + if (this == &r)
> + return *this;
> +
> + gcc_assert (!r.using_auto_storage ());
> + this->release ();
> + this->m_vec = r.m_vec;
> + r.m_vec = NULL;
> + return *this;
> + }
> +
> + auto_vec& operator= (auto_vec<T> &&r)
> + {
> + if (this == &r)
> + return *this;
> +
> gcc_assert (!r.using_auto_storage ());
> this->release ();
> this->m_vec = r.m_vec;
> r.m_vec = NULL;
> return *this;
> }
> +
> + // You probably don't want to copy a vector, so these are deleted to
> prevent
> + // unintentional use. If you really need a copy of the vectors contents
> you
> + // can use copy ().
> + auto_vec(const auto_vec &) = delete;
> + auto_vec &operator= (const auto_vec &) = delete;
> };
>
>
> @@ -2147,7 +2176,7 @@ template<typename T>
> inline bool
> vec<T, va_heap, vl_ptr>::using_auto_storage () const
> {
> - return m_vec->m_vecpfx.m_using_auto_storage;
> + return m_vec ? m_vec->m_vecpfx.m_using_auto_storage : false;
> }
>
> /* Release VEC and call release of all element vectors. */
> --
> 2.20.1
>
