On Fri, Feb 24, 2023 at 02:47:39PM +0100, Richard Biener wrote:
> * vec.h (vec<T, A, vl_embed>::m_vecdata): Remove.
> (vec<T, A, vl_embed>::m_vecpfx): Align as T to avoid
> changing alignment of vec<T, A, vl_embed> and simplifying
> address.
> (vec<T, A, vl_embed>::address): Compute as this + 1.
> (vec<T, A, vl_embed>::embedded_size): Use sizeof the
> vector instead of the offset of the m_vecdata member.
> (auto_vec<T, N>::m_data): Turn storage into
> uninitialized unsigned char.
> (auto_vec<T, N>::auto_vec): Allow allocation of one
> stack member. Initialize m_vec in a special way to
> avoid later stringop overflow diagnostics.
> * vec.cc (test_auto_alias): New.
> (vec_cc_tests): Call it.
> @@ -1559,8 +1560,14 @@ class auto_vec : public vec<T, va_heap>
> public:
> auto_vec ()
> {
> - m_auto.embedded_init (MAX (N, 2), 0, 1);
> - this->m_vec = &m_auto;
> + m_auto.embedded_init (N, 0, 1);
> + /* ??? Instead of initializing m_vec from &m_auto directly use an
> + expression that avoids refering to a specific member of 'this'
> + to derail the -Wstringop-overflow diagnostic code, avoiding
> + the impression that data accesses are supposed to be to the
> + m_auto memmber storage. */
s/memmber/member/
> + size_t off = (char *) &m_auto - (char *) this;
> + this->m_vec = (vec<T, va_heap, vl_embed> *) ((char *) this + off);
> }
>
> auto_vec (size_t s CXX_MEM_STAT_INFO)
> @@ -1571,7 +1578,7 @@ public:
> return;
> }
>
> - m_auto.embedded_init (MAX (N, 2), 0, 1);
> + m_auto.embedded_init (N, 0, 1);
> this->m_vec = &m_auto;
Don't we need the above 2 lines here as well (perhaps with a shorter comment
just referencing the earlier comment)?
Otherwise LGTM, thanks.
Jakub
