On 10/5/21 07:27, Richard Biener wrote:
On Mon, Oct 4, 2021 at 8:28 PM Jason Merrill via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
When r12-4038 introduced the global auto_vec save_opt_decoded_options,
it broke compilers configured with --enable-gather-detailed-mem-stats,
due to the memory descriptors getting discarded before the auto_vec was
destroyed. Attached below are two approaches to making this work,
either by using the init_priority attribute, or turning vec_mem_desc
into a singleton function. I prefer the first one, primarily because it
doesn't require auto_vec variables to force immediate allocation. It
relies on a G++ extension, but I figure that's OK for code that is only
exercised with a debugging configure flag.
Thoughts? Either one OK for trunk?
Hmm, isn't the way to fix this to turn the global auto_vec into
vec<> *x and allocate it at runtime (thus explicitly mange its
lifetime?). We don't want global CTORs/DTORs in general
because of startup cost and of course those pesky ordering issues...
That is the usual approach, yes. I was giving up on that, but perhaps
it's better to stick with it. Martin, want to make that fix for
save_opt_decoded_options?
Oh, and maybe we can make
static mem_alloc_description <vec_usage> vec_mem_desc;
statically initialized with some C++? (constexpr? constinit? whatever?
It can't be statically initialized, because it needs to allocate
multiple maps.
Jason
