On Wed, Jul 5, 2023 at 9:57 AM Thomas Schwinge <tho...@codesourcery.com> wrote: > > Hi! > > On 2023-07-04T15:56:23-0400, Lewis Hyatt via Gcc-patches > <gcc-patches@gcc.gnu.org> wrote: > > On Tue, Jul 4, 2023 at 11:50 AM Thomas Schwinge <tho...@codesourcery.com> > > wrote: > >> I came across this one here on my way working through another (somewhat > >> related) GTY issue. I generally do understand the issue here, but do > >> have a question about 'unsigned int len' field in > >> 'libcpp/include/symtab.h:struct ht_identifier': [...] > > > I don't think there is currently any possibility for a null byte to > > end up in an ht_identifier's string. I assumed that ht_identifier > > stores the length as an optimization (especially since it doesn't take > > up any extra space on 64-bit platforms, given the 32-bit hash code is > > stored as well there.) I created the string_length GTY markup mainly > > to support another patch that I have still pending review, which I > > thought would increase the likelihood of PCH needing to handle null > > bytes in general. When I did that, I added the markup to ht_identifier > > simply because the length was already there, so there was no reason > > not to add it. It does save a few cycles when streaming out the PCH, > > but I doubt it is meaningful. > > Thanks for confirming. OK thus to push the attached > "GTY: Enhance 'string_length' option documentation"?
OK. > Grüße > Thomas > > > ----------------- > Siemens Electronic Design Automation GmbH; Anschrift: Arnulfstraße 201, 80634 > München; Gesellschaft mit beschränkter Haftung; Geschäftsführer: Thomas > Heurung, Frank Thürauf; Sitz der Gesellschaft: München; Registergericht > München, HRB 106955
