maintainer-feedback requested: [Bug 274740] www/qt5-webengine: fix build with libc++ 17

[bugzilla-noreply at freebsd.org]

Bugzilla Automation <bugzilla at FreeBSD.org> has asked freebsd-kde (group)
<kde at FreeBSD.org> for maintainer-feedback:
Bug 274740: www/qt5-webengine: fix build with libc++ 17
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=274740



--- Description ---
Building www/qt5-webengine with libc++ 17 results in the following
compile errors:

  In file included from
../../../../kde-qtwebengine-5.15.15p0/src/3rdparty/chromium/third_party/perfett
o/src/trace_processor/trace_sorter.cc:17:
  In file included from /usr/include/c++/v1/algorithm:1803:
  In file included from /usr/include/c++/v1/__algorithm/nth_element.h:15:
  /usr/include/c++/v1/__algorithm/sort.h:577:14: error: no viable overloaded
'='
    577 |     *__begin = _Ops::__iter_move(__pivot_pos);
	|     ~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  /usr/include/c++/v1/__algorithm/sort.h:802:20: note: in instantiation of
function template specialization
'std::__bitset_partition<std::_ClassicAlgPolicy,
perfetto::base::CircularQueue<perfetto::trace_processor::TimestampedTracePiece>
::Iterator,
std::__less<void, void> &>' requested here
    802 |	      ? std::__bitset_partition<_AlgPolicy,
_RandomAccessIterator, _Compare>(__first, __last, __comp)
	|		     ^
  /usr/include/c++/v1/__algorithm/sort.h:878:8: note: in instantiation of
function template specialization 'std::__introsort<std::_ClassicAlgPolicy,
std::__less<void, void> &,
perfetto::base::CircularQueue<perfetto::trace_processor::TimestampedTracePiece>
::Iterator,
false>' requested here
    878 |   std::__introsort<_AlgPolicy,
	|	 ^
  /usr/include/c++/v1/__algorithm/sort.h:946:10: note: in instantiation of
function template specialization 'std::__sort_dispatch<std::_ClassicAlgPolicy,
perfetto::base::CircularQueue<perfetto::trace_processor::TimestampedTracePiece>
::Iterator,
std::__less<void, void>>' requested here
    946 |     std::__sort_dispatch<_AlgPolicy>(std::__unwrap_iter(__first),
std::__unwrap_iter(__last), __comp);
	|	   ^
  /usr/include/c++/v1/__algorithm/sort.h:954:8: note: in instantiation of
function template specialization 'std::__sort_impl<std::_ClassicAlgPolicy,
perfetto::base::CircularQueue<perfetto::trace_processor::TimestampedTracePiece>
::Iterator,
std::__less<void, void>>' requested here
    954 |   std::__sort_impl<_ClassicAlgPolicy>(std::move(__first),
std::move(__last), __comp);
	|	 ^
  /usr/include/c++/v1/__algorithm/sort.h:960:8: note: in instantiation of
function template specialization
'std::sort<perfetto::base::CircularQueue<perfetto::trace_processor::Timestamped
TracePiece>::Iterator,
std::__less<void, void>>' requested here
    960 |   std::sort(__first, __last, __less<>());
	|	 ^
 
../../../../kde-qtwebengine-5.15.15p0/src/3rdparty/chromium/third_party/perfett
o/src/trace_processor/trace_sorter.cc:51:8:
note: in instantiation of function template specialization
'std::sort<perfetto::base::CircularQueue<perfetto::trace_processor::Timestamped
TracePiece>::Iterator>'
requested here
     51 |   std::sort(sort_begin, events_.end());
	|	 ^
 
../../../../kde-qtwebengine-5.15.15p0/src/3rdparty/chromium/third_party/perfett
o/src/trace_processor/timestamped_trace_piece.h:191:26:
note: candidate function not viable: 'this' argument has type 'const
perfetto::trace_processor::TimestampedTracePiece', but method is not marked
const
    191 |   TimestampedTracePiece& operator=(TimestampedTracePiece&& ttp) {
	|			   ^
 
../../../../kde-qtwebengine-5.15.15p0/src/3rdparty/chromium/third_party/perfett
o/src/trace_processor/timestamped_trace_piece.h:202:26:
note: candidate function not viable: 'this' argument has type 'const
perfetto::trace_processor::TimestampedTracePiece', but method is not marked
const
    202 |   TimestampedTracePiece& operator=(const TimestampedTracePiece&) =
delete;
	|			   ^

This is because perfetto's CircularQueue template is only half
const-correct. Upstream fixed this in:

https://github.com/google/perfetto/commit/b82a213bcf71dd8e68b53941375936c7905c0
ff2

so apply that fix to qt5-webengine's older copy of perfetto.