[GNATS 27807] Boost header spurious diagnostic with xxx is inaccessible friend

[jhsedg]

Customer bug ID

27807.C (reduced test case), _27807.C (full test case)

Description

​The boost header,../boost/interprocess/mem_algo/rbtree_best_fit.hpp, triggers a diagnostic with our front end. THis is blocking 65 boost test cases.
​
​cpfe -DTEST_NUMBER=1 --c++20 -tused --gnu_version=120100 -w Test_name.c
​"../boost/interprocess/mem_algo/rbtree_best_fit.hpp", line 136: error: class
​ "boost::interprocess::rbtree_best_fit<MutexFamily, VoidPointer,
​ MemAlignment>::SizeHolder [with
​ MutexFamily=boost::interprocess::ipcdetail::intermodule_singleton_mut
​ ex_family, VoidPointer=boost::interprocess::offset_ptr<void,
​ std::ptrdiff_t, uintptr_t, 0UL>, MemAlignment=0UL]" (declared at line
​ 108) is inaccessible
​ { return a.SizeHolder::m_size < b.SizeHolder::m_size; }
​ ^
​ detected during:
​ instantiation of class
​ "boost::interprocess::rbtree_best_fit<MutexFamily,
​ VoidPointer, MemAlignment>::block_ctrl [with
​ MutexFamily=boost::interprocess::ipcdetail::intermodule_s
​ ingleton_mutex_family,
​ VoidPointer=boost::interprocess::offset_ptr<void,
​ std::ptrdiff_t, uintptr_t, 0UL>, MemAlignment=0UL]" at
​ line 408 of
​ "/mds/gnu/build/gcc-12.1.0/lib/gcc/x86_64-pc-linux-gnu/12
​ .1.0/../../../../include/c++/12.1.0/bits/stl_function.h"
​ instantiation of "bool std::less<_Tp>::operator()(const _Tp &,
​ const _Tp &) const [with
​ _Tp=boost::interprocess::rbtree_best_fit<boost::interproc
​ ess::ipcdetail::intermodule_singleton_mutex_family,
​ boost::interprocess::offset_ptr<void, std::ptrdiff_t,
​ uintptr_t, 0UL>, 0UL>::block_ctrl]" at line 170 of
​ "../boost/intrusive/detail/tree_value_compare.hpp"
​ instantiation of "Ret
​ boost::intrusive::tree_value_compare<ValuePtr,
​ KeyCompare, KeyOfValue, Ret, true>::operator()(const
​ boost::intrusive::tree_value_compare<ValuePtr,
​ KeyCompare, KeyOfValue, Ret, true>::key_type &, const
​ boost::intrusive::tree_value_compare<ValuePtr,
​ KeyCompare, KeyOfValue, Ret, true>::key_type &) const
​ [with
​ ValuePtr=boost::interprocess::offset_ptr<boost::interproc
​ ess::rbtree_best_fit<boost::interprocess::ipcdetail::inte
​ rmodule_singleton_mutex_family,
​ boost::interprocess::offset_ptr<void, std::ptrdiff_t,
​ uintptr_t, 0UL>, 0UL>::block_ctrl, long, unsigned long,
​ 0UL>,
​ KeyCompare=std::less<boost::interprocess::rbtree_best_fit
​ <boost::interprocess::ipcdetail::intermodule_singleton_mu
​ tex_family, boost::interprocess::offset_ptr<void,
​ std::ptrdiff_t, uintptr_t, 0UL>, 0UL>::block_ctrl>,
​ KeyOfValue=boost::move_detail::identity<boost::interproce
​ ss::rbtree_best_fit<boost::interprocess::ipcdetail::inter
​ module_singleton_mutex_family,
​ boost::interprocess::offset_ptr<void, std::ptrdiff_t,
​ uintptr_t, 0UL>, 0UL>::block_ctrl>, Ret=bool]" at line 98
​ of "../boost/intrusive/detail/key_nodeptr_comp.hpp"
​
​.....
​
​
​THere is a reduced test case , 27807.C and the full preprocessed test case is _27807.C