https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106953
--- Comment #2 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jonathan Wakely <r...@gcc.gnu.org>: https://gcc.gnu.org/g:cf0fded5d837bad590eb091d8a3dc4898872560f commit r13-2705-gcf0fded5d837bad590eb091d8a3dc4898872560f Author: Jonathan Wakely <jwak...@redhat.com> Date: Thu Sep 15 21:02:32 2022 +0100 libstdc++: Add preprocessor conditions for freestanding [PR106953] This adds checks for _GLIBCXX_HOSTED to a number of headers which are not currently installed for freestanding, but need to be for P1642R11 support. For example, <iterator> needs to be installed for C++23 freestanding mode, but without stream iterators and streambuf iterators. Similarly, <memory> needs to be installed, but without std::allocator and std::shared_ptr. This change disables the non-freestanding parts of those headers. libstdc++-v3/ChangeLog: PR libstdc++/106953 * include/backward/auto_ptr.h [!_GLIBCXX_HOSTED]: Do not define shared_ptr members. * include/bits/alloc_traits.h [!_GLIBCXX_HOSTED]: Do not declare std::allocator_traits<std::allocator<T>> specializations for freestanding. * include/bits/memoryfwd.h [!_GLIBCXX_HOSTED] (allocator): Do not declare for freestanding. * include/bits/stl_algo.h [!_GLIBCXX_HOSTED] (stable_partition): Do not define for freestanding. [!_GLIBCXX_HOSTED] (merge, stable_sort): Do not use temporary buffers for freestanding. * include/bits/stl_algobase.h [!_GLIBCXX_HOSTED]: Do not declare streambuf iterators and overloaded algorithms using them. * include/bits/stl_uninitialized.h [!_GLIBCXX_HOSTED]: Do not define specialized overloads for std::allocator. * include/bits/unique_ptr.h [!_GLIBCXX_HOSTED] (make_unique) (make_unique_for_overwrite, operator<<): Do not define for freestanding. * include/c_global/cstdlib [!_GLIBCXX_HOSTED] (_Exit): Declare. Use _GLIBCXX_NOTHROW instead of throw(). * include/debug/assertions.h [!_GLIBCXX_HOSTED]: Ignore _GLIBCXX_DEBUG for freestanding. * include/debug/debug.h [!_GLIBCXX_DEBUG]: Likewise. * include/std/bit [!_GLIBCXX_HOSTED]: Do not use the custom __int_traits if <ext/numeric_traits.h> is available. * include/std/functional [!_GLIBCXX_HOSTED]: Do not include headers that aren't valid for freestanding. (boyer_moore_searcher, boyer_moore_horspool_searcher): Do not define for freestanding. * include/std/iterator [!_GLIBCXX_HOSTED]: Do not include headers that aren't valid for freestanding. * include/std/memory [!_GLIBCXX_HOSTED]: Likewise. * include/std/ranges [!_GLIBCXX_HOSTED] (istream_view): Do not define for freestanding. (views::__detail::__is_basic_string_view) [!_GLIBCXX_HOSTED]: Do not define partial specialization for freestanding.