cpu_defines.h not installed in freestanding C++ library. Bug or feature?

[Doug Kwan (éæå) <dougkwan at google dot com>]

Hi,

    I tried to build the C++ library in freestanding mode.  It built
libsupc++ without any problem.  When I tested the built library, I got
an error because cpu_defines.h was included by c++cofing.h but not
installed.  I looked at libstdc++/include/Makefile.in and it said:

if GLIBCXX_HOSTED
install-data-local: install-headers
else
install-data-local: install-freestanding-headers
endif

# This is a subset of the full install-headers rule.  We only need <cstddef>,
# <limits>, <cstdlib>, <cstdarg>, <new>, <typeinfo>, <exception>, and any
# files which they include (and which we provide).  The last three headers
# are installed by libsupc++, so only the first four and the sub-includes
# are copied here.
install-freestanding-headers:
        $(mkinstalldirs) $(DESTDIR)${gxx_include_dir}
        $(mkinstalldirs) $(DESTDIR)${host_installdir}
        for file in ${host_srcdir}/os_defines.h
${host_builddir}/c++config.h; do \
          $(INSTALL_DATA) $${file} $(DESTDIR)${host_installdir}; done
        $(mkinstalldirs) $(DESTDIR)${gxx_include_dir}/${std_builddir}
        $(INSTALL_DATA) ${std_builddir}/limits
$(DESTDIR)${gxx_include_dir}/${std_builddir}
        $(mkinstalldirs) $(DESTDIR)${gxx_include_dir}/${c_base_builddir}
        for file in cstddef cstdlib cstdarg; do \
          $(INSTALL_DATA) ${c_base_builddir}/$${file}
$(DESTDIR)${gxx_include_dir}/${c_base_builddir}; done

I assumed this rule installed all necessary headers in a freestanding
implementation.  It did not appear to install cpu_defines.h though.
And c++config needed it.

...
// First includes.

// Pick up any OS-specific definitions.
#include <bits/os_defines.h>

// Pick up any CPU-specific definitions.
#include <bits/cpu_defines.h>
..


Is that intentional?

-Doug