Re: Order-of-includes issue building newlib [ RE: Build error CVS head ]

[Brian Dessent <brian at dessent dot net>]

Dave Korn wrote:

> although it's also possible that the intention of configure.host is that
> cygwin include headers are /meant/ to override newlib's own ones, in which
> case Corinna's patch should have kept the private stuff.

Yes, I always thought that was the intention, at least from the comments
below from toplevel configure.ac which is responsible for setting the
CC="gcc -isystem foo -isystem bar" when descending into newlib dir for
multilib:

FLAGS_FOR_TARGET=
case " $target_configdirs " in
 *" newlib "*)
  case " $target_configargs " in
  *" --with-newlib "*)
   case "$target" in
   *-cygwin*)
     FLAGS_FOR_TARGET=$FLAGS_FOR_TARGET' -L$$r/$(TARGET_SUBDIR)/winsup
-L$$r/$(TARGET_SUBDIR)/winsup/cygwin
-L$$r/$(TARGET_SUBDIR)/winsup/w32api/lib -isystem $$
s/winsup/include -isystem $$s/winsup/cygwin/include -isystem
$$s/winsup/w32api/include' ;;
   esac

   # If we're not building GCC, don't discard standard headers.
   if test -d ${srcdir}/gcc; then
     FLAGS_FOR_TARGET=$FLAGS_FOR_TARGET' -nostdinc'

     if test "${build}" != "${host}"; then
       # On Canadian crosses, CC_FOR_TARGET will have already been set
       # by `configure', so we won't have an opportunity to add -Bgcc/
       # to it.  This is right: we don't want to search that directory
       # for binaries, but we want the header files in there, so add
       # them explicitly.
       FLAGS_FOR_TARGET=$FLAGS_FOR_TARGET' -isystem
$$r/$(HOST_SUBDIR)/gcc/include'

       # Someone might think of using the pre-installed headers on
       # Canadian crosses, in case the installed compiler is not fully
       # compatible with the compiler being built.  In this case, it
       # would be better to flag an error than risking having
       # incompatible object files being constructed.  We can't
       # guarantee that an error will be flagged, but let's hope the
       # compiler will do it, when presented with incompatible header
       # files.
     fi
   fi

   case "${target}-${is_cross_compiler}" in
   i[[3456789]]86-*-linux*-no)
      # Here host == target, so we don't need to build gcc,
      # so we don't want to discard standard headers.
      FLAGS_FOR_TARGET=`echo " $FLAGS_FOR_TARGET " | sed -e 's/
-nostdinc / /'`
      ;;
   *)
      # If we're building newlib, use its generic headers last, but
search
      # for any libc-related directories first (so make it the last -B
      # switch).
      FLAGS_FOR_TARGET=$FLAGS_FOR_TARGET' -B$$r/$(TARGET_SUBDIR)/newlib/
-isystem $$r/$(TARGET_SUBDIR)/newlib/targ-include -isystem
$$s/newlib/libc/include'
      ;;
   esac
   ;;
  esac
  ;;
esac
case "$target" in
*-mingw*)
  # Can't be handled as Cygwin above since Mingw does not use newlib.
  FLAGS_FOR_TARGET=$FLAGS_FOR_TARGET'
-L$$r/$(TARGET_SUBDIR)/winsup/mingw
-L$$r/$(TARGET_SUBDIR)/winsup/w32api/lib -isystem
$$s/winsup/mingw/include -isystem $$
s/winsup/w32api/include' ;;
esac

Brian