RE: _AS_LN_S_PREPARE question

[Duft Markus]

Ralf Wildenhues <mailto:address@hidden> wrote:
> Hello Markus,
> 
> * Duft Markus wrote on Fri, Feb 08, 2008 at 10:44:39AM CET:
>> 
>> I have aquestion: I'm porting to windows (cross compiled from
>> interix). Interix has a working ln, but windows doesn't understand
>> those links. Now I wanted to check for winnt in _AS_LN_S_PREPARE.
>> Can I use AC_CANONICAL_HOST for this? What I'd need is the
>> config.guess output. 
> 
> No, _AS_LN_S_PREPARE comes very early in the scripts, and you
> basically cannot rely on any other macros.  Can you explain what goes
> wrong with the test, because if ln is working as expected, then
> _AS_LN_S_PREPARE should just detect that?  Adding `set -x' before and
> `set +x' after the test, in the configure script, is a good method to
> see what's happening. 

No, the test goes ok, but i have the following situation:

I configure something with --build=i586-pc-winnt on an i586-pc-interix*
host. I use build to keep anybody from thinking, that we're cross
compiling (in reality i am cross-compiling, but still i can execute
those binaries). As compiler i use a wrapper that calls microsoft's
cl.exe in native windows.

Now autoconf detects (correctly) that softlinks work fine, and everybody
is happy - except cl.exe which doesn't understand those softlinks. I
manage to catch most of them (e.g. links to libraries) in my wrapper
around cl.exe, but i cannot catch linked header files, since the
.c/.cc/.cpp files just say include, and the compiler looks up the files.
If one of those include'd files is a link, cl.exe crashes.

For this reason i have in my latest libtool HEAD patch:

  AC_REQUIRE([AC_PROG_LN_S])dnl
  test -z "$LN_S" && LN_S="ln -s"

  # on winnt, the microsoft compiler is used behind the scenes.
  # the wrapper around it is capable of resolving links, but still
  # cl.exe chokes on header files which are linked (the wrapper
  # cannot know of these...).
  # this should be fixed in autoconf (_AS_LN_S_PREPARE), not here,
  # but i don't know autoconf that well, and i have no idea how i
  # can check the host_os at that point...
  case $host_os in
  winnt*) LN_S="cp -p" ;;
  esac

  _LT_DECL([], [LN_S], [1], [Whether we need soft or hard links])dnl

I don't really like that one, because it's not a libtool issue really.
It would be cool if autoconf would know that...

Note: i586-pc-winnt is the host triplet i chose for my wrapper around
microsoft's tools, see
http://lists.gnu.org/archive/html/libtool-patches/2008-02/msg00004.html.

Cheers, Markus

> 
> Also, please note that the macro has undergone some changes since
> 2.61. 
> 
> Cheers,
> Ralf