Re: trunk r115773: Port xcrun configuration to GNU/Linux.

["Jan Djärv" <jan.h.d@swipnet.se>]

Hello.

29 dec 2013 kl. 22:16 skrev Eli Zaretskii <eliz@gnu.org>:

>> From: Jan Djärv <jan.h.d@swipnet.se>
>> Date: Sun, 29 Dec 2013 22:04:02 +0100
>> Cc: emacs-devel <emacs-devel@gnu.org>
>> 
>> Hello.
>> 
>> 29 dec 2013 kl. 20:01 skrev Eli Zaretskii <eliz@gnu.org>:
>> 
>>>> From: Jan Djärv <jan.h.d@swipnet.se>
>>>> Date: Sun, 29 Dec 2013 19:41:28 +0100
>>>> Cc: "emacs-devel@gnu.org" <emacs-devel@gnu.org>
>>>> 
>>>> This has nothing to do with builddir, but include directories passed to the compiler with -I.  As this has to do with the configure code and how it handles spaces, I'm pretty sure this fails everywhere. 
>>> 
>>> The solution might be to use relative file names.
>> 
>> It would not help here, the trees are urelated.
>> I.e. the relative path would also have a space in it, something like:
>> 
>> ../../../../Volumes/Macintosh HD/...
> 
> How about stuffing the file name into an environment variable, and
> using that in configure?

Good try, but no.  I think this is impossible without modifying configure variables, i.e. ac_compile.

ac_compile is:

  ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'

As said, it is used like this:

  (eval "$ac_compile") 2>conftest.err

Eval first expands the variables, and then word splits on whitespace, regardless of quoting characters.
So there is no way to put something in CPPFLAGS with a whitespace that eval wont word-split on that whitespace.
This is a fundamental limitation in autoconf.

I'm happy to be proven wrong, but I can't see any way to do it, except modifying ac_compile.

	Jan D.