Re: linking a shared library with -pthread omits -pthread on the link line.

[Albert Chin]

On Sun, Dec 15, 2002 at 12:33:12AM -0600, Bob Friesenhahn wrote:
> On Sat, 14 Dec 2002, Albert Chin wrote:
> 
> > On Sat, Dec 14, 2002 at 05:43:45PM -0600, Bob Friesenhahn wrote:
> > > On Sat, 14 Dec 2002, Albert Chin wrote:
> > >
> > > > Because libtool knows nothing about $CFLAGS, it's not possible for it
> > > > to know about the appropriate switch (+DD64 in this case) to build
> > > > 64-bit object files. Even though the answer was in $CFLAGS, libtool
> > > > doesn't get passed $CFLAGS. My solution was CC="cc +DD64".
> > > >
> > > > So, do we teach libtool to inherit $CFLAGS?
> > >
> > > That would be a very bad idea indeed.  Libtool would loose all value
> > > as a stand-alone utility if we were to do this.
> >
> > Huh? If "libtool --mode=link" causes a program to get built, I think
> > it makes sense to use $CFLAGS.
> 
> Not really.  Note that CFLAGS is peculiar to a given project which
> uses libtool to control the compile/link, but the libtool may be
> derived from simply downloading GNU libtool and installing it.  If
> libtool was simply an extension to Automake (which it could have been)
> then the story would be entirely different.
> 
> If I do
> 
>  libtool --mode=link gcc -pg blah blah
> 
> then I want the -pg passed to gcc used as the linker regardless of the
> options used when libtool is installed.

I'm not arguing this point. What you want is correct.

> > So is the following behaviour correct?
> >   $ sh pdemo-make.conf
> >   ...
> >   /bin/sh ./libtool --mode=link cc  +O2 -Ae -z +ESlit +Onofltacc
> >   +DAportable +Oentrysched +Odataprefetch +Onolimit   -o helldl
> >   -export-dynamic -dlpreopen libhello.la longer_file_name_dlmain.o
> >   rm -f .libs/helldl.nm .libs/helldl.nmS .libs/helldl.nmT
> >   creating .libs/helldlS.c
> >   extracting global C symbols from `./.libs/libhello.a'
> >   (cd .libs && cc -c  +Z -DPIC "helldlS.c")
> 
> I can't say.

The above case is the point of contention. Note that I asked libtool
to generate helldl. In the process of doing so, *libtool* creates
helldlS.c and compiles it. So, does libtool compile this
self-generated helldlS.c with $CFLAGS or not? If the latter, then we
must allow CC to be set to a command with spaces. This is the only
condition under which I would argue for libtool using $CFLAGS. But,
I'm happy with it using the flags passed in on the link line above.

-- 
albert chin (address@hidden)