Re: i370 port - constructing compile script

["Ulrich Weigand" <uweigand@de.ibm.com>]

Paul Edwards wrote:

> > Huh.  I've never seen this before.  Is this with your patches to
> > generate a "single executable" or without?
> 
> My patches are applied, but shouldn't be activated, because
> I haven't defined SINGLE_EXECUTABLE.
> 
> I could try taking it back to raw 3.4.6 though and see if that has
> the same problem.

Might be interesting ...

> > For the cross-compiler,
> > you shouldn't need any of the MVS host-specific patches ...
> 
> My target is new basically.  It's closest to mvsdignus, which
> was used as a starting point, but it has evolved.  :-)

Host vs. target confusion again? :-)  You have some patches needed
to support MVS as *target* of compilation.  You have some other
patches needed to support MVS as *host* of the compiler itself.

I'm saying that for the cross-compiler, you need the first set
of patches, but you do not need the second set of patches.

For the native compiler, you'll then need both sets ...

> > However, once you *run* this i370-mvs-gcc, and it processes a source
> > file using #include <stdio.h>, the compiler will search the directory
> > /home/gccmvs/sysroot/include for the stdio.h header file, and it will
> > invoke the cross-linker passing /home/gccmvs/sysroot/lib as the 
> > location to search for standard libraries like libc.  (Note that the
> > names of such standard libraries, if any, are defined by the MVS
> > target definitions, in particular the setting of target macros like
> > LIB_SPEC in your target header files in config/i370/*.h.)
> 
> I don't seem to have that variable defined.  Not surprising since
> there's no include or lib directories like that on MVS.

I'm not sure how this works on MVS, but the C standard says that if
your application uses #include <stdio.h>, this must work and find
the appropriate system header ...

When running the compiler natively on MVS, there may not be a notion
of "directories" in the Unix sense, but I guess those headers must
still come from *somewhere*, right?

For the *cross-compiler*, because it is hosted on a Unix system, it
must provide those same headers in a directory somewhere.  This is
the directory you specify via --with-sysroot.

Bye,
Ulrich

-- 
  Dr. Ulrich Weigand
  GNU Toolchain for Linux on System z and Cell BE
  Ulrich.Weigand@de.ibm.com