Re: link and run a (fortran) program redirecting its stdout/stderr

[Stefano Lattarini]

At Tuesday 13 October 2009, Ralf Wildenhues <address@hidden> wrote:
> * Stefano Lattarini wrote on Mon, Oct 12, 2009 at 09:20:04PM CEST:
> > I have to compile and link a Fortran 77 test program. and then
> > run it redirecting its stdout/stderr (I need to do so to verify
> > that the `stop' builtin is silent when called without arguments
> > -- unfortunately this is not always the case, e.g. when using
> > gfortran-4.0).
>
> Can you explain what this means or does?  If this is similar to
> checking for the declaration of a C function, then it should be
> handled similarly, i.e., by a suitable compile or link test, rather
> than by trying to parse compiler and/or output.
OK, I must admit that the description of my intentions was really badly
expressed.  I'll try to restate them more clearly.

I *don't* care about compiler warnings or messages at compile time.

What matters to me is that the *program generated* by the compiler,
when executed, is not too verbose w.r.t. the `stop' builtin.

For example, assume that I have a fortran source using the `stop'
builtin *without arguments*, as in:
  
  $ cat foo.f
        program foo
        stop
        end

If I compile the `foo.f' file into the `foo.exe' executable:
  $ f77 -o foo.exe foo.f
then I'd expect that running `foo.exe' will simply produce a sucessful
exit status, and *no message* on stdout or stderr.  This is indeed what
happens with "modern" gfortran (version 4.3) and with the `fort77'
compiler (wrapper arounf f2c + gcc): the generated program behaves
as expected, being completely quiet.

Unfortunately, the foo.exe produced by gfortran-4.0 ends up doing
someting like this:
  $ gfortran-4.0 -o foo.exe foo.f  # no errors or warnings here
  $ ./foo.exe  # this produces the following unwanted message
  STOP 0

To summarize, what I must verify is that the Fortran compiler, when
processing a call to `stop' *without arguments*, does not produce code
which, when executed, will end up writing "STOP 0" or sometinhg similar
on stdout/stderr.  The only way I can think of to accomplish this is to
compile and link a simple test program (like the `foo.f' above), run it
redirecting its output, and analyze this output.  And here I'm stuck,
for the problems described in my previous mail.

Hope things are clearer now.

Thanks,
     Stefano