[Bug fortran/35820] internal compiler error with nested FORALL

["burnus at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #8 from burnus at gcc dot gnu dot org  2008-10-22 16:27 -------
> > Confirm. While I do not get any crash like Dominique, valgrind shows that
> > there is a problem:
>
> How do you extract this diagnostic from valgrind?  I have never used it before
> but found it rolled into FC9.

Well, that is simple: Run gfortran with the -v option, search for the line
where f951 is called, copy that line and run

valgrind <insert the copied line here>

That's all what is needed, you might try some special options, but most of the
time the defaults are sufficient.
(Note: Whether writes/reads are diagnosed to be invalid depend on the exact
memory layout, sometimes small changes on a program make valgrind fail to
detect a problem, though most of the time the diagnosis is quite stable.)

==31901== Invalid write of size 8
==31901==    at 0x470F8E: gfc_resolve_forall (resolve.c:6264)
==31901==    by 0x47204C: resolve_code (resolve.c:6523)

The line in question is:

      /* Record the current FORALL index.  */
      var_expr[nvar] = gfc_copy_expr (fa->var);

To run f951 in the debugger, one simply run then
  gdb --args <copy f951 line here>


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35820