[Bug fortran/18022] problem with structure and calling a function

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

------- Additional Comments From tobi at gcc dot gnu dot org  2005-07-09 11:47 -------
For the record, in the testcase Paul posted together with his patch
<http://gcc.gnu.org/ml/fortran/2005-07/msg00098.html>, we call foo as follows:
    struct array1_real4 parm.11;
    struct array1_mytype parm.10;

    parm.10.dtype = 553;
    parm.10.dim[0].lbound = 1;
    parm.10.dim[0].ubound = 4;
    parm.10.dim[0].stride = 1;
    parm.10.data = (void *) (struct mytype[0:] *) &z[0];
    parm.10.offset = 0;
    parm.11.dtype = 281;
    parm.11.dim[0].lbound = 1;
    parm.11.dim[0].ubound = 4;
    parm.11.dim[0].stride = 1;
    parm.11.data = (void *) (real4[0:] *) &b[0];
    parm.11.offset = 0;
    foo (&parm.10, &parm.11);

So instead of setting up an array which points to the x (or y) components of z,
we pass z as a whole, which of course doesn't make sense.  There seem to be two
possible solutions:
- use a temporary.  This is what Paul's patch does (even though there should be
a more intuitive way to check for this case, and there are probably other cases
where we incorrectly assume that stuff is contiguous)
- setup an array descriptor which points to the right parts of the array, in our
case this would be (if I get it right):
    parm.10.dtype = 281;
    parm.10.dim[0].lbound = 1;
    parm.10.dim[0].ubound = 4;
    parm.10.dim[0].stride = 2; /* Increased stride to walk past y component */
    parm.10.data = (void *) (struct real4[0:] *) &z[0].x;
    parm.10.offset = 0;
for the x component, and
    parm.10.dtype = 281;
    parm.10.dim[0].lbound = 1;
    parm.10.dim[0].ubound = 4;
    parm.10.dim[0].stride = 2; /* Increased stride to walk past y component */
    parm.10.data = (void *) (struct real4[0:] *) &z[0].y;
    parm.10.offset = 0;
for the y component.



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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18022