[Patch, fortran] PR69566 - Failure of SELECT TYPE with unlimited polymorphic function result

[Paul Richard Thomas <paul dot richard dot thomas at gmail dot com>]

Dear All,

This bug was caused by 'associate name' and 'associate entity'
expressions being incomplete when the 'selector' was an intrinsic
function result. I tried to fix this at source, in match_select _type
and gfc_get_variable_expr, but caused a vast number of breakages.
Undoubtedly, this would be the ecologically sound way to proceed but
applying fixups in resolve_select_type, gfc_conv_class_to_class and
trans_associate_var proved to be the path of least resistance.

Depending on which form of select type is used, the defective
expressions either lacked the correct value for rank, a full array
reference, a symbol with an array spec or had type BT_DERIVED for a
polymorphic symbol; these either singly or in combination depending of
the form of select type.

The patch, taken with the ChangeLogs, is fairly self-explanatory.
Please note that I have suppressed whitespace changes (suppression of
trailing blanks), so use patch with the -l option.

Bootstraps and regtests on FC21/x86_64 - OK for trunk?

Best regards

Paul

2016-10-18  Paul Thomas  <pault@gcc.gnu.org>

    PR fortran/69566
    * resolve.c (fixup_array_ref): New function.
    (resolve_select_type): Gather up the rank and array reference,
    if any, from the selector. Fix up the 'associate name' and the
    'associate entities' as necessary.
    * trans-expr.c (gfc_conv_class_to_class): If the symbol backend
    decl is a FUNCTION_DECL, use the 'fake_result_decl' instead.
    * trans-stmt.c (trans_associate_var): Extend 'unlimited' to
    include expressions which are themsleves not unlimited
    polymorphic but the symbol is.

2016-10-18  Paul Thomas  <pault@gcc.gnu.org>

    PR fortran/69566
    * gfortran.dg/select_type_37.f03: New test.

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