[Bug fortran/56423] New: F08/0071: Shall reject invalid Vector subscript target with Pointer assignment

[Bug fortran/56423] New: F08/0071: Shall reject invalid Vector subscript target with Pointer assignment

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56423

             Bug #: 56423
           Summary: F08/0071: Shall reject invalid Vector subscript target
                    with Pointer assignment
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Keywords: ice-on-invalid-code
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: burnus@gcc.gnu.org


Interp F08/0071, http://www.j3-fortran.org/doc/year/13/13-250.txt

Note: The J3/WG5 vote is still pending.


Case (4) of the test case below is invalid per clarified constraint F2008,
C724:

  "A variable that is a pointer target shall have either the TARGET
   or POINTER attribute, and shall not be an array section with a
   vector subscript."

Currently, gfortran ICEs with:
internal compiler error: in gfc_conv_expr_descriptor, at
fortran/trans-array.c:6589

  PROGRAM m197006
    REAL,TARGET :: x(100) = [ (i,i=1,100) ]
    REAL,POINTER :: p(:)
    TYPE t
      REAL,POINTER :: q(:)
    END TYPE
    TYPE(t) y
    p => x                     ! (1)
    y = t(x)                   ! (2)
!   p => x( [ 1,4,9,25 ] )     ! (3)  ! Invalid and rejected
    y = t(x( [ 1,4,9,25 ] ))   ! (4)  ! Invalid per IR F08/0071 but not
rejected
    PRINT *,y%q
  END PROGRAM

[Bug fortran/56423] F08/0071: Shall reject invalid Vector subscript target with Pointer assignment

[dominiq at lps dot ens.fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56423

Dominique d'Humieres <dominiq at lps dot ens.fr> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2015-10-10
     Ever confirmed|0                           |1
      Known to fail|                            |4.8.5, 4.9.3, 5.2.0, 6.0

--- Comment #1 from Dominique d'Humieres <dominiq at lps dot ens.fr> ---
>From my version of the F2015 draft

C725 (R737) The expr shall be a designator that designates a variable with
either
            the TARGET or POINTER attribute and is not an array section with
            a vector subscript, or it shall be a reference to a function that
            returns a data pointer.

Note that 't(x( [ 1,4,9,25 ] ))' is not rejected but gives an ICE from 4.8 up
to trunk (6.0):

[Book15] f90/bug% gfortran pr56423.f90
pr56423.f90:11:0:

     y = t(x( [ 1,4,9,25 ] ))   ! (4)  ! Invalid per IR F08/0071 but not
rejected
 1
internal compiler error: in gfc_conv_expr_descriptor, at
fortran/trans-array.c:6702

where gfortran is 5.2.0.