J3/14-163
To:      J3
From:    Van Snyder
Subject: Interp concerning coarrays and ultimate components
Date: 2014 May 30

----------------------------------------------------------------------

NUMBER: TBD
TITLE: ultimate components and coarrays
KEYWORD: ultimate components, coarrays
DEFECT TYPE: Erratum
STATUS: J3 consideration in progress

QUESTIONS:

1. Is the declaration of V permitted:

  type :: one
    real :: C[*]
  end type one

  type :: two
    type(one), allocatable :: A
  end type two

  type(two), pointer :: V(:)

2. Is the declaration of X permitted:

  type :: three
    real :: C
  end type three

  type :: four
    type(three) :: A[*]
  end type four

  type(four) :: X

3. Is the declaration of ARG permitted:

  type(two), value :: ARG

4. Is the allocation of V permitted:

  allocate ( two :: V )

5. Is the allocation of V permitted:

  type(two) :: W
  allocate ( V, source=W )

6. Is the definition of FIVE permitted:

  type :: five
    type(two), allocatable :: F
  end type five

ANSWERS:

1.  Although V%A%C is a coarray, it is not an ultimate component of V.
Therefore the declaration of V is permitted, i.e.,  V is permitted to
have the POINTER attribute.

It was intended that the declaration of V not be permitted:

C525 An entity whose type has a coarray ultimate component shall be a
     nonpointer nonallocatable scalar, shall not be a coarray, and shall
     not be a function result.

Edits are provided to correct this mistake.

2. Although X%C is a coarray, it is not an ultimate component of X.
Therefore the declaration of X is permitted, i.e., X is not required to
be a dummy argument or have the ALLOCATABLE or SAVE attribute.

It was intended that the declaration of X not be permitted:

C526 A coarray or an object with a coarray ultimate component shall be a
     dummy argument or have the ALLOCATABLE or SAVE attribute.

Edits are provided to correct this mistake.

3. Although ARG%A%C is a coarray, it is not an ultimate component of A.
Therefore the declaration of ARG is permitted, i.e., ARG is permitted to
have the VALUE attribute.

It was intended that the declaration of ARG not be permitted:

C557 An entity with the VALUE attribute shall be a dummy data object
     that ... does not have a coarray ultimate component.

Edits are provided to correct this mistake.

4. Although V%A%C is a coarray, it is not an ultimate component of V.
Therefore allocation of V is permitted.

It was intended that allocation of V not be permitted:

C640 (R626) <type-spec> shall not specify a type that has a coarray
     ultimate component.

Edits are provided to correct this mistake.

5. Although W%A%C is a coarray, it is not an ultimate component of W.
Therefore allocation of V is permitted.

It was intended that allocation of V not be permitted:

C643 (R630) The declared type of <source-expr> shall not have a coarray
     ultimate component.

Edits are provided to correct this mistake.

6. Although the component F of type FIVE is allocatable, the C component
of the A component is not an ultimate component.  Therefore, the
definition of type FIVE is permitted.

It was intended that definition of type FIVE not be permitted:

C444 A data component whose type has a coarray ultimate component shall
     be a nonpointer nonallocatable scalar and shall not be a coarray.

Edits are provided to correct this mistake.

EDITS:

After definition 1.3.33.2 "parent component", introduce a definition

"1.3.33.2a potential subobject component
   a nonpointer component, or a potential subobject component of a
   nonpointer component"

In constraint C444 in subclause 4.5.4.1, replace "ultimate component"
with "potential subobject component".

In constraint C525 in subclause 5.3.6.1, replace "ultimate component"
with "potential subobject component".

In constraint C526 in subclause 5.3.6.1, replace "ultimate component"
with "potential subobject component".

In constraint C557 in subclause 5.3.18, replace "ultimate component"
with "potential subobject component".

In constraint C640 in subclause 6.7.2.2, replace "ultimate component"
with "potential subobject component".

In constraint C643 in subclause 6.7.2.2, replace "ultimate component"
with "potential subobject component".

SUBMITTED BY: Van Snyder

HISTORY: m204  13-xxx    F08/xxxx  Submitted

----------------------------------------------------------------------