(j3.2006) (SC22WG5.5332) J3 Fortran interp letter ballot #31 revised - due 6-Oct-2014

Whitlock, Stan stan.whitlock
Thu Sep 11 23:19:17 EDT 2014


                                                        J3/14-233r1
To:        J3 Members
From:      Stan Whitlock
Subject:   J3 Fortran interp letter ballot #31 revised - due 6-Oct-2014
Date:      11-Sep-2014

I was mistaken about the interps passed at meeting #204:  only 5
interps were passed not 7.  These two interps:

    F08/0110   Interdependence of specifier values in input/output
                         statements
    F08/0111   Undefinition

did not pass the J3 meeting so I am removing them from this letter
ballot #31.  The ballot is still due 6-Oct-2014.  My apologies for
the misunderstanding.

Enclosed in the next letter ballot on Fortran interpretations.

The rules for interpretation handling by which we operate say:

    o   J3 votes on the answer at a J3 meeting; a simple majority
        vote marks the answer as "passed by J3 meeting".

    o   Between J3 meetings the chair of /interp sends a J3 letter
        ballot to J3 to approve interp answers that have been "passed
        by J3 meeting".  The letter ballot runs for 30 days.  Not
        voting on three of four consecutive J3 letter ballots is
        grounds to terminate J3 membership.  An interp answer passes
        by a 2/3rds vote;  a no vote must be accompanied by an
        explanation of the changes necessary to change the member's
        vote to yes.

        J3/interp reserves the right to recall an interp answer for
        more study even if the answer passes.

5 Fortran interpretations are currently "Passed by J3 meeting" after
J3 meeting #204.  This is the letter ballot phase to go from "Passed
by J3 meeting" to "Passed by J3 letter ballot".

The following Fortran interpretations are being balloted:

Yes  No   Number     Title

---  ---  F08/0108   ultimate components and coarrays
---  ---  F08/0109   LOCK_TYPE and unlimited polymorphic
---  ---  F08/0112   STAT= and ERRMSG= in ALLOCATE and DEALLOCATE
---  ---  F08/0113   Specifiers in image control statements
---  ---  F08/0114   Can LOCK_TYPE components have the POINTER attribute?

The text of these interpretations is attached.  Each interpretation
starts with a row of "-"s.

Please mark the above -Y- in the Yes column for "yes", -C- in the Yes
column for "yes with comment", or -N- in the No column for a "no"
answer {be sure to include your reasons with "no"} and send only the
above text {not this entire mail message} with any comments to

        j3 at j3-fortran.org

by 11:59:59PM, PDT, Monday, 6-Oct-2014, in order to be counted.


Thanks                         /Stan

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

NUMBER: F08/0108
TITLE: ultimate components and coarrays
KEYWORD: ultimate components, coarrays
DEFECT TYPE: Interpretation
STATUS: Passed by J3 meeting

QUESTIONS:

1. Is the declaration of V permitted:

  type :: one
    real, allocatable :: 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), allocatable :: A[:]
  end type four

  type(four) :: X

ANSWERS:

1. Type two is not conforming, because the entity A has a coarray
   ultimate component and C525 requires such an entity to be a
   nonpointer nonallocatable scalar.  Therefore the declaration of V
   is not permitted.

2. X satisfies C525, so declaration of X is permitted.  X has an
   ultimate (allocatable) coarray component (A[:]), and therefore
   acording to C526 must be a dummy argument or have the ALLOCATABLE
   or SAVE attribute.

EDITS:

None.

SUBMITTED BY: Van Snyder

HISTORY: 14-163    m204  F08/0108 submitted
         14-163r1  m204  Fixed examples in questions, revised
                         answer - passed by J3 meeting

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

NUMBER: F08/0109
TITLE: LOCK_TYPE and unlimited polymorphic
KEYWORD: LOCK_TYPE, unlimited polymorphic
DEFECT TYPE: Erratum
STATUS: Passed by J3 meeting

QUESTION:

Assume type LOCK_TYPE from the intrinsic module ISO_Fortran_Env is
available.

Q1. Is allocation of X%C permitted?

  TYPE t
    TYPE(LOCK_TYPE),ALLOCATABLE :: c
  END TYPE
  TYPE(t) :: x[*],y[*]
  ALLOCATE(y%c)
  ALLOCATE(x%c,SOURCE=y%c)

Q2. Is allocation of C permitted?

  class(*), pointer :: C
  type(lock_type), intent(in) :: L[*]

  allocate ( C, source=L )

Q3. Is allocation of C permitted?

  class(*), pointer :: C

  allocate ( LOCK_TYPE :: C )

Q4. Is pointer assignment to C permitted?

  class(*), pointer :: C
  type(lock_type), intent(in), target :: L[*]

  c => L

Q5. Is this ALLOCATE statement conforming?

  CLASS(*),ALLOCATABLE :: C[:]
  TYPE(LOCK_TYPE) :: X
  ALLOCATE(C,MOLD=X)

ANSWER:

A1. Allocation of X%C is not intended to be allowed.  An edit is
    supplied to correct the requirements on allocation of LOCK_TYPE.

A2. Allocation of C is not intended to be allowed.  An edit is
    supplied to correct the requirements on allocation of LOCK_TYPE.

A3. This allocation of C is permitted.

A4. Pointer assignment to C is permitted.

A5. This statement was intended to be permitted.  An edit is supplied
    to correct the requirements.

EDITS:

[6:7+] After definition 1.3.33.2 parent component, insert new term
  "1.3.33.2a
   potential subobject component
   nonpointer component, or potential subobject component of a
   nonpointer component (4.5.1)".

[127:8-9] 6.7.1.1 Syntax, C643,
          Change "C_PTR," to "C_PTR or"
          Delete ", LOCK_TYPE ... LOCK_TYPE".

[127:9+] Insert new constraint
  "C643a (R627) If SOURCE= appears, the declared type of <source-expr>
         shall not be LOCK_TYPE or have a potential subobject
         component of type LOCK_TYPE."

[127:18-19] 6.7.1.1, p4,
  "If" -> "If an ALLOCATE statement has a SOURCE= specifier and an",
{There is no problem with MOLD=.  "subcomponent" works ok here because
we have an object not a type.}

SUBMITTED BY: Van Snyder

HISTORY: 14-164    m204  F08/0109 submitted
         14-164r3  m204  As amended, passed by J3 meeting

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

NUMBER: F08/0112
TITLE: STAT= and ERRMSG= in ALLOCATE and DEALLOCATE
KEYWORDS: STAT=, ERRMSG=, ALLOCATE, DEALLOCATE
DEFECT TYPE: Erratum
STATUS: Passed by J3 meeting

QUESTION:

Consider

  CHARACTER(80) text(0:100), msg
  INTEGER stat,istat(0:80)
  REAL,ALLOCATABLE :: x(:),y(:,:)
  ...
  ALLOCATE(x(10),STAT=stat,ERRMSG=text(stat)) ! A
  DEALLOCATE(x,STAT=stat,ERRMSG=text(stat))   ! B
  msg = ''
  ALLOCATE(y(999999,999999),STAT=istat(LEN_TRIM(msg)),ERRMSG=msg) ! C
  msg = ''
  DEALLOCATE(x,STAT=istat(LEN_TRIM(msg)),ERRMSG=msg) ! D

In each of the statements labelled A-D, there is a dependency between
the STAT= specifier and the ERRMSG= specifier (from STAT= to ERRMSG=
in A and B, and from ERRMSG= to STAT in C and D).  There appears to be
no prohibition against this (though there are many prohibitions
against other dependencies in ALLOCATE and DEALLOCATE).

Are all these examples conforming, and if so, is the dependent
variable referenced with the value of the other variable at the
beginning of execution of the statement or at the end of execution of
the statement?

ANSWER:

These are not standard-conforming, as no interpretation is established
for them.  An edit is supplied to clarify this prohibition.

EDITS:

[132:4] 6.7.4 STAT= specifier, p1, append
  "The <stat-variable> shall not depend on the value of the
   <errmsg-variable>.".

[132:22] 6.7.5 ERRMSG= specifier, p1, append
  "The <errmsg-variable> shall not depend on the value of the
   <stat-variable>.".

SUBMITTED BY: Malcolm Cohen

HISTORY: 14-208    m204  F08/0112 submitted - passed by J3 meeting

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

NUMBER: F08/0113
TITLE: Specifiers in image control statements
KEYWORDS: STAT=, ERRMSG=, ACQUIRED_LOCK=, image control
DEFECT TYPE: Erratum
STATUS: Passed by J3 meeting

QUESTION:

Consider

  CHARACTER(80) text(0:100),msg
  INTEGER stat,istat(2)
  REAL,ALLOCATABLE :: x(:)
  TYPE(LOCK_TYPE) :: lock[*], alock(0:80)[*]
  LOGICAL acq, aacq(0:80)
  ...
  SYNC ALL(STAT=stat,ERRMSG=text(stat))       ! A
  SYNC IMAGES (*,STAT=stat,ERRMSG=text(stat)) ! B
  SYNC MEMORY(STAT=stat,ERRMSG=text(stat))    ! C
  LOCK(lock,ACQUIRED_LOCK=acq, &
       STAT=istat(MERGE(1,2,acq)), &
       ERRMSG=text(istat(MERGE(1,2,acq))))    ! D
  UNLOCK(lock,STAT=stat,ERRMSG=text(stat))    ! E
  LOCK(alock(stat),STAT=stat)                 ! F
  msg = ''
  UNLOCK(alock(LEN_TRIM(msg)),STAT=stat, &
         ERRMSG=msg)                          ! G
  stat = 13
  SYNC IMAGES(stat,STAT=stat)                 ! H
  msg = 'oops'
  SYNC IMAGES(LEN_TRIM(msg),STAT=stat, &
              ERRMSG=msg)                     ! I

In each of the statements labelled A-F, there is a dependency between
the STAT= specifier and the ERRMSG= specifier.  There appears to be no
prohibition against this.

Additionally, in the LOCK statement (D), there is a dependency between
the ACQUIRED_LOCK= specifier and the STAT= specifier (there is no
dependency between ACQUIRED_LOCK= and ERRMSG= because the former is
only set on successful execution and the latter is only set on an
error condition).  There appears to be no restrictions at all on any
dependencies from ACQUIRED_LOCK=.

In the LOCK statement (F), there is a dependency between the STAT=
specifier and the lock variable.  Similarly for the UNLOCK (G), there
is a dependency between the lock variable and the ERRMSG= specifier.

In the SYNC IMAGES statement (H), there is a dependency between the
STAT= variable and the image set.  In the SYNC IMAGES statement (I),
there is a dependency between the ERRMSG= variable and the image set.

Are all these examples conforming, and if so, is the dependent
variable referenced with the value of the other variable at the
beginning of execution of the statement or at the end of execution of
the statement?

ANSWER:

No interpretation is established and therefore these are not
conforming.  An edit is provided to clarify this.

EDITS:

[190:16-] 8.5.4 SYNC IMAGES statement, insert new p1,
  "The value of <image-set> shall not depend on the value of
   <stat-variable> or <errmsg-variable>.".

[194:6-] 8.5.6 LOCK and UNLOCK statements, insert new p1,
  "The <lock-variable> shall not depend on the value of
   <stat-variable>, <errmsg-variable>, or the
   <scalar-logical-variable> in the ACQUIRED_LOCK= specifier.
   The <scalar-logical-variable> shall not depend on the
   <lock-variable>, <stat-variable>, or <errmsg-variable>.".

[195:2-] 8.5.7 STAT= and ERRMSG= specifiers..., insert new p1,
  "The <stat-variable> shall not depend on the value of the
   <errmsg-variable>, <lock-variable>, or the
   <scalar-logical-variable> in the ACQUIRED_LOCK= specifier.
   The <errmsg-variable> shall not depend on the value of the
   <stat-variable>, <lock-variable>, or the <scalar-logical-variable>
   in the ACQUIRED_LOCK= specifier.".

SUBMITTED BY: Malcolm Cohen

HISTORY: 14-209    m204  F08/0113 submitted - passed by J3 meeting

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

NUMBER: F08/0114
TITLE: Can LOCK_TYPE components have the POINTER attribute?
KEYWORD: LOCK_TYPE component, POINTER
DEFECT TYPE: Erratum
STATUS: Passed by J3 meeting

Assume LOCK_TYPE is accessible from ISO_Fortran_Env.

QUESTION:

The following type definition and variable declaration are permitted by
C1302:

  type :: One
    type(lock_type), pointer :: L
  end type One

  type(one), allocatable :: L1[*]

C1302 requires a named variable of LOCK_TYPE to be a coarray.  C526
requires a coarray to be allocatable or to have the SAVE attribute.

The following declaration is apparently prohibited because L4 is
not a coarray:

  type(lock_type), pointer :: L4

Was it intended that pointer components of type LOCK_TYPE be permitted,
but that named variables of type LOCK_TYPE with the POINTER attribute be
prohibited?

ANSWER:

It was intended that components of type LOCK_TYPE not be permitted to
have the POINTER attribute.  Edits are provided to correct this mistake.

EDITS:

[399:18+] 13.8.2.16 LOCK_TYPE, after C1302, insert new constraint
  "C1302a A component of type LOCK_TYPE, or that has a nonallocatable
         direct component of type LOCK_TYPE, shall not have the
         POINTER attribute.".

SUBMITTED BY: Van Snyder

HISTORY: 14-140    m204  F08/0114 submitted
         14-140r1  m204  Revised to reverse decision
         14-140r2  m204  Passed by J3 meeting

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