J3/17-107r4
To: J3
From: John Reid & Bill Long & Jon Steidel & Malcolm Cohen
Subject: STAT= wording clarification for ALLOCATE
Date: 2017 February 15


1. Discussion

The text in 9.7.1.2 Execution of an ALLOCATE statement, p4, says
    "no error condition other than STAT_STOPPED_IMAGE or
     STAT_FAILED_IMAGE"
however these are just words not error conditions (we don't even say they
are the entities from ISO_FORTRAN_ENV, but even those are named constants
not error conditions as such).  This should be clarified.  Similarly for
the DEALLOCATE statement.

The text in 9.7.4 STAT= specifier sometimes assumes that there is a
STAT= specifier (not surprisingly).  However, the subclause heading
does not have normative effect, so this should be more precisely
stated.

The STAT= specifier in ALLOCATE or DEALLOCATE is no longer unambiguously
determined, due to the STAT= specifier in an image selector.  More
specific wording is required.

The text for handling failed images does not specify that it only applies
when there is a coarray allocate-object.  It also does not specify that
the failed image must be in the current team.

The text for describing the stopped/failed image cases long-windedly
elaborates the condition, instead of simply saying the current team
"has a stopped/failed image".  We should use the simpler wording, like we
do elsewhere.

We should not redundantly specify that the value of STAT_STOPPED_IMAGE is
positive, processor-dependent, and an integer, here; this is already
correctly specified in 16.10.2.29.  Similarly STAT_FAILED_IMAGE.

The long paragraph 3 would be clearer if split into two, one to handle
the assignment of stat-variable, and one to handle the effects on the
allocate-objects.

Subclause 9.7.5 ERRMSG=, paragraph 2, has a similar flaw in that it
definitively assigns a value to errmsg-variable without asking if ERRMSG=
even appears in the statement.


2. Edits to 17-007

[142:33-34] 9.7.1.2 Execution of an ALLOCATE statement, p4, change
              "On those images, if no error condition other than
               STAT_STOPPED_IMAGE or STAT_FAILED_IMAGE occurs, execution"
            to
  "If the current team contains a stopped or failed image, an error
   condition occurs.  If no other error condition occurs, execution
   on the active images",
making that whole paragraph read
  "When an ALLOCATE statement is executed for which an <allocate-object>
   is a coarray, there is an implicit synchronization of all active images
   in the current team. If the current team contains a stopped or failed
   image, an error condition occurs.  If no other error condition occurs,
   execution on the active images of the segment (11.6.2) following the
   statement is delayed until all other active images in the current team
   have executed the same statement the same number of times in this team.
   The coarray shall not become allocated on an image unless it is
   successfully allocated on all active images in this team."
{Properly specify the stopped/failed image error condition.}

[146:5-6] 9.7.3.2 Deallocation of allocatable variables, p10, change
            "On those images, if no error condition other than
             STAT_STOPPED_IMAGE or STAT_FAILED_IMAGE occurs, execution"
          to
  "If the current team contains a stopped or failed image, an error
   condition occurs.  If no other error condition occurs, execution
   on the active images",
making that whole paragraph read
  "When a statement that deallocates a coarray is executed, there is an
   implicit synchronization of all active images in the current team. If
   the current team contains a stopped or failed image, an error condition
   occurs.  If no other error condition occurs, execution on the active
   images of the segment (11.6.2) following the statement is delayed until
   all other active images in the current team have executed the same
   statement the same number of times in this team."
{Properly specify the stopped/failed image error condition.}

[146:22+] 9.7.4 STAT= specifier, before existing para 1, insert new para
  "This subclause applies where an <alloc-opt> or <dealloc-opt> that is
   a STAT= specifier appears in an ALLOCATE or DEALLOCATE statement."
{Limit the universe of discourse to when there is an appropriate STAT=
 specifier, and establish the context.}

[146:27] Same subclause, p2,
         Change "If the STAT= specifier appears, successful"
         to     "Successful".
{Simplify.}

[147:1-2] Same subclause, p3,
          Change "one or more images of the current team has initiated
                  normal termination of execution"
          to "the current team contains a stopped image".
{Simplify.  Hyperlink "stopped image".}

[147:3] Same paragraph, change
          "processor-dependent positive integer value of the constant"
        to
          "value".
{Simplify.}

[147:4] Same paragraph, change  "a failed image is detected" to
          "an <allocate-object> is a coarray and the current team contains
           a failed image".
{Repair specificational defect.  Use standard wording.}

[147:5-6] Same paragraph, delete
  ", each allocate-object is successfully allocated or deallocated on all
   active images of the current team and"
{This will reappear when we split the paragraph into two.}

[147:9-10] Same subclause, before "In any case,"
           insert a paragraph break, and
           change "In any case," to
  "If <stat-variable> became defined with the value STAT_FAILED_IMAGE,
   each <allocate-object> is successfully allocated or deallocated on all
   the active images of the current team.  If any other error condition
   occurs,".
{Make a new paragraph for the effects on the allocate-objects.}

[147:22] 9.7.5 ERRMSG= specifier, p2,
         After "or DEALLOCATE statement"
         insert "with an ERRMSG= specifier".
{Don't make an assumption about errmsg-variable.}

The edits for 9.7.4p3 create a new p3 and p4 as follows:
    "If an ALLOCATE or DEALLOCATE statement with a coarray
     <allocate-object> is executed when the current team contains a
     stopped image, the <stat-variable> becomes defined with the value
     STAT_STOPPED_IMAGE from the intrinsic module ISO_FORTRAN_ENV
     (16.10.2).  Otherwise, if an <allocate-object> is a coarray and the
     current team contains a failed image, and no other error condition
     occurs, the <stat-variable> becomes defined with the value
     STAT_FAILED_IMAGE from the intrinsic module ISO_FORTRAN_ENV. If any
     other error condition occurs during execution of the ALLOCATE or
     DEALLOCATE statement, the stat-variable becomes defined with a
     processor-dependent positive integer value different from
     STAT_STOPPED_IMAGE and STAT_FAILED_IMAGE.

     If <stat-variable> became defined with the value STAT_FAILED_IMAGE,
     each <allocate-object> is successfully allocated or deallocated on
     all the active images of the current team.  If any other error
     condition occurs, each <allocate-object> has a processor-dependent
     status:
        - each <allocate-object> that was successfully allocated shall
          have an allocation status of allocated or a pointer association
          status of associated;
        - each <allocate-object> that was successfully deallocated shall
          have an allocation status of unallocated or a pointer
          association status of disassociated;
        - each <allocate-object> that was not successfully allocated or
          deallocated shall retain its previous allocation status or
          pointer association status."

===END===