08-295

To: J3
From: Malcolm Cohen
Subject: External procedures and binding labels
Date: 2008 November 16
References: Interp F03/0076, 08-007r2, 08-187, 08-196.

1.  Introduction

Interp F03/0076 concluded that an external procedure having a given
binding label has to have the same procedure name in every scope.

It was suggested that this ought to be changed in F2008, as part of the
process of interp reconsideration and integration.

Edits were suggested in 08-187 that would result in the names of
external procedures that have binding labels being local identifiers.

As a general principle, global entities that have a binding label
have that binding label as their global identifier; the name of such
an entity should not be a global identifier.  Thus this should be
straightened for common blocks as well as external procedures.  Section
3 contains the additional edits that are required for this.

2.  Edit for procedures

[439:16.2p1 2nd sentence]
  After "external procedure" insert "with no binding label",
  delete "and shall not ... in the same program"
  (i.e. everything after the first "global identifier").
  In the third sentence (beginning "The submodule") delete
  "and shall ... other submodule" (i.e. stop after "global identifier".)
  In the fourth sentence (beginning "A binding label") delete
  "and shall ... in case".
{Shorten paragraph by just defining global entities and global
 identifiers.}

[439:16.2p1+] Insert new paragraph
  "The global identifier of an entity shall not be the same as the global
   identifier of any other entity.  Furthermore, a binding label shall not
   be the same as the global identifier of any other global entity,
   ignoring differences in case."
{New paragraph giving the restrictions on global identifiers.}

[439:16.2 Note 16.1] Replace note with
  "An intrinsic module is not a program unit, so a global identifier can be
   the same as the name of an intrinsic module."
{Make sure it is clear that this is allowed, with reasoning.
 The previous note is now a trivial consequence of the preceding
  paragraphs, so we don't need to spell it out.}

[440:16.3.1p1]
  Change "intrinsic procedure" to "intrinsic procedures",
  After "intrinsic procedures," insert
    "external procedures that have binding labels, intrinsic modules,",

[440:16.3.1p2]
  Join this paragraph to p1, i.e. we should not have a sentence that
  extends over two paragraphs!

[441:16.3.2p1]
  Change "COMMON or SAVE" to "BIND, COMMON, or SAVE"
{Fix bug in F2003 C interop.}


3. Edits for common blocks

[439:16.2p1 2nd sentence]
  After "common block" insert "with no binding label".
{A common block name should not be global if it has a binding label.}

[440:16.3.1p1]
  In item (2), delete final "and",
  Append to item (3) ", and"
  Append to list new item
    "(4) common blocks that have binding labels"
{Local identifiers of common blocks, these should not be class 1.}

[440:16.3.1p3]
  After "class (1)" insert "or class (4)".

[441:16.3.2p1]
  After "If a local identifier" insert "of class (1)".
{Don't get confused when the local identifier *is* a common block.}

===END===