WG15 Defect Report Ref: 14519-01
Topic: Missing Parameters from FLUSH_IO


This is an approved interpretation of 14519:1994.

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Last update: 1997-05-20


                                                                14519-92 #1

	Class: Defect situation

The standard omitted some information ( a parameter), and as such
no conformance distinction can be made between alternative implementations.
However, it is recommended that applications avoid use of this feature; 
concerns have been raised about this which are being referred to the 
sponsor for consideration as a future amendment.

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	Topic:			Missing Parameters from FLUSH_IO 
				generic operations
	Relevant Sections:	ISO/IEC 14519:1994, section 8.2.2.1


Defect Report:
-----------------------

The FLUSH_IO generic procedure should have a parameter to indicate
exactly which file object should be flushed.  This was the intent of
the operation, as described in the Rationale, and informally during
the development of the standard.


WG15 response for 9945-1:1990 (9945-1:1990):
--------------------------------------------------

The standard is currently incorrect, in that the intent was for the
FLUSH_IO operations to have a parameter indicating the specific file
to be flushed.  In the absence of any such parameter, a reasonable
interpretation of the standard as written would be to flush all files
of the appropriate type.  Due to implementation costs, and the
original intent, this interpretation of the standard is not required
of POSIX/Ada implementations.

Until the standard is changed to reflect the original intent,
conforming applications should not use the FLUSH_IO routines.


Rationale for Interpretation:
-----------------------------

We detected the missing parameters too late in the documentation
process to fix the bug, but the intent was that there would be a
parameter indicating the specific file to be flushed.  

An interpretation of FLUSH_IO without any parameters is to flush all
files of the FILE_TYPE used to instantiate the procedure.  However,
this would require substantial changes to current Ada implementations
to maintain the type-specific list of files.  Given this amount of
work, and the original intent, we do not mandate this interpretation
of the standard.  Instead, we strongly suggest that conforming
applications not use this operation until the standard is changed to
reflect the original intent.

Editorial note for future revision of standard (not part of the interpretation)
-------------------------------------------------------------------------------

This is planned for the 14519 revision.

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