PI90075: AINSERT SUPPORT FOR SEQUENCE SYMBOLS AND LOOKAHEAD

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Unpredictable results could occur when using AINSERT statements
  to insert code which defined or referenced conditional assembly
  sequence symbols.  Symptoms include "ASMA140W END record
  missing", program checks or incorrect conditional assembly
  branches.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: Users of HLASM for z/OS, z/VM, z/VSE and     *
  *                 Linux on z                                   *
  ****************************************************************
  * PROBLEM DESCRIPTION: AINSERT support for sequence symbols    *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  1. Unpredictable results could occur when using AINSERT
     statements to insert code which defined or referenced
     conditional assembly sequence symbols, or code which
     triggered lookahead processing.  Symptoms include "ASMA140W
     END record missing", program checks or incorrect conditional
     assembly branches.
  
  2. In some cases AINSERT statements were processed at unexpected
     points, in particular if a new AINSERT sequence was created
     before a previous one had finished being processed.
  
  3. The source indicator prefix in the column after the statement
     number could sometimes be inconsistent, including the
     following cases:
  
     - When a library macro was invoked from COPY code and had
       previously been referenced within the same assembly, any
       continuation lines on the macro call were previously
       missing the "=" prefix for COPY code.
  
  
     - COPY code within an in-line macro was missing the "="
       prefix.
  
     - MHELP output could incorrectly be prefixed with ">" or "=".
  
     - When code was being read from lookahead, for example
       because of a conditional assembly branch back, SYSIN
       statements after a COPY code section could be flagged with
       "=" as if they were part of the COPY section.
  

Problem conclusion

• 1. AINSERT now fully supports the use of open code conditional
     assembly and lookahead within inserted code sequences,
     including within COPY statements inserted using AINSERT.
  
  2. AINSERT processing has been revised so that the whole
     sequence is inserted into the input stream at the relevant
     point and the active buffer queue is reset to empty, instead
     of input records being taken from the active AINSERT buffer
     queue.  This prevents any unexpected interaction when AINSERT
     is used in multiple ways within the same assembly.
  
     When processing reaches the end of an AINSERT sequence, or
     uses a conditional assembly branch to jump out of the
     sequence, the sequence is discarded and any sequence symbols
     which were defined within the sequence are deleted, so it is
     not possible to jump back into the sequence.
  
  3. Source indicator prefixes are now set consistently according
     to the input type.
  
  The MVS PTF for this APAR also contains another copy of the
  JCLIN for PTF UI42852 because the z/OS 2.3 Serverpac copy of
  HLASM was built with an older level of the JCLIN, causing the
  ALIAS IEV90 added in that PTF to go missing from SASMMOD1.
  
  DOCUMENTATION UPDATES:
  
  In the HLASM Language Reference manual SC26-4940-08 the
  following changes are required to the topic "AINSERT
  instruction".
  
  Replace the first paragraph with the following revised text
  (which clarifies how the instruction operates without any
  functional change):
  
     The AINSERT instruction inserts records into the input
     stream.  If it is used in a macro, the records are queued
     until the macro generator has completed expanding the current
     outermost macro instruction.  At that point the internal
     buffer queue is inserted into the input stream, so that it
     provides the next record or records.  If AINSERT is used in
     open code, the buffer queue only contains one record, which
     is inserted immediately after the AINSERT instruction.  An
     operand controls the sequence of the records within the
     internal buffer queue.
  
  After note 3, add the following additional notes, describing the
  revised method of processing:
  
  
  4. After the buffer queue has been inserted into the input
     stream, any further AINSERT instruction starts a new buffer
     queue.  This is inserted at the appropriate point in the
     input stream, which may be before the remaining records from
     a previous inserted buffer queue.
  
  5. Processing of each inserted buffer queue is terminated either
     when input processing reaches the end of the queue or when a
     conditional assembly branch is taken to a sequence symbol
     before or after the point at which the queue was inserted.
     At this point, any unprocessed source code in the queue or
     included members is discarded, and any sequence symbols
     defined by the inserted or included code are deleted.  It is
     not possible for conditional assembly to branch back into the
     inserted source code.
  
  6. Records in the AINSERT buffer queue are not visible to
     lookahead processing until the queue has been inserted into
     the input stream.  However, the AREAD instruction takes input
     records from the AINSERT buffer queue before reading the
     input stream.
  
  END OF DOCUMENTATION UPDATES
  

Temporary fix

Comments

• ×**** PE18/02/06 FIX IN ERROR. SEE APAR PI93326  FOR DESCRIPTION
  ×**** AE18/04/20 FIX IN ERROR. SEE APAR PI96968  FOR DESCRIPTION
  ×**** AE18/06/25 FIX IN ERROR. SEE APAR PI99545  FOR DESCRIPTION
  

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

  UI53045 UI53046 UI53047

Modules/Macros

•    ASMAINFO ASMA1A   ASMA1F   ASMA1J   ASMA1L
  ASMA1M   ASMA1N   ASMA1P   ASMA1R   ASMA1S   ASMA1W   ASMA11
  ASMA13   ASMA17   ASMA2R   ASMA2V   ASMA20   ASMA25   ASMA26
  ASMA9Z   ASMA90   ASMA93   HMQ4160J
  

Fix information

• Fixed component name

  HLASM MVS, VM &

• Fixed component ID

  569623400

Applicable component levels

• R160 PSY UI53046

     UP18/01/09 P F801

• R360 PSY UI53045

     UP18/01/08 P 1801

• R689 PSY UI53047

     UP18/01/08 I 1000

Fix is available

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